Patent US4379748A successfully refreshed from Google Patents.
US4379748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of separating paper and plastic pieces
Assignee: ESMIL INTERNATIONAL BV
•
Filing: 1981-02-09
•
Granted: 1983-04-12
•
Expires: 2001-02-09
Abstract
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° 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° C. and leave it at about 70° C.
Inventors
- 👤 Arie Hoogendoorn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:31
CPC Classifications
D; D21; D21B; D21B1/00; D21B1/02; D21B1/026; D21B1/028; B; B03; B03B; B03B9/00; B03B9/06; B03B9/061; B07; B07B; B07B11/00; B07B11/02; B07B4/00; B07B4/02; B07B4/04; B29; B29B; B29B17/00; B29B17/02; B29B2017/0213; B29B2017/0217; B29B2017/0234; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2711/00; B29K2711/12; B29L; B29L2007/00; B29L2007/008; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/52; Y02W30/62; Y10; Y10S; Y10S423/00; Y10S423/18
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
160 words
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° 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.
Claim 2
Dependent Claim
160 words
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° 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.
Claim 3
Dependent Claim
43 words
A method according to claim 1 wherein the pieces of paper in the said wetted mixture, before entering said upwardly moving stream of gas, have a moisture content of at least 35% by weight moisture of the total weight of paper and moisture.
Claim 4
Dependent Claim
86 words
A method according to claim 1 or claim 2 wherein introducing said gas, for producing said upwardly moving stream of gas, at said lower end of said path at a level below the level of introduction of said wetted mixture of paper and plastic, establishing generally upward flow of said gas, for producing said upwardly moving stream of gas, from said downward end to said upward end, and recirculating a portion of said upwardly moving stream of gas from said upward end to said downward end.
Claim 5
Dependent Claim
53 words
A method according to claim 3 wherein the said wetted mixture is passed into the path through a feed duct intermediate said upward end and said downward end, and said gas, for producing said upwardly moving stream of gas, is supplied to said feed duct through a gas-permeable portion of the wall thereof.
Claim 6
Dependent Claim
65 words
A method according to claim 3 wherein the speed of movement of the gas, forming said upwardly moving stream of gas, remains substantially constant along the path, the cross section of the upwardly moving stream of gas decreasing along said path with increasing distance from the downward end of said path so as to compensate for reduction in the volume of the gas moving upwardly.
Claim 7
Dependent Claim
53 words
A method according to claim 2 wherein the said wetted mixture is passed into the path through a feed duct intermediate said upward end and said downward end, and said gas, for producing said upwardly moving stream of gas, is supplied to said feed duct through a gas-permeable portion of the wall thereof.
Claim 8
Dependent Claim
65 words
A method according to claim 2 wherein the speed of movement of the gas, forming said upwardly moving stream of gas, remains substantially constant along the path, the cross section of the upwardly moving steam of gas decreasing along said path with increasing distance from the downward end of said path so as to compensate for reduction in the volume of the gas moving upwardly.
Claim 9
Dependent Claim
53 words
A method according to claim 1 wherein the said wetted mixture is passed into the path through a feed duct intermediate said upward end and said downward end, and said gas, for producing said upwardly moving stream of gas, is supplied to said feed duct through a gas-permeable portion of the wall thereof.
Claim 10
Dependent Claim
65 words
A method according to claim 8 wherein the speed of movement of the gas, forming said upwardly moving stream of gas, remains substantially constant along the path, the cross section of the upwardly moving steam of gas decreasing along said path with increasing distance from the downward end of said path so as to compensate for reduction in the volume of the gas moving upwardly.
Claim 11
Dependent Claim
65 words
A method according to claim 1 wherein the speed of movement of the gas, forming said upwardly moving stream of gas, remains substantially constant along the path, the cross section of the upwardly moving steam of gas decreasing along said path with increasing distance from the downward end of said path so as to compensate for reduction in the volume of the gas moving upwardly.
Claim 12
Dependent Claim
19 words
The method according to claim 1 including drying said plastic sheeting pieces to a greater extent than said paper.
Claim 13
Independent Claim
159 words
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° 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.
Claim 14
Independent Claim
159 words
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° 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.
References Cited (Backward Citations)
US2494153A
Cited
US3441131A
Cited
US3524594A
Cited
US3655043A
Cited
US3814420A
Cited
US3929628A
Cited
DE2441811A1
Cited
US4034862A
Cited
US4003136A
Cited
US4160722A
Cited
EP0002122A1
Cited
DE2804548A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-11 | 1986-10-11 | 1987-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-11 | 1990-10-11 | 1991-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-11 | 1994-10-11 | 1995-04-12 | $7700.00 | Window Closed / Lapsed |