HIGH-STRENGTH POLYETHYLENE FIBERS FROM SOLUTION AND GEL SPINNING

There are many recent reports in the literature of high-strength, high-stiffness polyethylene fibers produced by a variety of techniques, all of which involve at some stage crystallizing the polymer (invariably a high molecular weight material) from solution. In this review the authors place these reports in their proper context and show how and why the various techniques have been developed. To do this we present brief historical reviews of two distinct subjects: the drawing of single-crystal mats and the preparation of 'shish kebabs'. Both of these have, when used in conjunction with very high molecular weight material, led to very strong and stiff fibers. We then describe the recent gel spinning techniques and arrive at the conclusion that there are essentially just two distinct processes involved: the solid state deformation of single crystals, and the crystallization of pre-extended chains to form shish kebabs.