ABSTRACT
Oi fferent scientific studies have shown the effects of reprocessing on mechanical properties of polyethylene. Gibbs (4) studied the properties of recycled HOPE from two recyclers and considered the suitability of recycled HOPE for blow molding. The samples studied were post-consumer samples. The results of such studies are shown in Table I. The regrind controls were made by processing the control resins with a thermal history similar to that of the recycled resins. The results indicate that the recycled commercial blow molding resins have flexural modulus, low-temperature brittleness and tensi le strength comparable to those found for control resins and to those of regrind controls. However, important losses in elongation at break and moderate losses in tensile impact were observed for the recycled resins. A blend of recycled resin! virgin control with a 40/60 composition was also studied and showed similar properties to those of the regrind controls with the exception of the elongation at break. It has been presumed (3) that these effects of reprocessing on the mechanical properties of HOPE can be attributed to the contaminants present in the reclaimed resins. From these results , it was concluded that the reclaimed resins may be useful for non-critical applications, but development efforts in washing, extrusion and stabilization are required to successfully utilize recycled HOPE in blow molding.
