| 摘要 |
<p>PURPOSE:To obtain the subject film possessing the balanced biaxial direction mechanical and heat seal quality by a method wherein an unspread pipe type film, the necking of which is capable for extension, is spread to both the circumference direction and the longitudinal direction by the elastic spreading rate or less under a specific state. CONSTITUTION:The thermoplastic resin unextended film F3 is received by the low speed side grooved nip roll 14, is made to pass on the preheating mandrel 5 to take the appropriate temperature for spreading and is made permissive to have the necking extension. Then, the film F3 is extended on the cone bench type circumferencial direction extension mandrel 6 by the elastic spreading rate or less to the circumferencial direction making it slightly contract to the longitudinal direction and is changed to the circumferencial direction uniaxial extension film 4. Next thereto, this film is changed to the extension pipe type film 5 on the process between the cylindrical extensive tension control mandrel 7 and the high speed side nip roll 10 and then, in this state, being made slightly to contract to the circumferencial direction, this film is spread to the longitudinal direction under the elastic spreading rate or less, thus, it is changed into the film 6 extended to both the circumferencial direction and the longitudinal direction.</p> |
