Polypropylene container and process for making the same
AssigneeBall Corporation
InventorsGuy Richards, A. B. M. Bazlur Rashid, Robert W. Knoll, Sahin Emre, Kevin James Curie, Randolph Lee Davidson
Life of this patent
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Abstract
A multilayer plastic container comprises a layer of a polypropylene and an intermediate layer directly adjacent the layer of polypropylene wherein at least one of the polypropylene and intermediate layers comprises an adhesive such as maleic anhydride incorporated therein to adhere the layer of polypropylene to the layer of EVOH.
Claims18
A method of manufacturing a container, the method comprising:
- (a) providing a preform comprised of at least 90% polypropylene and having a finish and a preform blow section, the preform blow section having a neck extending from the finish, a sidewall extending from the neck and a base closing the blow section, the base having a portion of increased thickness defining a thickness greater than all other portions of the blow section, the base being located inward of the sidewall;
- (b) inducing radial stretching of the preform blow section to produce an average radial stretch ratio of less than approximately 4.5:1;
- (c) inducing axial stretching of the preform blow section to produce an average axial stretch ratio of less than approximately 1.6:1;
- and
- (d) conforming the preform to a mold having at least a neck, a sidewall extending from the neck and a base;
- wherein the portion of increased thickness does not contact the sidewall of the mold during the axial or radial stretching of the preform.
A method of manufacturing a container comprising at least 90% polypropylene, the method comprising:
- (a) providing a preform having a finish and a preform blow section, the preform blow section having a neck extending from the finish, a sidewall extending from the neck and a base closing the blow section, the base having a portion of increased thickness defining a thickness greater than all other portions of the blow section, the base being located inward of the sidewall;
- (b) heating the preform;
- (c) inducing radial stretching of the preform to produce an average radial stretch ratio of less than approximately 4.5:1;
- and
- (d) inducing axial stretching of the preform to produce an average axial stretch ratio of less than approximately 1.6:1.
A method of manufacturing a container, the method comprising:
- (a) providing a preform having a first layer comprising polypropylene and an adhesive in an amount of up to approximately 0.20% by weight, and a second layer comprising a barrier material, the adhesive bonding the first layer bonded directly to the second layer, the preform having a finish and a preform blow section, the preform blow section having a neck extending from the finish, a sidewall extending from the neck and a base closing the blow section, the base having a portion of increased thickness defining a thickness greater than all other portions of the blow section, the base being located inward of the sidewall and the portion of increased thickness does not cover a longitudinal axis of the preform;
- (b) heating the preform;
- (c) inducing radial and axial stretching of the preform to conform the preform to a mold.
Dependencies are inferred from the claim text.