Sieve assembly for repulping paper fiber suspensions, especially from waste paper with impurities for recycling, has bars with a plasma-supported surface treatment to deposit foreign ions and a hard coating

摘要

The assembly to repulp mechanically water suspensions of paper fibers, and especially from waste paper with impurities for recycling, has metal bars (3) secured to the sieves (1) by screw bolts (8). The bars are treated with foreign ions at their surface, by a plasma-supported process to give them a penetration depth of at least 500 mu m together with a coating of hard material at the same time. The hard coating is a nitrite, carbide and/or oxide, carbonitride and/or oxicarbonitride of the elements of groups IVb, Vb and VIb of the periodic system, or a nitride of the elements boron, aluminum, silicon, molybdenum, tungsten or of titanium carbonitride and/or titanium nitride.