| 摘要 |
PROBLEM TO BE SOLVED: To obtain the balance between tensile strength, tensile elongation and elongation at break by drawing an ultrahigh mol.wt. polyolefin molded object having a specific viscosity average mol.wt. in specific magnification and shrinking the stretched one under a specific ondition before again drawing the same. SOLUTION: A molded object is produced from ultrahigh mol.wt. polyolefin with a viscosity average mol.wt. of 500000 or more by a method wherein a molding material supplied on an endless belt 6 from a hopper 16 is fed to a position where an endless belt 5 is provided while preheated if necessary to be held between the endless belts 5, 6 and subjected to compression molding by press plates 13, 14 operated by a hydraulic cylinder 15 while moved between the endless belts in this state to form a sheetlike molded object. This molded object is drawn by 30 times or more to form a draw molded object which is, in turn, shrunk in the stretching direction so that a shrinkage factor becomes 0.3-80% to be again stretched. |
