Summary

This communication is concerned with the gel-splnning of ultra-high molecular weight polyethylene (UHMWPE) at speeds up to 1500 m/mln. It was found that 5 wt % solutions of UHMWPE in paraffin oil could be extruded through a conical die at a rate of 100 m/min. without the appearance of filament irregularities due to elastic solution fracture. These elastic turbulences occur at extrusion speeds of about 5 m/min. Without the addition of I wt % of Aluminlum-stearate the spinllne could be stretched at most to 60 m/min at 170 ~ but at 210 ~ it did not break at a speed of 1500 m/min. These hlgh-speed gel-splnning experiments at temperatures around 200~ yielded polyethylene fibers with a tensile strength of 3.5 GPa. It was observed that drying of the as-spun fiber containing n-hexane at constant length led to excessive crazing. Introductlon In recent years there has been a steadily increasing researc