Solid state microcellular foaming method including continuous saturation of solid polymeric material
AssigneeDart Container Corporation
InventorMichael Waggoner
Life of this patent
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Abstract
A method for saturating a thermoplastic polymer material includes continuously moving the polymer material through a pressurized pressure vessel. To do this, the method includes sealing the pressure vessel with a series of dynamic seals that allows the polymer material to continuously move through the pressure vessel while maintaining the pressure inside the pressure vessel.
Claims20
A solid state microcellular foaming method that includes saturating a solid polymeric material with a pressurized inert gas in a pressure vessel, the method comprising:
- continuously passing the solid polymeric material through a first set of cascading seals fluidly sealing an inlet to the pressure vessel;
- exposing the solid polymeric material passing through an interior of the pressure vessel to the pressurized inert gas to form a saturated solid polymeric material, wherein the inert gas in the saturated solid polymeric material forms microcellular bubbles in the saturated solid polymeric material in a subsequent foaming stage;
- continuously passing the saturated solid polymeric material through a second set of cascading seals fluidly sealing an outlet to the pressure vessel;
- and
- operating a pressure regulation system to control the pressure across each of the first set of cascading seals, the second set of cascading seals, and the interior of the pressure vessel.
A solid state microcellular foaming method that includes saturating a sheet of solid thermoplastic polymeric material with a pressurized inert gas in a pressure vessel, the method comprising:
- continuously passing the sheet of solid thermoplastic polymeric material through a first set of cascading seals fluidly sealing an inlet to the pressure vessel;
- exposing the sheet of solid thermoplastic polymeric material passing through an interior of the pressure vessel to the pressurized inert gas to form a saturated sheet of solid thermoplastic polymeric material, wherein the inert gas in the saturated sheet of solid thermoplastic polymeric material forms microcellular bubbles in the saturated sheet of solid thermoplastic polymeric material in a subsequent foaming stage;
- continuously passing the saturated sheet of solid thermoplastic polymeric material through a second set of cascading seals fluidly sealing an outlet to the pressure vessel;
- and
- operating a pressure regulation system to control the pressure across each of the first set of cascading seals, the second set of cascading seals, and the interior of the pressure vessel.
A solid state microcellular foaming method that includes saturating a solid polymeric material with a pressurized inert gas in a pressure vessel, the method comprising:
- continuously passing the solid polymeric material through a first set of cascading seals fluidly sealing an inlet to the pressure vessel;
- exposing the solid polymeric material passing through an interior of the pressure vessel to the pressurized inert gas to allow continuous saturation and to form a saturated solid polymeric material, wherein the inert gas in the saturated solid polymeric material forms microcellular bubbles in the saturated solid polymeric material in a subsequent foaming stage;
- continuously passing the saturated solid polymeric material through a second set of cascading seals fluidly sealing an outlet to the pressure vessel;
- and
- operating a pressure regulation system to control the pressure across each of the first set of cascading seals, the second set of cascading seals, and the interior of the pressure vessel.
Dependencies are inferred from the claim text.