| 摘要 |
For indicating the wear of plastic bristles for brushes or the like, it is provided that the plastic bristle be formed from a supporting core and a working layer concentrically surrounding the latter, the core and working layer consisting of differently coloured plastics possibly of different types and the working layer being formed of a sleeve closed at one end, into which sleeve the core is inserted. The expiry of the useful life during use of the implement equipped with such plastic bristles is recognisable by the appearance of the differently coloured core.
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