Technology
Airtight zipper materials compared
TPU, PEVA, silicone rubber and nylon woven, compared using only the values the manufacturer publishes. Where no figure is published, this page says so rather than filling the gap.
Comparison
Four materials, what is published for each
Every value below comes from the published product parameter tables or from the published technical guides. Nothing has been measured, converted or estimated for this page.
| Material | Where it appears in the range | Published properties | Series using it |
|---|---|---|---|
| TPU | The one-piece body of the #10 resin, #5 resin, self-healing and circular airtight zippers. It is also published as the coating over polyester tape on the #5 and #8 nylon woven builds, and as one half of the TPU/PVC material of the high-speed roller door zipper. |
| |
| PEVA | The PEVA airtight zipper — one series in the functional airtight range, published as the cost-optimised option for everyday waterproofing. |
| |
| Silicone rubber | The drysuit envelope zipper, where continuous immersion and salt water — rather than splash resistance — are the deciding conditions. |
| |
| Nylon woven with a TPU coating | The #5 and #8 nylon woven waterproof zippers. The published construction is a TPU coating over polyester tape with nylon teeth — a composite rather than a one-piece sheet. |
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How the selection guide puts it
The published selection guide describes the four materials in one line each. This is the manufacturer’s own wording, unchanged.
- TPU: best all-round performance — elasticity, abrasion and hydrolysis resistance, -30 to 70°C range, first choice for airtight sealing.
- PEVA: lightweight and low-cost, for everyday waterproofing.
- Silicone rubber: highly flexible and weather-resistant, used for drysuit envelopes.
- Nylon: soft, good for watertight uses, but less effective than one-piece TPU for high-pressure airtight sealing.
Material behaviour for continuous immersion
The drysuit envelope guide compares the same materials specifically against deep-sea and salt-water exposure.
| Material | Behaviour | Suited to |
|---|---|---|
| Silicone rubber | Highly flexible, weather-resistant, excellent saltwater resistance | Drysuit envelopes, deep-sea and underwater rescue work |
| TPU | Elasticity, abrasion and hydrolysis resistance, -30 to 70°C | Airtight pressure-sealed assemblies |
| Nylon woven + TPU | Soft and flexible, good watertight performance | Watertight garments where a one-piece TPU build is unnecessary |
Read the full guide: Drysuit zipper materials and test standards
Honest gaps
What is not published for these materials
A material comparison is only useful if it is complete about its own limits. These figures are not published anywhere in the manufacturer’s material, so they are not stated here.
TPU
No hardness, density or elongation figure is published for TPU.
PEVA
No temperature, seal-strength, tensile or cycle figure is published for PEVA. The published -30°C ~ 70°C figure belongs to TPU, not PEVA.
Silicone rubber
No temperature range and no seal-strength figure is published for silicone rubber.
Nylon woven with a TPU coating
No temperature range and no seal-strength figure is published for the nylon woven builds.
Temperature range
The published reference temperature range of approximately -30°C to 70°C applies to TPU. The manufacturer states that PEVA and silicone rubber have different temperature ranges, and that the specific figure is subject to the material chosen and your project testing.
Cost
No price or cost comparison is published for any material. PEVA is published as the cost-optimised option and TPU as the first choice for airtight sealing; beyond that, material selection is confirmed per project.
Send us the host material and we will confirm the build
Material choice depends on the pressure, the flexing, the temperature and how the zipper is joined to your product. Tell us those four things and we will confirm the material and the process.