Recycling polystyrene packaging

Toloken, S., Thermoformer Elm Packaging buys NPRC, Plastics News, July 5,1999, p. 1. Ehrlich, R.J., The Economic Realities of Recycling, Polystyrene Packaging Council, http // www.polystyrene.org/environment/econ.html. 

Apart from the reprocessors of post consumer plastics, other companies have continued to specialize in waste plastics from industrial and commercial operations. The recycling of plastic pallet wrap is expanding across the country. Used electrical wire and cable is being reprocessed primarily for the recovery of metals however a number of specialized operations recycle the cable insulators, polyethylene and polyvinyl chloride. Similarly a few facilities exist to recycle waste automotive trim and foam polystyrene packaging. A considerable effort is being expended to find applications for plastic auto shredder residue which is the by product of the automobile recycling industry which currently recovers metals from end of life automobiles. At present viable applications are still understudy and current residues continue to be landfilled. 

Eoamed polystyrene sheet has exceUent strength, thermal resistance, formabUity, and shock resistance, as weU as low density. It is widely known for its use in beverage cups, food containers, building insulation panels, and shock absorbent packaging. Polystyrene products can be recycled if suitable coUection methods are estabUshed. Eoamed polystyrene sheet can also be easily therm oformed (see Styrene plastics). 

The most difficult recyclates are the MSW, which usually consists of more or less dirty plastics of various types and sources. According to one report [15] the plastic portion of MSW contains typically 50% PE (mainly low density polyethylene, LDPE), 8-14% polypropylene (PP), 15% polystyrene (PS), 10% polyvinylchloride (PVC) and 5% polyethylene terephthalate (PET), and 5% other polymers, while the hard packaging fraction consists of approx. 60% of PP and HDPE [16]. 

Zabaniotou, A. and Kassidi, E., Life cycle assessment applied to egg packaging made from polystyrene and recycled paper, J. Cleaner Prod. II, 549-559, 2003. 

Apparently, AMSd is also useful in the reduction of the molecular weight of waste polymer.491 Heating polystyrene foam pieces recycled from food packaging materials at 160 °C for 1 h in the presence of AMSd reduced the Mn from approximately 70 000 to 10 000. The mode of action is unknown, but it is presumed that AMS radicals are generated and abstract hydrogen atoms from the polystyrene backbone, resulting in chain cleavage. 

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