Power-operated brushing tools (brushes) are composed of a brush core and the filling material, e.g. steel wire whose tips form the working surface. They are used on stationary machinery and on hand-held grinding tools to work the surface of wooden or metal work pieces. These rotating tools are subject to centrifugal tensions which may cause bursting of the tools. In this case the operator may be seriously injured by fragments of the fixing elements and filling material flung out of the working zone at high speed.
The breaking strength of commercial brushing tools was analysed in centrifugal tests and partly by way of calculation.
With only one exception, all investigated brushing tools complied with the safety requirements of the German accident prevention regulation "Grinding and brushing tools" stipulating that the fracture speed must be 50% higher than the indicated operating speed. Nevertheless, the tests revealed that single steel wires or plastic bristles from the filling material may get loose even below the admissible operating speed. Injuries of the eyes, which might result from such incidents, should be prevented by always wearing eye protection especially when working with hand-held grinding machines.
metal workingType of hazard:
Mechanische Gefährdung, UnfallverhütungDescription, key words:
mechanical hazard, metal working, power-operated brushing tools, brushes, safety, centrifugal tests