MANUFACTURE OF ORIENTATED POLYETHYLENE

摘要

PURPOSE:To arrange so that a mixture of special polyethylene and praffinic wax may be highly elastic and highly strengthened by melting and kneading the mixture, extruding it from a die at a specific temperature and then orientating it. CONSTITUTION:A mixture of 15-97wt% of polyethylene having an ultimate viscosity eta of 1.5dl/g min. and not more than 5dl/g and 85-3wt% of paraffinic wax having a melting point of 40-120 deg.C and a molecular weight of 2,000 max are melted and kneaded at temperatures of 190-280 deg.C. This mixture is extruded from a die at the temperature higher than a melting point and not higher than 210 deg.C in an unoriented form. Next, it is orientated at least at an stretch ratio of more than 20 times as much. An orientated polyethylene obtained in the above- mentioned way has high tensile strength and also high elasticity. In addition, the orientated polyethylene is better looking through the blending of paraffinic wax because an stretch ratio which causes a whitening becomes higher.