PROCESS FOR THE PREPARATION OF BLOWN FILM AND ORIENTED FILM

摘要

A process for well-oriented film comprises steps to; (i) melt a polymer (the base of the polymer is LDPE having density of 910-940 kg/m3); (ii) squeeze the above melt-polymer (i) out through a ring- shape die and blow into balloon shape of film by on gas from the die- hole; (iii) cool and flaten the above balloon; and (iv) roll up the film into a roll. Melt index of polymer compsn. by ASTM D 1238 is 0.3-30 dg/min. When melt index to exceed 25 dg/min, the influence on mechanical properties decreases, and 0.4-0.9 mm of die gap is suit able for the production of film.