Reduced cuffing in blow molding processes
AssigneeExxonMobil Chemical Patents Inc.
InventorsEric R. Smith, Clyde J. Bohne
Life of this patent
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Abstract
Defects in a blow molding process are reduced or eliminated by providing a small amount of a low molecular weight polyethylene glycol to the composition blow molded.
Claims23
A process of manufacturing a blow molded article comprising:
- (a) blow molding a first composition comprising a first polyethylene into a shaped article;
- (b) perceiving parison cuffing defects in said process or said blow molded article;
- (c) providing to said process a second polyethylene having a lower melt index than said first polyethylene, measured according to ASTM D-1238, and having incorporated therein a small amount of a low molecular weight polyethylene glycol;
- and
- (d) blow molding the composition comprising said second polyethylene into an article.
A process of manufacturing a blow molded article comprising:
- (a) blow molding a first composition comprising a first polyethylene into a shaped article;
- (b) perceiving parison cuffing defects in said process or said blow molded article;
- (c) selecting at least one second polyethylene from HDPE homopolymers having a melt index of from about 0.25 to about 0.80 grams/10 minutes measured according to ASTM D-1238, and having incorporated therein a small amount of a low molecular weight polyethylene glycol and an effective amount of an antioxidant;
- and
- (d) blow molding the composition comprising said second polyethylene into an article.
A method of reducing cuffing in the blow molding of a composition comprising HDPE, said method comprising incorporating a small amount of a low molecular weight polyethylene glycol in said composition prior to blow molding to provide a new composition and then blow molding said new composition, wherein said new composition does not contain a fluorocarbon polymer, phosphate, or stearate.
A method of manufacturing a blow molded article comprising the steps of:
- a. providing a first HDPE having a first melt index in a blow molding process and blow molding said first HDPE into an article;
- b. detecting unacceptable cuffing in said process;
- c. transitioning from said first HDPE in said process to a composition comprising a second HDPE having a second melt index and having incorporated therein a small amount of a low molecular weight polyethylene glycol, wherein said second melt index is lower than said first melt index, measured according to ASTM D-1238;
- and
- d. blow molding the composition comprising said second HDPE into an article.
Dependencies are inferred from the claim text.