Mould maker

Working with Acmos Chemie, researchers at the Fraunhofer Institute for Manufacturing Engineering and Applied Materials Research (IFAM) in Bremen have developed a new type of coating for metal moulds.

Traditionally, manufacturers of fibre-reinforced plastic parts have to apply four to six layers of separating agent into a metal mould before they pour in a mixture of resin, plastic and textile fibres.

These separating agents are dissolved in a solvent which evaporates after each application, creating an environmental problem.  Europe’s polyurethane industry alone, for example, which supplies car manufacturers with such parts as tubes, seats and dashboards, uses several thousand tons of such hydrocarbon-based solvents every year.

But the researchers’ new plasma polymer coating only has to be renewed after thirty to a hundred cycles, 'In some applications, it even lasts up to a thousand cycles,' said IFAM project manager Gregor Graßl. 'This accelerates production and is kind to the environment, as no solvent is released into the air.'

It also takes less time to clean the mould after each component, as less material sticks to the surface. Another advantage is that the finished plastic parts no longer need to be stripped before painting. Until now, they were always covered in residues of non-stick solvent, which prevented paints or adhesives sticking to them as well.

The coating process will be on display at the K2007 plastics trade fair in Düsseldorf (Stand E91, Hall 3) from October 24 to 31.