US4138374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for manufacturing shaped polyester article using scrap materials
Assignee: EIDP Inc
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Filing: 1978-02-03
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Granted: 1979-02-06
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Expires: 1998-02-03
Abstract
Abstract An improved process is disclosed for manufacturing a shaped article of polyester material wherein scrap polyester is blended with fully polymerized virgin polyester at reduced pressure.
Inventors
- 👤 Robert M. Currie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:41
CPC Classifications
C; C08; C08J; C08J11/00; C08J11/04; C08J11/06; B; B29; B29K; B29K2105/00; B29K2105/0002; C08J2367/00; C08J2367/02; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/62
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
123 words
A process for manufacturing a shaped article of polyester material comprising the steps of: (a) continuously polymerizing polyester in a closed, flowing, steady state polymerizing stream by a polycondensation reaction comprising (i) adding low viscosity, low molecular weight polyester prepolymer to the beginning of the stream, (ii) maintaining conditions in the stream at elevated temperature and reduced pressure, and (iii) removing water and other polycondensation by-products from the stream, to yield high viscosity, high molecular weight virgin polyester at the end of the stream; (b) adding scrap polyester to the virgin polyester at the end of the stream to yield polyester material blend; (c) withdrawing polyester material blend from the polymerizing stream; and (d) forcing the polyester material blend through an extrusion die.
Claim 2
Dependent Claim
123 words
A process for manufacturing a shaped article of polyester material comprising the steps of: (a) continuously polymerizing polyester in a closed, flowing, steady state polymerizing stream by a polycondensation reaction comprising (i) adding low viscosity, low molecular weight polyester prepolymer to the beginning of the stream, (ii) maintaining conditions in the stream at elevated temperature and reduced pressure, and (iii) removing water and other polycondensation by-products from the stream, to yield high viscosity, high molecular weight virgin polyester at the end of the stream; (b) adding scrap polyester to the virgin polyester at the end of the stream to yield polyester material blend; (c) withdrawing polyester material blend from the polymerizing stream; and (d) forcing the polyester material blend through an extrusion die.
Claim 3
Dependent Claim
30 words
The process of claim 1 wherein the scrap polyester is added to the virgin polyester at substantially the same point along the stream as the polyester material blend is withdrawn.
Claim 4
Dependent Claim
30 words
The process of claim 1 wherein the temperature of the scrap polyester as it is being added to the virgin polyester is less than the temperature of the virgin polyester.
Claim 5
Dependent Claim
28 words
The process of claims 1 or 3 wherein the temperature of the virgin polyester is from about 280 to 310 degrees Celsius before scrap polyester is added thereto.
Claim 6
Dependent Claim
48 words
The process of claim 1 wherein the shaped article is a polyester film web and wherein there are the added steps of (e) trimming scrap polyester from the film web; (f) transporting the scrap polyester back to the end of the stream; to be used in step (b).
Claim 7
Dependent Claim
28 words
The process of claims 1 or 5 wherein the scrap polyester is dried to a water content of less than 0.05 weight percent of water before step (b).
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein the polyester material is polyethylene terephthalate.
Claim 9
Dependent Claim
64 words
A process for manufacturing a shaped article of polyester material comprising the steps of: (a) continuously operating a polymerization finisher to manufacture high viscosity, high molecular weight virgin polyester; (b) adding scrap polyester to the virgin polyester in the finisher to yield polyester material blend; (c) withdrawing polyester material blend from the finisher; and (d) forcing the polyester material blend through an extrusion die.
Claim 10
Dependent Claim
64 words
A process for manufacturing a shaped article of polyester material comprising the steps of: (a) continuously operating a polymerization finisher to manufacture high viscosity, high molecular weight virgin polyester; (b) adding scrap polyester to the virgin polyester in the finisher to yield polyester material blend; (c) withdrawing polyester material blend from the finisher; and (d) forcing the polyester material blend through an extrusion die.
Claim 11
Dependent Claim
30 words
The process of claim 8 wherein the scrap polyester is added to the virgin polyester at substantially the same point along the finisher as the polyester material blend is withdrawn.
Claim 12
Dependent Claim
30 words
The process of claim 9 wherein the temperature of the scrap polyester as it is being added to the virgin polyester is less than the temperature of the virgin polyester.
Claim 13
Dependent Claim
28 words
The process of claims 8 or 10 wherein the temperature of the virgin polyester is from about 280 to 310 degrees Celsius before scrap polyester is added thereto.
Claim 14
Dependent Claim
45 words
The process of claim 8 wherein the shaped article in a polyester film web and wherein there are the added steps of (e) trimming scrap polyester from the film web; (f) transporting the scrap polyester back to the finisher; to be used in step (b).
Claim 15
Dependent Claim
28 words
The process of claims 8 or 12 wherein the scrap polyester is dried to a water content of less than 0.05 weight percent of water before step (b).
Claim 16
Dependent Claim
12 words
The process of claim 8 wherein the polyester material is polyethylene terephthalate.
Claim 17
Dependent Claim
29 words
The process of claims 3 or 10 wherein the temperature of the scrap polyester is from 2 to 50 Celsius degrees less than the temperature of the virgin polyester.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-05 | 1982-08-07 | 1983-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-05 | 1986-08-07 | 1987-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-05 | 1990-08-07 | 1991-02-06 | $7700.00 | Window Closed / Lapsed |