Date of Award


Degree Name

Bachelor of Science


Paper Science and Engineering


Low density polyethylene is a very popular plastic which is commonly found in laminations which are extruded onto paper and paperboard. It is often used on products used for food packaging because of its inert and protective properties. With the aid of a corona discharge, polyethylene becomes ink receptive and forms a strong bond with the substrate; however, this bond is not a major problem when polyethylene laminated paper is recycled. The problems with recyclingcan be contributed to the heat sensitivity of the polyethylene. At high temperatures the polymer stretches and forms tangled conglomerations which trap fibers. Therefore the key to recycling of material lies in finding the proper equipment to disentegrate the polyethylene laminated paper.

The scope of this thesis describes variables that affect the separation of low density polyethylene and presents an experimental procedure which can be used to obtain a successful separation using conventional screening and reverse cleaning equipment in a aqueous medium.

In general, the experimental data shows that low temperatures and long beating times are required. In a pilot plant trial the low density polyethylene was disintegrated in a Hollander Beater and screened through a Jonsson Screen, Selectifier Screen and C.E. Bauer reverse cleaner.