{"id":10639,"date":"2026-07-23T01:28:42","date_gmt":"2026-07-23T01:28:42","guid":{"rendered":"https:\/\/www.lyasilicone.com\/?p=10639"},"modified":"2026-07-23T01:28:42","modified_gmt":"2026-07-23T01:28:42","slug":"silicone-straw-cup-leak-flow-design-guide","status":"publish","type":"post","link":"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/","title":{"rendered":"Why Do Silicone Straw Cups Leak, Drip, or Become Hard to Drink From? An OEM Design Guide"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_73 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Zawarto\u015b\u0107<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#Introduction\" title=\"Wprowadzenie\">Wprowadzenie<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#Answer_Excerpt\" title=\"Answer Excerpt\">Answer Excerpt<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#1_A_Straw_Cup_Is_a_Sealing_and_Airflow_System\" title=\"1. A Straw Cup Is a Sealing and Airflow System\">1. A Straw Cup Is a Sealing and Airflow System<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#2_First_Identify_the_Exact_Leakage_Path\" title=\"2. First Identify the Exact Leakage Path\">2. First Identify the Exact Leakage Path<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#3_The_Cup_Rim_and_Lid_Must_Form_Continuous_Contact\" title=\"3. The Cup Rim and Lid Must Form Continuous Contact\">3. The Cup Rim and Lid Must Form Continuous Contact<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#4_Cup-Rim_Roundness_Is_Critical\" title=\"4. Cup-Rim Roundness Is Critical\">4. Cup-Rim Roundness Is Critical<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#5_A_Lid_Can_Be_Too_Tight\" title=\"5. A Lid Can Be Too Tight\">5. A Lid Can Be Too Tight<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#6_A_Lid_Can_Also_Be_Too_Loose\" title=\"6. A Lid Can Also Be Too Loose\">6. A Lid Can Also Be Too Loose<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#7_The_Straw_Hole_Requires_Controlled_Interference\" title=\"7. The Straw Hole Requires Controlled Interference\">7. The Straw Hole Requires Controlled Interference<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#8_Straw_Compression_Can_Restrict_Drinking_Flow\" title=\"8. Straw Compression Can Restrict Drinking Flow\">8. Straw Compression Can Restrict Drinking Flow<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#9_The_Air_Vent_Controls_Drinking_Comfort\" title=\"9. The Air Vent Controls Drinking Comfort\">9. The Air Vent Controls Drinking Comfort<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#10_Anti-Spill_Valve_Design_Requires_a_Balanced_Opening_Force\" title=\"10. Anti-Spill Valve Design Requires a Balanced Opening Force\">10. Anti-Spill Valve Design Requires a Balanced Opening Force<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#11_Straw_Inside_Diameter_and_Length_Affect_Flow_Resistance\" title=\"11. Straw Inside Diameter and Length Affect Flow Resistance\">11. Straw Inside Diameter and Length Affect Flow Resistance<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#12_The_Bottom_of_the_Straw_Must_Remain_Open\" title=\"12. The Bottom of the Straw Must Remain Open\">12. The Bottom of the Straw Must Remain Open<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#13_Drink_Type_Changes_the_Test_Result\" title=\"13. Drink Type Changes the Test Result\">13. Drink Type Changes the Test Result<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#14_A_Soft_Cup_Body_Can_Create_Pressure-Driven_Leakage\" title=\"14. A Soft Cup Body Can Create Pressure-Driven Leakage\">14. A Soft Cup Body Can Create Pressure-Driven Leakage<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#15_Handle_Position_Can_Influence_Leakage\" title=\"15. Handle Position Can Influence Leakage\">15. Handle Position Can Influence Leakage<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#16_Wall_Thickness_and_Cup_Shape_Affect_Structural_Stability\" title=\"16. Wall Thickness and Cup Shape Affect Structural Stability\">16. Wall Thickness and Cup Shape Affect Structural Stability<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#17_Parting_Lines_and_Flash_Can_Interrupt_the_Seal\" title=\"17. Parting Lines and Flash Can Interrupt the Seal\">17. Parting Lines and Flash Can Interrupt the Seal<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#18_Small_Holes_and_Valve_Features_Increase_Molding_Difficulty\" title=\"18. Small Holes and Valve Features Increase Molding Difficulty\">18. Small Holes and Valve Features Increase Molding Difficulty<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#19_Assembly_Direction_and_Sequence_Matter\" title=\"19. Assembly Direction and Sequence Matter\">19. Assembly Direction and Sequence Matter<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#20_Cleaning_Can_Change_Valve_and_Seal_Performance\" title=\"20. Cleaning Can Change Valve and Seal Performance\">20. Cleaning Can Change Valve and Seal Performance<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#21_Packaging_Can_Distort_the_Cup_Lid_or_Straw\" title=\"21. Packaging Can Distort the Cup, Lid, or Straw\">21. Packaging Can Distort the Cup, Lid, or Straw<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#22_Sample_Testing_Should_Reproduce_Real_Use\" title=\"22. Sample Testing Should Reproduce Real Use\">22. Sample Testing Should Reproduce Real Use<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#23_Why_Can_Samples_Pass_While_Mass_Production_Fails\" title=\"23. Why Can Samples Pass While Mass Production Fails?\">23. Why Can Samples Pass While Mass Production Fails?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#24_A_Practical_Straw_Cup_Failure-Analysis_Sequence\" title=\"24. A Practical Straw Cup Failure-Analysis Sequence\">24. A Practical Straw Cup Failure-Analysis Sequence<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#25_What_Should_Be_Validated_Before_Mass_Production\" title=\"25. What Should Be Validated Before Mass Production?\">25. What Should Be Validated Before Mass Production?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#How_LYA_Silicone_Supports_Custom_Straw_Cup_Projects\" title=\"How LYA Silicone Supports Custom Straw Cup Projects\">How LYA Silicone Supports Custom Straw Cup Projects<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#What_Information_Should_Buyers_Provide\" title=\"What Information Should Buyers Provide?\">What Information Should Buyers Provide?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#Frequently_Asked_Questions\" title=\"Frequently Asked Questions\">Frequently Asked Questions<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/www.lyasilicone.com\/pl\/silicone-straw-cup-leak-flow-design-guide\/#Conclusion\" title=\"Wnioski\">Wnioski<\/a><\/li><\/ul><\/nav><\/div>\n<h2 data-section-id=\"13ax1s5\" data-start=\"2041\" data-end=\"2056\"><span class=\"ez-toc-section\" id=\"Introduction\"><\/span>Wprowadzenie<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"2058\" data-end=\"2156\">A silicone straw cup may appear to be a simple combination of a cup body, lid, and drinking straw.<\/p>\n<p data-start=\"2158\" data-end=\"2266\">In actual use, however, these components form a complete pressure, airflow, liquid-flow, and sealing system.<\/p>\n<p data-start=\"2268\" data-end=\"2341\">When one dimension or structure is not properly coordinated, the cup may:<\/p>\n<ul data-start=\"2343\" data-end=\"2759\">\n<li data-section-id=\"1yxglsg\" data-start=\"2343\" data-end=\"2364\">Leak around the lid<\/li>\n<li data-section-id=\"16rmvg3\" data-start=\"2365\" data-end=\"2399\">Drip continuously from the straw<\/li>\n<li data-section-id=\"s1agli\" data-start=\"2400\" data-end=\"2440\">Spray liquid when the body is squeezed<\/li>\n<li data-section-id=\"kbycg0\" data-start=\"2441\" data-end=\"2470\">Leak when shaken or dropped<\/li>\n<li data-section-id=\"bxbfdi\" data-start=\"2471\" data-end=\"2503\">Become difficult to drink from<\/li>\n<li data-section-id=\"sh3mow\" data-start=\"2504\" data-end=\"2537\">Require excessive suction force<\/li>\n<li data-section-id=\"14pfqv6\" data-start=\"2538\" data-end=\"2579\">Produce an unstable or interrupted flow<\/li>\n<li data-section-id=\"1ruihob\" data-start=\"2580\" data-end=\"2609\">Allow the straw to pull out<\/li>\n<li data-section-id=\"1icvee0\" data-start=\"2610\" data-end=\"2635\">Collapse around the lid<\/li>\n<li data-section-id=\"z5e2lj\" data-start=\"2636\" data-end=\"2666\">Leak after repeated assembly<\/li>\n<li data-section-id=\"1asuv6r\" data-start=\"2667\" data-end=\"2724\">Perform differently with water, milk, or thicker drinks<\/li>\n<li data-section-id=\"1ovmg5d\" data-start=\"2725\" data-end=\"2759\">Become deformed during packaging<\/li>\n<\/ul>\n<p data-start=\"2761\" data-end=\"2841\">These failures are not caused by one sealing ring or one material specification.<\/p>\n<p data-start=\"2843\" data-end=\"2901\">The final performance depends on the relationship between:<\/p>\n<ul data-start=\"2903\" data-end=\"3264\">\n<li data-section-id=\"1r0kxfc\" data-start=\"2903\" data-end=\"2922\">Cup-body material<\/li>\n<li data-section-id=\"od7j0k\" data-start=\"2923\" data-end=\"2942\">Silicone hardness<\/li>\n<li data-section-id=\"6f79ns\" data-start=\"2943\" data-end=\"2959\">Wall thickness<\/li>\n<li data-section-id=\"19hz7z0\" data-start=\"2960\" data-end=\"2979\">Cup-rim roundness<\/li>\n<li data-section-id=\"1dtmxg\" data-start=\"2980\" data-end=\"2996\">Lid engagement<\/li>\n<li data-section-id=\"1ng800v\" data-start=\"2997\" data-end=\"3018\">Lid-sealing contact<\/li>\n<li data-section-id=\"14pl5kb\" data-start=\"3019\" data-end=\"3042\">Straw-hole dimensions<\/li>\n<li data-section-id=\"1x5rbfd\" data-start=\"3043\" data-end=\"3067\">Straw outside diameter<\/li>\n<li data-section-id=\"1x86tyo\" data-start=\"3068\" data-end=\"3091\">Straw inside diameter<\/li>\n<li data-section-id=\"5mbjsz\" data-start=\"3092\" data-end=\"3112\">Air-vent structure<\/li>\n<li data-section-id=\"1724zsl\" data-start=\"3113\" data-end=\"3131\">Anti-spill valve<\/li>\n<li data-section-id=\"18mul3m\" data-start=\"3132\" data-end=\"3160\">Drinking-liquid properties<\/li>\n<li data-section-id=\"1j9qd8p\" data-start=\"3161\" data-end=\"3178\">Assembly method<\/li>\n<li data-section-id=\"1djqgcf\" data-start=\"3179\" data-end=\"3194\">Mold accuracy<\/li>\n<li data-section-id=\"1p707fp\" data-start=\"3195\" data-end=\"3214\">Product shrinkage<\/li>\n<li data-section-id=\"18occcv\" data-start=\"3215\" data-end=\"3240\">Cleaning and reassembly<\/li>\n<li data-section-id=\"jn6ftx\" data-start=\"3241\" data-end=\"3264\">Packaging and storage<\/li>\n<\/ul>\n<p data-start=\"3266\" data-end=\"3387\">For baby brands, importers, wholesalers, private-label sellers, and product developers, the correct question is not only:<\/p>\n<p data-start=\"3389\" data-end=\"3413\">\u201cIs this cup leakproof?\u201d<\/p>\n<p data-start=\"3415\" data-end=\"3443\">The more useful question is:<\/p>\n<p data-start=\"3445\" data-end=\"3601\">\u201cUnder which orientation, liquid, temperature, pressure, assembly, and use conditions can the cup control spills while still allowing comfortable drinking?\u201d<\/p>\n<p data-start=\"3603\" data-end=\"3730\">This guide explains what buyers should evaluate before <a href=\"https:\/\/www.lyasilicone.com\/zh\/product\/custom-silicone-straw-cup-manufacturer\/\">custom silicone straw cup<\/a> tooling, sample approval, and mass production.<\/p>\n<h2 data-section-id=\"1ewu1tg\" data-start=\"3732\" data-end=\"3749\"><span class=\"ez-toc-section\" id=\"Answer_Excerpt\"><\/span>Answer Excerpt<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"3751\" data-end=\"4029\">Silicone straw cups can leak or become difficult to drink from when the cup rim and lid do not seal evenly, the straw hole is too loose or too tight, the air vent is blocked, the anti-spill valve is incorrectly designed, or the straw dimensions create excessive flow resistance.<\/p>\n<p data-start=\"4031\" data-end=\"4226\">Cup-body softness, squeezing pressure, liquid temperature, drink viscosity, assembly direction, molding variation, flash, packaging deformation, and repeated cleaning can also change performance.<\/p>\n<p data-start=\"4228\" data-end=\"4362\">A cup that does not leak while standing upright may still leak when tilted, shaken, dropped, carried in a bag, or squeezed by a child.<\/p>\n<p data-start=\"4364\" data-end=\"4537\">Reliable performance requires the cup body, rim, lid, straw, vent, valve, handles, material, mold, packaging, and test method to be evaluated as one complete product system.