Trexel tackles blow molding process

Trexel, Inc. (Wilmington, MA) has extended its MuCell processing solution for injection molding to blow molded automotive components with similarly impressive savings in part weight. In working closely with their OEM and Tier I customers, the company has recognized the need for lightweighting plastic parts beyond the traditional and proven injection molded interior, exterior and under the hood applications, hence its move into the process.

MuCell blow-molded polyethylene air duct realizes density reduction of 41% compared to solid.

To develop this robust MuCell blow molding process, Trexel worked with ABC Group (Toronto, ON), a leading supplier of blow molded products to the North American automotive industry over the past year. Through these efforts, the first Mucell blow molding process was achieved with an automotive application. The part is a reinforced polyethylene air duct with 1.5-2-mm wall thickness. The Mucell process realized a density reduction of 41% of the foamed material, resulting in a 32% net weight saving of the finished part compared to solid.

"We are very excited about the results we have achieved so far," said Steve Braig, President and CEO of Trexel, Inc. "Commercial development of additional MuCell foamed blow molded parts including design and material optimization should result in higher than 40% weight reduction compared to the solid molded part. These results will be very attractive to OEM and Tier suppliers, and ultimately to car buyers who will enjoy improved fuel efficiency of their vehicles."

Besides weight savings, there are reportedly several highly desirable attributes of foamed versus solid blow molded parts: the microcellular material structure improves thermal insulation and also provides for improved acoustical properties. The MuCell technology, a physical foaming process, reportedly also has several advantages over the use of chemical foaming agents: no chemical reaction at narrow processing window, no chemical additive residue in final parts, and most importantly, MuCell foamed parts can be recycled in their original polymer designation; the process does not alter the chemistry of the polymer.