| 摘要 |
This invention relates to an improved shrink film obtained by selectively controlling and optimizing the melt index and density differential between at least two polyolefin polymer components to provide narrow density splits. One aspect of this invention relates to a biaxially oriented polyolefin shrink film having balanced properties and another aspect of this invention relates to an oriented shrink film having improved toughness. This invention also relates to a biaxial orientation method of making an improved shrink film using elaborate shrink orientation techniques such as tenter framing, double-bubble, trapped bubble, tape orientation or combination thereof. Most preferably, the first polyolefin polymer component is a lower density, substantially linear ethylene/alpha-olefin interpolymer and the second polyolefin polymer component is a higher density, heterogeneously branched ethylene/alpha-olefin interpolymer. |
