PRODUCTION AND PROPERTIES OF BIAXIALLY ORIENTED POLYETHYLENE TUBES

A study of the production of biaxially oriented polyethylene tubes by the die-drawing process was carried out examining the effects of draw temperature, haul-off speed, and mandrel size. The effect of postmandr el cooling was also studied. A range of biaxially oriented tubes of va rious draw ratios and thicknesses were produced. The Young's modulus a nd the tensile strength of biaxially drawn samples show considerable e nhancement in both directions over the isotropic material. Biaxially d rawn samples show remarkable improvement in their impact strength over the isotropic material. The crystalline orientation and texture of th ese samples are characterized using wide-angle Xray scattering pole fi gure analysis. (C) 1996 John Wiley & Sons, Inc.