| 摘要 |
PURPOSE:To prepare a stretched article having a wide range of a cross-sectional area while holding high strength and high modulus of elasticity, by a method wherein a molded article being a molding of macromolecular polyethylene and having a relatively large wall thickness is subjected to preheating/wetting treatment under a specific condition and subsequently subjected to dipping/swelling treatment in a solvent heated to the melting starting temp. of polyethylene or more and next preparatorily stretched within a specific temp. range and cooled before being stretched at raised temp. CONSTITUTION:Preheating/wetting treatment is applied to a molded body composed of polyethylene having wt. average MW of 1X10<6> or more. Next, the molded body is dipped and swollen in a solvent capable of swelling said polyethylene at a temp. range from the melting starting temp. of polyethylene or more to temp. below the b.p. of the solvent. Subsequently, the obtained swollen body is preparatorily stretched at a draw ratio of two times or more and subsequently solidified under cooling and further raised in its temp. to be stretched. By this method, a high performance stretched article can be efficiently and stably prepared without performing complicated operation and even a stretched article having a relatively large cross-sectional area said to be difficult to prepare up to now can be prepared. |
