Method of separating paper and plastic pieces
AssigneeEsmil International B.V.
InventorArie Hoogendoorn
Life of this patent
Estimating the term…
Abstract
In an upward gas stream sifter for separating sheet-like pieces of paper and plastic in a wetted mixture, the gas is heated to at least 60.degree. C. in order to dry surface moisture on the plastic. The temperature of the gas is not so high that the plastic shrivels. This increases the difference in density between the pieces of plastic and wet paper, thus assisting the separation. Optionally some gas may enter the mixture feed duct through a gas permeable part of its wall, to prevent accumulation of mixture on the wall. If the mixture is derived from household rubbish and the plastic is mostly polyethylene the gas may enter the sifter at 120.degree. C. and leave it at about 70.degree. C.
Claims12
In a method of separating paper and plastics, in a wetted mixture consisting substantially of paper and plastic sheeting pieces, by use of an upwardly moving stream of gas moving along a flow path into which said path said wetted mixture is passed, said path having an upward end and a downward end,
- the improvement comprising:
- admitting a gas, for producing said upwardly moving stream of gas, into said path at an elevated temperature which is at least 60.degree. C. but is not so high that the plastic sheeting deforms through the action of heat, and
- employing said gas to effect at least partial drying of said plastic sheeting pieces such that separation will be improved, by a downward movement of said paper in said upwardly moving stream of gas and by upward movement of said plastic sheeting pieces in said upwardly moving stream of gas due to the enhanced differences in densities of said paper and said plastic sheeting.
A method of separating pieces of plastics material from pieces of paper in a wetted mixture consisting substantially entirely of sheet shaped pieces of paper and plastics material in which:
- (a) a stream of gas moves upwardly along a path from a downward end to an upward end, the temperature of the gas at the downward end being at least 60.degree. C. but not so high that the said sheet shaped pieces of plastics material deform through the action of heat;
- (b) the said mixture is passed into the path of the said upwardly moving stream;
- (c) said paper sheet shaped pieces from said mixture fall downwardly through the said upwardly moving stream and are removed from the stream at the downward end thereof;
- (d) said plastic sheet shaped pieces from said mixture are carried upwardly by the said upwardly moving stream of gas past the upward end of the path and are subsequently separated from the gas stream.
Dependencies are inferred from the claim text.