Abstract: The invention relates to a blown film coextrusion process. The process involves extruding core contact layers through a die exit at a specified speed and cooling, orienting and crystallizing the multi-layer film formed at a specified deformation rate to form a the frost line is a specified distance from the die exit by withdrawing film at a take up speed. The core and core contact layers are of a film forming polymer composition comprising at least 90 wt % of ethylene based polymer. The ethylene based polymer of the core layer has an average density of ethylene based polymers equal to or higher than that of ethylene based polymer of the core contact layers. The invention specifically concerns the feature that the core layer composition contains a portion of and the composition of the core contact layers contains a portion of a linear polyethylene so as to make the core layer more resistant to deformation than the skin layers.

Abstract: The invention relates to a blown film coextrusion process. The process involves extruding core contact layers through a die exit at a specified speed and cooling, orienting and crystallizing the multi-layer film formed at a specified deformation rate to form a the frost line is a specified distance from the die exit by withdrawing film at a take up speed. The core and core contact layers are of a film forming polymer composition comprising at least 90 wt % of ethylene based polymer. The ethylene based polymer of the core layer has an average density of ethylene based polymers equal to or higher than that of ethylene based polymer of the core contact layers. The invention specifically concerns the feature that the core layer composition contains a portion of and the composition of the core contact layers contains a portion of a linear polyethylene so as to make the core layer more resistant to deformation than the skin layers.