Ethylene/alpha-olefin interpolymer resins that can make films with improved optical properties (haze, gloss, and/or clarity), puncture properties, and high shrinkage (shrink tension or % free shrink) create high value especially for shrink films, such as collation shrink films. Additionally, a high modulus is advantageous. It is difficult to obtain a balance of these properties with one resin. For instance, high shrinkage may be obtained by a very high molecular weight. This high molecular weight, however, often results in poor optical properties as very high molecular weight materials tend to be highly elastic and upon extrusion create a high surface roughness on the film leading to lower optical properties. Another example is that generally to increase the modulus the density is increased. When the density is increased, however, the puncture properties generally decrease.
The ethylene/alpha-olefin interpolymer of the present invention provides good properties (such as optical, puncture, shrinkage, and modulus) without any one of such properties being negatively impacted.