process for the manufacture of a biaxiaal molecular centred tubular mace of poly epsilon capronamide, and the resulting mace.

摘要

A biaxially molecule-oriented film of poly- epsilon -caproamide resin having an improved dimensional stability and surface slip characteristic is prepared by extruding the molten resin downward through an annular die, quenching and solidifying the extruded film by means of an internally liquid-cooled, cooling mandrel having a specific shape to form a substantially amorphous, non-stretched tubular film substantially free of any hydrogen bond, allowing the thus obtained film to come in contact with a heating gas while heating the film at a temperature of from 45 DEG to 70 DEG C and keeping a water content of the film at not more than 2 % based on the weight of the film, biaxially stretching the heated film simultaneously at a stretching ratio of 2 to 4 in both longitudinal and transversal directions by introducing a pressurized gas into the tubular film between a low speed feeding section and a high speed take-up section of the film, and heat-setting the thus stretched film while keeping a water content of the film at least at 1 % based on the weight of the film to an equilibrium water absorption content in water.