| 摘要 |
PURPOSE:To prevent tearing at the time of lateral twist by thermocompression- bonding a straight chain low-density polyethylene film with a high-density polyethylene group film and forming a film for a twist wrapping through monoaxial stretching. CONSTITUTION:A high-density polyethylene filmy article extruded from a mold at 180-280 deg.C is cooled and solidified on a chill roll at 60-100 deg.C, thus shaping a film not oriented. The film not oriented is heated by a preheating roll at 80-120 deg.C, a previously film-formed straight chain low-density polyethylene film is heat-bonded between a pair of pinched metallic roll and rubber roll, and a thermal adhesive film is monoaxial-stretched at drawing speed of 30-12m/min and a draw ratio of 4-10 times, thus acquiring a film for twist wrapping. The film acquired has ductility, vertical tearing is prevented, lateral twist holding properties are improved, and excellent packaging-machine aptitude is obtained. |
