Multi-layer heat-sealable polypropylene films

摘要

A heat-sealable multi-layer film structure charactised by consisting essentially of: (i) an outer heat sealable layer (A), a core layer (B), and an outer layer (C), the outer heat sealable layer (A) being coextensively adherent to the upper surface of the core layer (B), and the outer layer (C) being coextensively adherent to the lower surface of the core layer (B) said outer layer (A) being formed from a polymer composition (a) consisting essentially of heat sealable resin compounded with one or more slip additives which are incompatible with polypropylene. (ii) said core layer (B) being derived from a polymer composition (b) consisting essentially of an isotactic polypropylene homopolymer compounded with one or more slip additives which are incompatible with polypropylene, and (iii) said outer layer (c) being formed from a polymer composition consisting essentially of isotactic polypropylene homopolymer in the substantial absence of slip additives; wherein the total amount of slip additive in said film structure is effective to provide the outer surface of outer layer (A) with a coefficient of friction sufficient for high speed heat sealing packaging operations but insufficient to cause substantial hazing of said structure.