US3892830A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Precise temperature adjustment of reheated parison preforms
Assignee: Phillips Petroleum Co
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Filing: 1973-10-03
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Granted: 1975-07-01
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Expires: 1993-10-03
Abstract
Abstract Tubular parison preforms for blow molding generally oval-shaped oriented hollow articles such as bottles are reheated to orientation temperature and the sides of the parison which are to be expanded out along a major axis of a mold are contacted with textured fingers so as to lower the temperature a very small amount. This allows the portion of the parison corresponding to the major axis of the mold to resist stretching and thus compensates for the unequal wall thickness which otherwise results when the parison touches the walls of the mold opposite the minor axis and is thereby chilled.
Inventors
- 👤 Jimmie E Hudson
- 👤 Jimmy W Snelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:21
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/64; B29C49/6409; B29C49/6436; B29C49/02; B29C49/04; B29C2949/00; B29C2949/07; B29C2949/0715; B29C2949/079; B29C2949/08; B29C49/06; B29C49/6458; B29C49/6463; B29C49/6465; B29C49/6467; B29K; B29K2105/00; B29K2105/25; B29K2105/253; B29K2105/258; B65; B65D; B65D2501/00; B65D2501/0009; B65D2501/0081
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
101 words
A METHOD OF FORMING A BIAXIALLY ORIENTED HOLLOW ARTICLE HAVING AN IRREGULAR CONFIGURATION WHEREIN AT LEAST A PORTION THEREOF HAS A RATIO OF A MAJOR AXIS TO MINOR AXIS OF AT LEAST 1.25 TO 1 COMPRISING: INTRODUCING A CYLINDRICAL THERMOPLASTIC PARISON PERFORM INTO A HEATING ZONE, IMPARTING SUFFICIENT HEAT TO BRING THE ENTIRE PARISON PREFORM TO ORIENTATION TEMPERATURE, THEREAFTER COOLING A PORTION OF AT LEAST ONE SIDE OF SAID PARISON WHICH IS TO CORRESPOND TO SAID MAJOR AXIS TO AN AVERAGE OF 0.25* TO 10*F BELOW THE TEMPERATURE OF THE REST OF THE PARISON BUT STILL WITHIN THE RANGE OF ORIENTATION
Claim 2
Independent Claim
101 words
A METHOD OF FORMING A BIAXIALLY ORIENTED HOLLOW ARTICLE HAVING AN IRREGULAR CONFIGURATION WHEREIN AT LEAST A PORTION THEREOF HAS A RATIO OF A MAJOR AXIS TO MINOR AXIS OF AT LEAST 1.25 TO 1 COMPRISING: INTRODUCING A CYLINDRICAL THERMOPLASTIC PARISON PERFORM INTO A HEATING ZONE, IMPARTING SUFFICIENT HEAT TO BRING THE ENTIRE PARISON PREFORM TO ORIENTATION TEMPERATURE, THEREAFTER COOLING A PORTION OF AT LEAST ONE SIDE OF SAID PARISON WHICH IS TO CORRESPOND TO SAID MAJOR AXIS TO AN AVERAGE OF 0.25* TO 10*F BELOW THE TEMPERATURE OF THE REST OF THE PARISON BUT STILL WITHIN THE RANGE OF ORIENTATION
Claim 3
Dependent Claim
29 words
A method according to claim 1 wherein said portion of said parison is adjusted to a temperature of 0.5* to 2*F below that of the rest of the parison.
Claim 4
Dependent Claim
11 words
A method according to claim 1 wherein said thermoplastic is polypropylene.
Claim 5
Dependent Claim
35 words
A method according to claim 1 wherein said thermoplastic is a crystalline copolymer of propylene with a minor amount of combined ethylene, having a density of 0.900 to 0.905 and a melt flow of 1-3.
Claim 6
Dependent Claim
29 words
A method according to claim 4 wherein said article is a bottle and wherein said heat is imparted in a circulating air oven adjusted to a temperature of 305*-308*F.
Claim 7
Dependent Claim
29 words
A method according to claim 5 wherein said portion of said parison is adjusted to a temperature of 0.5* to 2*F below that of the rest of the parison.
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) | 1978-06-30 | 1978-12-30 | 1979-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-30 | 1982-12-30 | 1983-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-30 | 1986-12-30 | 1987-07-01 | $7700.00 | Window Closed / Lapsed |