METHOD FOR EXTENDING SAPONIFICATED MATERIAL OF ETHYLENE-VINYL ACETATE COPOLYMERIZATION INTO TWO TUBULAR AXES

摘要

PURPOSE:To enable the industrial two-axis extension to be performed by increasing the temperature of film, which is made of the material described in the subject and is not extended yet, and wherein the rate of water inclusion is decreased, to a specified temperature by heating the film for a short time, and heating the material quickly, immediately after the previous heating, in order to bring the starting point of the extension into a specified temperature range. CONSTITUTION:The rate of the water inclusion of the tubular film which is not extended yet and is made of saponificated material of ethylene-vinyl acetate copolymerization is made to 2.0% or less. The material is preliminarily heated to 50- 70 deg.C by passing it through the continuous heating region within 5 seconds. Immediately after the process, the starting point of film extension is brought to 70-100 deg.C quickly, and the extension is performed in two axes of longitudinal and lateral directions simultaneously.