Patent ID: 8182733

Claim:
A method for the preparation of a molded article formed of an olefin polymer comprising: a) providing a molding feedstock comprising a particulate α-olefin polymer composition, wherein the particulate olefin polymer is selected from ethylene homopolymers, propylene homopolymers, or copolymers of ethylene or propylene and C 2 -C 8 olefin polymers; b) providing a densification aid comprising polyethylene glycol, c) introducing said olefin polymer composition and said densification aid in an amount of less than 1 weight percent based upon the amount of said olefin polymer into a mold cavity configured to provide a mold of a desired shape; d) heating said olefin polymer composition in the presence of said densification aid in said mold cavity to a temperature sufficient to provide a molten state to form a molded article configured to the shape of said mold cavity, wherein the mold is rotated during the heating of said olefin polymer to a molten state; e) thereafter cooling said molten polymer composition within the confines of said mold cavity to a temperature effective to solidify said olefin polymer composition within the confines of said mold cavity; and f) retrieving said solidified molded article from said mold cavity, wherein subsequent to the introduction of said olefin polymer composition and said densification additive into said mold cavity, said polymer is heated to a sintering temperature in which individual particles of said olefin polymer are coaleased followed densification of said molten polymer and the increase of the temperature in said mold cavity to a peak internal air temperature within said mold cavity followed by the cooling of said mold cavity to a crystallization temperature for the solidification of said molten polymer to produce said molded article wherein the peak internal air temperature within said mold cavity to produce a designated number of air bubbles within said molten polymer is reduced by an increment of at least 10° C. from the peak internal air temperature required to produce the designated number of air bubbles for a polymer molded under identical conditions without the introduction of said densification aid into said mold cavity.