Sausage casings based on polyamide having improved peelability characteristics

摘要

Coextruded multilayer biaxially stretched tubular seamless sausage skins with improved tearing-off characteristics in the filled state coupled with reduced tendency to bursting upon cutting into the sausage, are comprised of at least two layers which form the innermost and outermost surfaces of the tubular skin and which consist predominantly of aliphatic polyamide; at least one interior layer with water vapour barrier properties and having a polyolefinic character; and at least one interior layer having oxygen barrier properties and consisting predominantly of ethylene-vinyl alcohol copolymer (EVOH), and the tubular skins have a quotient of the tear propagation strengths (DIN 53363) in the crosswise and lengthwise directions of 0.65 - 0.85 and a degree of area stretching of the film prod. of 8-11. Pref. the innermost and outermost layers are made predominantly of linear aliphatic polyamides such as PA 6, PA 66, PA 11, PA 12 and/or linear copolyamides such as PA 6.66, PA 6.8, PA 6.9, PA 6.10, PA 6.11, PA 6.12 or a mixt. of these, opt. in combination with an aromatic or partially aromatic (co)polyamide, polyolefinic (co)polymers (eg EVA, EVOH, ionomer resin, acid modified ethylene or propylene copolymers) and/or (co)polyesters. The layer with water vapour barrier properties is pref. of polyethylene or polypropylene or copolymers based on ethylene or propylene or mixts. of these. The layer with oxygen barrier properties is pref. of EVOH. At least one of the layers, partic. the outermost layer, may be pigmented, esp. by incorporating a masterbatch. Pref. the sum of the thicknesses of the layers in the coextruded skin is 35-70 (40-65) mu m.