Method of forming a container
AssigneeDiscma AG
InventorsRobert A. Cooper, Theodore F. Eberle, G. David Lisch, Kirk Edward Maki
Life of this patent
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Abstract
A method of forming a plastic container from a preform. The method comprises injecting a forming liquid into the preform at a predetermined system pressure range, a predetermined flow rate, and a predetermined duration sufficient to create a pressure spike at a peak pressure. The peak pressure being greater than the system pressure to urge the preform into the mold cavity, thus creating enhanced container definition, reduced post mold shrinkage, lower residual material stresses, and/or an improved transfer of the mold geometry and engraving to the final formed container.
Claims26
A method of forming a plastic container from a preform, the method comprising:
- injecting a forming liquid into the preform at a predetermined system pressure range, a predetermined flow rate range, and for a first predetermined duration range sufficient to create a hydraulic shock and a pressure spike at a peak pressure as a result of the hydraulic shock, said peak pressure being greater than said system pressure range and urging the preform into a mold cavity to form the plastic container;
- and
- maintaining a holding pressure within the plastic container for a second predetermined duration range after said injecting a forming liquid, said holding pressure being less than said peak pressure.
A method of forming a plastic container from a preform, the method comprising:
- pressurizing a system with fluid to a first predetermined system pressure;
- forming and filling the container with said fluid to create a hydraulic shock and at a second predetermined system pressure wherein said fluid is urged into said container thereby forming said container against a mold cavity;
- maintaining said second predetermined system pressure constant for a duration sufficient to harden and cool the container;
- and
- depressurizing said system from said second predetermined system pressure to said first predetermined system pressure;
- wherein said second predetermined system pressure is created in response to the hydraulic shock.
A method of forming a plastic container from a preform, the method comprising:
- injecting a forming liquid into the preform at a predetermined system pressure range, a predetermined flow rate range, and for a first predetermined duration range sufficient to create a hydraulic shock and a pressure spike at a peak pressure as a result of the hydraulic shock, said peak pressure being greater than said system pressure range and urging the preform into a mold cavity to form the plastic container, said injecting of said forming liquid and said resulting pressure spike defining a pressure profile curve having a predetermined pressure increase rate;
- and
- maintaining a holding pressure within the plastic container for a second predetermined duration range after said injecting a forming liquid, said holding pressure being less than said peak pressure.
Dependencies are inferred from the claim text.