<\/p>\n<p data-start=\"4364\" data-end=\"4537\"><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone size-medium wp-image-10643\" src=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-leak-comparison.jpg-300x300.jpg\" alt=\"Silicone straw cup leaking comparison\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-leak-comparison.jpg-300x300.jpg 300w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-leak-comparison.jpg-150x150.jpg 150w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-leak-comparison.jpg-768x768.jpg 768w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-leak-comparison.jpg-12x12.jpg 12w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-leak-comparison.jpg-600x600.jpg 600w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-leak-comparison.jpg-100x100.jpg 100w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-leak-comparison.jpg.jpg 800w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<h2 data-section-id=\"168kqt4\" data-start=\"4539\" data-end=\"4588\"><span class=\"ez-toc-section\" id=\"1_A_Straw_Cup_Is_a_Sealing_and_Airflow_System\"><\/span>1. A Straw Cup Is a Sealing and Airflow System<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"4590\" data-end=\"4696\">During <a href=\"https:\/\/www.lyasilicone.com\/zh\/custom-silicone-straw-cup-manufacturing-what-should-baby-brands-know\/\">custom silicone straw cup manufacturing<\/a>, the cup body, lid, straw and vent should be reviewed as one functional assembly.<\/p>\n<p data-start=\"4590\" data-end=\"4696\">Liquid cannot flow steadily out of a closed cup unless air can enter and replace the liquid being removed.<\/p>\n<p data-start=\"4698\" data-end=\"4758\">A functional straw cup therefore needs to control two paths:<\/p>\n<ol data-start=\"4760\" data-end=\"4884\">\n<li data-section-id=\"1enkfqb\" data-start=\"4760\" data-end=\"4798\">The liquid path through the straw<\/li>\n<li data-section-id=\"106nhi1\" data-start=\"4799\" data-end=\"4884\">The air path through a vent, valve, lid clearance, or another controlled opening<\/li>\n<\/ol>\n<p data-start=\"4886\" data-end=\"4943\">If the liquid path is too open, the cup may drip or leak.<\/p>\n<p data-start=\"4945\" data-end=\"5004\">If the air path is too restricted, the user may experience:<\/p>\n<ul data-start=\"5006\" data-end=\"5151\">\n<li data-section-id=\"1ux9lbw\" data-start=\"5006\" data-end=\"5031\">High suction resistance<\/li>\n<li data-section-id=\"10fpolw\" data-start=\"5032\" data-end=\"5054\">Interrupted drinking<\/li>\n<li data-section-id=\"3o3fr2\" data-start=\"5055\" data-end=\"5074\">Cup-wall collapse<\/li>\n<li data-section-id=\"fcank1\" data-start=\"5075\" data-end=\"5091\">A pulsing flow<\/li>\n<li data-section-id=\"1cg4m86\" data-start=\"5092\" data-end=\"5112\">No liquid movement<\/li>\n<li data-section-id=\"1tb9j60\" data-start=\"5113\" data-end=\"5151\">Sudden release after pressure builds<\/li>\n<\/ul>\n<p data-start=\"5153\" data-end=\"5216\">If the air path is too open, the cup may leak more easily when:<\/p>\n<ul data-start=\"5218\" data-end=\"5293\">\n<li data-section-id=\"5mbgoc\" data-start=\"5218\" data-end=\"5226\">Tilted<\/li>\n<li data-section-id=\"68ut4i\" data-start=\"5227\" data-end=\"5235\">Shaken<\/li>\n<li data-section-id=\"esndc\" data-start=\"5236\" data-end=\"5245\">Dropped<\/li>\n<li data-section-id=\"1cumtas\" data-start=\"5246\" data-end=\"5263\">Stored sideways<\/li>\n<li data-section-id=\"x42zd0\" data-start=\"5264\" data-end=\"5274\">Squeezed<\/li>\n<li data-section-id=\"qce3sw\" data-start=\"5275\" data-end=\"5293\">Carried in a bag<\/li>\n<\/ul>\n<p data-start=\"5295\" data-end=\"5366\">Spill control and drinking comfort must therefore be designed together.<\/p>\n<p data-start=\"5368\" data-end=\"5464\">A cup should not be made more difficult to drink from simply to improve one static leakage test.<\/p>\n<h2 data-section-id=\"p37spk\" data-start=\"5466\" data-end=\"5509\"><span class=\"ez-toc-section\" id=\"2_First_Identify_the_Exact_Leakage_Path\"><\/span>2. First Identify the Exact Leakage Path<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"5511\" data-end=\"5543\">\u201cCup leakage\u201d is not one defect.<\/p>\n<p data-start=\"5545\" data-end=\"5568\">Liquid may escape from:<\/p>\n<ul data-start=\"5570\" data-end=\"5781\">\n<li data-section-id=\"49wf3s\" data-start=\"5570\" data-end=\"5596\">The lid-to-rim interface<\/li>\n<li data-section-id=\"u0nlnx\" data-start=\"5597\" data-end=\"5625\">The straw-to-lid interface<\/li>\n<li data-section-id=\"1twioue\" data-start=\"5626\" data-end=\"5645\">The straw opening<\/li>\n<li data-section-id=\"2c5x6q\" data-start=\"5646\" data-end=\"5660\">The air vent<\/li>\n<li data-section-id=\"18rtmmb\" data-start=\"5661\" data-end=\"5675\">A valve slit<\/li>\n<li data-section-id=\"ke0gtk\" data-start=\"5676\" data-end=\"5691\">A cap or plug<\/li>\n<li data-section-id=\"fulzoz\" data-start=\"5692\" data-end=\"5719\">The cup-body parting line<\/li>\n<li data-section-id=\"1xwztej\" data-start=\"5720\" data-end=\"5738\">A molded pinhole<\/li>\n<li data-section-id=\"1g28mcp\" data-start=\"5739\" data-end=\"5760\">A damaged component<\/li>\n<li data-section-id=\"1fch8un\" data-start=\"5761\" data-end=\"5781\">Incorrect assembly<\/li>\n<\/ul>\n<p data-start=\"5783\" data-end=\"5829\">The failure condition should also be recorded.<\/p>\n<p data-start=\"5831\" data-end=\"5843\">For example:<\/p>\n<ul data-start=\"5845\" data-end=\"6164\">\n<li data-section-id=\"hrivbb\" data-start=\"5845\" data-end=\"5875\">Does it leak while standing?<\/li>\n<li data-section-id=\"4hhxhs\" data-start=\"5876\" data-end=\"5908\">Does it leak only when tilted?<\/li>\n<li data-section-id=\"pf0f35\" data-start=\"5909\" data-end=\"5938\">Does it leak after shaking?<\/li>\n<li data-section-id=\"1sh6m6k\" data-start=\"5939\" data-end=\"5968\">Does it leak when squeezed?<\/li>\n<li data-section-id=\"36w0vg\" data-start=\"5969\" data-end=\"6009\">Does it leak with the straw installed?<\/li>\n<li data-section-id=\"1b1465e\" data-start=\"6010\" data-end=\"6043\">Does it leak without the straw?<\/li>\n<li data-section-id=\"19e356l\" data-start=\"6044\" data-end=\"6073\">Does it leak after washing?<\/li>\n<li data-section-id=\"13d57l3\" data-start=\"6074\" data-end=\"6111\">Does it leak only with warm liquid?<\/li>\n<li data-section-id=\"6ebtwa\" data-start=\"6112\" data-end=\"6164\">Does it leak from every sample or one mold cavity?<\/li>\n<\/ul>\n<p data-start=\"6166\" data-end=\"6223\">The corrective action depends on the actual leakage path.<\/p>\n<p data-start=\"6225\" data-end=\"6325\">Tightening the lid will not solve a leak caused by an oversized straw opening or damaged valve slit.<\/p>\n<p data-start=\"6225\" data-end=\"6325\">Buyers can compare different <a href=\"https:\/\/www.lyasilicone.com\/zh\/product-category\/silicone-baby-products\/silicone-straw-cup\/\">silicone straw cup structures<\/a> before selecting an existing product or developing a new mold.<\/p>\n<h2 data-section-id=\"1fzrx33\" data-start=\"6327\" data-end=\"6381\"><span class=\"ez-toc-section\" id=\"3_The_Cup_Rim_and_Lid_Must_Form_Continuous_Contact\"><\/span>3. The Cup Rim and Lid Must Form Continuous Contact<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"6383\" data-end=\"6450\">The lid normally seals through controlled contact with the cup rim.<\/p>\n<p data-start=\"6452\" data-end=\"6493\">Depending on the design, the lid may use:<\/p>\n<ul data-start=\"6495\" data-end=\"6653\">\n<li data-section-id=\"1ckdevd\" data-start=\"6495\" data-end=\"6516\">An external overlap<\/li>\n<li data-section-id=\"xs22b1\" data-start=\"6517\" data-end=\"6543\">An internal sealing wall<\/li>\n<li data-section-id=\"1agi2un\" data-start=\"6544\" data-end=\"6554\">A groove<\/li>\n<li data-section-id=\"1i5ohgn\" data-start=\"6555\" data-end=\"6567\">A lip seal<\/li>\n<li data-section-id=\"8xg550\" data-start=\"6568\" data-end=\"6589\">An interference fit<\/li>\n<li data-section-id=\"1qou4y9\" data-start=\"6590\" data-end=\"6606\">A snap feature<\/li>\n<li data-section-id=\"10inbah\" data-start=\"6607\" data-end=\"6630\">Multiple sealing ribs<\/li>\n<li data-section-id=\"1n0oe6d\" data-start=\"6631\" data-end=\"6653\">A rigid support ring<\/li>\n<\/ul>\n<p data-start=\"6655\" data-end=\"6732\">The sealing contact must remain continuous around the complete circumference.<\/p>\n<p data-start=\"6734\" data-end=\"6760\">Possible problems include:<\/p>\n<ul data-start=\"6762\" data-end=\"6999\">\n<li data-section-id=\"1lf30dl\" data-start=\"6762\" data-end=\"6793\">One side engaging more deeply<\/li>\n<li data-section-id=\"14ih3pc\" data-start=\"6794\" data-end=\"6806\">Local gaps<\/li>\n<li data-section-id=\"2qj3fm\" data-start=\"6807\" data-end=\"6823\">Lid distortion<\/li>\n<li data-section-id=\"e6wr4l\" data-start=\"6824\" data-end=\"6840\">Rim distortion<\/li>\n<li data-section-id=\"nf7tyw\" data-start=\"6841\" data-end=\"6862\">Incomplete assembly<\/li>\n<li data-section-id=\"nuubzp\" data-start=\"6863\" data-end=\"6888\">Uneven sealing pressure<\/li>\n<li data-section-id=\"12ady39\" data-start=\"6889\" data-end=\"6919\">Flash on the contact surface<\/li>\n<li data-section-id=\"197anq6\" data-start=\"6920\" data-end=\"6953\">Parting lines crossing the seal<\/li>\n<li data-section-id=\"1oh7ges\" data-start=\"6954\" data-end=\"6999\">Different shrinkage between the cup and lid<\/li>\n<\/ul>\n<p data-start=\"7001\" data-end=\"7075\">A lid may feel tight to the user but still contain one local leakage path.<\/p>\n<p data-start=\"7077\" data-end=\"7147\">Assembly force and sealing effectiveness are not the same measurement.<\/p>\n<p data-start=\"7077\" data-end=\"7147\"><img decoding=\"async\" class=\"alignnone size-medium wp-image-10644\" src=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-lid-rim-seal-design.jpg-300x300.jpg\" alt=\"Silicone straw cup lid and rim seal design\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-lid-rim-seal-design.jpg-300x300.jpg 300w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-lid-rim-seal-design.jpg-150x150.jpg 150w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-lid-rim-seal-design.jpg-768x768.jpg 768w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-lid-rim-seal-design.jpg-12x12.jpg 12w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-lid-rim-seal-design.jpg-600x600.jpg 600w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-lid-rim-seal-design.jpg-100x100.jpg 100w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-lid-rim-seal-design.jpg.jpg 800w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<h2 data-section-id=\"lg70d6\" data-start=\"7149\" data-end=\"7184\"><span class=\"ez-toc-section\" id=\"4_Cup-Rim_Roundness_Is_Critical\"><\/span>4. Cup-Rim Roundness Is Critical<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"7186\" data-end=\"7256\">A circular lid cannot seal reliably against an oval or warped cup rim.<\/p>\n<p data-start=\"7258\" data-end=\"7301\">The cup may become out of round because of:<\/p>\n<ul data-start=\"7303\" data-end=\"7522\">\n<li data-section-id=\"1khk9mz\" data-start=\"7303\" data-end=\"7326\">Uneven wall thickness<\/li>\n<li data-section-id=\"axwsfq\" data-start=\"7327\" data-end=\"7347\">Silicone shrinkage<\/li>\n<li data-section-id=\"1293kyx\" data-start=\"7348\" data-end=\"7371\">Demolding deformation<\/li>\n<li data-section-id=\"167keep\" data-start=\"7372\" data-end=\"7399\">Incorrect cooling support<\/li>\n<li data-section-id=\"ju8yfm\" data-start=\"7400\" data-end=\"7420\">Packaging pressure<\/li>\n<li data-section-id=\"lfq24v\" data-start=\"7421\" data-end=\"7441\">Long-term stacking<\/li>\n<li data-section-id=\"1qzj34p\" data-start=\"7442\" data-end=\"7469\">Excessively soft material<\/li>\n<li data-section-id=\"s5k2iv\" data-start=\"7470\" data-end=\"7487\">Lid compression<\/li>\n<li data-section-id=\"21js7u\" data-start=\"7488\" data-end=\"7522\">Different mold-cavity conditions<\/li>\n<\/ul>\n<p data-start=\"7524\" data-end=\"7568\">Even a small change in roundness can create:<\/p>\n<ul data-start=\"7570\" data-end=\"7718\">\n<li data-section-id=\"1qit8dz\" data-start=\"7570\" data-end=\"7593\">Uneven lid engagement<\/li>\n<li data-section-id=\"11dif9a\" data-start=\"7594\" data-end=\"7613\">One-sided leakage<\/li>\n<li data-section-id=\"1b5u5l\" data-start=\"7614\" data-end=\"7634\">Loose lid sections<\/li>\n<li data-section-id=\"4tou6a\" data-start=\"7635\" data-end=\"7682\">Excessive assembly force on the opposite side<\/li>\n<li data-section-id=\"ogjh\" data-start=\"7683\" data-end=\"7697\">Lid rotation<\/li>\n<li data-section-id=\"1isukar\" data-start=\"7698\" data-end=\"7718\">Straw misalignment<\/li>\n<\/ul>\n<p data-start=\"7720\" data-end=\"7783\">Rim inspection should therefore include more than one diameter.