Pig Bristle

Pig Bristle belongs to the natural animal bristle group, supplied as natural bristle, drawn in natural irregular cross-section sections and set in straight rows, helical, staggered, zoned, wavy and random fill patterns.

Pig Bristle is used in custom cleaning brushes for hand brushes, polishing and general natural-bristle cleaning where moderate stiffness and liquid carrying are useful.

The realistic alternatives are Horsehair, Nylon PA and PBT. What separates them here is moisture uptake and working temperature, not headline strength.

Compare Pig Bristle with Horsehair, nylon, PBT. Change material when wet stiffness, temperature, chemical resistance, conductivity, particle shedding, or surface marking becomes the limiting factor.

Pig Bristle is medium natural bristle; similar to boar bristle for polishing and gentle scrubbing. Use finer filament and longer trim for conformable contact; use coarser filament, shorter trim, or higher density for stronger displacement or cutting.

Published ranges for the filament itself. A finished brush runs below them, because the fill carries load and heat at the same time.

The part people get wrong: stiffness is not a property of the material on its own. A 0.50 mm filament on a 15 mm trim is stiffer than a 0.30 mm filament on a 25 mm trim in the same grade. Fix diameter and trim first, then confirm the material.

Pig bristle holds roughly 5–20% moisture depending on grade and condition, and its tip softens as it takes water up.

Absorbent fiber that carries liquid and softens slightly when wet.

What this means for your application: the filament grows and softens as it takes on water, and tip pressure goes with it. The reach you measured dry is not the reach you get wet.

A practical check: run one wet cycle and compare tip contact against the dry state. If the wet brush leaves residue behind or no longer reaches the bottom of the bore, change the material rather than the geometry.

Use animal-hair fills mainly at ambient to moderate process temperatures unless the supplier provides a validated higher-temperature rating for the exact brush. Avoid treating a generic 70–80°C value as a universal continuous limit.

The filament tables quote 80°C continuous and 110°C peak. The tighter number above is the one to build to, because a brush is loaded while it is hot.

Where it stops working: If the filament takes a permanent set under load, step up to PBT or Nylon PA, which hold a higher continuous temperature.

Diameter, trim length and applied load all shift the real limit, so a thin filament touching lightly survives conditions that would flatten a thick one under pressure.

Compatible with water and mild detergent; strong alkali, bleach and prolonged soaking shorten fiber life.

Compatibility is a function of concentration, temperature and contact time together. A short rinse in a dilute solution is a different exposure from an overnight soak in a concentrated one, even with the same chemical on the label.

Before you commit to a quantity: Specify the exact Pig Bristle grade or alloy, filament or profile size, color, straight or crimped form, working temperature, wet or dry use, chemical exposure, surface finish, and any required material documentation.

The floor is roughly 0.05 mm; finer than that and the filament snaps rather than flexes. In practice you are choosing inside 0.05–2.00 mm.

Free trim runs 3–300 mm, and the two interact: a finer filament needs a shorter trim to keep useful stiffness, while a thicker one carries a longer trim and still lands pressure on the tip.

Split the range by duty: roughly 0.05–0.54 mm for light wiping, dusting and surfaces that mark easily, and 0.54–2.00 mm where residue is packed on and point pressure matters more than surface risk.

Tip treatments available on this filament: cleaning, carding, bleaching and setting.

In practical brush terms: reaching deep into a bore or crevice is a diameter problem before it is a length problem. A thicker filament on a moderate trim pushes further in before the tips fold over.

Hand brushes, polishing and general natural-bristle cleaning where moderate stiffness and liquid carrying are useful.

The applications that keep coming back to this grade:

• Bottle & Container Cleaning
• Cup & Mug Cleaning
• Hydration Bag Cleaning
• Dust Removal
• Leather & Shoe Processing Brush Use
• Ceramic Glaze Line & Tile Brush Use

The constructions that usually carry it:

• Custom Handheld Detail Brushes
• Custom Roller and Conveyor Brushes
• Custom Polishing Buffing Wheels

The trade-off: Not for high-temperature, strong chemical or sterile process claims.

Send the brush type, filament diameter, free trim length, density, contact setting, wet or dry duty, working temperature and the actual cleaning chemistry together. Any one of them on its own leaves the stiffness undefined.

What usually goes wrong at this step:

• Selecting Pig Bristle from the material name alone without setting filament diameter, trim length, and density
• Using dry stiffness to predict wet behavior without checking moisture absorption or liquid exposure
• Ignoring trapped abrasive particles, chemical concentration, temperature, or contact motion when assessing surface risk

Reference standards behind the figures on this page: ISO 139; ISO 5079; ISO 20743.

Source: American Brush Manufacturers Association — Brush Lingo — natural bristle. Pig bristle is graded by origin, length and stiffness, and the flagged tip is the reason it is still used where a synthetic would leave streaks. It swells and softens in water, so working stiffness wet is not working stiffness dry.