DEFORMATION BANDS IN COMPRESSION OF BIAXIALLY ORIENTED NYLON 6

Abstract

The deformation bands are formed in the rolled planes of the drawn and rolled nylon 6 and 6.10 filaments, compressed at above 100°C perpendicular to the rolled planes. We examined the effects on the formation of deformation bands, such as temperature of compression, temperature of annealing of the specimens, regain of the specimen and dimensional changes of the specimens caused by the compression. Higher the temperature of compression is, more deformation bands are formed. Deformation bands are formed more easily with decreasing crystallinity and increasing regain.Breaking strength and elongation of the compressed specimen with deformation bands were examined. Cracks are initiated at the deformation bands and the breaking strength of these specimens decreases. Especially its value decreases remarkably for the specimen compressed at above 150°C and reaches about 10Kg/mm2 for that compressed at 180°C. Water absorbed storngly influences the formation of deformation bands, and decreases the breaking strength. Compression at high temperature gives rise to the structural changes, such as disorientation of the crystallites and change of density, and the lowering of the strength may be due to not only the formation of deformation bands but also to these structural changes.Deformation bands formed by the bending deformation at high temperature were also examined. Similar results were obtained for the formation of deformation bands and the lowering of the strength.