<\/p>\n<p data-start=\"7785\" data-end=\"7854\">For precision projects, the buyer and manufacturer may need to check:<\/p>\n<ul data-start=\"7856\" data-end=\"7970\">\n<li data-section-id=\"1gj3rif\" data-start=\"7856\" data-end=\"7874\">Maximum diameter<\/li>\n<li data-section-id=\"19g49nd\" data-start=\"7875\" data-end=\"7893\">Minimum diameter<\/li>\n<li data-section-id=\"1qomnyg\" data-start=\"7894\" data-end=\"7909\">Rim thickness<\/li>\n<li data-section-id=\"yvevup\" data-start=\"7910\" data-end=\"7922\">Rim height<\/li>\n<li data-section-id=\"1lhw4yk\" data-start=\"7923\" data-end=\"7933\">Flatness<\/li>\n<li data-section-id=\"yh8rnh\" data-start=\"7934\" data-end=\"7947\">Circularity<\/li>\n<li data-section-id=\"5e0v7d\" data-start=\"7948\" data-end=\"7970\">Lid engagement depth<\/li>\n<\/ul>\n<p data-start=\"7972\" data-end=\"8067\">The cup should also be checked after packaging and storage, not only immediately after molding.<\/p>\n<h2 data-section-id=\"1k0liav\" data-start=\"8069\" data-end=\"8097\"><span class=\"ez-toc-section\" id=\"5_A_Lid_Can_Be_Too_Tight\"><\/span>5. A Lid Can Be Too Tight<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"8099\" data-end=\"8185\">A very tight lid may appear safer, but excessive interference can create new problems.<\/p>\n<p data-start=\"8187\" data-end=\"8212\">Possible results include:<\/p>\n<ul data-start=\"8214\" data-end=\"8413\">\n<li data-section-id=\"z3rpz0\" data-start=\"8214\" data-end=\"8234\">Difficult assembly<\/li>\n<li data-section-id=\"1si7ll8\" data-start=\"8235\" data-end=\"8254\">Difficult removal<\/li>\n<li data-section-id=\"12bkotb\" data-start=\"8255\" data-end=\"8277\">Cup-wall deformation<\/li>\n<li data-section-id=\"jcvk2r\" data-start=\"8278\" data-end=\"8291\">Rim rolling<\/li>\n<li data-section-id=\"2qj3fm\" data-start=\"8292\" data-end=\"8308\">Lid distortion<\/li>\n<li data-section-id=\"m6myit\" data-start=\"8309\" data-end=\"8323\">Cup collapse<\/li>\n<li data-section-id=\"idhdve\" data-start=\"8324\" data-end=\"8356\">Liquid spraying during opening<\/li>\n<li data-section-id=\"6ot5ow\" data-start=\"8357\" data-end=\"8375\">User frustration<\/li>\n<li data-section-id=\"1o7c3u0\" data-start=\"8376\" data-end=\"8413\">Excessive stress after repeated use<\/li>\n<\/ul>\n<p data-start=\"8415\" data-end=\"8501\">A soft cup body may deform before the lid fully reaches its intended sealing position.<\/p>\n<p data-start=\"8503\" data-end=\"8614\">This can create the misleading situation in which the lid feels extremely tight but is not assembled correctly.<\/p>\n<p data-start=\"8616\" data-end=\"8718\">The target should be controlled engagement with repeatable sealing contact\u2014not maximum assembly force.<\/p>\n<h2 data-section-id=\"ocubt5\" data-start=\"8720\" data-end=\"8753\"><span class=\"ez-toc-section\" id=\"6_A_Lid_Can_Also_Be_Too_Loose\"><\/span>6. A Lid Can Also Be Too Loose<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"8755\" data-end=\"8779\">An overly loose lid may:<\/p>\n<ul data-start=\"8781\" data-end=\"8973\">\n<li data-section-id=\"jga973\" data-start=\"8781\" data-end=\"8805\">Detach during carrying<\/li>\n<li data-section-id=\"59fnvx\" data-start=\"8806\" data-end=\"8829\">Rotate around the cup<\/li>\n<li data-section-id=\"1r3tkst\" data-start=\"8830\" data-end=\"8851\">Leak during tilting<\/li>\n<li data-section-id=\"so2fkz\" data-start=\"8852\" data-end=\"8875\">Lose sealing pressure<\/li>\n<li data-section-id=\"12ul9tc\" data-start=\"8876\" data-end=\"8902\">Allow the straw to shift<\/li>\n<li data-section-id=\"1ip2bbp\" data-start=\"8903\" data-end=\"8933\">Open when the cup is dropped<\/li>\n<li data-section-id=\"1jxov44\" data-start=\"8934\" data-end=\"8973\">Become less secure after repeated use<\/li>\n<\/ul>\n<p data-start=\"8975\" data-end=\"9001\">Looseness may result from:<\/p>\n<ul data-start=\"9003\" data-end=\"9181\">\n<li data-section-id=\"xdr437\" data-start=\"9003\" data-end=\"9034\">Excessive lid inside diameter<\/li>\n<li data-section-id=\"br0rot\" data-start=\"9035\" data-end=\"9059\">Small cup-rim diameter<\/li>\n<li data-section-id=\"7l3pet\" data-start=\"9060\" data-end=\"9080\">Material shrinkage<\/li>\n<li data-section-id=\"666thh\" data-start=\"9081\" data-end=\"9101\">Incorrect hardness<\/li>\n<li data-section-id=\"wd9nmq\" data-start=\"9102\" data-end=\"9121\">Thin sealing ribs<\/li>\n<li data-section-id=\"11vua6b\" data-start=\"9122\" data-end=\"9133\">Mold wear<\/li>\n<li data-section-id=\"1dz8a3h\" data-start=\"9134\" data-end=\"9157\">Packaging deformation<\/li>\n<li data-section-id=\"gnumk3\" data-start=\"9158\" data-end=\"9181\">Measurement variation<\/li>\n<\/ul>\n<p data-start=\"9183\" data-end=\"9252\">The lid and cup should be sampled and measured as a matched assembly.<\/p>\n<p data-start=\"9254\" data-end=\"9318\">Approving the cup and lid independently creates additional risk.<\/p>\n<h2 data-section-id=\"1barfwk\" data-start=\"9320\" data-end=\"9373\"><span class=\"ez-toc-section\" id=\"7_The_Straw_Hole_Requires_Controlled_Interference\"><\/span>7. The Straw Hole Requires Controlled Interference<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"9375\" data-end=\"9490\">The hole around the straw must normally remain tight enough to reduce leakage while allowing assembly and cleaning.<\/p>\n<p data-start=\"9492\" data-end=\"9550\">If the straw hole is too large, possible problems include:<\/p>\n<ul data-start=\"9552\" data-end=\"9706\">\n<li data-section-id=\"p9pz0u\" data-start=\"9552\" data-end=\"9579\">Dripping around the straw<\/li>\n<li data-section-id=\"tpmnaw\" data-start=\"9580\" data-end=\"9601\">Leakage when tilted<\/li>\n<li data-section-id=\"iw0y4o\" data-start=\"9602\" data-end=\"9618\">Straw movement<\/li>\n<li data-section-id=\"3i1668\" data-start=\"9619\" data-end=\"9638\">Straw pulling out<\/li>\n<li data-section-id=\"76jtxl\" data-start=\"9639\" data-end=\"9681\">Air entering through an uncontrolled gap<\/li>\n<li data-section-id=\"cby4xy\" data-start=\"9682\" data-end=\"9706\">Variable drinking flow<\/li>\n<\/ul>\n<p data-start=\"9708\" data-end=\"9760\">If the hole is too small, possible problems include:<\/p>\n<ul data-start=\"9762\" data-end=\"9934\">\n<li data-section-id=\"n641p9\" data-start=\"9762\" data-end=\"9792\">Difficult straw installation<\/li>\n<li data-section-id=\"9gfflw\" data-start=\"9793\" data-end=\"9822\">Excessive straw compression<\/li>\n<li data-section-id=\"1fgh7ta\" data-start=\"9823\" data-end=\"9851\">Reduced internal flow area<\/li>\n<li data-section-id=\"1jb88ng\" data-start=\"9852\" data-end=\"9867\">Straw kinking<\/li>\n<li data-section-id=\"2qj3fm\" data-start=\"9868\" data-end=\"9884\">Lid distortion<\/li>\n<li data-section-id=\"h5uht0\" data-start=\"9885\" data-end=\"9913\">Tearing around the opening<\/li>\n<li data-section-id=\"3krjit\" data-start=\"9914\" data-end=\"9934\">High removal force<\/li>\n<\/ul>\n<p data-start=\"9936\" data-end=\"9965\">The design should coordinate:<\/p>\n<ul data-start=\"9967\" data-end=\"10141\">\n<li data-section-id=\"1x5rbfd\" data-start=\"9967\" data-end=\"9991\">Straw outside diameter<\/li>\n<li data-section-id=\"123w6y3\" data-start=\"9992\" data-end=\"10014\">Straw wall thickness<\/li>\n<li data-section-id=\"16scaj1\" data-start=\"10015\" data-end=\"10034\">Lid-hole diameter<\/li>\n<li data-section-id=\"l34y8b\" data-start=\"10035\" data-end=\"10056\">Hole-wall thickness<\/li>\n<li data-section-id=\"5pchzb\" data-start=\"10057\" data-end=\"10076\">Hole-entry radius<\/li>\n<li data-section-id=\"od7j0k\" data-start=\"10077\" data-end=\"10096\">Silicone hardness<\/li>\n<li data-section-id=\"terdt7\" data-start=\"10097\" data-end=\"10113\">Assembly force<\/li>\n<li data-section-id=\"15lxgn3\" data-start=\"10114\" data-end=\"10141\">Required sealing pressure<\/li>\n<\/ul>\n<p data-start=\"10143\" data-end=\"10219\">The straw and lid must be evaluated together using actual molded components.<\/p>\n<h2 data-section-id=\"1wcc27a\" data-start=\"10221\" data-end=\"10271\"><span class=\"ez-toc-section\" id=\"8_Straw_Compression_Can_Restrict_Drinking_Flow\"><\/span>8. Straw Compression Can Restrict Drinking Flow<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"10273\" data-end=\"10404\">A straw may have the correct nominal inside diameter before assembly but become partially closed after being inserted into the lid.<\/p>\n<p data-start=\"10406\" data-end=\"10427\">This may happen when:<\/p>\n<ul data-start=\"10429\" data-end=\"10640\">\n<li data-section-id=\"14bnwhb\" data-start=\"10429\" data-end=\"10456\">The lid hole is too small<\/li>\n<li data-section-id=\"x05m5k\" data-start=\"10457\" data-end=\"10486\">The straw wall is very soft<\/li>\n<li data-section-id=\"1jumx2v\" data-start=\"10487\" data-end=\"10505\">The lid is thick<\/li>\n<li data-section-id=\"v0w81q\" data-start=\"10506\" data-end=\"10530\">The hole edge is sharp<\/li>\n<li data-section-id=\"1wt9gh1\" data-start=\"10531\" data-end=\"10566\">The straw is inserted at an angle<\/li>\n<li data-section-id=\"tn8ijk\" data-start=\"10567\" data-end=\"10603\">The straw is bent close to the lid<\/li>\n<li data-section-id=\"1utl2tk\" data-start=\"10604\" data-end=\"10640\">The straw is pulled too far upward<\/li>\n<\/ul>\n<p data-start=\"10642\" data-end=\"10668\">Possible symptoms include:<\/p>\n<ul data-start=\"10670\" data-end=\"10795\">\n<li data-section-id=\"1ux9lbw\" data-start=\"10670\" data-end=\"10695\">High suction resistance<\/li>\n<li data-section-id=\"13u3gc1\" data-start=\"10696\" data-end=\"10714\">Slow liquid flow<\/li>\n<li data-section-id=\"13rymyk\" data-start=\"10715\" data-end=\"10733\">Interrupted flow<\/li>\n<li data-section-id=\"mxourf\" data-start=\"10734\" data-end=\"10755\">Straw-wall collapse<\/li>\n<li data-section-id=\"65gvwq\" data-start=\"10756\" data-end=\"10795\">Different performance between samples<\/li>\n<\/ul>\n<p data-start=\"10797\" data-end=\"10854\">The straw should be inspected in its installed condition.<\/p>\n<p data-start=\"10856\" data-end=\"10956\">Measuring an unassembled straw alone does not confirm the effective drinking passage after assembly.<\/p>\n<h2 data-section-id=\"f55nw8\" data-start=\"10958\" data-end=\"11002\"><span class=\"ez-toc-section\" id=\"9_The_Air_Vent_Controls_Drinking_Comfort\"><\/span>9. The Air Vent Controls Drinking Comfort<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"11004\" data-end=\"11080\">An air vent allows replacement air to enter the cup while liquid is removed.<\/p>\n<p data-start=\"11082\" data-end=\"11099\">The vent may use:<\/p>\n<ul data-start=\"11101\" data-end=\"11264\">\n<li data-section-id=\"1upm6ks\" data-start=\"11101\" data-end=\"11120\">A small open hole<\/li>\n<li data-section-id=\"11rltkz\" data-start=\"11121\" data-end=\"11135\">A slit valve<\/li>\n<li data-section-id=\"1yi0ufb\" data-start=\"11136\" data-end=\"11153\">A one-way valve<\/li>\n<li data-section-id=\"dks8hv\" data-start=\"11154\" data-end=\"11175\">A flexible membrane<\/li>\n<li data-section-id=\"80sle\" data-start=\"11176\" data-end=\"11193\">A separate plug<\/li>\n<li data-section-id=\"md0rl\" data-start=\"11194\" data-end=\"11220\">A controlled lid channel<\/li>\n<li data-section-id=\"10p2qck\" data-start=\"11221\" data-end=\"11264\">A valve integrated into the straw opening<\/li>\n<\/ul>\n<p data-start=\"11266\" data-end=\"11339\">If the vent is too restricted, the user may need excessive suction force.<\/p>\n<p data-start=\"11341\" data-end=\"11402\">If it is too open, the vent may become a direct leakage path.<\/p>\n<p data-start=\"11404\" data-end=\"11432\">Vent performance depends on:<\/p>\n<ul data-start=\"11434\" data-end=\"11633\">\n<li data-section-id=\"l4bou9\" data-start=\"11434\" data-end=\"11449\">Hole diameter<\/li>\n<li data-section-id=\"1pmuquu\" data-start=\"11450\" data-end=\"11463\">Slit length<\/li>\n<li data-section-id=\"e0tdc1\" data-start=\"11464\" data-end=\"11484\">Membrane thickness<\/li>\n<li data-section-id=\"145sdsk\" data-start=\"11485\" data-end=\"11501\">Valve hardness<\/li>\n<li data-section-id=\"jbaljd\" data-start=\"11502\" data-end=\"11523\">Valve opening force<\/li>\n<li data-section-id=\"xl7305\" data-start=\"11524\" data-end=\"11548\">Liquid surface tension<\/li>\n<li data-section-id=\"cd4b14\" data-start=\"11549\" data-end=\"11566\">Cup orientation<\/li>\n<li data-section-id=\"157bvd6\" data-start=\"11567\" data-end=\"11586\">Internal pressure<\/li>\n<li data-section-id=\"1fvs4ym\" data-start=\"11587\" data-end=\"11607\">Cleaning condition<\/li>\n<li data-section-id=\"1xt99x5\" data-start=\"11608\" data-end=\"11633\">Manufacturing variation<\/li>\n<\/ul>\n<p data-start=\"11635\" data-end=\"11707\">The vent should be evaluated under both drinking and leakage conditions.