EXTRUSION AND FOLDING MODELS FOR THE PASSAGE OF PRESSURE SENSITIVE ADHESIVE MATERIALS THROUGH SLOTTED PRESSURE SCREENING DEVICES IN PAPER RECYCLING

摘要

One of the major concerns in paper recycling is the presence of pressure sensitive adhesives in the recycled material. One useful process in the paper industry to remove the pressure sensitive adhesive (PSA) particles from the recycled material is pressurized screening. The objective of this research was to determine if an extrusion or folding model could predict the passage of PSA particles through a laboratory single slot device. Both a folding and extrusion model were fitted to experimental data. The average yield stress of the PSA materials was calculated from the fits of the data and was within the range of the independently measured yield stress values, indicating utility of either of the models. A large scatter in the data around the model predictions indicates that another factor affecting passage exists.