abstract |
A shrink film comprising a biaxially oriented polymer film comprising polypropylene having a machine direction shrinkage and a transverse direction shrinkage that is less than or equal to 50% of the machine direction shrinkage, and wherein the machine direction shrinkage is greater than 15% and the transverse direction shrinkage is less than 10% at about 140 DEG C. The shrink film is formed by a process comprising subjecting a biaxially oriented polymer film to a treatment which comprises the heating the film to a temperature of about 100 DEG C. to 180 DEG C. The heated film is drawn under conditions to extend it by at least 1.05 times its original length in the machine direction. The drawn film is cooled under tension to produce a shrink film having the specified ratio between the machine direction shrinkage and the transverse direction shrinkage in addition to having a kinetic film-to-film coefficient of friction of about 0.05 to 0.40. The shrink film is suitable for wrapping contoured articles. |