<\/p>\n<h2 data-section-id=\"95jccx\" data-start=\"11709\" data-end=\"11773\"><span class=\"ez-toc-section\" id=\"10_Anti-Spill_Valve_Design_Requires_a_Balanced_Opening_Force\"><\/span>10. Anti-Spill Valve Design Requires a Balanced Opening Force<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"11775\" data-end=\"11905\">Some straw cups use a cross slit, straight slit, duckbill valve, or another flexible structure to reduce uncontrolled liquid flow.<\/p>\n<p data-start=\"11907\" data-end=\"12005\">The valve should remain closed under normal gravity and open under the intended drinking pressure.<\/p>\n<p data-start=\"12007\" data-end=\"12065\">If the valve is too soft or the slit is too large, it may:<\/p>\n<ul data-start=\"12067\" data-end=\"12212\">\n<li data-section-id=\"kjtqpr\" data-start=\"12067\" data-end=\"12086\">Drip continuously<\/li>\n<li data-section-id=\"yobp0b\" data-start=\"12087\" data-end=\"12105\">Leak when tilted<\/li>\n<li data-section-id=\"srjexa\" data-start=\"12106\" data-end=\"12127\">Open during shaking<\/li>\n<li data-section-id=\"1sqyj4g\" data-start=\"12128\" data-end=\"12169\">Release liquid when the cup is squeezed<\/li>\n<li data-section-id=\"6274u\" data-start=\"12170\" data-end=\"12212\">Become less effective after repeated use<\/li>\n<\/ul>\n<p data-start=\"12214\" data-end=\"12272\">If the valve is too firm or the slit is too small, it may:<\/p>\n<ul data-start=\"12274\" data-end=\"12466\">\n<li data-section-id=\"1m4o0hp\" data-start=\"12274\" data-end=\"12301\">Require excessive suction<\/li>\n<li data-section-id=\"17fsrbs\" data-start=\"12302\" data-end=\"12332\">Prevent comfortable drinking<\/li>\n<li data-section-id=\"18xy5bd\" data-start=\"12333\" data-end=\"12362\">Produce an interrupted flow<\/li>\n<li data-section-id=\"1kz9dhr\" data-start=\"12363\" data-end=\"12392\">Remain closed after washing<\/li>\n<li data-section-id=\"185dq3b\" data-start=\"12393\" data-end=\"12422\">Stick together after drying<\/li>\n<li data-section-id=\"abmgf4\" data-start=\"12423\" data-end=\"12466\">Perform differently at lower temperatures<\/li>\n<\/ul>\n<p data-start=\"12468\" data-end=\"12525\">Valve performance depends on more than material hardness.<\/p>\n<p data-start=\"12527\" data-end=\"12555\">Important variables include:<\/p>\n<ul data-start=\"12557\" data-end=\"12728\">\n<li data-section-id=\"1pmuquu\" data-start=\"12557\" data-end=\"12570\">Slit length<\/li>\n<li data-section-id=\"njrqef\" data-start=\"12571\" data-end=\"12583\">Slit depth<\/li>\n<li data-section-id=\"e0tdc1\" data-start=\"12584\" data-end=\"12604\">Membrane thickness<\/li>\n<li data-section-id=\"117j8pb\" data-start=\"12605\" data-end=\"12618\">Valve shape<\/li>\n<li data-section-id=\"1szpgx2\" data-start=\"12619\" data-end=\"12633\">Edge quality<\/li>\n<li data-section-id=\"1nz34y\" data-start=\"12634\" data-end=\"12656\">Silicone formulation<\/li>\n<li data-section-id=\"1djqgcf\" data-start=\"12657\" data-end=\"12672\">Mold accuracy<\/li>\n<li data-section-id=\"tfn27d\" data-start=\"12673\" data-end=\"12689\">Residual flash<\/li>\n<li data-section-id=\"1i8pqik\" data-start=\"12690\" data-end=\"12703\">Liquid type<\/li>\n<li data-section-id=\"rwcmxx\" data-start=\"12704\" data-end=\"12728\">Required suction force<\/li>\n<\/ul>\n<p data-start=\"12730\" data-end=\"12816\">The valve should be validated through actual flow testing, not only visual inspection.<\/p>\n<p data-start=\"12730\" data-end=\"12816\"><img decoding=\"async\" class=\"alignnone size-medium wp-image-10645\" src=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-valve-flow-design.jpg-300x300.jpg\" alt=\"Silicone straw cup anti-spill valve flow design\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-valve-flow-design.jpg-300x300.jpg 300w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-valve-flow-design.jpg-150x150.jpg 150w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-valve-flow-design.jpg-768x768.jpg 768w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-valve-flow-design.jpg-12x12.jpg 12w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-valve-flow-design.jpg-600x600.jpg 600w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-valve-flow-design.jpg-100x100.jpg 100w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-valve-flow-design.jpg.jpg 800w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<h2 data-section-id=\"1asdkjq\" data-start=\"12818\" data-end=\"12880\"><span class=\"ez-toc-section\" id=\"11_Straw_Inside_Diameter_and_Length_Affect_Flow_Resistance\"><\/span>11. Straw Inside Diameter and Length Affect Flow Resistance<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"12882\" data-end=\"12958\">A longer or narrower straw generally creates more resistance to liquid flow.<\/p>\n<p data-start=\"12960\" data-end=\"13011\">The required suction effort may also increase when:<\/p>\n<ul data-start=\"13013\" data-end=\"13276\">\n<li data-section-id=\"t9lrcs\" data-start=\"13013\" data-end=\"13041\">The straw has a sharp bend<\/li>\n<li data-section-id=\"ji9mzv\" data-start=\"13042\" data-end=\"13079\">The bottom end touches the cup wall<\/li>\n<li data-section-id=\"7vtpnf\" data-start=\"13080\" data-end=\"13114\">The straw collapses under vacuum<\/li>\n<li data-section-id=\"ztmziq\" data-start=\"13115\" data-end=\"13155\">The straw opening is partially blocked<\/li>\n<li data-section-id=\"10dmvct\" data-start=\"13156\" data-end=\"13189\">The drink is thicker than water<\/li>\n<li data-section-id=\"wa40yi\" data-start=\"13190\" data-end=\"13229\">A valve is installed in the flow path<\/li>\n<li data-section-id=\"1ov0z71\" data-start=\"13230\" data-end=\"13276\">The user must lift liquid through a tall cup<\/li>\n<\/ul>\n<p data-start=\"13278\" data-end=\"13303\">The design should review:<\/p>\n<ul data-start=\"13305\" data-end=\"13497\">\n<li data-section-id=\"1x86tyo\" data-start=\"13305\" data-end=\"13328\">Straw inside diameter<\/li>\n<li data-section-id=\"1x5rbfd\" data-start=\"13329\" data-end=\"13353\">Straw outside diameter<\/li>\n<li data-section-id=\"11eg4uv\" data-start=\"13354\" data-end=\"13368\">Straw length<\/li>\n<li data-section-id=\"6f79ns\" data-start=\"13369\" data-end=\"13385\">Wall thickness<\/li>\n<li data-section-id=\"132jp8d\" data-start=\"13386\" data-end=\"13402\">Bending radius<\/li>\n<li data-section-id=\"rmz8ne\" data-start=\"13403\" data-end=\"13421\">Bottom-end shape<\/li>\n<li data-section-id=\"1pkd8zb\" data-start=\"13422\" data-end=\"13450\">Distance from the cup base<\/li>\n<li data-section-id=\"1u79dbt\" data-start=\"13451\" data-end=\"13467\">Valve position<\/li>\n<li data-section-id=\"8cfxqp\" data-start=\"13468\" data-end=\"13480\">Cup height<\/li>\n<li data-section-id=\"cbtf4f\" data-start=\"13481\" data-end=\"13497\">Intended drink<\/li>\n<\/ul>\n<p data-start=\"13499\" data-end=\"13618\">A straw selected for a small water cup may not provide the same performance in a taller cup or with a thicker beverage.<\/p>\n<h2 data-section-id=\"1izm7zu\" data-start=\"13620\" data-end=\"13667\"><span class=\"ez-toc-section\" id=\"12_The_Bottom_of_the_Straw_Must_Remain_Open\"><\/span>12. The Bottom of the Straw Must Remain Open<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"13669\" data-end=\"13726\">The lower end of the straw may become restricted when it:<\/p>\n<ul data-start=\"13728\" data-end=\"13947\">\n<li data-section-id=\"o6n5jf\" data-start=\"13728\" data-end=\"13763\">Presses flat against the cup base<\/li>\n<li data-section-id=\"1hq2d4f\" data-start=\"13764\" data-end=\"13787\">Contacts the sidewall<\/li>\n<li data-section-id=\"1ul8abl\" data-start=\"13788\" data-end=\"13819\">Is cut at an unsuitable angle<\/li>\n<li data-section-id=\"vo5meg\" data-start=\"13820\" data-end=\"13851\">Bends during lid installation<\/li>\n<li data-section-id=\"c69ecs\" data-start=\"13852\" data-end=\"13865\">Is too long<\/li>\n<li data-section-id=\"cjvntg\" data-start=\"13866\" data-end=\"13901\">Is compressed by a bottom feature<\/li>\n<li data-section-id=\"no52mv\" data-start=\"13902\" data-end=\"13947\">Becomes blocked by thicker food or sediment<\/li>\n<\/ul>\n<p data-start=\"13949\" data-end=\"13987\">Possible structural solutions include:<\/p>\n<ul data-start=\"13989\" data-end=\"14146\">\n<li data-section-id=\"pjf741\" data-start=\"13989\" data-end=\"14007\">Angled straw end<\/li>\n<li data-section-id=\"zou6sn\" data-start=\"14008\" data-end=\"14022\">Side opening<\/li>\n<li data-section-id=\"lqopu1\" data-start=\"14023\" data-end=\"14036\">Rounded cut<\/li>\n<li data-section-id=\"zqm0zs\" data-start=\"14037\" data-end=\"14073\">Controlled clearance from the base<\/li>\n<li data-section-id=\"qthyz3\" data-start=\"14074\" data-end=\"14103\">Internal locating structure<\/li>\n<li data-section-id=\"1t55t4e\" data-start=\"14104\" data-end=\"14119\">Shorter straw<\/li>\n<li data-section-id=\"1w09c0b\" data-start=\"14120\" data-end=\"14146\">Reinforced lower section<\/li>\n<\/ul>\n<p data-start=\"14148\" data-end=\"14275\">The straw should remain positioned so that liquid can enter without creating excessive residual liquid or blocking the opening.<\/p>\n<h2 data-section-id=\"1ydifvc\" data-start=\"14277\" data-end=\"14318\"><span class=\"ez-toc-section\" id=\"13_Drink_Type_Changes_the_Test_Result\"><\/span>13. Drink Type Changes the Test Result<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"14320\" data-end=\"14402\">Water is useful for initial testing, but it cannot represent every intended drink.<\/p>\n<p data-start=\"14404\" data-end=\"14449\">Flow and leakage performance may change with:<\/p>\n<ul data-start=\"14451\" data-end=\"14581\">\n<li data-section-id=\"1j3zrsb\" data-start=\"14451\" data-end=\"14457\">Milk<\/li>\n<li data-section-id=\"y7i55y\" data-start=\"14458\" data-end=\"14467\">Formula<\/li>\n<li data-section-id=\"16svr7c\" data-start=\"14468\" data-end=\"14475\">Juice<\/li>\n<li data-section-id=\"idxdat\" data-start=\"14476\" data-end=\"14487\">Smoothies<\/li>\n<li data-section-id=\"10nu7xg\" data-start=\"14488\" data-end=\"14500\">Thin puree<\/li>\n<li data-section-id=\"1gc6mwu\" data-start=\"14501\" data-end=\"14515\">Warm liquids<\/li>\n<li data-section-id=\"11cmilv\" data-start=\"14516\" data-end=\"14530\">Cold liquids<\/li>\n<li data-section-id=\"1tk3p8w\" data-start=\"14531\" data-end=\"14551\">Carbonated liquids<\/li>\n<li data-section-id=\"42j3qu\" data-start=\"14552\" data-end=\"14581\">Drinks containing particles<\/li>\n<\/ul>\n<p data-start=\"14583\" data-end=\"14687\">A thicker liquid may require more suction force and may not pass easily through a narrow straw or valve.<\/p>\n<p data-start=\"14689\" data-end=\"14712\">Warm liquid may change:<\/p>\n<ul data-start=\"14714\" data-end=\"14812\">\n<li data-section-id=\"1mvkpcd\" data-start=\"14714\" data-end=\"14736\">Silicone flexibility<\/li>\n<li data-section-id=\"i1x5io\" data-start=\"14737\" data-end=\"14760\">Internal air pressure<\/li>\n<li data-section-id=\"9jq3er\" data-start=\"14761\" data-end=\"14777\">Valve response<\/li>\n<li data-section-id=\"1dtmxg\" data-start=\"14778\" data-end=\"14794\">Lid engagement<\/li>\n<li data-section-id=\"1gdyqhg\" data-start=\"14795\" data-end=\"14812\">User perception<\/li>\n<\/ul>\n<p data-start=\"14814\" data-end=\"14920\">A cup should be tested with the intended drink or a representative test liquid with similar flow behavior.<\/p>\n<p data-start=\"14922\" data-end=\"15006\">The product instructions and marketing claims should match the validated conditions.<\/p>\n<h2 data-section-id=\"1g4rxrp\" data-start=\"15008\" data-end=\"15065\"><span class=\"ez-toc-section\" id=\"14_A_Soft_Cup_Body_Can_Create_Pressure-Driven_Leakage\"><\/span>14. A Soft Cup Body Can Create Pressure-Driven Leakage<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"15067\" data-end=\"15134\">Children may grip, squeeze, drop, or press the cup body during use.<\/p>\n<p data-start=\"15136\" data-end=\"15193\">When a flexible cup is squeezed, internal pressure rises.