| 摘要 |
The invention concerns a surface treatment for parts of plastic die-casting and extrusion machines which come into contact with molten plastics. Especially polyvinylchloride, polycarbonates, fluorcarbon derivates, polyethylene, ethylene vinyl acetate copolymere, polyethylene terephthalate and acryl butyl styrene. The parts, like die-cast and extruder screws, cylinders, one-way valves, connecting flanges, extruder nozzles and dies are electrolytic or electroless plated with a layer of nickel-phosphorus or cobalt-phosphorus. The layer of nickel-phosphorus or cobalt-phosphorus contains 2 to 25 % phosphorus and 75 to 98 % nickel or cobalt and a thickness of minimal 2 micron. The invention accepts a maximum of 7 % contamination of the coating compound. |
