Tianli/Products/Square base brush seal

Square Base Brush Seal

A small square base carrying a handful of rigid strands mixed with soft filament, rather than the full-width filament bed used on our other lines. Already running in production for a U.S. buyer.

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.

stiff-filament brush seal mixed filament brush seal stiff bristle brush seal combination brush seal
Filament height Base width
Plain square base · rigid strands plus one soft filament
Pile directors
With pile directors · a raised lip each side braces the tuft

Made to your channel, not ours

The two dimensions called out on that drawing are both yours to set. Strand mix, base size and whether you want pile directors are all variables here — tell us how many rigid strands versus soft filament, the base footprint, and how hard the opening is cycled.

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

Mixing a small number of rigid strands into an otherwise soft brush is a standard way to add stiffness and wear resistance without losing the soft filament's sealing contact — useful where the brush has to hold its shape against repeated mechanical contact. The specific end use for this construction is still being confirmed with the plant.

Where it is used

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.

Square base brush seal · as manufactured
AttributeRange
Base size3.0 – 3.2 mm × 3.0 – 3.5 mm
Filament height9.5 – 25 mm (0.374″ – 0.984″) on current tooling
ConstructionRigid strands plus one soft filament
Pile-to-backing bondHeat-fused, polypropylene to polypropylene — no adhesive in the bond
UV stabilisationAvailable on request — dosed to the filament, base yarns and backing film
ColoursMultiple standard; custom on request
Dimensional tolerance±0.15 mm
Standard spool lengthMade to your put-up — tell us the run length
Minimum order quantityScales with price — small runs welcome, quoted per volume
Sample lead time15 days on existing tooling; 30 days if a new backing profile has to be cut
Production lead time15 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.

See the full backing-width table →

How to specify it

Four things get you a quote and a matched sample. If you only have two of them, send two.

  1. The backing width you runGive it however you have it — .270″, 7 mm, or the die drawing. We convert.
  2. The pile height you needOr the gap you are sealing, if the height was never specified.
  3. Fin or no finAnd silicone treatment or not. These are the two that change the part number.
  4. Annual volume and colourRough is fine. It decides the run size, not the price of the sample.

Related lines

Spec sheet — Square base brush 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.

PDF · Rev A · August 2026
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