Polymer compositions, articles made from such compositons, and methods for molding such compositions
AssigneeMilliken & Company
InventorsJohn D. Price, Nathan A. Mehl
Life of this patent
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Abstract
A polymer composition comprises a thermoplastic polymer, a polymer additive selected from the group consisting of nucleating agents, clarifying agents, and combinations thereof, and a fluoropolymer. A molded article comprises at least one wall defining a cavity, the wall having an opening therein permitting access to the cavity. The wall comprises a polymer composition comprising a thermoplastic polymer, a polymer additive selected from the group consisting of nucleating agents, clarifying agents, and combinations thereof, and a fluoropolymer. A method for molding a polymer composition is also provided.
Claims24
A polymer composition comprising:
- (a) a thermoplastic polymer;
- (b) a polymer additive selected from the group consisting of nucleating agents, clarifying agents, and combinations thereof;
- and
- (c) a fluoropolymer, the fluoropolymer having a Melt Flow Index of about 4 to about 30 g/10 minutes as measured in accordance with ASTM D1238-04c at 265° C. using a 5 kg weight.
A method for molding a polymer composition, the method comprising the steps of:
- (a) providing an apparatus comprising a die and a mold cavity, the mold cavity having an interior surface defining a shape for a molded article;
- (b) providing a polymer composition comprising (i) a thermoplastic polymer;
- (ii) a polymer additive selected from the group consisting of nucleating agents, clarifying agents, and combinations thereof;
- and (iii) a fluoropolymer, the fluoropolymer having a Melt Flow Index of about 4 to about 30 g/10 minutes as measured in accordance with ASTM D1238-04c at 265° C. using a 5 kg weight;
- (c) heating the polymer composition to a temperature sufficient to melt the polymer composition so that it may be extruded through the die;
- (d) extruding the molten polymer composition through the die to form a parison;
- (e) capturing the parison in the mold cavity;
- (f) blowing a pressurized fluid into the parison under sufficient pressure to inflate the parison so that it conforms to the interior surface of the mold cavity and produces a molded article;
- (g) allowing the molded article to cool to a temperature at which the polymer composition at least partially solidifies so that the molded article retains its shape;
- and
- (h) removing the molded article from the mold cavity.
Dependencies are inferred from the claim text.