<\/p>\n<p data-start=\"15195\" data-end=\"15234\">That pressure may force liquid through:<\/p>\n<ul data-start=\"15236\" data-end=\"15311\">\n<li data-section-id=\"1kzimj6\" data-start=\"15236\" data-end=\"15247\">The straw<\/li>\n<li data-section-id=\"2c5x6q\" data-start=\"15248\" data-end=\"15262\">The air vent<\/li>\n<li data-section-id=\"8aw8ht\" data-start=\"15263\" data-end=\"15272\">A valve<\/li>\n<li data-section-id=\"19z69rf\" data-start=\"15273\" data-end=\"15287\">The lid seal<\/li>\n<li data-section-id=\"1y0fbus\" data-start=\"15288\" data-end=\"15311\">A loose straw opening<\/li>\n<\/ul>\n<p data-start=\"15313\" data-end=\"15339\">Possible symptoms include:<\/p>\n<ul data-start=\"15341\" data-end=\"15460\">\n<li data-section-id=\"1dv0b8h\" data-start=\"15341\" data-end=\"15373\">Liquid spraying from the straw<\/li>\n<li data-section-id=\"19adi8r\" data-start=\"15374\" data-end=\"15410\">Dripping after the cup is released<\/li>\n<li data-section-id=\"h92rz5\" data-start=\"15411\" data-end=\"15425\">Vent leakage<\/li>\n<li data-section-id=\"1tfgfem\" data-start=\"15426\" data-end=\"15439\">Lid lifting<\/li>\n<li data-section-id=\"oa3tfg\" data-start=\"15440\" data-end=\"15460\">Straw displacement<\/li>\n<\/ul>\n<p data-start=\"15462\" data-end=\"15524\"><a href=\"https:\/\/www.lyasilicone.com\/zh\/how-to-choose-silicone-hardness-custom-products\/\">Silicone hardness<\/a> should therefore be evaluated together with:<\/p>\n<ul data-start=\"15526\" data-end=\"15650\">\n<li data-section-id=\"gzcfr7\" data-start=\"15526\" data-end=\"15546\">Cup-wall thickness<\/li>\n<li data-section-id=\"q3hmh5\" data-start=\"15547\" data-end=\"15561\">Cup diameter<\/li>\n<li data-section-id=\"1bsxzuj\" data-start=\"15562\" data-end=\"15579\">Handle position<\/li>\n<li data-section-id=\"1nhtcs3\" data-start=\"15580\" data-end=\"15591\">Grip area<\/li>\n<li data-section-id=\"10i67c7\" data-start=\"15592\" data-end=\"15609\">Internal volume<\/li>\n<li data-section-id=\"5bn0vw\" data-start=\"15610\" data-end=\"15625\">Lid structure<\/li>\n<li data-section-id=\"1mgn5wx\" data-start=\"15626\" data-end=\"15650\">Valve opening pressure<\/li>\n<\/ul>\n<p data-start=\"15652\" data-end=\"15745\">An overly firm cup may reduce squeezing but become uncomfortable or difficult to manufacture.<\/p>\n<p data-start=\"15747\" data-end=\"15849\">An overly soft cup may feel pleasant but create uncontrolled internal pressure during normal handling.<\/p>\n<h2 data-section-id=\"1i1swrp\" data-start=\"15851\" data-end=\"15895\"><span class=\"ez-toc-section\" id=\"15_Handle_Position_Can_Influence_Leakage\"><\/span>15. Handle Position Can Influence Leakage<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"15897\" data-end=\"15950\">Handles change where and how the child applies force.<\/p>\n<p data-start=\"15952\" data-end=\"16014\">If the handles are connected to a flexible area, gripping may:<\/p>\n<ul data-start=\"16016\" data-end=\"16156\">\n<li data-section-id=\"2qahbq\" data-start=\"16016\" data-end=\"16037\">Deform the cup wall<\/li>\n<li data-section-id=\"hml1rg\" data-start=\"16038\" data-end=\"16060\">Pull the rim outward<\/li>\n<li data-section-id=\"1ujzyxb\" data-start=\"16061\" data-end=\"16081\">Change lid contact<\/li>\n<li data-section-id=\"12yvycu\" data-start=\"16082\" data-end=\"16110\">Increase internal pressure<\/li>\n<li data-section-id=\"k7mcqq\" data-start=\"16111\" data-end=\"16138\">Tilt the cup unexpectedly<\/li>\n<li data-section-id=\"1tln0r6\" data-start=\"16139\" data-end=\"16156\">Shift the straw<\/li>\n<\/ul>\n<p data-start=\"16158\" data-end=\"16193\">Important handle variables include:<\/p>\n<ul data-start=\"16195\" data-end=\"16352\">\n<li data-section-id=\"15eghct\" data-start=\"16195\" data-end=\"16210\">Handle height<\/li>\n<li data-section-id=\"axz5ig\" data-start=\"16211\" data-end=\"16233\">Connection thickness<\/li>\n<li data-section-id=\"14n3elu\" data-start=\"16234\" data-end=\"16257\">Distance from the rim<\/li>\n<li data-section-id=\"159qpmh\" data-start=\"16258\" data-end=\"16272\">Opening size<\/li>\n<li data-section-id=\"1fdt5zi\" data-start=\"16273\" data-end=\"16294\">Left-right symmetry<\/li>\n<li data-section-id=\"lzi0xn\" data-start=\"16295\" data-end=\"16309\">Grip texture<\/li>\n<li data-section-id=\"114cl0k\" data-start=\"16310\" data-end=\"16327\">Child hand size<\/li>\n<li data-section-id=\"1lsj8s\" data-start=\"16328\" data-end=\"16352\">Cup-body reinforcement<\/li>\n<\/ul>\n<p data-start=\"16354\" data-end=\"16441\">The cup should be tested while held by the handles, not only while standing on a table.<\/p>\n<h2 data-section-id=\"66f5x\" data-start=\"16443\" data-end=\"16506\"><span class=\"ez-toc-section\" id=\"16_Wall_Thickness_and_Cup_Shape_Affect_Structural_Stability\"><\/span>16. Wall Thickness and Cup Shape Affect Structural Stability<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"16508\" data-end=\"16570\">A tall, narrow cup behaves differently from a short, wide cup.<\/p>\n<p data-start=\"16572\" data-end=\"16597\">Cup stability depends on:<\/p>\n<ul data-start=\"16599\" data-end=\"16760\">\n<li data-section-id=\"yfv2e0\" data-start=\"16599\" data-end=\"16615\">Overall height<\/li>\n<li data-section-id=\"4xbbve\" data-start=\"16616\" data-end=\"16631\">Base diameter<\/li>\n<li data-section-id=\"4jafkp\" data-start=\"16632\" data-end=\"16646\">Rim diameter<\/li>\n<li data-section-id=\"6f79ns\" data-start=\"16647\" data-end=\"16663\">Wall thickness<\/li>\n<li data-section-id=\"yil0yk\" data-start=\"16664\" data-end=\"16674\">Pojemno\u015b\u0107<\/li>\n<li data-section-id=\"1bsxzuj\" data-start=\"16675\" data-end=\"16692\">Handle position<\/li>\n<li data-section-id=\"pe8vgp\" data-start=\"16693\" data-end=\"16705\">Lid weight<\/li>\n<li data-section-id=\"yywwqc\" data-start=\"16706\" data-end=\"16720\">Straw height<\/li>\n<li data-section-id=\"od7j0k\" data-start=\"16721\" data-end=\"16740\">Silicone hardness<\/li>\n<li data-section-id=\"6d2bh\" data-start=\"16741\" data-end=\"16760\">Liquid fill level<\/li>\n<\/ul>\n<p data-start=\"16762\" data-end=\"16777\">Thin walls may:<\/p>\n<ul data-start=\"16779\" data-end=\"16909\">\n<li data-section-id=\"1f4fdui\" data-start=\"16779\" data-end=\"16805\">Collapse during drinking<\/li>\n<li data-section-id=\"1e07oqb\" data-start=\"16806\" data-end=\"16833\">Deform under lid pressure<\/li>\n<li data-section-id=\"lqxh7j\" data-start=\"16834\" data-end=\"16847\">Become oval<\/li>\n<li data-section-id=\"ppmgph\" data-start=\"16848\" data-end=\"16876\">Spray liquid when squeezed<\/li>\n<li data-section-id=\"1yuozzv\" data-start=\"16877\" data-end=\"16909\">Recover slowly after packaging<\/li>\n<\/ul>\n<p data-start=\"16911\" data-end=\"16927\">Thick walls may:<\/p>\n<ul data-start=\"16929\" data-end=\"17063\">\n<li data-section-id=\"usl7qg\" data-start=\"16929\" data-end=\"16959\">Require greater molding time<\/li>\n<li data-section-id=\"1949q7b\" data-start=\"16960\" data-end=\"16985\">Increase product weight<\/li>\n<li data-section-id=\"1bjj5v9\" data-start=\"16986\" data-end=\"17006\">Reduce flexibility<\/li>\n<li data-section-id=\"14rspna\" data-start=\"17007\" data-end=\"17032\">Make the cup feel bulky<\/li>\n<li data-section-id=\"12266ah\" data-start=\"17033\" data-end=\"17063\">Affect cooling and shrinkage<\/li>\n<\/ul>\n<p data-start=\"17065\" data-end=\"17195\">Wall thickness should be adjusted according to the complete geometry instead of using one uniform value without structural review.<\/p>\n<h2 data-section-id=\"1sny9bp\" data-start=\"17197\" data-end=\"17250\"><span class=\"ez-toc-section\" id=\"17_Parting_Lines_and_Flash_Can_Interrupt_the_Seal\"><\/span>17. Parting Lines and Flash Can Interrupt the Seal<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"17252\" data-end=\"17284\">The mold parting line may cross:<\/p>\n<ul data-start=\"17286\" data-end=\"17379\">\n<li data-section-id=\"eb88kh\" data-start=\"17286\" data-end=\"17299\">The cup rim<\/li>\n<li data-section-id=\"xl9nf9\" data-start=\"17300\" data-end=\"17318\">Lid-sealing ribs<\/li>\n<li data-section-id=\"13syy6u\" data-start=\"17319\" data-end=\"17332\">Straw holes<\/li>\n<li data-section-id=\"117m4sx\" data-start=\"17333\" data-end=\"17346\">Valve slits<\/li>\n<li data-section-id=\"1uoa6iv\" data-start=\"17347\" data-end=\"17364\">Vent structures<\/li>\n<li data-section-id=\"bwt5rm\" data-start=\"17365\" data-end=\"17379\">Handle edges<\/li>\n<\/ul>\n<p data-start=\"17381\" data-end=\"17434\">Excessive flash or an uneven parting line can create:<\/p>\n<ul data-start=\"17436\" data-end=\"17578\">\n<li data-section-id=\"1in82o5\" data-start=\"17436\" data-end=\"17451\">Local leakage<\/li>\n<li data-section-id=\"z3rpz0\" data-start=\"17452\" data-end=\"17472\">Difficult assembly<\/li>\n<li data-section-id=\"1y7djrn\" data-start=\"17473\" data-end=\"17498\">Rough drinking surfaces<\/li>\n<li data-section-id=\"1fo5x76\" data-start=\"17499\" data-end=\"17518\">Valve obstruction<\/li>\n<li data-section-id=\"u3qo92\" data-start=\"17519\" data-end=\"17541\">Inconsistent venting<\/li>\n<li data-section-id=\"16n9kqo\" data-start=\"17542\" data-end=\"17556\">Straw damage<\/li>\n<li data-section-id=\"18lpgpq\" data-start=\"17557\" data-end=\"17578\">Cleaning difficulty<\/li>\n<\/ul>\n<p data-start=\"17580\" data-end=\"17655\">Critical sealing areas should have a defined appearance and flash standard.<\/p>\n<p data-start=\"17657\" data-end=\"17816\">A general instruction such as \u201cno flash\u201d is difficult to apply unless the buyer identifies which areas directly affect sealing, drinking, comfort, or cleaning.<\/p>\n<h2 data-section-id=\"1l1y55l\" data-start=\"17818\" data-end=\"17883\"><span class=\"ez-toc-section\" id=\"18_Small_Holes_and_Valve_Features_Increase_Molding_Difficulty\"><\/span>18. Small Holes and Valve Features Increase Molding Difficulty<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"17885\" data-end=\"18003\">Straw holes, air vents, valve slits, and narrow channels may require small mold cores or precision shutoff structures.<\/p>\n<p data-start=\"18005\" data-end=\"18045\">Potential manufacturing defects include:<\/p>\n<ul data-start=\"18047\" data-end=\"18252\">\n<li data-section-id=\"36st71\" data-start=\"18047\" data-end=\"18063\">Hole too small<\/li>\n<li data-section-id=\"3plm27\" data-start=\"18064\" data-end=\"18080\">Hole too large<\/li>\n<li data-section-id=\"1apqntd\" data-start=\"18081\" data-end=\"18099\">Partial blockage<\/li>\n<li data-section-id=\"smkad0\" data-start=\"18100\" data-end=\"18124\">Thin silicone membrane<\/li>\n<li data-section-id=\"1b0smcz\" data-start=\"18125\" data-end=\"18148\">Flash inside the hole<\/li>\n<li data-section-id=\"1exw32f\" data-start=\"18149\" data-end=\"18169\">Misaligned opening<\/li>\n<li data-section-id=\"q4a0zo\" data-start=\"18170\" data-end=\"18189\">Uneven slit depth<\/li>\n<li data-section-id=\"582yp0\" data-start=\"18190\" data-end=\"18207\">Torn valve edge<\/li>\n<li data-section-id=\"c18zqg\" data-start=\"18208\" data-end=\"18223\">Core-pin wear<\/li>\n<li data-section-id=\"1gezqle\" data-start=\"18224\" data-end=\"18252\">Cavity-to-cavity variation<\/li>\n<\/ul>\n<p data-start=\"18254\" data-end=\"18277\">Inspection may require:<\/p>\n<ul data-start=\"18279\" data-end=\"18429\">\n<li data-section-id=\"1jtroot\" data-start=\"18279\" data-end=\"18291\">Pin gauges<\/li>\n<li data-section-id=\"1ulste6\" data-start=\"18292\" data-end=\"18313\">Optical measurement<\/li>\n<li data-section-id=\"s29m42\" data-start=\"18314\" data-end=\"18333\">Vision inspection<\/li>\n<li data-section-id=\"14ouonq\" data-start=\"18334\" data-end=\"18351\">Airflow testing<\/li>\n<li data-section-id=\"1bhx2ic\" data-start=\"18352\" data-end=\"18372\">Water-flow testing<\/li>\n<li data-section-id=\"sm8xc0\" data-start=\"18373\" data-end=\"18391\">Assembly testing<\/li>\n<li data-section-id=\"ol0wxq\" data-start=\"18392\" data-end=\"18429\">Defined suction or pressure testing<\/li>\n<\/ul>\n<p data-start=\"18431\" data-end=\"18546\">These details should be reviewed during <a href=\"https:\/\/www.lyasilicone.com\/zh\/custom-silicone-mold-development-checklist\/\">custom silicone mold development<\/a> rather than relying on manual hole trimming after molding.<\/p>\n<h2 data-section-id=\"1cq152v\" data-start=\"18548\" data-end=\"18593\"><span class=\"ez-toc-section\" id=\"19_Assembly_Direction_and_Sequence_Matter\"><\/span>19. Assembly Direction and Sequence Matter<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"18595\" data-end=\"18684\">A cup may leak because the user or assembly operator installs the components incorrectly.