An Investigation on the Shearing of Automotive Grade Polypropylene and Acrylonitrile-Butadiene-Styrene to Facilitate Recycling
 
 

Kristin K. Philipps | MS | 1995

ABSTRACT:

Landfills are filling faster than new ones can be built in many parts of the U.S. This is the cause of growing concern over potential ways waste streams could be reduced. The automotive industry is feeling increased pressure to come up with ways to deal with the portion of vehicles which end up in landfills. The waste from autos composed of plastics, glass, foam, fluids, rubber, and other materials, is the subject of much study aimed particularly at reclaiming the potentially valuable plastics.

Plastics must be reduced in size to small pieces to aid the separation of commingled plastics, and allow further processing. Granulators are used to reduce in-plant scrap from molding machines to small pieces so they can be recycled. Despite the success of the granulator industry, the process that occurs when plastics are reduced is not well understood. There is little consensus between granulator manufacturers on what designs and operating conditions work best.

The purpose of this study was to simulate the action in granulators with a punch and die to gain a better understanding of the deformation process, and apply the results to make suggestions for real granulating processes. Of the five variables studied, tool geometry and strain rate were found to have the greatest effects on the deformation process.

Very little information was found in the literature pertaining to transverse shearing of polymers and so no studies on punching or blanking polymers were encountered. Due to the complex nature of polymer behavior it was difficult to apply traditional metal blanking and sheeting analysis tools to this problem.

If you have any comments or suggestions please e-mail jwsuther@mtu.edu.