Does a faster brush clean better?
Only up to a point. A brush cleans through relative motion and the controlled bending of its filament. Raising the speed or the engagement improves removal while the tips still do the work. Once the filament runs on its side, or no longer springs back between passes, heat and wear climb faster than the cleaning does.
How do you work out surface speed?
Rotary brush surface speed is π × D × n. With the outside diameter D in meters and the shaft speed n in rpm, the result is in meters per minute; divide by 60 for meters per second. A 200 mm brush at 600 rpm runs at about 377 m/min, or 6.3 m/s.
A larger brush at the same shaft speed has a higher tip speed, so compare surface speed, not shaft speed, whenever the diameter changes. Turning against a moving belt adds the belt speed to the relative speed; turning with it takes it away.
How far should the filament bend?
| Contact | What the filament does | Use |
|---|---|---|
| Light tip contact | Bends a little; little heat or drag | Dusting, wiping, polishing, delicate surfaces |
| Controlled bend | Tips sweep and scrub and recover on every pass | General cleaning, wet scrubbing, conveyor and panel work |
| Heavy side loading | Filament folds over and rubs on its sides | Avoid: heat, smearing, set, motor load and fast wear |
Where does the heat come from?
- High relative speed without enough fluid or airflow.
- Too much engagement, or a brush too large for the gap.
- Short, coarse, dense fill that cannot let debris go.
- Sticky residue coating the face and raising friction.
- Staying on one spot too long, poor alignment or shaft runout.
- A polymer running above its continuous working temperature.
How do you fix a brush that runs hot?
- Clean the brush face and check alignment and runout.
- Reduce engagement before you reduce the strength of the fill.
- Lower the surface speed, or change the direction of rotation.
- Open the face pattern, or add liquid, air or vacuum to carry debris off.
- Use longer, finer filament so it follows the surface, or a material rated for the heat.
- Run the sample again and record cleaning, temperature, motor current, finish and wear.
What should you record on the line?
Brush outside diameter, shaft speed, line speed, direction of rotation, engagement, contact width, dwell, motor current, surface temperature, coolant or wash flow, filament diameter, trim, density, the residue and the finish that is accepted.
