Recycling Long Glass Fiber Reinforced Polypropylene Instrument Panel Trim Offal 2008-01-1340
Production of soft, padded instrument panels (IP's) with a Long Fiber Reinforced Polypropylene (LFPP) substrate have areas for HVAC outlets, air bag doors, IP clusters and glove box doors that are molded over with substrate/ urethane foam/ skin. These openings are subsequently die punched out. These areas are molded over to prevent foam bleed to the backside of the IP during the production foaming process. Typically they are 12% of the total material usage.
The punched sections of composite substrate/foam/skin (punch outs) have traditionally gone to landfill, typically at a cost of $0.05/lb. to the Tier 1 supplier. Wipag Recycling in Germany has developed a process whereby the substrate material is recovered from the composite structure, separating the resin from the foam and skin. The resin has 99.8% purity and can be subsequently blended back into virgin resin for production at a specified percentage without statistically varying the physical properties of the LFPP IP substrate. The WIPAG laminate separation process has been in commercial operation at American Commodities Inc. (ACI) in Flint, MI for the past 7 years albeit with SMA, PC/ABS and TPO substrates.
With regard to recycling LFPP, traditional wisdom dictates that the material properties of the resin will be reduced after each heat history due to glass fiber length attrition, caused from the processing of the material. This study shows that up to 30% of resin reclaimed from the composite substrate can be added to virgin material with a minimal effect on the properties of the final part.