초록 ▼

The vessel portion of a gas-tight container suitable for packaging fresh foods is produced as a composite of paperboard and polymer film. A pair of folded paperboard blanks, pre-cut and pre-formed, are inserted into the opposite halves of split mold elements to a blow molding machine. Vacuum orifice

The vessel portion of a gas-tight container suitable for packaging fresh foods is produced as a composite of paperboard and polymer film. A pair of folded paperboard blanks, pre-cut and pre-formed, are inserted into the opposite halves of split mold elements to a blow molding machine. Vacuum orifices in each mold half unit temporarily secure the position of a respective paperboard blank. The paperboard lined mold halves are closed upon a hot, extruded parison of malleable polymer leaving an end portion of the parison tube projecting from the closed mold unit. A fluid conducting needle penetrates this projected end portion to inflate the parison with an appropriate blowing gas. Such inflation expands the malleable polymer, seamlessly and creaselessly, into the internal corners and crevices of the folded paperboard blanks. Following chilling, the mold unit is opened and the pair of paperboard flanks are ejected as a singular unit, joined by a molded flange portion of the continuous polymer film. Finally, the two polymer coated paperboard vessels are separated by trimming about the flange.

대표청구항 ▼

A blow molded composite material fluid container comprising a paperboard exterior substrate having a thickness of 0.007 to 0.035 inches formed to a fluid containment configuration having an interior vessel surface area, said formed paperboard substrate having a seamless, creaseless and unlapped flui

A blow molded composite material fluid container comprising a paperboard exterior substrate having a thickness of 0.007 to 0.035 inches formed to a fluid containment configuration having an interior vessel surface area, said formed paperboard substrate having a seamless, creaseless and unlapped fluid barrier coating of blow molded polymer integrally bonded to substantially the entire vessel surface area thereof, said barrier coating having an average thickness about half of said paperboard thickness.