E-Weekly
Sep 15th, 2008                                Print this article

Injection molding: SABIC seeks route to compression molding glazing simulation

By Modern Plastics Editorial Staff

SABIC Innovative Plastics’ polycarbonate (PC) based automotive glazing unit, Exatec, has created a computer-aided engineering (CAE) method to model the two-component injection compression molding (ICM) process used to mold PC glazing with lower stress and higher optical quality. SABIC’s Derek Buckmaster told MPW there are several commercial process simulation packages that can simulate the injection-compression molding and 2K processes, but they can only simulate these processes individually, not in combination, which is the scenario when molding a 2K automotive window.

Buckmaster says the company has not modified the commercial software, only changed the inputs for the second part of the process—the second shot—so that the results more closely match the actual process, saying the research has garnered commercial interest. “Several OEMs and Tier One suppliers have asked us if there is a way to fill the ‘gap’ in the processing software where injection-compression needs to be combined with a second shot in the same tool,” adding that SABIC has used this technique on several new projects it’s currently working on.

The companies say they proved out the process with a prototype roof and computer-predicted results that correlated with real-life trials of the ICM process. SABIC believes the software will help designers achieve superior glazing applications using PC with wet and plasma coats.

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