Patent ID: 8158052
Filing Date: 2012-04-17
Classification: B29B,B29C,B29K,B29L,B32B,B65D,Y10T

Abstract:
1. 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.