Patent ID: 8337743

Claim:
A process for producing a multi-layer film or sheet containing at least one polyethylene layer adjacent to at least one polypropylene layer comprising: feeding polypropylene to a first extruder of an coextrusion film unit; feeding polyethylene to a second extruder of the coextrusion film unit; coextruding the polypropylene and the polyethylene through a die to form a molten extrudate; blowing the molten extrudate into a film; and cooling the film to form a multi-layer film, wherein a freezing time of the extrudate is less than 10 seconds and the polyethylene is not a low density polyethylene produced by a high pressure polymerisation process, wherein the polyethylene is produced with a metallocene catalyst having the general formula: R(THI) 2 MQ Z-2 wherein THI is a tetrahydrogenated indenyl group which may be substituted or not, R is a substituted or unsubstituted C 1 -C 4 alkylidene radical, a dialkyl germanium, a dialkyl silicon, a diaryl silicon, a di-alkoxysilane, a diphenoxysilane, or an alkyl phosphine or amine radical bridging two tetrahydrogenated indenyl groups, Q is a hydrocarbyl radical, hydrocarboxy radical having 1-20 carbon atoms or halogen and can be the same or different from each other, M is a group 4, 5 or 6 transition metal, and Z is the valence of the transition metal.