<\/p>\n<p data-start=\"18686\" data-end=\"18710\">Possible errors include:<\/p>\n<ul data-start=\"18712\" data-end=\"18985\">\n<li data-section-id=\"1wr3kic\" data-start=\"18712\" data-end=\"18734\">Lid not fully seated<\/li>\n<li data-section-id=\"hzis6s\" data-start=\"18735\" data-end=\"18776\">Straw inserted from the wrong direction<\/li>\n<li data-section-id=\"1j2jg6z\" data-start=\"18777\" data-end=\"18820\">Straw not pulled into its locating groove<\/li>\n<li data-section-id=\"d565vv\" data-start=\"18821\" data-end=\"18847\">Valve installed backward<\/li>\n<li data-section-id=\"1rpzbyg\" data-start=\"18848\" data-end=\"18870\">Vent plug not closed<\/li>\n<li data-section-id=\"147p4m2\" data-start=\"18871\" data-end=\"18904\">Lid twisted during installation<\/li>\n<li data-section-id=\"o4vg57\" data-start=\"18905\" data-end=\"18941\">Straw length installed incorrectly<\/li>\n<li data-section-id=\"30ofpd\" data-start=\"18942\" data-end=\"18985\">Components mixed between product versions<\/li>\n<\/ul>\n<p data-start=\"18987\" data-end=\"19031\">The design should reduce assembly ambiguity.<\/p>\n<p data-start=\"19033\" data-end=\"19059\">Possible controls include:<\/p>\n<ul data-start=\"19061\" data-end=\"19230\">\n<li data-section-id=\"7ma2kn\" data-start=\"19061\" data-end=\"19080\">Clear orientation<\/li>\n<li data-section-id=\"3re9o8\" data-start=\"19081\" data-end=\"19111\">Asymmetric locating features<\/li>\n<li data-section-id=\"2xbl4n\" data-start=\"19112\" data-end=\"19132\">Tactile engagement<\/li>\n<li data-section-id=\"9mcxs5\" data-start=\"19133\" data-end=\"19157\">Visual alignment marks<\/li>\n<li data-section-id=\"586k6\" data-start=\"19158\" data-end=\"19185\">Component differentiation<\/li>\n<li data-section-id=\"1l4kiy5\" data-start=\"19186\" data-end=\"19207\">Simple instructions<\/li>\n<li data-section-id=\"1chy6fi\" data-start=\"19208\" data-end=\"19230\">Poka-yoke structures<\/li>\n<\/ul>\n<p data-start=\"19232\" data-end=\"19318\">For retail products, testing should include normal consumer reassembly after cleaning.<\/p>\n<h2 data-section-id=\"1o8hksm\" data-start=\"19320\" data-end=\"19373\"><span class=\"ez-toc-section\" id=\"20_Cleaning_Can_Change_Valve_and_Seal_Performance\"><\/span>20. Cleaning Can Change Valve and Seal Performance<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"19375\" data-end=\"19427\">Straw cups are frequently disassembled for cleaning.<\/p>\n<p data-start=\"19429\" data-end=\"19468\">After washing, possible issues include:<\/p>\n<ul data-start=\"19470\" data-end=\"19727\">\n<li data-section-id=\"nrgn6e\" data-start=\"19470\" data-end=\"19500\">Valve slit sticking together<\/li>\n<li data-section-id=\"dswikm\" data-start=\"19501\" data-end=\"19530\">Straw inserted incompletely<\/li>\n<li data-section-id=\"ssertc\" data-start=\"19531\" data-end=\"19556\">Lid installed while wet<\/li>\n<li data-section-id=\"9aksnq\" data-start=\"19557\" data-end=\"19598\">Soap residue affecting surface behavior<\/li>\n<li data-section-id=\"1j0msm6\" data-start=\"19599\" data-end=\"19630\">Small holes remaining blocked<\/li>\n<li data-section-id=\"99vqnj\" data-start=\"19631\" data-end=\"19658\">Components becoming mixed<\/li>\n<li data-section-id=\"1d0bsmh\" data-start=\"19659\" data-end=\"19692\">Straw stretching during removal<\/li>\n<li data-section-id=\"rtfd9v\" data-start=\"19693\" data-end=\"19727\">Valve damage from cleaning tools<\/li>\n<\/ul>\n<p data-start=\"19729\" data-end=\"19775\">The design should provide practical access to:<\/p>\n<ul data-start=\"19777\" data-end=\"19881\">\n<li data-section-id=\"1qdwhy3\" data-start=\"19777\" data-end=\"19793\">Straw interior<\/li>\n<li data-section-id=\"12rigm2\" data-start=\"19794\" data-end=\"19809\">Lid underside<\/li>\n<li data-section-id=\"1hv9iez\" data-start=\"19810\" data-end=\"19820\">Air vent<\/li>\n<li data-section-id=\"1l3aesi\" data-start=\"19821\" data-end=\"19833\">Valve slit<\/li>\n<li data-section-id=\"lg40l\" data-start=\"19834\" data-end=\"19850\">Sealing groove<\/li>\n<li data-section-id=\"juuibc\" data-start=\"19851\" data-end=\"19860\">Cup rim<\/li>\n<li data-section-id=\"p4brc7\" data-start=\"19861\" data-end=\"19881\">Handle connections<\/li>\n<\/ul>\n<p data-start=\"19883\" data-end=\"20000\">A product should not achieve good spill control by creating hidden areas that users cannot clean or inspect properly.<\/p>\n<p data-start=\"20002\" data-end=\"20060\">Cleaning and reassembly should be part of sample approval.<\/p>\n<p data-start=\"20002\" data-end=\"20060\">When the cup is sold with bowls, spoons, plates or bibs, buyers should also evaluate it as part of the complete <a href=\"https:\/\/www.lyasilicone.com\/pl\/is-silicone-baby-feeding-set-safe-oem-checklist\/\">silikonowy zestaw do karmienia niemowl\u0105t<\/a>.<\/p>\n<h2 data-section-id=\"1oi98vs\" data-start=\"20062\" data-end=\"20113\"><span class=\"ez-toc-section\" id=\"21_Packaging_Can_Distort_the_Cup_Lid_or_Straw\"><\/span>21. Packaging Can Distort the Cup, Lid, or Straw<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"20115\" data-end=\"20181\">A correctly molded straw cup may become defective after packaging.<\/p>\n<p data-start=\"20183\" data-end=\"20205\">Common causes include:<\/p>\n<ul data-start=\"20207\" data-end=\"20433\">\n<li data-section-id=\"faucwu\" data-start=\"20207\" data-end=\"20240\">Cup compressed into a small box<\/li>\n<li data-section-id=\"lfint5\" data-start=\"20241\" data-end=\"20265\">Lid stored at an angle<\/li>\n<li data-section-id=\"1wip7pi\" data-start=\"20266\" data-end=\"20288\">Straw sharply folded<\/li>\n<li data-section-id=\"1xvhl2o\" data-start=\"20289\" data-end=\"20313\">Handles pressed inward<\/li>\n<li data-section-id=\"1a9ta7w\" data-start=\"20314\" data-end=\"20351\">Heavy accessories placed on the rim<\/li>\n<li data-section-id=\"65w7k9\" data-start=\"20352\" data-end=\"20372\">Tight plastic bags<\/li>\n<li data-section-id=\"lfq24v\" data-start=\"20373\" data-end=\"20393\">Long-term stacking<\/li>\n<li data-section-id=\"jluzvt\" data-start=\"20394\" data-end=\"20433\">Heat during storage or transportation<\/li>\n<\/ul>\n<p data-start=\"20435\" data-end=\"20460\">Possible results include:<\/p>\n<ul data-start=\"20462\" data-end=\"20596\">\n<li data-section-id=\"1np64zw\" data-start=\"20462\" data-end=\"20476\">Oval cup rim<\/li>\n<li data-section-id=\"stvrr0\" data-start=\"20477\" data-end=\"20489\">Warped lid<\/li>\n<li data-section-id=\"64xbe5\" data-start=\"20490\" data-end=\"20504\">Kinked straw<\/li>\n<li data-section-id=\"35yfme\" data-start=\"20505\" data-end=\"20521\">Deformed valve<\/li>\n<li data-section-id=\"163zr1k\" data-start=\"20522\" data-end=\"20537\">Loose lid fit<\/li>\n<li data-section-id=\"1lifc40\" data-start=\"20538\" data-end=\"20565\">Uneven straw-hole sealing<\/li>\n<li data-section-id=\"1mui2he\" data-start=\"20566\" data-end=\"20596\">Permanent handle deformation<\/li>\n<\/ul>\n<p data-start=\"20598\" data-end=\"20677\">Packaging tests should use actual molded samples and final packaging materials.<\/p>\n<p data-start=\"20679\" data-end=\"20808\">The product should be inspected before packaging, after storage, after transport simulation, and after a defined recovery period.<\/p>\n<h2 data-section-id=\"1272dmu\" data-start=\"20810\" data-end=\"20857\"><span class=\"ez-toc-section\" id=\"22_Sample_Testing_Should_Reproduce_Real_Use\"><\/span>22. Sample Testing Should Reproduce Real Use<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"20859\" data-end=\"20947\">A straw cup should not be approved only because it does not leak while standing upright.<\/p>\n<p data-start=\"20949\" data-end=\"20983\">A practical test plan may include:<\/p>\n<ul data-start=\"20985\" data-end=\"21388\">\n<li data-section-id=\"117lzjr\" data-start=\"20985\" data-end=\"21008\">Upright standing test<\/li>\n<li data-section-id=\"1a0z1hp\" data-start=\"21009\" data-end=\"21025\">Side-tilt test<\/li>\n<li data-section-id=\"11i08q5\" data-start=\"21026\" data-end=\"21041\">Inverted test<\/li>\n<li data-section-id=\"1v8dysv\" data-start=\"21042\" data-end=\"21056\">Shaking test<\/li>\n<li data-section-id=\"14gio2a\" data-start=\"21057\" data-end=\"21074\">Drop simulation<\/li>\n<li data-section-id=\"1g0oxal\" data-start=\"21075\" data-end=\"21098\">Cup-body squeeze test<\/li>\n<li data-section-id=\"1lvwtcl\" data-start=\"21099\" data-end=\"21117\">Handle-grip test<\/li>\n<li data-section-id=\"3oh7o8\" data-start=\"21118\" data-end=\"21135\">Straw pull test<\/li>\n<li data-section-id=\"1ubswr6\" data-start=\"21136\" data-end=\"21162\">Lid assembly and removal<\/li>\n<li data-section-id=\"17mtlo2\" data-start=\"21163\" data-end=\"21193\">Repeated opening and closing<\/li>\n<li data-section-id=\"octowk\" data-start=\"21194\" data-end=\"21211\">Water-flow test<\/li>\n<li data-section-id=\"1dw0w53\" data-start=\"21212\" data-end=\"21239\">Representative drink test<\/li>\n<li data-section-id=\"zzv7dy\" data-start=\"21240\" data-end=\"21267\">Suction-effort evaluation<\/li>\n<li data-section-id=\"8t8jnz\" data-start=\"21268\" data-end=\"21288\">Valve-opening test<\/li>\n<li data-section-id=\"724ghk\" data-start=\"21289\" data-end=\"21309\">Vent-function test<\/li>\n<li data-section-id=\"18occcv\" data-start=\"21310\" data-end=\"21335\">Cleaning and reassembly<\/li>\n<li data-section-id=\"1wonzhw\" data-start=\"21336\" data-end=\"21367\">Warm- and cold-liquid testing<\/li>\n<li data-section-id=\"1ggy60k\" data-start=\"21368\" data-end=\"21388\">Packaging recovery<\/li>\n<\/ul>\n<p data-start=\"21390\" data-end=\"21420\">The test method should define:<\/p>\n<ul data-start=\"21422\" data-end=\"21614\">\n<li data-section-id=\"h984bz\" data-start=\"21422\" data-end=\"21435\">Fill volume<\/li>\n<li data-section-id=\"1i8pqik\" data-start=\"21436\" data-end=\"21449\">Liquid type<\/li>\n<li data-section-id=\"1v4zap4\" data-start=\"21450\" data-end=\"21470\">Liquid temperature<\/li>\n<li data-section-id=\"cd4b14\" data-start=\"21471\" data-end=\"21488\">Cup orientation<\/li>\n<li data-section-id=\"17f78dc\" data-start=\"21489\" data-end=\"21504\">Test duration<\/li>\n<li data-section-id=\"1os9qrq\" data-start=\"21505\" data-end=\"21521\">Shaking method<\/li>\n<li data-section-id=\"1ccuhy5\" data-start=\"21522\" data-end=\"21540\">Squeeze location<\/li>\n<li data-section-id=\"t3gxnl\" data-start=\"21541\" data-end=\"21559\">Number of cycles<\/li>\n<li data-section-id=\"1gyydim\" data-start=\"21560\" data-end=\"21587\">Acceptable leakage amount<\/li>\n<li data-section-id=\"1h4cwlm\" data-start=\"21588\" data-end=\"21614\">Acceptable drinking flow<\/li>\n<\/ul>\n<p data-start=\"21616\" data-end=\"21720\">\u201cLeakproof\u201d and \u201ceasy to drink from\u201d are not measurable standards until the test conditions are defined.<\/p>\n<p data-start=\"21616\" data-end=\"21720\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-10646\" src=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-sample-testing.jpg-300x300.jpg\" alt=\"Silicone straw cup leakage and flow testing\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-sample-testing.jpg-300x300.jpg 300w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-sample-testing.jpg-150x150.jpg 150w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-sample-testing.jpg-768x768.jpg 768w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-sample-testing.jpg-12x12.jpg 12w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-sample-testing.jpg-600x600.jpg 600w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-sample-testing.jpg-100x100.jpg 100w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-sample-testing.jpg.jpg 800w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<h2 data-section-id=\"gis9ui\" data-start=\"21722\" data-end=\"21778\"><span class=\"ez-toc-section\" id=\"23_Why_Can_Samples_Pass_While_Mass_Production_Fails\"><\/span>23. Why Can Samples Pass While Mass Production Fails?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"21780\" data-end=\"21841\">Development samples are usually made under close supervision.