Abstract Apparatus for and method of compacting thermoplastic materials such as expanded or foam polystyrene. The apparatus includes a hopper for receiving quantities of the material therein either as chunks or as a pulverulent mass; and in the case of large pieces or chunks, breaker mechanism is included in association with the hopper for reducing such chunks to smaller units. Compaction mechanism in communication with the outlet of the hopper provides heated rollers that engage the material and elevate the temperature thereof to the softening point, thereby enabling the material to fuse into a higher density mass; that reduce or restrict the thickness of the material to a dimension enabling relatively rapid heat transmission therethrough; and that deliver the fused mass in sheet-like form which may naturally accumulate in accordion-type folds or be further compacted by coiling the sheet into a generally cylindrical roll. The method includes heating a low density mass of thermoplastic foam material, restricting the thickness thereof essentially to a surface layer, and compressing the same at an elevated temperature into a higher density mass.
Apparatus for reducing a low density, thermoplastic foam material to a higher density mass thereof, comprising: frame structure; a receiver supported by said frame structure and having an inlet through which quantities of such low density material are admitted and an outlet through which material leaves; and compaction mechanism in communication with said outlet for receiving material therefrom and operative to concentrate such material into a higher density mass, said compaction mechanism including heater structure for heating such material to the softening temperature thereof, a pair of rollers having facing surface areas adapted to pass such heat softened material therebetween while compressing the same, drive mechanism for rotating said rollers, each of said rollers being equipped with a heating element effective to elevate the temperature of the cylindrical surface of said roller to provide said heater structure which heats a relatively thin layer of such material to the softening temperature thereof, the heating element with which each of said rollers is equipped extending substantially from end to end thereof, means associated with each of said rollers for supporting the associated heating element for thermal expansion and contractions in generally longitudinally directions, and electric connector means associated with each of said rollers for establishing electrical connection with the heating element thereof and effective to accommodate such longitudinal expansions and contractions thereof.
Claim 2
Dependent Claim
220 words
Apparatus for reducing a low density, thermoplastic foam material to a higher density mass thereof, comprising: frame structure; a receiver supported by said frame structure and having an inlet through which quantities of such low density material are admitted and an outlet through which material leaves; and compaction mechanism in communication with said outlet for receiving material therefrom and operative to concentrate such material into a higher density mass, said compaction mechanism including heater structure for heating such material to the softening temperature thereof, a pair of rollers having facing surface areas adapted to pass such heat softened material therebetween while compressing the same, drive mechanism for rotating said rollers, each of said rollers being equipped with a heating element effective to elevate the temperature of the cylindrical surface of said roller to provide said heater structure which heats a relatively thin layer of such material to the softening temperature thereof, the heating element with which each of said rollers is equipped extending substantially from end to end thereof, means associated with each of said rollers for supporting the associated heating element for thermal expansion and contractions in generally longitudinally directions, and electric connector means associated with each of said rollers for establishing electrical connection with the heating element thereof and effective to accommodate such longitudinal expansions and contractions thereof.