Silicone-Treated Fin Seal
A polypropylene centre fin running the full length of the strip, combined with silicone treatment on the filament. Air is stopped by the fin; water is stopped by the treatment. This is the combination most U.S. sliding fenestration runs.
Made to order Backing width, pile height, fin, colour — all specified by you. Standard sizes ship from stock; non-standard is the larger half of what we run.
Made to your channel, not ours
The two dimensions called out on that drawing are both yours to set. Fin height and pile height are the two we are asked to move most often on this line, and neither needs new tooling.
No tooling charge
- Pile height
- Anything from 2.5 mm upward
- Fin or no fin
- Added or removed on any construction
- Silicone treatment
- On or off, on any construction
- Put-up
- Spool length and core to suit your line
Quoted once, credited back
- Colour
- Multiple standard; custom matched on request
- Non-standard backing width
- Tooling quoted once, credited against your production orders
- Non-standard backing profile
- Same terms. The tooling stays reserved to your part number
Send a drawing or send a physical piece — both are accepted, and the tooling we cut for you stays reserved to your part number. Large suppliers sell from a fixed catalogue and treat a non-standard size as an inconvenience. We were built the other way round.
Why this construction
Pile on its own is a filament bed — air moves through it. A centre fin gives the assembly a solid barrier down the middle, which is what turns a dust seal into an air seal. Adding silicone treatment on top of that covers the second failure mode, water wicking.
Where it is used
- U.S. sliding windowsHorizontal sliders in vinyl and aluminium extrusion.
- Single- and double-hung windowsJamb liner and sash track.
- Sliding patio doorsWhere air-infiltration numbers have to be met.
- Garage doorsSold into that trade as brush seal; the construction is the same.
Sizes
Ranges below apply to this line. The full backing-width table, with the U.S. nominal each size sits against, is on the specifications section of the home page.
| Attribute | Range |
|---|---|
| Backing width | 4.5 – 11.0 mm (0.177″ – 0.433″) |
| Pile height | from 2.5 mm (0.098″) upward |
| Pile material | Polypropylene |
| Colours | Multiple standard; custom on request |
| Dimensional tolerance | ±0.15 mm |
| Standard spool length | Made to your put-up — tell us the run length |
| Minimum order quantity | Scales with price — small runs welcome, quoted per volume |
| Sample lead time | 15 days on existing tooling; 30 days if a new backing profile has to be cut |
| Production lead time | 15 days ex-works on a first order, from receipt of deposit. U.S. contract volumes have run 30–45 days. Add 10 days if the filament colour has to be spun to order. |
How to specify it
Four things get you a quote and a matched sample. If you only have two of them, send two.
- The backing width you runGive it however you have it — .270″, 7 mm, or the die drawing. We convert.
- The pile height you needOr the gap you are sealing, if the height was never specified.
- Fin or no finAnd silicone treatment or not. These are the two that change the part number.
- Annual volume and colourRough is fine. It decides the run size, not the price of the sample.
Related lines
Spec sheet — Silicone-treated fin seal
This line’s own sheet: its section drawing, its published ranges, and the backing-width routing table. Fields still being confirmed with the plant are marked as such rather than filled in with a guess.