Patent ID: 8568125

Claim:
A thermoforming system, comprising: an oven system for continuously generating a sheet of microcellular foamed material from a sheet of gas-impregnated thermoplastic material by heating the sheet of gas-impregnated thermoplastic material and allowing the sheet to expand unconstrained to at least 1.25 times its area, the oven system comprising: an oven chamber having an entrance opening and an exit opening, a plurality of downwardly directed air nozzles disposed in the oven chamber, that, while the material moves from the entrance opening toward the exit opening, expels hot air to suspend the material in the oven chamber, and heats the material to a temperature that causes the gas in the material to form bubbles, a plurality of upwardly directed air nozzles disposed in the oven chamber, that, while the material moves from the entrance opening toward the exit opening, expels hot air to suspend the material in the oven chamber, and heats the material to a temperature that causes the gas in the material to form bubbles; a thermoformer assembly for sequentially thermoforming subsequently adjacent portions of the sheet of the microcellular foamed material generated in the oven system; and an accumulation system for collecting the microcellular foamed material leaving the exit opening of the oven chamber before the microcellular foamed material enters the thermoformer assembly, the accumulation system comprising: an enclosure disposed between the oven system's exit opening and the thermoformer assembly and attached to the oven system, the enclosure having an interior; a nip roller, disposed in the interior and adjacent the oven system's exit opening, for tensioning the gas-impregnated thermoplastic material as the material moves through the oven chamber; another nip roller, disposed in the interior and adjacent the thermoformer assembly; and a heater for keeping the microcellular foamed material warm in the enclosure's interior.