Fin Seal Weatherstrip
Polypropylene pile with a centre fin running the full length of the strip. The fin is the part that resists air infiltration; the pile carries the sliding contact. Silicone treatment is an option on this line rather than a separate product — one more step on the same strip.
Made to order Backing width, pile height, fin, colour — all specified by you. Standard sizes run on existing tooling; non-standard is the larger half of what we run.
Also called fin pile, poly fin seal, center fin weatherstrip, fin seal weatherstripping, fin pile weather stripping, brush seal with fin, siliconized fin seal, silicone fin seal weatherstripping, treated fin seal, fin pile weatherstrip and kerf pile weatherstrip with fin.
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. Whether the filament is silicone-treated is settled here too.
No tooling charge
- Pile height
- Anything from 2.5 mm upward
- Fin or no fin
- Added or removed on any construction
- Silicone treatment
- Siliconized filament on any size we make
- Put-up
- Spool length and core to suit your requirement
- Private label
- Your label on the spool flange, printed with your size, colour and quantity — we already run this for other buyers
New tooling, on us
- Colour
- Multiple standard; custom matched on request
- Non-standard backing width
- We cut the die and carry the cost — nothing to pay up front
- Non-standard backing profile
- Same terms. Post us 50 mm of the extrusion and we cut to it; the die stays reserved to your part number
Send a drawing, and post us 50 mm or more of the extrusion — we match the backing to the section itself. Any tooling we have to cut is ours to pay for, and it 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
If the specification calls out an air-infiltration figure rather than just a dust or rattle requirement, the fin is doing that work. Without it the filament bed is porous by construction, no matter how dense the pile is. Silicone treatment covers the other failure mode: untreated pile wicks water along the filament, past the seal and into the channel. Outdoors, ask for both on the one strip.
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 and folding doorsLong runs where an air-infiltration number applies.
- Garage door side and top sealsKnown in that trade as brush seal.
- Curtain wall ventsWhere a specified air-leakage rate applies.
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 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 |
| Pile-to-backing bond | Heat-fused, polypropylene to polypropylene — no adhesive in the bond |
| UV stabilisation | Available on request — dosed to the filament, base yarns and backing film |
| 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 — Fin seal weatherstrip
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.