Method and apparatus for recovery of plastics and non-plastics from plastic-coated waste material

Claim 2

In a method for recovering from plastic-coated cellulosic waste material both the plastic and the cellulosic components thereof, the steps of wet-pulping the waste material to form a water suspension of cellulosic fibers and plastic materials, transferring the latter water suspension into a diluting tank and diluting the water suspension in the latter tank with additional water to an extent sufficient for floating most of the plastic material to the upper region of the diluted suspension in which the cellulosic material and a small part of the plastic material remain beneath the floating plastic material, mechanically raising the floating plastic material up out of the diluted suspension to leave the cellulosic and residual plastic materials therein with most of the plastic material separated therefrom by being mechanically raised out of the diluted suspension, transferring the diluted suspension to a further tank, and separating the residual plastic from the cellulosic material in the diluted suspension in the latter tank.

Claim 3

In a method as recited in claim 1 and wherein the plastic is a material selected from the group consisting of polyolephinic resins, polyvinyl chloride resins, and polyester resins.

Claim 4

In a method as recited in claim 1 and wherein the plastic material is maintained in the dilution tank in a fragmented form in which the plastic particles are larger than the cellulosic fibres.

Claim 5

In a method as recited in claim 3 and wherein the floating of the plastic material in the diluted suspension is accompanied by stirring of the latter suspension.

Claim 6

In a method as recited in claim 4 and wherein the water suspension resulting from the wet-pulping has a solid content of 5-10%, while the diluted suspension in which the plastic is floated has a solid content of 0.7-1.3%.

Claim 7

In a method as recited in claim 3 and wherein the water suspension resulting from wet-pulping has a solid content of over 8% while the diluted suspension in which the plastic is floated has a solid content of 0.7-1.3%.

Claim 8

In a method as recited in claim 1 and wherein subsequent to the removal of the plastic material from the suspension in which it floats the plastic material is screened and washed.

Claim 9

In an apparatus for recovering both plastic and non-plastic materials from plastic-coated waste material, wet-pulping means for forming a suspension from the waste material, dilution tank means situated beneath said wet-pulping means for receiving the suspension therefrom so that the latter suspension can be diluted in the dilution tank means to float the plastic material in the diluted suspension, valve means situated at the lower region of said wet-pulping means for providing a gravitational flow of the suspension from the wet-pulping means to the dilution-tank means, conveyor means in the form of a screen extending at an incline into the dilution tank means for raising the floating plastic material up out of the latter, first receiving means situated beneath said conveyor means for receiving the plastic material therefrom and for further treating the plastic material, second receiving means situated beneath said dilution tank means for receiving the diluted suspension therefrom, and means in said second receiving means for separating residual plastic material out of the diluted suspension in said second receiving means.

Claim 10

In an apparatus for recovering both plastic and non-plastic materials from plastic-coated waste material, wet-pulping means for forming a suspension from the waste material, dilution tank means situated beneath said wet-pulping means for receiving the suspension therefrom so that the latter suspension can be diluted in the dilution tank means to float the plastic material in the diluted suspension, valve means situated at the lower region of said wet-pulping means for providing a gravitational flow of the suspension from the wet-pulping means to the dilution-tank means, conveyor means in the form of a screen extending at an incline into the dilution tank means for raising the floating plastic material up out of the latter, first receiving means situated beneath said conveyor means for receiving the plastic material therefrom and for further treating the plastic material, second receiving means situated beneath said dilution tank means for receiving the diluted suspension therefrom, and means in said second receiving means for separating residual plastic material out of the diluted suspension in said second receiving means.

Claim 11

In an apparatus for recovering both plastic and non-plastic materials from plastic-coated waste material, wet-pulping means for forming a suspension from the waste material, dilution tank means situated beneath said wet-pulping means for receiving the suspension therefrom so that the latter suspension can be diluted in the dilution tank means to float the plastic material in the diluted suspension, valve means situated at the lower region of said wet-pulping means for providing a gravitational flow of the suspension from the wet-pulping means to the dilution-tank means, conveyer means in the form of a screen extending at an incline into the dilution tank means for raising the floating plastic material up out of the latter, first receiving means situated beneath said conveyor means for receiving the plastic material therefrom and for further treating the plastic material, second receiving means situated beneath said dilution tank means for receiving the diluted suspension therefrom, and means in said second receiving means for separating residual plastic material out of the diluted suspension in said second receiving means, said first receiving means including a tank into which the plastic material drops from said conveyer means and a rotary cylindrical screen which is inclined with respect to a horizontal plane and has a lower end extending into the tank of said first receiving means, said rotary cylindrical screen having in its interior a screw conveyor for conveying the plastic material upwardly along the interior of the rotary screen, said lower end of said rotary cylindrical screen being open at least to an extent sufficient to receive plastic material in said rotary cylindrical screen through said lower end thereof to be conveyed upwardly along the interior of said rotary cylindrical screen by said screw conveyer.

Claim 12

In an apparatus for recovering both plastic and non-plastic materials from plastic-coated waste material, wet-pulping means for forming a suspension from the waste material, dilution tank means situated beneath said wet-pulping means for receiving the suspension therefrom so that the latter suspension can be diluted in the dilution tank means to float the plastic material in the diluted suspension, valve means situated at the lower region of said wet-pulping means for providing a gravitational flow of the suspension from the wet-pulping means to the dilution-tank means, conveyer means in the form of a screen extending at an incline into the dilution tank means for raising the floating plastic material up out of the latter, first receiving means situated beneath said conveyor means for receiving the plastic material therefrom and for further treating the plastic material, second receiving means situated beneath said dilution tank means for receiving the diluted suspension therefrom, and means in said second receiving means for separating residual plastic material out of the diluted suspension in said second receiving means, said first receiving means including a tank into which the plastic material drops from said conveyer means and a rotary cylindrical screen which is inclined with respect to a horizontal plane and has a lower end extending into the tank of said first receiving means, said rotary cylindrical screen having in its interior a screw conveyor for conveying the plastic material upwardly along the interior of the rotary screen, said lower end of said rotary cylindrical screen being open at least to an extent sufficient to receive plastic material in said rotary cylindrical screen through said lower end thereof to be conveyed upwardly along the interior of said rotary cylindrical screen by said screw conveyer.

Claim 13

The combination of claim 9 and wherein a spray means is situated in the rotary cylindrical screen for spraying the plastic material conveyed therein.

Claim 14

The combination of claim 10 and wherein said second receiving means is identical with the first receiving means and includes said separating means which is in the form of a rotary cylindrical screen identical with that of said first receiving means for separating in the tank of said second receiving means the residual plastic from the diluted suspension in the latter tank.

Claim 15

The combination of claim 11 and wherein a pair of dilution tank means and a pair of screen conveyers respectively cooperating therewith are situated on the one hand beneath said wet-pulping means and on the other hand over the tanks of said receiving means, with said wet-pulping means having a pair of valve means for alternately delivering the suspension from said wet-pulping means to the dilution tank means.