To provide a method for producing stretched multilayer film casing in which the excessive generation of heat shrinkage stress is prevented while securing required heat shrinkability, and which is suitable for the automatic packing of a content having (half) fluidity.
A stretched multilayer film for stretched multilayer film casing obtained by back-seaming a stretched multilayer film composed of at least three layers of both external layers composed of the same kind of polyolefin system resin and a gas barrier intermediate layer composed of a polyamide system resin, and in which thermal shrinkage stress at 50C is 2 MPa in both of the longitudinal direction and horizontal direction, and hot water shrinkability at 90C is 5 to 20% on both the external layers is produced through biaxial inflation at a suitable stretching magnification and a heat treatment stage with steam or warm water at a relatively low temperature.
ITO TADAYOSHI
HAYASHI HIDEKAZU
TSUKAMOTO HAJIME
Next Patent: APPARATUS AND METHOD FOR FORMING PATTERN