US4617111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the separation of a mixture of polyvinyl chloride and polyethylene terephtalate
Assignee: Plastic Recycling Foundation Inc
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Filing: 1985-07-26
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Granted: 1986-10-14
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Expires: 2005-07-26
Abstract
Abstract A method for the separation of a mixture of polyvinyl chloride particles and polyethylene terephtalate particles comprising the steps of applying a solution composed of a low density solvent of polyvinyl chloride, water and sodium hydroxide to flakes of polyvinyl chloride and polyethylene terephtalate whereby the polyvinyl chloride absorbs the solvent contained in the solution, which changes the density of the polyvinyl chloride so that it is less than the density of the polyethylene terephtalate. The plastics may then be differential density separated by flotation or centrifugation and recovered.
Inventors
- 👤 Michael J. Grimm
- 👤 Trannie R. Sehlmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:14
CPC Classifications
B; B29; B29B; B29B17/00; B29B17/02; B03; B03B; B03B1/00; B03B1/04; B03B9/00; B03B9/06; B03B9/061; C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; B29B2017/0203; B29B2017/0213; B29B2017/0217; B29B2017/0231; B29B2017/0237; B29B2017/0244; B29K; B29K2027/00; B29K2027/06; B29K2067/00; B29L; B29L2031/00; B29L2031/712; B29L2031/7158; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/52; Y02W30/62
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
135 words
A method for the separation of a mixture of polyvinyl chloride particles and polyethylene terephtalate which comprises the steps of: (a) applying a solution composed of a solvent of polyvinyl chloride having a density of less than 0.95 grams/cc and water to flakes of polyvinyl chloride and polyethylene terephtalate; (b) conditioning said flakes of polyvinyl chloride and polyethylene terephtalate in said solution of solvent and water for a predetermined period of time whereby said flakes of polyvinyl chloride absorb the solvent contained in said solution of solvent and water while said flakes of polethylene terephtalate do not absorb said solvent changing the density of said flakes of polyvinyl chloride so that they have less density than do said flakes of polyethylene terephtalate; (c) separating said flakes of polyvinyl chloride from said flakes of polyethylene terephtalate.
Claim 2
Independent Claim
135 words
A method for the separation of a mixture of polyvinyl chloride particles and polyethylene terephtalate which comprises the steps of: (a) applying a solution composed of a solvent of polyvinyl chloride having a density of less than 0.95 grams/cc and water to flakes of polyvinyl chloride and polyethylene terephtalate; (b) conditioning said flakes of polyvinyl chloride and polyethylene terephtalate in said solution of solvent and water for a predetermined period of time whereby said flakes of polyvinyl chloride absorb the solvent contained in said solution of solvent and water while said flakes of polethylene terephtalate do not absorb said solvent changing the density of said flakes of polyvinyl chloride so that they have less density than do said flakes of polyethylene terephtalate; (c) separating said flakes of polyvinyl chloride from said flakes of polyethylene terephtalate.
Claim 3
Dependent Claim
29 words
The method according to claim 1, wherein said solution of solvent and water is composed of from about 30-90%, by weight, solvent and from about 10-70%, by weight, water.
Claim 4
Dependent Claim
22 words
The method according to claim 2, wherein said solution of solvent and water also includes from about 0-12%, by weight, sodium hydroxide.
Claim 5
Dependent Claim
36 words
The method according to claim 3, wherein said mixture of particles plastic is present in a proportion of from about 1 to 3 parts by weight per 100 parts of said solution of solvent and water.
Claim 6
Dependent Claim
17 words
The method according to claim 4, wherein said predetermined period of itme is from about 5-20 minutes.
Claim 7
Dependent Claim
25 words
The method according to claim 5, wherein said conditioning is done at a temperature in the range of from about 55° C to 65° C.
Claim 8
Dependent Claim
12 words
The method according to claim 1, wherein said solvent is methyethyl ketone.
Claim 9
Dependent Claim
12 words
The method according to claim 1, wherein said solvent is an alcohol.
Claim 10
Dependent Claim
12 words
The method according to claim 1, wherein said solvent is a ketone.
Claim 11
Dependent Claim
12 words
The method according to claim 1, wherein said solvent is an ester.
Claim 12
Dependent Claim
12 words
The method according to claim 1, wherein said solvent is an ether.
Claim 13
Dependent Claim
26 words
The method according to claim 1, wherein said separation of said flakes of polyvinyl chloride from said flakes of polyethylene terephtalate occurs in a flotation cell.
Claim 14
Dependent Claim
26 words
The method according to claim 1, wherein said separation of said flakes of polyvinyl chloride from said flakes of polyethylene terephtalate occurs in a certrifugal separator.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-13 | 1990-04-14 | 1990-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-13 | 1994-04-14 | 1994-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-13 | 1998-04-14 | 1998-10-14 | $7700.00 | Window Closed / Lapsed |