Bristle material decides almost everything about a brush roller: how long it lasts, what surfaces it can safely touch, and what it costs. Four filaments cover the large majority of industrial applications — nylon, polypropylene, abrasive wire, and steel wire. This guide explains what each is good at and when it wins.
Nylon (PA 6 / PA 6.6)
Nylon is the workhorse filament. Nylon 6.6 resists abrasion and holds its shape well, and it tolerates heat up to roughly 120°C. It is the default recommendation for glass washing, general conveying, and most industrial cleaning where you need durability without scratching the substrate. Nylon 6.12 is an alternative when moisture retention matters more, since it absorbs less water and keeps better resilience in humid environments.
Choose nylon when: the task is general-purpose cleaning or conveying, the surface is moderately sensitive, and you want the best wear life per dollar.
Polypropylene (PP)
PP does not retain moisture, resists acids and alkalis, and costs less than nylon. It is the right call for food-contact washing, chemical environments, and any wet application where nylon would absorb water. Food-grade PP is available for direct food contact and meets FDA and EC 1935/2004 requirements; certificates are available on request.
PP is also the safer choice for delicate surfaces where nylon might be marginally too stiff. Its abrasion resistance is lower than nylon 6.6, so for heavy-duty scrubbing it is the second choice — but for wash tunnels and hygiene-critical lines it is the first.
Abrasive Filament (SiC / Al2O3)
Embedded silicon-carbide or aluminium-oxide grit turns a brush into a finishing tool rather than a cleaning tool. Abrasive filaments are used for wood sanding, denibbing, and deburring: they deliver a consistent cut with less loading than a fixed abrasive belt, and because they flex they conform to profiled and curved surfaces that belts simply cannot reach.
Choose grit by task: 80–180 for calibrating and heavy stock removal, 240–600 for denibbing and fine finishing before a top coat. Silicon carbide suits hard woods and MDF; aluminium oxide is the general-purpose option.
Steel Wire
Steel wire delivers maximum scrub for road sweepers, heavy deburring, and rust or scale removal. It outlasts any synthetic filament on asphalt and packed debris. The trade-off is harshness: steel wire will mark soft or finished surfaces, so use it only where surface marking is not a concern, or in mixed brushes where steel sections do the heavy lifting and PP sections protect the edges.
Other Filaments Worth Knowing
- Pig bristle and horse hair: natural filaments for polishing, buffing, and delicate nap raising where a soft touch matters.
- Antistatic / conductive nylon: for film, plastics, and synthetic textile lines where static causes clinging or dust attraction.
- PBT: heat-resistant polyester, food-contact rated, a good middle ground where moisture and temperature both matter.
How to Choose
- Durable, general-purpose: nylon 6.6.
- Wet, food, or chemical: PP (food-grade if in contact).
- Sanding or finishing: abrasive filament, grit matched to the target finish.
- Heavy scrub and debris: steel wire, accepting surface marking.