Abstract
During paper recycling, two types of waste are typically derived as a result of extracting cellulose fibre from paper. The first is known as de-inked residue (DIR), and the second is mixed waste plastic (MWP). One office paper recycling facility alone can produce 30 000 t of DIR and 3000 t of MWP per annum. These wastes are usually disposed of by means of landfilling or by incineration. In this paper, plastic extrusion is evaluated as a disposal method for these wastes. The DIR was dried to a moisture content of <8%. The MWP was prepared for the experiments by grinding to 6 mm diameter and cleared of ‘foreign debris’ before being dried to a moisture content of <8%. Samples were processed in a twin-screw extruder at three varying material ratios of the waste materials (75:25, 25:75, and 50:50). Tensile, flexural, and Charpy impacts were carried out to establish the mechanical properties of the samples. It was found that 75% loadings of DIR did not consolidate. Of the other two blends, higher loading of DIR produced better strength and modulus properties, but with reduced elongation and toughness. The project demonstrated that waste byproduct materials from the paper recycling industry can be effectively prepared and extruded into suitable sample components. However, the highly variable nature of the MWP provides potential problems for further utilisation of this technology without plastic sorting.
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