PURPOSE: To obtain the titled film which has a high tensile strength, impact resistance and elongation and is excellent in transparency and luster and most suitable for use as a wrapping material by such an arrangement wherein the molecular orientation of a specific polystylene compound is accelerated by the single operation of inflation method.
CONSTITUTION: A resin compound prepared by adding 0W7.0 part of impact resistible polystylene to 100 part of a resin compound composed of 10W90(wt)% of polystylene and 90W10% of stylene-butadiene copolymer is extruded from a die 1 as a tubular film 2. Then, it is caused to elongate in the direction of extrusion without causing it to inflate, and after that, simultaneously with elongation in the direction of extrusion, temperature adjusted air is blown out from an air ring 3 so that it is caused to inflate by internal gas 5 in the direction perpendicular to that of extrusion and the tubular resin is cooled, and a film is formed by using a film draft ratio of 12W100, blow ratio of 1.5W10.1 and an overall deformation ratio of 18W1,000 and the objective film is thus obtained.
YAMAMOTO KATSUHIKO
SAKAI KEISUKE
HOSHINO NOBUHIKO
TOYO KAGAKU KK
| JPS49108177A | 1974-10-15 | |||
| JPS5493057A | 1979-07-23 | |||
| JPS4961252A | 1974-06-13 | |||
| JPS5347462A | 1978-04-27 | |||
| JPS503787A | 1975-01-16 |
Next Patent: LINK DEVICE FOR STRETCHING SHEETLIKE MATERIAL AND STRETCHING DEVICE USING IT