| abstract |
A low density opaque polymer film containing at least one layer having a propylene polymer matrix that has been cavitated by a two component cavitation system, wherein the first component of the two component cavitation system is a beta-nucleating agent to produce the beta-crystalline form of polypropylene, and the second component is filler. A method of manufacturing a low density cavitated opaque polymer film, including: forming a melt containing a propylene polymer, a beta nucleating agent and filler; cooling the melt to form a film layer; and stretching the film layer to form voids therein. The cavitated opaque film has a density falling within the range of 0.2 g/cm 3 to 0.45 g/cm 3 . |