<\/p>\n<p data-start=\"21843\" data-end=\"21859\">During sampling:<\/p>\n<ul data-start=\"21861\" data-end=\"22087\">\n<li data-section-id=\"1hh6o61\" data-start=\"21861\" data-end=\"21906\">Cup and lid pairs may be selected carefully<\/li>\n<li data-section-id=\"1u83mje\" data-start=\"21907\" data-end=\"21944\">Mold conditions are adjusted slowly<\/li>\n<li data-section-id=\"mtwjo6\" data-start=\"21945\" data-end=\"21970\">Every hole is inspected<\/li>\n<li data-section-id=\"1tlh57z\" data-start=\"21971\" data-end=\"22022\">Components are assembled by experienced engineers<\/li>\n<li data-section-id=\"1pmfba2\" data-start=\"22023\" data-end=\"22060\">Only one material batch may be used<\/li>\n<li data-section-id=\"iwno5y\" data-start=\"22061\" data-end=\"22087\">Production time is short<\/li>\n<\/ul>\n<p data-start=\"22089\" data-end=\"22116\">Mass production introduces:<\/p>\n<ul data-start=\"22118\" data-end=\"22363\">\n<li data-section-id=\"1frkwv8\" data-start=\"22118\" data-end=\"22142\">Multiple mold cavities<\/li>\n<li data-section-id=\"uob876\" data-start=\"22143\" data-end=\"22167\">Longer continuous runs<\/li>\n<li data-section-id=\"sti70j\" data-start=\"22168\" data-end=\"22194\">Material-batch variation<\/li>\n<li data-section-id=\"1sq04nh\" data-start=\"22195\" data-end=\"22215\">Hardness variation<\/li>\n<li data-section-id=\"o1blxu\" data-start=\"22216\" data-end=\"22244\">Mold-temperature variation<\/li>\n<li data-section-id=\"c18zqg\" data-start=\"22245\" data-end=\"22260\">Core-pin wear<\/li>\n<li data-section-id=\"18fn5i9\" data-start=\"22261\" data-end=\"22281\">Vent contamination<\/li>\n<li data-section-id=\"1i8y3wd\" data-start=\"22282\" data-end=\"22300\">Operator changes<\/li>\n<li data-section-id=\"193v3il\" data-start=\"22301\" data-end=\"22327\">Assembly-speed variation<\/li>\n<li data-section-id=\"ju8yfm\" data-start=\"22328\" data-end=\"22348\">Packaging pressure<\/li>\n<li data-section-id=\"19j0nok\" data-start=\"22349\" data-end=\"22363\">Storage time<\/li>\n<\/ul>\n<p data-start=\"22365\" data-end=\"22499\">A design with little tolerance margin may produce acceptable engineering samples but become inconsistent during continuous production.<\/p>\n<p data-start=\"22501\" data-end=\"22533\">Pilot production should compare:<\/p>\n<ul data-start=\"22535\" data-end=\"22743\">\n<li data-section-id=\"1bz65w6\" data-start=\"22535\" data-end=\"22555\">Cup-rim dimensions<\/li>\n<li data-section-id=\"1x2ry6i\" data-start=\"22556\" data-end=\"22572\">Lid dimensions<\/li>\n<li data-section-id=\"1nn5sy0\" data-start=\"22573\" data-end=\"22591\">Straw dimensions<\/li>\n<li data-section-id=\"1g0n3k3\" data-start=\"22592\" data-end=\"22603\">Hole size<\/li>\n<li data-section-id=\"w19hmg\" data-start=\"22604\" data-end=\"22623\">Valve performance<\/li>\n<li data-section-id=\"zwbex\" data-start=\"22624\" data-end=\"22638\">Vent airflow<\/li>\n<li data-section-id=\"1dtmxg\" data-start=\"22639\" data-end=\"22655\">Lid engagement<\/li>\n<li data-section-id=\"ujvyq0\" data-start=\"22656\" data-end=\"22665\">Leakage<\/li>\n<li data-section-id=\"bupio0\" data-start=\"22666\" data-end=\"22681\">Drinking flow<\/li>\n<li data-section-id=\"2k0cof\" data-start=\"22682\" data-end=\"22701\">Every mold cavity<\/li>\n<li data-section-id=\"1ox9ckf\" data-start=\"22702\" data-end=\"22743\">Beginning and end of the production run<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-10647\" src=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-production-consistency.jpg-300x300.jpg\" alt=\"Silicone straw cup mass production consistency\" width=\"300\" height=\"300\" srcset=\"https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-production-consistency.jpg-300x300.jpg 300w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-production-consistency.jpg-150x150.jpg 150w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-production-consistency.jpg-768x768.jpg 768w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-production-consistency.jpg-12x12.jpg 12w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-production-consistency.jpg-600x600.jpg 600w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-production-consistency.jpg-100x100.jpg 100w, https:\/\/www.lyasilicone.com\/wp-content\/uploads\/2026\/07\/silicone-straw-cup-production-consistency.jpg.jpg 800w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<h2 data-section-id=\"1xm0eey\" data-start=\"22745\" data-end=\"22799\"><span class=\"ez-toc-section\" id=\"24_A_Practical_Straw_Cup_Failure-Analysis_Sequence\"><\/span>24. A Practical Straw Cup Failure-Analysis Sequence<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"22801\" data-end=\"22908\">When a silicone straw cup leaks or becomes difficult to drink from, investigate the problem systematically.<\/p>\n<p data-start=\"22910\" data-end=\"22931\">Recommended sequence:<\/p>\n<ol data-start=\"22933\" data-end=\"23810\">\n<li data-section-id=\"kgavco\" data-start=\"22933\" data-end=\"22973\">Record the exact failure condition.<\/li>\n<li data-section-id=\"1dfva0n\" data-start=\"22974\" data-end=\"23009\">Identify the leakage location.<\/li>\n<li data-section-id=\"srzb1q\" data-start=\"23010\" data-end=\"23055\">Confirm the liquid type and temperature.<\/li>\n<li data-section-id=\"psvwqd\" data-start=\"23056\" data-end=\"23088\">Record the cup orientation.<\/li>\n<li data-section-id=\"xhnvmg\" data-start=\"23089\" data-end=\"23125\">Test the cup without squeezing.<\/li>\n<li data-section-id=\"573kpx\" data-start=\"23126\" data-end=\"23182\">Repeat the test while gripping the body or handles.<\/li>\n<li data-section-id=\"1iolk7h\" data-start=\"23183\" data-end=\"23219\">Test the cup without the straw.<\/li>\n<li data-section-id=\"9infsl\" data-start=\"23220\" data-end=\"23273\">Test the cup with the vent temporarily isolated.<\/li>\n<li data-section-id=\"vpeihz\" data-start=\"23274\" data-end=\"23307\">Measure the cup rim and lid.<\/li>\n<li data-section-id=\"14uh91u\" data-start=\"23308\" data-end=\"23369\">Check lid engagement around the complete circumference.<\/li>\n<li data-section-id=\"xgj937\" data-start=\"23370\" data-end=\"23407\">Measure the straw and lid hole.<\/li>\n<li data-section-id=\"1udo03a\" data-start=\"23408\" data-end=\"23459\">Inspect the straw in its assembled condition.<\/li>\n<li data-section-id=\"gtv4ne\" data-start=\"23460\" data-end=\"23500\">Check the air vent and valve slit.<\/li>\n<li data-section-id=\"1nvfm2y\" data-start=\"23501\" data-end=\"23543\">Compare passing and failing samples.<\/li>\n<li data-section-id=\"171cf9e\" data-start=\"23544\" data-end=\"23579\">Identify mold-cavity numbers.<\/li>\n<li data-section-id=\"10htxyb\" data-start=\"23580\" data-end=\"23620\">Review molding and curing records.<\/li>\n<li data-section-id=\"1eiwlsv\" data-start=\"23621\" data-end=\"23672\">Check for flash, membranes, or core-pin wear.<\/li>\n<li data-section-id=\"16uwwc9\" data-start=\"23673\" data-end=\"23715\">Review cleaning and assembly method.<\/li>\n<li data-section-id=\"1kfpmi6\" data-start=\"23716\" data-end=\"23752\">Inspect packaging deformation.<\/li>\n<li data-section-id=\"1ahqo9m\" data-start=\"23753\" data-end=\"23810\">Change one controlled variable and repeat the test.<\/li>\n<\/ol>\n<p data-start=\"23812\" data-end=\"23914\">Do not change lid dimensions, straw size, valve slit, material hardness, and packaging simultaneously.<\/p>\n<p data-start=\"23916\" data-end=\"23987\">Changing one variable at a time makes the root cause easier to confirm.<\/p>\n<h2 data-section-id=\"8ir1hf\" data-start=\"23989\" data-end=\"24044\"><span class=\"ez-toc-section\" id=\"25_What_Should_Be_Validated_Before_Mass_Production\"><\/span>25. What Should Be Validated Before Mass Production?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"24046\" data-end=\"24132\">Before approving a custom silicone straw cup, buyers and manufacturers should confirm:<\/p>\n<ul data-start=\"24134\" data-end=\"24824\">\n<li data-section-id=\"1cff96b\" data-start=\"24134\" data-end=\"24163\">Intended user and age range<\/li>\n<li data-section-id=\"11dewoq\" data-start=\"24164\" data-end=\"24178\">Cup capacity<\/li>\n<li data-section-id=\"qkykx9\" data-start=\"24179\" data-end=\"24195\">Cup dimensions<\/li>\n<li data-section-id=\"1sfxgu3\" data-start=\"24196\" data-end=\"24215\">Silicone material<\/li>\n<li data-section-id=\"1ayp3a6\" data-start=\"24216\" data-end=\"24234\">Shore A hardness<\/li>\n<li data-section-id=\"gzcfr7\" data-start=\"24235\" data-end=\"24255\">Cup-wall thickness<\/li>\n<li data-section-id=\"1bz65w6\" data-start=\"24256\" data-end=\"24276\">Cup-rim dimensions<\/li>\n<li data-section-id=\"19hz7z0\" data-start=\"24277\" data-end=\"24296\">Cup-rim roundness<\/li>\n<li data-section-id=\"i7xc5e\" data-start=\"24297\" data-end=\"24311\">Lid material<\/li>\n<li data-section-id=\"1x2ry6i\" data-start=\"24312\" data-end=\"24328\">Lid dimensions<\/li>\n<li data-section-id=\"1dtmxg\" data-start=\"24329\" data-end=\"24345\">Lid engagement<\/li>\n<li data-section-id=\"mgxsur\" data-start=\"24346\" data-end=\"24363\">Sealing contact<\/li>\n<li data-section-id=\"vni4hs\" data-start=\"24364\" data-end=\"24380\">Straw material<\/li>\n<li data-section-id=\"1x5rbfd\" data-start=\"24381\" data-end=\"24405\">Straw outside diameter<\/li>\n<li data-section-id=\"1x86tyo\" data-start=\"24406\" data-end=\"24429\">Straw inside diameter<\/li>\n<li data-section-id=\"11eg4uv\" data-start=\"24430\" data-end=\"24444\">Straw length<\/li>\n<li data-section-id=\"1iyw5g9\" data-start=\"24445\" data-end=\"24469\">Straw-bottom clearance<\/li>\n<li data-section-id=\"14pl5kb\" data-start=\"24470\" data-end=\"24493\">Straw-hole dimensions<\/li>\n<li data-section-id=\"5mbjsz\" data-start=\"24494\" data-end=\"24514\">Air-vent structure<\/li>\n<li data-section-id=\"1l397p4\" data-start=\"24515\" data-end=\"24527\">Valve type<\/li>\n<li data-section-id=\"jbaljd\" data-start=\"24528\" data-end=\"24549\">Valve opening force<\/li>\n<li data-section-id=\"b7i3uf\" data-start=\"24550\" data-end=\"24568\">Handle structure<\/li>\n<li data-section-id=\"h984bz\" data-start=\"24569\" data-end=\"24582\">Fill volume<\/li>\n<li data-section-id=\"3sd56s\" data-start=\"24583\" data-end=\"24605\">Intended drink types<\/li>\n<li data-section-id=\"twmfoz\" data-start=\"24606\" data-end=\"24631\">Leakage-test conditions<\/li>\n<li data-section-id=\"13flynv\" data-start=\"24632\" data-end=\"24652\">Drinking-flow test<\/li>\n<li data-section-id=\"18r942a\" data-start=\"24653\" data-end=\"24670\">Cleaning method<\/li>\n<li data-section-id=\"17py13x\" data-start=\"24671\" data-end=\"24694\">Assembly instructions<\/li>\n<li data-section-id=\"16fzbzw\" data-start=\"24695\" data-end=\"24728\">Parting-line and flash standard<\/li>\n<li data-section-id=\"m0f86a\" data-start=\"24729\" data-end=\"24750\">Packaging structure<\/li>\n<li data-section-id=\"jv2g6q\" data-start=\"24751\" data-end=\"24777\">Pilot-production results<\/li>\n<li data-section-id=\"196t8t7\" data-start=\"24778\" data-end=\"24799\">Cavity traceability<\/li>\n<li data-section-id=\"n66c15\" data-start=\"24800\" data-end=\"24824\">Final reference sample<\/li>\n<\/ul>\n<p data-start=\"24826\" data-end=\"24888\">Approval should cover both spill control and drinking comfort.<\/p>\n<p data-start=\"24890\" data-end=\"24972\">A cup that never leaks but cannot be used comfortably is not a successful product.<\/p>\n<h2 data-section-id=\"4o7b9x\" data-start=\"24974\" data-end=\"25028\"><span class=\"ez-toc-section\" id=\"How_LYA_Silicone_Supports_Custom_Straw_Cup_Projects\"><\/span>How LYA Silicone Supports Custom Straw Cup Projects<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"25030\" data-end=\"25200\">LYA Silicone supports <a href=\"https:\/\/www.lyasilicone.com\/pl\/oem-service\/\">OEM and ODM development<\/a> for custom silicone baby feeding, drinking, teething, bathing, pet, outdoor, educational, household, and lifestyle products.