Electrostatic separation of plastic film from shredded waste

Claim 1

A waste separation system adapted for separation of processed shredded waste comprising light shredded plastic materials and shredded waste paper, the system comprising: (a) means having a shredded waste separation chamber and providing a generally vertically oriented passageway through which the shredded waste descends; (b) shredded waste feed means positioned to deliver into the top of the passageway; (c) rotating plastic separating means disposed on a generally vertical axis and having a surface area portion exposed to said passageway through an aperture in said waste separation chamber; (d) electrostatic charging means connected to said rotating means for imparting an electrostatic charge to said surface area portion of said rotating plastic separating means to separate and attract to said area and retain shredded plastic waste from the shredded waste paper; (e) means for removing the separated plastic waste from said surface area portion; (f) means located within said passageway adjacently below said shredded waste feed means and operating to effect spreading of the descending shredded waste within said chamber passageway; (g) means below said spreading means for effecting swirling circulation movement of the descending shredded waste to enhance contact of the shredded waste with said surface area portion; wherein said spreader means comprise a conical spreader having spreader promoting means thereon, and said swirling movement effecting means comprise a vertical series of paddles, a shaft supporting said spreader and said paddles, and means for rotatably driving the shaft to effect rotation of the spreader and the paddles.

Claim 13

A method for separating shredded plastic material from processed shredded waste paper, comprising: (a) depositing processed shredded waste paper having shredded plastic mixed therewith into the upper end of a waste separation tower passageway; (b) continuously swirling a shower of the descending shredded waste in said passageway; (c) rotating a separator on a substantially vertical axis; (d) exposing a surface area portion of the separator in exposed relation to the shredded waste swirling in said passageway, effecting attachment of the shredded plastic to said surface area and thereby separating the plastic from the shredded waste paper; (e) cleaning the plastic from the surface area portion separately from removal of the separated shredded waste paper from said passageway; and (f) effecting spreading of the shredded waste paper as it is deposited in the top of said passage, and subjecting the descending shredded waste paper and plastic to a combination of biasing air and mechanical stirring and thereby promoting separating exposure of the shredded plastic to said surface area portion.

Claim 14

A method for separating shredded plastic material from processed shredded waste paper, comprising: (a) depositing processed shredded waste paper having shredded plastic mixed therewith into the upper end of a waste separation tower passageway; (b) continuously swirling a shower of the descending shredded waste in said passageway; (c) rotating a separator on a substantially vertical axis; (d) exposing a surface area portion of the separator in exposed relation to the shredded waste swirling in said passageway, effecting attachment of the shredded plastic to said surface area and thereby separating the plastic from the shredded waste paper; (e) cleaning the plastic from the surface area portion separately from removal of the separated shredded waste paper from said passageway; and (f) effecting spreading of the shredded waste paper as it is deposited in the top of said passage, and subjecting the descending shredded waste paper and plastic to a combination of biasing air and mechanical stirring and thereby promoting separating exposure of the shredded plastic to said surface area portion.