Patent ID: 8945459
Filing Date: 2015-02-03
Classification: B29C

Abstract:
1. A method for expanding a preform made from plastic film to form a container, the preform having a longitudinal axis that extends from an open top to a closed bottom, the method comprising: pressurizing the preform with a first pressure sufficient to cause side walls of the preform to expand outwardly to increase a width of the preform transversely to the longitudinal axis, and to cause the bottom of the preform to be drawn inwardly to reduce the length of the preform along the longitudinal axis; closing side molds around the side walls of the preform; closing a bottom mold to adjoin or be adjacent to the inwardly drawn bottom of the preform after pressurizing the preform with the first pressure and thereby forming a mold cavity having a length that is substantially the same as the reduced length of the of the preform; and pressurizing the preform with a second pressure sufficient to stretch the plastic film and expand the preform to fill the closed molds and thereby providing the expanded preform with a length that is not substantially greater than the reduced length of the preform.