US5154361A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Comminution of plastic scrap
Assignee: United States Gypsum Co
•
Filing: 1989-11-06
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Granted: 1992-10-13
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Expires: 2009-11-06
Abstract
Abstract A method for comminuting plastic scrap material wherein the plastic scrap is suspended in water and an antifoam agent is added to the suspension which is then passed through a disc refiner or a Valley beater to comminute the plastic scrap. The antifoam agent is selected from defoamers having an HLB value of from about 0.5 to about 10 and a polypropylene glycol having an average molecular weight of from about 900 to about 1500. The comminuted plastic scrap is useful as an additive to the core material of a gypsum wallboard.
Inventors
- 👤 Michael D. Willoughby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:33
CPC Classifications
B; B29; B29B; B29B13/00; B29B13/10; B29B17/00; B29B17/0026; C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
48 words
A method for comminuting plastic scraps comprising passing a suspension of said scraps in water containing at least one antifoam agent selected from the class consisting of a defoamer having an HLB value of from about 0.5 to about 10 and a polypropylene glycol through a comminuting machine.
Claim 2
Independent Claim
48 words
A method for comminuting plastic scraps comprising passing a suspension of said scraps in water containing at least one antifoam agent selected from the class consisting of a defoamer having an HLB value of from about 0.5 to about 10 and a polypropylene glycol through a comminuting machine.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the scraps are sheets of plastic.
Claim 4
Dependent Claim
10 words
The method of claim 1 wherein the scraps are macro-sized.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein the average residence time in the comminuting machine is up to about 10 minutes.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein the amount of surface active agent is from about 0.05 to about 1% by weight of the total aqueous suspension.
Claim 7
Dependent Claim
15 words
The method of claim 1 characterized further in that the aqueous suspension also contains paper.
Claim 8
Dependent Claim
40 words
The method of claim 1 wherein the antifoam agent is a polypropylene glycol having an average molecular weight of about 1200 and the amount thereof is from about 0.05% to about 1% of the total weight of the aqueous suspension.
Claim 9
Independent Claim
38 words
A method for comminuting plastic scraps comprising passing an aqueous suspension of said scraps containing an antifoam agent having an HLB value of from about 5 to about 10 through a comminuting machine and recovering a comminuted plastic.
Claim 10
Independent Claim
38 words
A method for comminuting plastic scraps comprising passing an aqueous suspension of said scraps containing an antifoam agent having an HLB value of from about 5 to about 10 through a comminuting machine and recovering a comminuted plastic.
Claim 11
Dependent Claim
21 words
The method of claim 8 wherein the scraps are sheets of plastic having a thickness of up to about 60 mils.
Claim 12
Dependent Claim
10 words
The method of claim 8 wherein the scraps are macro-sized.
Claim 13
Dependent Claim
39 words
The method of claim 8 wherein the comminuting machine is selected from a Valley beater and a disc refiner and the average residence time for the aqueous suspension in the activated comminuting machine is up to about 10 minutes.
Claim 14
Dependent Claim
13 words
The method of claim 8 wherein the aqueous suspension also contains cellulosic fibers.
Claim 15
Dependent Claim
41 words
The method of claim 12 wherein the antifoam agent is present in the aqueous suspension in an amount ranging from about 1 to about 5% by weight of the total weight of the plastic scraps and cellulose fibers in the suspension.
Claim 16
Dependent Claim
27 words
The method of claim 8 wherein the antifoam agent is present in the aqueous suspension in an amount ranging from about 0.05 to about 1% by weight.
Claim 17
Independent Claim
39 words
A method for comminuting plastic scraps comprising passing an aqueous suspension of said scraps containing a polypropylene glycol having an average molecular weight of from about 900 to about 1500 through a comminuting machine and recovering a comminuted plastic.
Claim 18
Independent Claim
39 words
A method for comminuting plastic scraps comprising passing an aqueous suspension of said scraps containing a polypropylene glycol having an average molecular weight of from about 900 to about 1500 through a comminuting machine and recovering a comminuted plastic.
Claim 19
Dependent Claim
29 words
The method of claim 15 wherein the scraps are selected from the group consisting of plastic sheets having a thickness up to about 60 mils and macro-sized plastic pieces.
Claim 20
Dependent Claim
39 words
The method of claim 15 wherein the comminuting machine is selected from a Valley beater and a disc refiner and the average residence time for the aqueous suspension in the activated comminuting machine is up to about 10 minutes.
Claim 21
Dependent Claim
13 words
The method of claim 15 wherein the aqueous suspension also contains cellulose fibers.
Claim 22
Dependent Claim
38 words
The method of claim 18 wherein the polypropylene glycol is present in the aqueous suspension in an amount ranging from about 1 to about 5% by weight of the total weight of the plastic scraps and cellulose fibers.
Claim 23
Dependent Claim
27 words
The method of claim 15 wherein the polypropylene glycol is present in the aqueous suspension in an amount ranging from about 0.05 to about 1% by weight.
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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) | 1995-10-13 | 1996-04-13 | 1996-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-13 | 2000-04-13 | 2000-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-13 | 2004-04-13 | 2004-10-13 | $7700.00 | Window Closed / Lapsed |