Skin treatment

Those in the business of car production know that coating an injection-moulded plastic part such as a car bumper is often a long and costly procedure. But a two-step, in-mould coating process that combines injection moulding with reaction injection moulding could save them time and money.

In the process developed by

, a part is injection moulded then whirled around by a turntable to a second cavity. There, the part is reaction injected with two-component polyurethane, which rapidly cures in a closed mould.

Peter Neuwald, head of industry innovation transportation at Bayer MaterialScience, said the simultaneous injection moulding and curing ensures a shorter cycle time than in injection moulding of thermoplastics. With the traditional method, the cavity surface of the injection-moulding tool is first sprayed with a coating then the cavity is injection-filled with the melt.

The faster, simultaneous method means higher productivity, he said, adding that the process can lead to huge savings because the two-component polyurethane cures in a thermoplastic mould — making a second unnecessary.