| 摘要 |
PURPOSE:To achieve high drawing and to improve modulus of elasticity and the creep resistance of an orientated object by drawing the polyacetal containing the glass fiber in a selected range in a heated and pressurized condition. CONSTITUTION:The polyacetal forming material containing 2-18wt.% of glass fiber is pressurized by passing through pressurized fluid, and while the material is heated at the temperature equal to its softening point or lower, it is drawn by 10 times or more of draw ratio. As the pressurized fluid, liquid is generally used. This fluid is inert to the polyacetal, and exhibits fluidity at the drawing temperature. Consequently, the fibrillation is supressed and high ratio drawing is achieved, whereby a oriented polyacetal object is obtained which has a high strength in the drawing direction, the stability for external force in transverse direction, high modulus of 20GPa or higher and 9% or less creep strain after 1,000hr under a prestress of 0.4GPa. |
