Molding of polycarbonate+ABS parts for chrome electroplating.

摘要

Electroplating polymers provides products with the properties of both metals and plastics. Polycarbonate/ABS copolymers are the most popular plastics for plating due to the combination of part performance and platability. The ability to plate PC/ABS is innate due to the etching capability of the butadiene phase of the polymer. However, this is only possible if a butadiene-rich surface is achieved on the molded part.; The challenge for today's molders of electroplateable plastics is to determine the best injection molding parameters that produce plateable parts at the most economical cycles. This study examines the production of chrome-plated PC/ABS automotive wheel covers manufactured for General Motors. Parts were produced varying mold and melt temperatures, injection speed and pressure, as well as pack and hold settings. The parts produced were then chrome-plated on a commercial 36-tank rack and hoist plating system.; The results show that mold temperature and injection speed are the most significant variables. A slow injection speed and high mold temperature produces parts with a rich butadiene surface that the plating process can etch. Applying this knowledge, the scrap rate of the manufacturing facility was reduced by 30%, thereby significantly lowering operating costs.