| 摘要 |
PURPOSE:To make it possible to realize polyvinyl alcohol (PVA) products in various shapes higher in strength and elasticity modulus by a method wherein a polyvinyl alcohol molded part is oriented by heating with microwaves in two steps at specified orienting temperatures. CONSTITUTION:When a PVA molded part 1 is oriented by heating with microwaves, the part is heated with microwaves at an orienting temperature of 160 deg.C or lower and oriented at a draw ratio of 8. After that, the part is further heated with microwaves at an orienting temperature of 170-210 deg.C and oriented at least draw ratio of 15. Because high-strength PVA molded parts with high elasticity modulus in various shapes can be manufactured in such a manner as mentioned above, the resultant molded part can be used for various applications such as rope, tape material, communication cable material, film material, construction material and the like, to all of which the strength and resistance to deformation are requested. |
