Engel will demonstrate a new application for its low-pressure injection molding process—called coinmelt– at a technology seminar near Detroit June 29.
An Engel duo 16050/1650 WP US machine, with an integrated Engel viper 60 robot, will produce luggage compartment covers designed for use in a Daimler vehicle.
In the coinmelt injection compression molding process, lower clamping forces are said to allow output of thinner parts with reduced distortion than standard injection molding. Tooling for the application was developed by Georg Kaufmann Formenbau, Busslingen, Switzerland.
A special approach was required because the three-dimensional complex part geometry is strongly ribbed and has several undercuts. “Here, the injection compression process allows an excellent fine structure reproduction without warpage,” according to Engel.
In the injection compression molding process, the polymer melt is injected into the gap for the compression stroke, requiring less injection pressure compared to conventional injection molding. Just before the polymer melt flow stops, the clamping unit starts to close with controlled parallelism and a specific clamping force.
The sealing pressure replaces the post-injection pressure of the conventional process and is distributed along the entire length of the part.
One of the prerequisites of the process is a very precise opening stroke of the moving mold mounting platen, which is assured by the individually controlled short stroke pressure pads of the Engel duo machine.
The seminar, which will be held at the Laurel Manor Banquet & Conference Center in Livonia, Michigan, is part of Engel’s Trend Scout series.