Method for reclaiming waste thermoplastic resin film

Claim 1

A method of cleaning soiled, thermoplastic resin, waste film, which comprises the steps of cutting a mass of said soiled, thermoplastic resin, waste film to provide a mass of pieces of said waste film, which pieces are deformed and contain soil distributed thereon and adhering thereto; feeding said mass of pieces onto one end of the upper surface of an elongated, mesh conveyor which conveyor is disposed within a washing tank filled with heated aqueous cleaning liquid and is moving substantially horizontally therein whereby said pieces are immersed in said liquid, simultaneously supplying a first quantity of said liquid from outside said tank into said tank adjacent to said one end of said conveyor and forcibly directing said heated aqueous cleaning liquid in said tank in a direction lengthwise of said conveyor from said one end thereof toward the opposite end thereof whereby said liquid assists said conveyor in moving said pieces toward the opposite end of said conveyor, simultaneously directing into said tank jets of a second quantity of said liquid supplied from outside said tank, said jets being located above the upper surface of said conveyor close to but upstream of the opposite end of said conveyor, said jets being directed above the upper surface of said conveyor in a direction lengthwise of and opposite to the direction of movement of said conveyor, and simultaneously applying ultrasonic energy to said liquid from positions located longitudinally of said conveyor between said jets and said one end of said conveyor, said positions being opposed to each other and being located on opposite lateral sides of and above the upper surface of said conveyor so that said ultrasonic energy is directed laterally inwardly and across the upper surface of said conveyor substantially at right angles to the direction of movement thereof, said liquid being at a temperature sufficient to soften said pieces and to remove soil therefrom while said pieces are being subjected to said ultrasonic energy so as to be beaten thereby, to smooth the deformations thereof and to assist in removing soil therefrom; discharging said pieces from said tank at the opposite end of said conveyor and then washing said pieces with pressurized water.

Claim 2

A method of cleaning soiled, thermoplastic resin, waste film, which comprises the steps of cutting a mass of said soiled, thermoplastic resin, waste film to provide a mass of pieces of said waste film, which pieces are deformed and contain soil distributed thereon and adhering thereto; feeding said mass of pieces onto one end of the upper surface of an elongated, mesh conveyor which conveyor is disposed within a washing tank filled with heated aqueous cleaning liquid and is moving substantially horizontally therein whereby said pieces are immersed in said liquid, simultaneously supplying a first quantity of said liquid from outside said tank into said tank adjacent to said one end of said conveyor and forcibly directing said heated aqueous cleaning liquid in said tank in a direction lengthwise of said conveyor from said one end thereof toward the opposite end thereof whereby said liquid assists said conveyor in moving said pieces toward the opposite end of said conveyor, simultaneously directing into said tank jets of a second quantity of said liquid supplied from outside said tank, said jets being located above the upper surface of said conveyor close to but upstream of the opposite end of said conveyor, said jets being directed above the upper surface of said conveyor in a direction lengthwise of and opposite to the direction of movement of said conveyor, and simultaneously applying ultrasonic energy to said liquid from positions located longitudinally of said conveyor between said jets and said one end of said conveyor, said positions being opposed to each other and being located on opposite lateral sides of and above the upper surface of said conveyor so that said ultrasonic energy is directed laterally inwardly and across the upper surface of said conveyor substantially at right angles to the direction of movement thereof, said liquid being at a temperature sufficient to soften said pieces and to remove soil therefrom while said pieces are being subjected to said ultrasonic energy so as to be beaten thereby, to smooth the deformations thereof and to assist in removing soil therefrom; discharging said pieces from said tank at the opposite end of said conveyor and then washing said pieces with pressurized water.