Custom Reusable Silicone Food Storage Bag | Spanish 2026 Project
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Product |
Reusable Silicone Food Storage Bag (Self-Standing) |
|---|---|
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Order Quantity |
Initial Order: 30,000 pcs |
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Material |
Food-Grade Solid Silicone |
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Key Specs |
Hardness: Shore A40 |
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Certification |
REACH, RoHS, FDA, LFGB |
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Lead Time |
DFM Evaluation: 24 hrs |
Project details
A Spanish brand specializing in eco-friendly kitchenware wanted to develop a silicone food bag that could replace disposable plastic bags. The client provided an original 3D design of a self-standing silicone food bag with a snap-lock sealing rib at the top and a rounded self-standing structure at the bottom. During the pre-sampling evaluation, the client identified several issues: the right-angled ends of the sealing rib were prone to cracking after repeated use; the near-right angles of the bag’s inner corners resulted in creases after repeated folding; the self-standing structure at the bottom lacked sufficient support, causing it to tip over when loaded with heavy objects; and the uniform wall thickness resulted in insufficient strength in certain areas.
Z.S.R’s engineering department modified the client’s original 3D design and offered targeted suggestions: adding a 2.5 mm radius rounded transition at the base of both ends of the sealing rib, optimizing the corners and bottom self-standing structure of the bag body, and implementing a zoned wall thickness design for the food bag.
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
Rounded Transition at the Sealing Rib Base
To remove the right angles at the connection points between the sealing rib and the bag body, Z.S.R replaced them with a 2.5 mm rounded transition.
This silicone food bag relies on the sealing rib at the bag opening for a tight seal. Each opening and closing involves repeated bending of the rib’s ends. The right-angled base in the original design would cause stress concentration, leading to cracks that would gradually propagate from the sharp corner, resulting in leaks. The rounded base disperses stress and, combined with the gradually changing rib structure, improves the durability of the sealing rib during pinching and opening.
R15 mm Outer Corners
To eliminate stress concentration points at sharp angles, the four outer corners of the bag body were designed to R15 mm, and all inner corners to R≥2.0 mm.
Rounded corners distribute stress evenly during folding, preventing the bag from whitening or cracking even after repeated folding. Furthermore, the large rounded corners simplify mold processing and reduce the likelihood of material jamming during demolding.
Widened Bottom + Support Ribs
The width of the bottom of the bag from the vertical surface was changed from 25 mm to 35 mm, the inner corners of the bottom were rounded to R5.0 mm, the outer corners to R3.0 mm, and two horizontal support ribs added to the inner side of the bottom.
The widened bottom allows the bag to stand stably even when loaded with heavy objects. The internal horizontal support ribs further enhance the rigidity of the bag’s bottom.
Zoned Wall Thickness
The wall thickness of the sealing rib area at the bag opening was increased to 2.8 mm, the side wall thickness of the bag body set to 2.0 mm, and the bottom wall thickness to 3.0 mm, with a 15° gradual transition between all wall thicknesses.
The thicker sealing rib area enhances the rigidity of the concave and convex ribs, so the pressing and interlocking are tight and the sealing performance is good; the 2.0 mm side wall keeps a soft feel, making it convenient for customers to fold and store; the 3.0 mm bottom improves the load-bearing capacity; and the gradual transition of wall thickness avoids stress and uneven vulcanization shrinkage caused by abrupt changes in wall thickness.
Mold Making, Sample Production & Quality Verification
Mold Processing
Z.S.R Group is equipped with 10 advanced CNC machining centers and 4 EDM machines. Using a solid silicone molding process, the silicone food bags are produced with the bag body and opening formed in one piece.
Silicone Molding
Production is supported by 48 solid molding machines, 12 liquid molding machines, and 13 injection molding silicone machines, enabling the rapid molding of 20,000 silicone food bags within 20 days. Over 10 printing and spraying production lines also allow for printing logos or patterns on the silicone food bags.
Secondary Vulcanization
After molding, the silicone food bags undergo secondary vulcanization at 200°C for 2 hours.
The secondary curing process removes residual small-molecule volatiles and stabilizes the physical properties of the silicone before packaging and storage.
Quality Inspection
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Test |
Condition |
Acceptance Criteria |
Result |
|---|---|---|---|
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Sealing Ridge Fatigue Test |
Repeatedly folded and squeezed open/closed 8,000 times |
No breakage, obvious deformation; no leakage when inverted |
Pass |
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Liquid Leakage Test |
500 ml clear water, inverted for 24 h then upright for 24 h |
No leakage, no water marks |
Pass |
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Tear Strength Test |
Samples taken separately from side walls, rib roots, and bottom corners |
Tear strength ≥ 25 kN/m |
Pass |
|
Temperature Cycling Test |
-40°C ↔ 220°C, 5 cycles |
No deformation, no cracking, no obvious odor |
Pass |
|
FDA Food Contact Test |
Total migration test of food simulants |
Meets FDA 21 CFR 177.2600 requirements |
Pass |
The production samples passed the specified sealing ridge fatigue, liquid leakage, tear strength, temperature cycling, and FDA food contact inspections. In particular, no breakage or leakage was observed after 8,000 open/close cycles on the sealing ridge.
Related Silicone Bag Product
Customer reviews & feedback
“We are currently conducting tests, and so far, the test results for your silicone food bags are very satisfactory! Please give us some more time, and we will get back to you as soon as the tests are completed.”
Custom Silicone Food Bag
OEM & ODM solutions for brands, retailers, wholesalers, and Ecommerce sellers. Food-grade silicone food storage bags with REACH/RoHS/FDA/LFGB compliance.
Other Project
For industrial-scale production, ZSR Group also operates a dedicated silicone compression molding service for custom silicone parts.