<\/p>\n<p data-start=\"25202\" data-end=\"25252\">Our custom silicone straw cup support can include:<\/p>\n<ul data-start=\"25254\" data-end=\"25809\">\n<li data-section-id=\"1ci0wx7\" data-start=\"25254\" data-end=\"25282\">Product-requirement review<\/li>\n<li data-section-id=\"1esk7n\" data-start=\"25283\" data-end=\"25314\">Drawing and sample evaluation<\/li>\n<li data-section-id=\"1wc574s\" data-start=\"25315\" data-end=\"25342\">Cup-body structure review<\/li>\n<li data-section-id=\"1nmku4c\" data-start=\"25343\" data-end=\"25376\">Material and hardness selection<\/li>\n<li data-section-id=\"1mx21xw\" data-start=\"25377\" data-end=\"25405\">Rim and lid-fit evaluation<\/li>\n<li data-section-id=\"1la8fc1\" data-start=\"25406\" data-end=\"25430\">Straw dimension review<\/li>\n<li data-section-id=\"vuym6t\" data-start=\"25431\" data-end=\"25462\">Air-vent and valve discussion<\/li>\n<li data-section-id=\"e8ns8v\" data-start=\"25463\" data-end=\"25486\">Wall-thickness review<\/li>\n<li data-section-id=\"11qumo9\" data-start=\"25487\" data-end=\"25517\">Handle-structure development<\/li>\n<li data-section-id=\"1gmx01u\" data-start=\"25518\" data-end=\"25543\">Tworzenie form na zam\u00f3wienie<\/li>\n<li data-section-id=\"1tpzw7d\" data-start=\"25544\" data-end=\"25568\">Dopasowanie kolor\u00f3w Pantone<\/li>\n<li data-section-id=\"1i0uzrk\" data-start=\"25569\" data-end=\"25606\">Logo and surface-finish development<\/li>\n<li data-section-id=\"ear1ra\" data-start=\"25607\" data-end=\"25633\">Molded sample production<\/li>\n<li data-section-id=\"zsfjl4\" data-start=\"25634\" data-end=\"25668\">Leakage and flow testing support<\/li>\n<li data-section-id=\"1gbqghu\" data-start=\"25669\" data-end=\"25699\">Cleaning and assembly review<\/li>\n<li data-section-id=\"1ctrdvc\" data-start=\"25700\" data-end=\"25724\">Packaging coordination<\/li>\n<li data-section-id=\"1f2uujp\" data-start=\"25725\" data-end=\"25743\">Pilot production<\/li>\n<li data-section-id=\"1usbaou\" data-start=\"25744\" data-end=\"25783\">Appearance and dimensional inspection<\/li>\n<li data-section-id=\"1u4wjl5\" data-start=\"25784\" data-end=\"25809\">OEM\/ODM mass production<\/li>\n<\/ul>\n<p data-start=\"25811\" data-end=\"25997\">With 25+ years of silicone manufacturing experience, we help buyers evaluate the complete drinking system rather than treating the cup body, lid, straw, and vent as unrelated components.<\/p>\n<p data-start=\"25999\" data-end=\"26221\">The goal is to develop a straw cup that controls spills under defined conditions, allows comfortable drinking, remains easy to clean and assemble, recovers after packaging, and performs consistently during bulk production.<\/p>\n<h2 data-section-id=\"dkfr70\" data-start=\"26223\" data-end=\"26265\"><span class=\"ez-toc-section\" id=\"What_Information_Should_Buyers_Provide\"><\/span>What Information Should Buyers Provide?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"26267\" data-end=\"26338\">To evaluate a custom silicone straw cup project, buyers should provide:<\/p>\n<ul data-start=\"26340\" data-end=\"26879\">\n<li data-section-id=\"103ozr8\" data-start=\"26340\" data-end=\"26365\">Product reference photo<\/li>\n<li data-section-id=\"15kx7su\" data-start=\"26366\" data-end=\"26378\">2D drawing<\/li>\n<li data-section-id=\"1e36aew\" data-start=\"26379\" data-end=\"26404\">3D file, when available<\/li>\n<li data-section-id=\"1vmarei\" data-start=\"26405\" data-end=\"26438\">Physical sample, when available<\/li>\n<li data-section-id=\"1ba7nxh\" data-start=\"26439\" data-end=\"26467\">Intended user or age range<\/li>\n<li data-section-id=\"11dewoq\" data-start=\"26468\" data-end=\"26482\">Cup capacity<\/li>\n<li data-section-id=\"qkykx9\" data-start=\"26483\" data-end=\"26499\">Cup dimensions<\/li>\n<li data-section-id=\"1cduybo\" data-start=\"26500\" data-end=\"26531\">Silicone material requirement<\/li>\n<li data-section-id=\"1is84ef\" data-start=\"26532\" data-end=\"26553\">Hardness preference<\/li>\n<li data-section-id=\"5bn0vw\" data-start=\"26554\" data-end=\"26569\">Lid structure<\/li>\n<li data-section-id=\"1nn5sy0\" data-start=\"26570\" data-end=\"26588\">Straw dimensions<\/li>\n<li data-section-id=\"1rrxhwh\" data-start=\"26589\" data-end=\"26614\">Vent or valve structure<\/li>\n<li data-section-id=\"12o0a28\" data-start=\"26615\" data-end=\"26630\">Handle design<\/li>\n<li data-section-id=\"3sd56s\" data-start=\"26631\" data-end=\"26653\">Intended drink types<\/li>\n<li data-section-id=\"6o77av\" data-start=\"26654\" data-end=\"26675\">Leakage requirement<\/li>\n<li data-section-id=\"53e5wy\" data-start=\"26676\" data-end=\"26703\">Drinking-flow requirement<\/li>\n<li data-section-id=\"7uyp7i\" data-start=\"26704\" data-end=\"26719\">Product color<\/li>\n<li data-section-id=\"1ezsi3p\" data-start=\"26720\" data-end=\"26731\">Logo file<\/li>\n<li data-section-id=\"15baeha\" data-start=\"26732\" data-end=\"26748\">Surface finish<\/li>\n<li data-section-id=\"18r942a\" data-start=\"26749\" data-end=\"26766\">Cleaning method<\/li>\n<li data-section-id=\"dlbswn\" data-start=\"26767\" data-end=\"26786\">Packaging concept<\/li>\n<li data-section-id=\"iovhx1\" data-start=\"26787\" data-end=\"26808\">Target sales market<\/li>\n<li data-section-id=\"10w0ysy\" data-start=\"26809\" data-end=\"26831\">Testing requirements<\/li>\n<li data-section-id=\"1vn91j5\" data-start=\"26832\" data-end=\"26852\">Estimated quantity<\/li>\n<li data-section-id=\"h5i4a6\" data-start=\"26853\" data-end=\"26879\">Expected launch schedule<\/li>\n<\/ul>\n<p data-start=\"26881\" data-end=\"26952\">When an existing cup has a quality problem, buyers should also provide:<\/p>\n<ul data-start=\"26954\" data-end=\"27172\">\n<li data-section-id=\"lg28zu\" data-start=\"26954\" data-end=\"26970\">Leakage videos<\/li>\n<li data-section-id=\"j1wla6\" data-start=\"26971\" data-end=\"26995\">Exact leakage location<\/li>\n<li data-section-id=\"9klrob\" data-start=\"26996\" data-end=\"27025\">Liquid type and temperature<\/li>\n<li data-section-id=\"cd4b14\" data-start=\"27026\" data-end=\"27043\">Cup orientation<\/li>\n<li data-section-id=\"10cqcys\" data-start=\"27044\" data-end=\"27076\">Cup, lid, and straw dimensions<\/li>\n<li data-section-id=\"2rz2pc\" data-start=\"27077\" data-end=\"27112\">Material and hardness information<\/li>\n<li data-section-id=\"f0wfi4\" data-start=\"27113\" data-end=\"27133\">Mold-cavity number<\/li>\n<li data-section-id=\"14k2efc\" data-start=\"27134\" data-end=\"27152\">Packaging method<\/li>\n<li data-section-id=\"20x8ox\" data-start=\"27153\" data-end=\"27172\">Affected quantity<\/li>\n<\/ul>\n<h2 data-section-id=\"1r8frcv\" data-start=\"27174\" data-end=\"27203\"><span class=\"ez-toc-section\" id=\"Frequently_Asked_Questions\"><\/span>Frequently Asked Questions<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3 data-section-id=\"78jr7\" data-start=\"27205\" data-end=\"27254\">Why does the cup leak only when it is shaken?<\/h3>\n<p data-start=\"27256\" data-end=\"27414\">Shaking creates dynamic liquid pressure and may temporarily open the vent, valve, straw seal, or lid interface even when the cup passes a static upright test.<\/p>\n<h3 data-section-id=\"se7sqe\" data-start=\"27416\" data-end=\"27482\">Why does liquid spray from the straw when the cup is squeezed?<\/h3>\n<p data-start=\"27484\" data-end=\"27630\">Squeezing raises the internal pressure. If the straw or valve opens more easily than the vent or lid seal, liquid may be forced through the straw.<\/p>\n<h3 data-section-id=\"17zkiq2\" data-start=\"27632\" data-end=\"27678\">Does a tighter lid always prevent leakage?<\/h3>\n<p data-start=\"27680\" data-end=\"27842\">No. Excessive lid interference may deform the rim or prevent complete assembly. Sealing contact, roundness, dimensions, and material behavior must be coordinated.<\/p>\n<h3 data-section-id=\"13w0iro\" data-start=\"27844\" data-end=\"27893\">Why is the straw cup difficult to drink from?<\/h3>\n<p data-start=\"27895\" data-end=\"28043\">Possible causes include a blocked vent, overly firm valve, narrow straw, compressed straw wall, long flow path, thick liquid, or incorrect assembly.<\/p>\n<h3 data-section-id=\"14gs5sy\" data-start=\"28045\" data-end=\"28099\">Can a smaller straw hole improve spill resistance?<\/h3>\n<p data-start=\"28101\" data-end=\"28240\">A smaller hole may improve contact around the straw but can also compress the straw, reduce flow, increase assembly force, or tear the lid.<\/p>\n<h3 data-section-id=\"16wqf4n\" data-start=\"28242\" data-end=\"28282\">Why does the cup leak after washing?<\/h3>\n<p data-start=\"28284\" data-end=\"28450\">The lid, straw, valve, or vent may have been reassembled incorrectly. Soap residue, trapped water, stretched components, or a stuck valve can also change performance.<\/p>\n<h3 data-section-id=\"czpdf1\" data-start=\"28452\" data-end=\"28505\">Can the cup be described as completely leakproof?<\/h3>\n<p data-start=\"28507\" data-end=\"28716\">The appropriate claim depends on the lid, straw, vent, valve, orientation, pressure, liquid, temperature, assembly, and validated test conditions. \u201cSpill-resistant\u201d may be more appropriate for some structures.<\/p>\n<h3 data-section-id=\"bfkbrv\" data-start=\"28718\" data-end=\"28776\">Why does one production cavity leak more than another?<\/h3>\n<p data-start=\"28778\" data-end=\"28943\">Possible causes include cavity dimensional differences, core-pin wear, valve-slit variation, mold-temperature differences, flash, or lid and cup tolerance variation.<\/p>\n<h3 data-section-id=\"3ko7r2\" data-start=\"28945\" data-end=\"28997\">Should the product be tested with milk or juice?<\/h3>\n<p data-start=\"28999\" data-end=\"29164\">The cup should be tested with the intended drink or a representative liquid because viscosity, temperature, and residue can affect flow, valves, vents, and cleaning.<\/p>\n<h3 data-section-id=\"83l51x\" data-start=\"29166\" data-end=\"29220\">What should buyers approve before bulk production?<\/h3>\n<p data-start=\"29222\" data-end=\"29463\">Buyers should approve material, hardness, cup dimensions, rim roundness, lid fit, straw dimensions, vent, valve, handles, leakage conditions, drinking flow, cleaning, assembly, packaging, inspection standards, and the final reference sample.<\/p>\n<h2 data-section-id=\"8dtpi\" data-start=\"29465\" data-end=\"29478\"><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span>Wnioski<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p data-start=\"29480\" data-end=\"29562\">A reliable silicone straw cup must do more than remain dry while standing upright.<\/p>\n<p data-start=\"29564\" data-end=\"29723\">The cup should control spills during the defined use conditions while allowing the intended user to drink comfortably through a stable liquid and airflow path.<\/p>\n<p data-start=\"29725\" data-end=\"29841\">Leakage, dripping, spraying, high suction resistance, and interrupted flow are rarely caused by one component alone.<\/p>\n<p data-start=\"29843\" data-end=\"30053\">Cup-rim roundness, lid engagement, straw fit, venting, valve design, straw dimensions, cup softness, handle position, molding, assembly, cleaning, packaging, and real-use testing all influence the final result.<\/p>\n<p data-start=\"30055\" data-end=\"30288\">The most reliable approach is to review the complete cup system before tooling, produce actual molded samples, test several liquids and orientations, validate cleaning and reassembly, and confirm consistency through pilot production.<\/p>\n<p data-start=\"30290\" data-end=\"30668\">If you are developing a custom silicone straw cup or investigating leakage and drinking-flow problems, <a href=\"https:\/\/www.lyasilicone.com\/pl\/contact\/\">contact LYA Silicone<\/a> and send us your drawing, sample, cup capacity, material, hardness, lid, straw, vent, valve, test conditions, packaging, target market, and estimated quantity. Our team will review the project and provide an appropriate OEM or ODM manufacturing proposal.<\/p>","protected":false},"excerpt":{"rendered":"<p>Introduction A silicone straw cup may appear to be a simple combination of a cup body, lid, and drinking straw. [&hellip;]<\/p>","protected":false},"author":1,"featured_media":10642,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"none","_seopress_titles_title":"Silicone Straw Cup Leak & Flow Design | OEM Guide","_seopress_titles_desc":"Learn why silicone straw cups leak, drip or become difficult to drink from, and how lids, straws, vents, valves, hardness and packaging affect OEM quality.","_seopress_robots_index":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[36],"tags":[],"class_list":["post-10639","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/posts\/10639","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/comments?post=10639"}],"version-history":[{"count":1,"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/posts\/10639\/revisions"}],"predecessor-version":[{"id":10648,"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/posts\/10639\/revisions\/10648"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/media\/10642"}],"wp:attachment":[{"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/media?parent=10639"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/categories?post=10639"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lyasilicone.com\/pl\/wp-json\/wp\/v2\/tags?post=10639"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}