Abstract: A system for non-destructive, non-contacting use for detecting imperfections in multi-layered supply rolls of wound plastic film comprises a laser which scans the length of the particular roll being inspected with a photo-electric detector at a fixed reference angle which picks up reflected unimpeded and scattered light plus associated indicating and/or recording equipment. Defects in the roll, particularly those related to the upper longitudinal surface thereof, cause light scattering which decreases the signal strength to the indicator or recorder, thus noting the presence of a wrinkle or the like imperfection in the film roll.

Abstract: Plastic articles without foam spots are produced by an improved powder forming process wherein a powder of normally solid, thermoplastic polymer is compacted by means of vibratory energy into briquettes which are subsequently forged and formed into articles of fused polymer.