US 4,560,520 A · Single-layer elastic tubular film of polyamide used for packaging paste substances and a process for the production of such film

Abstract

The present invention relates to a tubular film used for packing foodstuffs in paste form, this tubular film being polyamide that can absorb at least 5% water, and which at an internal pressure between 0 and 0.6 bar permits substantially reversible deformation and which has a matt appearance. The present invention also relates to a process for the production of this tubular film by multiaxial stretching of the primary tube with stretch ratios of at least 1:2.3 in the longitudinal direction and at least 1:2.5 in the transverse direction, and total thermal fixing of the stretched tube during controlled shrinkage. In addition, the invention describes a boiled or cooked sausage as well as a soft cheese, these being packed in a tubular film according to the invention.

Claims11

Dependent claims

A process for the production of a tubular film consisting of at least a polyamide that can absorb at least 0.5% of its weight in water up to saturation, which tubular film is used for packaging and casing foodstuffs in paste form, especially footstuffs that are packed when hot or are subject to heat-treatment after packaging, comprising the steps of:

extruding a primary tube of polyamide and simultaneously multi-axially stretching the primary tube;
and
subjecting the extruded and multi-axially stretched primary tube to a controlled shrinkage by at least 15% and at most 40% in the transverse and the longitudinal direction in relation to its transverse and longitudinal dimension after stretching, at temperatures above 90.degree. C., thereby thermally fixing the primary tube.

Dependencies are inferred from the claim text.

Single-layer elastic tubular film of polyamide used for packaging paste substances and a process for the production of such film

Life of this patent

Single-layer elastic tubular film of polyamide used for packaging paste substances and a process for the production of such film

Life of this patent

Abstract

Claims11