| 摘要 |
PURPOSE:To manufacture a multi-layer polyamide-containing film with favorable heat shrinkability and without curling by a method wherein polyamide resin layer is treated under heat after or during the absorption of water content and further dried. CONSTITUTION:Firstly, a multi-layer film, which is formed by co-extruding polyamide resin as an outer layer and sealant as an inner layer, is oriented by inflation or the like. Secondly, said laminated and oriented film 9 is introduced in a hot water tank 10 in order to impregnate the outer polyamide layer with water at 7.0wt% or more. After that, the resultant film is pulled out of the tank with nip rolls 13 in order to treat said polyamide layer under heat by an outer heating oven 15, a hot-air blasting air-ring 16 and a hot-air suction air ring 17 and simultaneously to dry said layer to bring its water content to 2.5-6.5wt%. The sealatnt layer is set at said heating process and by the heater shrinkage with nip rolls 13 and 18. |
