US5540244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for cleaning and recycling post-consumer plastic films
Assignee: BANK OF OKLAHOMA NA
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Filing: 1993-12-22
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Granted: 1996-07-30
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Expires: 2013-12-22
Abstract
Abstract A system and method for removing fine cellulosic contaminants from plastic film utilizing a plurality of tanks, means for moving the plastic film sequentially through the tanks, means for recirculating an aqueous solution through each of the tanks, means for filtering the recirculating aqueous solution, and means for injecting flocculant into the recirculating solution. The subject system preferably includes at least two independent circulation modules, each having means for recirculating and filtering an aqueous solution and for minimizing liquid carry-over from one module to another. The system also preferably includes means for monitoring the turbidity of the recirculating aqueous solution and for injecting flocculant into the recirculating solution whenever the turbidity exceeds a predetermined maximum value.
Inventors
- 👤 J. Douglas Brooks
- 👤 Joe G. Brooks
- 👤 Joyce H. Rose
- 👤 Steve W. Pierce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:35
CPC Classifications
B; B29; B29B; B29B17/00; B29B17/02; B03; B03B; B03B9/00; B03B9/06; B03B9/061; B29B2017/0213; B29B2017/0217; B29B2017/0227; B29B2017/0237; B29B2017/0244; B29B2017/0268; B29B2017/0272; B29B2017/0286; B29B2017/0289; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2105/00; B29K2105/06; B29K2105/065; B29K2711/00; B29K2711/12; B29L; B29L2007/00; B29L2007/008; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/52; Y02W30/62
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
99 words
A system for removing paper and other contaminants from shredded plastic film, the system comprising a plurality of receptacles, means for moving the plastic film sequentially through the receptacles, means for recirculating aqueous solution through each of the receptacles, and means for filtering the recirculated aqueous solution, said recirculating and filtering means comprising at least two independent recirculation modules, each recirculation module having means for recirculating and filtering an aqueous solution and for restricting carryover of solution between modules, at least one recirculation module having means for introducing flocculant into the solution in response to measured or observed turbidity.
Claim 2
Independent Claim
99 words
A system for removing paper and other contaminants from shredded plastic film, the system comprising a plurality of receptacles, means for moving the plastic film sequentially through the receptacles, means for recirculating aqueous solution through each of the receptacles, and means for filtering the recirculated aqueous solution, said recirculating and filtering means comprising at least two independent recirculation modules, each recirculation module having means for recirculating and filtering an aqueous solution and for restricting carryover of solution between modules, at least one recirculation module having means for introducing flocculant into the solution in response to measured or observed turbidity.
Claim 3
Dependent Claim
39 words
The system of claim 1 wherein said means for introducing flocculant comprises means for monitoring the turbidity of the recirculating aqueous solution and means for intermittently injecting flocculant into the recirculating solution whenever the turbidity exceeds a predetermined value.
Claim 4
Dependent Claim
21 words
The system of claim 2, wherein the means for monitoring the turbidity of the recirculating aqueous solution comprises a turbidity meter.
Claim 5
Dependent Claim
16 words
The system of claim 3, wherein the turbidity meter is an in-line laser particle distribution analyzer.
Claim 6
Dependent Claim
19 words
The system of claim 1, wherein the means for restricting carry-over of solution between modules includes a screw press.
Claim 7
Dependent Claim
16 words
The system of claim 1, further comprising means for introducing a surfactant into the recirculating solution.
Claim 8
Dependent Claim
14 words
The system of claim 1, wherein the independent recirculation modules are closed-loop circulation systems.
References Cited (Backward Citations)
US2737435A
Cited
CA695881A
Cited
US3226343A
Cited
US3284282A
Cited
GB1228276A
Cited
US4000031A
Cited
US3843060A
Cited
US4076579A
Cited
US4092458A
Cited
US4160722A
Cited
US4138313A
Cited
US4332748A
Cited
US4134554A
Cited
US4123489A
Cited
US4162768A
Cited
DE3002061A1
Cited
US4436104A
Cited
US5048139A
Cited
US5007620A
Cited
US4751030A
Cited
US5084135A
Cited
US5259219A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-07-30 | 2000-01-29 | 2000-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-30 | 2004-01-29 | 2004-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-30 | 2008-01-29 | 2008-07-30 | $7700.00 | Window Closed / Lapsed |