Custom Silicone Cup Lid | Spanish 2025 Project
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Product |
Round Sealed Silicone Cup Lid with Handle |
|---|---|
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Order Quantity |
Initial Order: 72,000 pcs |
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Material |
Food-Grade Solid Silicone |
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Key Specs |
Hardness: Shore A45 |
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Certification |
FDA, LFGB, REACH Compliant, PFAS-Free |
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Lead Time |
DFM Evaluation: 24 hrs |
Project details
A Spanish household goods brand specializes in sealing lids for various water cups and food storage containers. This client planned to develop a lid with a handle for easier handling. Previous lids they encountered suffered from issues such as unstable sealing at high temperatures, easy breakage of the handle, and high resistance during assembly.
The client found Z.S.R through LinkedIn and conveyed their ideas to the factory. Z.S.R’s engineering team conducted DFM analysis, modeling and prototyping, focusing on sealing structure, stress distribution, assembly experience, and mold venting. This ensured the finished product’s sealing stability in high and low temperature environments and that the handle wouldn’t break under repeated lifting, meeting food safety contact standards.
Based on the DFM results, the project moved into mold making and sample production, followed by quality verification of the first batch before mass production.
Delivery data
Engineering DFM Assessment
Optimized Sealing Lip Structure
Engineers adopted a sealing lip with a gradually thinning structure. Three micro-pressure relief notches, 0.2 mm deep and 1.5 mm wide, were added to the lip ring. The lip root was thickened to 1.2 mm, and the lip tip thinned to 0.5 mm. Based on the compression set curve of Shore A 45 silicone at 85°C, the lip interference was precisely calculated to be 0.35 mm.
When the cup is filled with hot water, a single-ring, uniformly thick sealing lip cannot release the positive pressure within the high-temperature sealed space, causing the lid to lift, resulting in bulging and leakage. A gradient lip, combined with tiny pressure-relief grooves, releases excess internal pressure while maintaining a seal. Calculating the interference fit according to the actual compression curve avoids excessive interference leading to compression deformation at high temperatures, or insufficient interference causing leakage at room temperature.
Rounded Corner at Handle Root + Smooth Wall Thickness Transition
The handle root features a large 2.5 mm rounded transition, with a wall thickness gradient design from 3.0 mm to 1.8 mm. A 0.6 mm high transverse reinforcing rib was added inside the handle.
The handle is a stress-bearing area. A large R2.5 arc combined with a gradient wall thickness allows the tensile force to be evenly distributed along the arc. Reinforcing ribs further expand the stress from a point to a surface, improving the fatigue resistance of this part.
0.5 mm Rounded Corner at the Sealing Lip Opening
To address the issue of high assembly resistance at right-angled lips, Z.S.R added a 0.5 mm rounded corner at the outer edge of the lip opening, allowing the sealing lip to smoothly enter the cup mouth and reducing the risk of scratches during assembly.
A sealing lip with a right-angled edge is prone to scraping and buckling against the cup rim during assembly, increasing the resistance to capping. The chamfered guide design of the lip reduces assembly resistance and extends service life.
Gate and Venting Optimization
To address the potential air trapping issue in thick areas such as the handle, Z.S.R employs a side-mounted submerged gate for feeding and adds a fine venting groove with a depth of 0.02 mm at the end of the handle.
If gases cannot escape during the silicone curing process, air bubbles or voids will form inside the handle, significantly increasing the risk of breakage. The optimized gate location, combined with the local venting channels, ensures that the thick material area is fully filled and the structural strength is stable.
Mold Making, Sample Production & Quality Verification
Mold Processing
Z.S.R Group is equipped with 10 advanced CNC machining centers and 4 EDM machines for silicone cup lid mold making. High-strength grinding of the parting surface ensures no flash during sealing.
Silicone Molding
Production is supported by 48 solid-state molding machines, 12 liquid molding machines, and 13 injection molding silicone machines using solid-state silicone molding technology, enabling the rapid production of 30,000 silicone cup lids within 20 days. Over 10 printing and spraying production lines also allow for printing logos or patterns on the silicone cup lids.
Secondary Vulcanization
After molding, the silicone cup lids undergo secondary vulcanization at 200°C for 2 hours.
The secondary curing process removes small-molecule volatiles and reduces product odor before packaging and storage.
Quality Inspection
|
Test |
Condition |
Acceptance Criteria |
Result |
|---|---|---|---|
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Sealing Performance Test |
85°C hot water, inverted and left to stand for 2 hours after sealing |
No water seepage, no dripping |
Pass |
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Handle Fatigue Test |
Repeated handle pulling for 5,000 cycles |
No cracks or fracture at the handle base |
Pass |
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Thermal Cycling Test |
30 cycles between -40°C and 180°C |
No cracking, significant deformation or hardening |
Pass |
|
Dimensional Inspection |
CMM and caliper measurement of critical dimensions |
Tolerance controlled within ±0.12 mm |
Pass |
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Visual Inspection |
Full inspection of product surface and sealing lip |
No bubbles, voids, flash or scratches |
Pass |
|
Food Contact Migration Test |
Laboratory chemical migration testing |
Meets project-required FDA and LFGB standards |
Pass |
|
Hazardous Substance Test |
REACH SVHC and PFAS testing |
Meets project limit requirements |
Pass |
The production samples passed the specified sealing performance, handle fatigue, thermal cycling, dimensional, visual, food contact, and hazardous substance inspections. In particular, no cracks or fracture was observed at the handle base after 5,000 pulling cycles.
Related Silicone Cup Lid Product
Customer reviews & feedback
“I received all the silicone cup lids! They are fantastic! Exactly what I expected. You guys did a great job! I will definitely order from you again next time I need them! Thank you so much!”
Custom Silicone Cup Lid
OEM & ODM solutions for brands, retailers, wholesalers, and Ecommerce sellers. Food-grade silicone cup lids with FDA/LFGB/REACH compliance.
Other Project
For industrial-scale production, ZSR Group also operates a dedicated silicone compression molding service for custom silicone parts.
