Orientation of films to improve barrier and UV stability

A method of wrapping a material, object or objects, to create an anaerobic atmosphere within a wrapping envelope, said method including providing a relaxed plastics material film with a decreased oxygen permeability uniformly across a transverse cross-section of said film, said film being pre-stretched at atmospheric temperature biaxially beyond its yield point to increase its length and width and decrease its thickness, the transverse cross-section being transverse to a longitudinal stretching direction, and said film being relaxed in the transverse direction and also substantially uniformly relaxed across the transverse cross-section in said longitudinal stretching direction by between 5 and 20% of said plastic material film's total stretched length, and applying said plastics material film to be wrapped in at least one layer with at least sufficient applied further tension to form said wrapping envelope with an anaerobic atmosphere therewithin.

A method of making silage, including providing a bale of silage making material, forming a wrapping envelope about said bale utilising a partially relaxed plastics material film with a decreased oxygen permeability uniformly across a transverse cross-section of said film, said film being pre-stretched at atmospheric temperature biaxially beyond its yield point to increase its length and width and decrease its thickness, the transverse cross-section being transverse to a longitudinal stretching direction, and said film being relaxed in the transverse direction and also substantially uniformly relaxed across the transverse cross-section in said longitudinal stretching direction by between 5 and 20% of said film's total stretched length, and applying said plastics material film to be wrapped in at least one overlapping layer to form said wrapping envelope with an anaerobic atmosphere therewithin.

A method of making silage, including providing a bale of silage making material, providing a plastics material film having a longitudinal direction and a transverse direction, said film having been uniformly pre-stretched at atmospheric temperature in the longitudinal direction beyond the film's yield point to increase the film's length and width and decrease the film's thickness, the film being relaxed in the transverse direction and also substantially relaxed across the transverse cross-section in said longitudinal direction by between 5 and 20% of said film's total pre-stretched length, forming a wrapping envelope about said bale utilising said pre-stretched and partially relaxed film by wrapping said plastics film about said bale while exerting a secondary stretch in the longitudinal direction of said plastics film to further increase the film's length and decrease the film's thickness such that said plastics film is arranged in at least one overlapping layer to form said wrapping envelope and exhibits both a decreased oxygen permeability across the plastics film traverse width and an improved resistance to degradation from UV light radiation uniformly across the plastics film transverse width.