Carbon Fiber

In the conductive carbon filament family, Carbon Fiber is specified, supplied as continuous carbon filament bundle, conductive tuft and carbon-fiber strip or roller fill, drawn in round and flat bundle sections and set in straight rows, staggered, zoned and fan pattern fill patterns.

Carbon Fiber is used in custom cleaning brushes for grounded static-removal strips and precision contact on films, optics and electronics where very fine conductive fibers are required.

It is usually weighed against Conductive Nylon and Anti-static Filament, and the deciding difference is moisture uptake and working temperature rather than anything you can read off the name.

Compare Carbon Fiber with Conductive nylon, anti-static filament, stainless micro-wire, standard nylon. Change material when wet stiffness, temperature, chemical resistance, conductivity, particle shedding, or surface marking becomes the limiting factor.

Carbon Fiber is high axial modulus at the fiber level, but a brush tuft flexible because its filaments are extremely fine and unsupported. It Carbon Fiber changes brush stiffness through filament diameter, free trim, density, crimp, and contact. Use finer filament and longer trim for conformable contact; use coarser filament, shorter trim, or higher density for stronger displacement or cutting.

Filament-level figures for this grade and the ones it is usually compared to. A finished brush behaves differently again.

The part people get wrong: the same grade can feel soft or aggressive depending on diameter, trim and density. Specify that geometry before the material, or the sample will surprise you.

The carbon fiber itself takes up no more than about 0.10%, so the filament dimension is stable; what moves in wet service is the resin or binder around it.

Low water sensitivity in the fiber does not settle the question: bonding and electrical contact both have to be tested in the wet condition the brush will actually see.

What this means for your application: moisture uptake is low enough to ignore in service, which is why this grade holds its stiffness through washdown.

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.

No single brush-service temperature should be assigned from the carbon fiber name alone. Fiber sizing, binder or holder material, grounding hardware, and the finished assembly set the usable limit.

The filament tables quote 200–350 (Limited by Sizing / Binder)°C continuous and 400–500 (Inert Environment / Short-Term, industry reference range)°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: validate with a sample if the process sits near the top of that band. A permanent bend under load means the answer is a higher-temperature filament family, not a heavier trim.

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.

Resistant to many acids, alkalis, salts, and solvents, with finished performance controlled by surface sizing and holder resin.

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 Carbon Fiber 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 0.005 mm; finer than that and the filament snaps rather than flexes. In practice you are choosing inside 0.005–0.012 mm.

Free trim runs 2–100 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 0.005–0.01 mm for light wiping, dusting and surfaces that mark easily, and 0.01–0.012 mm where residue is packed on and point pressure matters more than surface risk.

Tip treatments available on this filament: sizing, desizing, nickel plating, conductive-adhesive fixing and end trimming.

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.

Grounded static-removal strips and precision contact on films, optics and electronics where very fine conductive fibers are required.

Where it turns up in practice:

• Dust Removal
• Connector & Slot Cleaning
• PCB Cleaning
• Printer & Scanner Cleaning
• Brick, Tile & Building Material Machine Brush Use
• Carpet Machine Cleaning

It is normally set into these constructions:

• Custom Roller and Conveyor Brushes
• Custom Handheld Detail Brushes

If the sample comes back rejected: Brittle fiber fragments, conductive contamination and incomplete grounding can make carbon fiber unsuitable for exposed electronics or cleanliness-critical areas.

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 Carbon Fiber 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: ASTM D3039/D3039M; ISO 14125; ISO 10618; IEC 61340-5-1:2024; IEC TS 61340-5-4:2021; ASTM D257.

Source: Toray Composite Materials America — Carbon fibre product data. Carbon fibre works here as a fine conductive fill rather than as a structural reinforcement. Flex-fatigue resistance is low compared with metal wire, and no universal finished-brush temperature limit follows from the fibre — the anchoring and the process set that.