Combining injection molding and composite prepreg for auto panels

Scientists at Germany's Technical University of Chemnitz who are working to develop new production processes that combine thermoplastic fiber compound prepregs such as organic sheets with injection molding technology, now are using Engel organomelt injection molding technology, which was first seen at K 2010 in a lightweight technology production cell.

Collaborating with partners from the machine and plant engineering, automotive, and aerospace industries, as well as with Engel, the TU Chemnitz scientists seek to bring this technology to the level of series production. The primary end use market is clearly the auto industry, but the resulting strong, lightweight panels and other parts are suited also for aerospace and other sectors.

The production cell, whose heart is a vertical Engel insert 1800 H/500 L/400/90 injection machine, combines composite prepreg technology with the injection molding system, and includes an articulated arm robot. The prepreg module, which is positioned as an additional clamping unit above the rotary platen of the vertical IM, molds the fiber prepregs into the right shape for back injection.

"The plant [production cell] enables us to implement closed and energy-efficient process chains for near-serial production of fiber reinforced structural components", says TU Chemnitz chair holder Prof. Lothar Kroll. The plant supports a variety of process combinations including injection-compression molding, two-component injection molding, and microstructure foaming. The multi-axis robot provides an interface to future automation solutions.

At the system's inauguration, over 50 automakers, suppliers, and German plastics processors saw a variety of test parts molded using a mold supplied by Engel and made by its working partner FKT Triptis, a German moldmaker located near Chemnitz in east-central Germany. —Rob Neilley