| 摘要 |
PURPOSE:To obtain the titled film having a specific physical property values, restricted orientation and good tear strength balance by preparing film from copolymer of ethylene and alpha-olefin. CONSTITUTION:This is ultra-high impact resistant film obtained from copolymer both of ethylene (density 0.895-0.935g/m<3>, melt index 0.5g/10min max.) and alpha- olefin of C3-18 and has orientation function fbeta -0.1 min., orientation function fepsilon 0.1 max. and thickness 30mum max. Said film is prepared in air cooling 2 by constricting a cylindrical melting body extruded from a die 1 to the diameter smaller than the diameter of the die along a conical inner mandrel 4 arranged concentrically to the die, then, expanding it to the blow-up ratio 3 min. to form a bubble and making the height of the fixed portion 3 from the outlet of the die 5 times min. as large as the diameter of the die. |
