Unique polyethylene morphologies produced under extrusion conditions

Unusual morphologies have been shown to be produced in high density polyethylene near its melting point and under selective conditions of orientation and pressure existing in an Instron capillary extrusion rheometer. Points of study involve the remarkably high optical clarity and tensile moduli for the morphologies produced in these filaments. Details of the crystallization procedure are provided. The morphologies resulting from the Instron procedure have been analyzed by several different techniques. X‐ray, calorimetry, microscopy and modulus data are discussed. The transparent filaments are composed of a large number of microfibers having a high degree of crystalline orientation parallel to the capillary axis. Electron diffraction and calorimetric studies indicate that a portion of the strands have an unusually high degree of order. Structural models for the strands are also proposed.