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Method and apparatus for producing sealed and filled containers

  • US 5,090,180 A
  • Filed: 10/03/1990
  • Issued: 02/25/1992
  • Est. Priority Date: 12/29/1988
  • Status: Expired due to Fees
First Claim
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1. A method of producing a sealed and filled container comprising providing a preform of crystallizable plastic material having a body, a closed bottom portion and an open mouth portion, filling the preform with goods to be sealed therein, applying a mechanical forming and thermocrystallizing tool against the closed bottom portion of the preform, with pressure, to reshape the bottom portion of the preform by displacing at least a part of the bottom portion of the preform inwardly of the body towards the open mouth of the preform, heating the tool at the surface thereof applied against the bottom portion of the preform to raise the temperture of said bottom portion to a value greater than the glass transition temperature (Tg) of the plastic material, maintaining contact of the heated tool with the bottom portion during its reshaping for a length of time sufficient for the plastic material to obtain thermocrystallization of at least 15% at least at the surface in contact with said tool, the thermocrystallization of the bottom portion causing strengthening of said bottom portion and mechanical stability in its reshaped state to resist deformation and relatively high tempertures, and sealing said open mouth portion to produce a sealed and filled container.

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