US4764323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating hollow articles, in particular polyethylene terephthalate preforms
Assignee: Cobarr SpA
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Filing: 1986-11-12
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Granted: 1988-08-16
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Expires: 2006-11-12
Abstract
Abstract A method of treating PET preforms and bottles consists of subjecting the preforms or the bottles to a carbon dioxide atmosphere at a higher temperature than the critical temperature of carbon dioxide, a higher pressure than ambient pressure, and for a set time period. The treatment reduces the acetaldehyde concentration in the head of the treated bottles or in the bottles obtained from the treated preforms by stretch-blowing, and also reduces the permeability of gases through the bottle walls.
Inventors
- 👤 Hussain A. Al Ghatta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:33
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/88; C08G63/90; B; B29; B29B; B29B13/00; B29C; B29C49/00; B29C49/0005; B29C71/00; B29C71/009; B29C71/0009; B29C2071/0027; B29K; B29K2067/00; B29K2105/00; B29K2105/0002; B29K2105/25; B29K2105/253
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
72 words
A method of reducing the acetaldehyde content and the gas permeability of the walls of polyethylene terephthalate and polyethylene terephthalate copolymer hollow articles, comprising treating said hollow articles in an autoclave containing a carbon-dioxide atmosphere at a partial pressure exceeding 50 bars and at a temperature above 31° C. for a time sufficient to obtain a substantial reduction in the acetaldehyde content and the permeability of the walls of said hollow articles.
Claim 2
Independent Claim
72 words
A method of reducing the acetaldehyde content and the gas permeability of the walls of polyethylene terephthalate and polyethylene terephthalate copolymer hollow articles, comprising treating said hollow articles in an autoclave containing a carbon-dioxide atmosphere at a partial pressure exceeding 50 bars and at a temperature above 31° C. for a time sufficient to obtain a substantial reduction in the acetaldehyde content and the permeability of the walls of said hollow articles.
Claim 3
Dependent Claim
19 words
A method according to claim 1, characterized in that the treatment temperature is between 31° C. and 90° C.
Claim 4
Dependent Claim
17 words
A method according to claim 1, characterized in that said atmosphere comprises carbon dioxide saturated with steam.
Claim 5
Dependent Claim
19 words
A method according to claim 1, characterized in that the hollow articles are swept by a continuous gas stream.
Claim 6
Independent Claim
27 words
A method according to any of the preceding claims, characterized in that said hollow articles are preforms as used to produce bioriented containers by stretch-blowing such preforms.
Claim 7
Independent Claim
18 words
A method according to any of the claims 1-4, characterized in that said hollow articles are bioriented containers.
Claim 8
Dependent Claim
18 words
A method according to claim 1, characterized in that the partial pressure of carbon dioxide exceeds 50 bars.
Claim 9
Dependent Claim
18 words
A method according to claim 2, characterized in that the treatment temperature is from 45° to 80° C.
Claim 10
Dependent Claim
19 words
A method according to claim 1, characterized in that the treatment time is from 5 minutes to 10 hours.
Claim 11
Dependent Claim
19 words
A method according to claim 9, characterized in that the treatment time is from 12 minutes to 3 hours.
References Cited (Backward Citations)
US4260567A
Cited
JPS59219328A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |