Surface adhesion
Fluoropolymers do not bond. To join a liner to a jacket, the surface has to be changed first.
Published values
| Property | Value | Source |
|---|---|---|
| PTFE contact angle — before | 110° | Principal brochure |
| PTFE contact angle — after etching | 46° | Principal brochure |
| Etch durability | Over 12 months | Principal brochure |
| Method | Plasma surface treatment, no chemical reagents | Principal brochure |
| Polyimide direct bonding | Nylon · TPU | Principal Company Profile |
The 110° → 46° contact angle shift is the whole point of the process. Untreated PTFE accepts neither adhesive nor reflow.
Etching weakens with time. Stock past twelve months can be restored by secondary etching — it does not have to be scrapped.
Polyimide is the exception: it bonds directly to nylon and TPU, which means the surface-treatment step can be skipped.
If one of these constrains your design
For items that need a number — tolerance, sterilisation, adhesion — tell us the requirement and we confirm it with the principal.