Evaluation of Co-Injection Molding: An Alternative to Recycling Scrap Painted Bumpers

Thumbnail Image



Journal Title

Journal ISSN

Volume Title


The Ohio State University

Research Projects

Organizational Units

Journal Issue


Implementing co-injection molding into manufacturing processes can benefit both a company and the Earth. Honda recently began studying the use of recycled material for their bumpers, which are made out of thermoplastic polyolefin (TPO). Any bumpers that are delcared "scrap" before being painted can simply be ground up and re-used in the injection molding process. The dilemma occurs, however, after the bumpers have been painted. At this point, there are no present recycling capabilities. The painted scrap, if molded and mixed with the virgin material, will not give an acceptable surface quality. It is anticipated that co-injection molding will allow the painted bumpers to be re-grinded and used as the inner core of a new bumper. This research will identify the conditions needed to avoid core surfacing in the bumper. The goal for Honda will be to maximize the amount of recycled material used while meeting the current specifications.



Co-Injection Molding, Bumpers, Recycling, Reduce scrap