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AssigneeThe Dow Chemical Company
InventorsRalph E. Ayres, Kenneth J. Cleereman, Walter J. Schrenk
Estimating the term…
A scrap free process for rapidly making thermoplastic containers wherein the resultant containers can, if desired, be multilayered for vapor or gas barrier or other reasons, or be oriented for toughness and improved stress crack resistance. The containers can be formed from multilayered or homogeneous plastic sheets wherein a relatively thin thermoplastic blank is provided. This blank is lubricated, heated and forged into a desired shape preform with a predetermined lip configuration. The center portion of each said preform is maintained at a forming temperature while the peripheral portion thereof is rapidly brought below the softening point of the plastic resin. The preform is then immediately thermoformed into a container having a desired shape and size, and cooled. If desired, the preform can be forged, cooled and recovered from a subsequent thermoforming operation.
A biaxially oriented thermoplastic container having a molded lip about its periphery and formed from a biaxially oriented preform, said preform formed from an unexpanded thermoplastic blank, said container having a greater degree of biaxial orientation than said preform and improved strength due to the greater degree of orientation.
An oriented container formed from a high speed process comprising the steps of:
Dependencies are inferred from the claim text.