Patent US3882213A successfully refreshed from Google Patents.
US3882213A
Expired / Lapsed
US
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Method of making blown plastic articles
Assignee: OI Glass Inc
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Filing: 1974-02-15
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Granted: 1975-05-06
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Expires: 1994-02-15
Abstract
Abstract The present invention provides a method for thermally conditioning a blowable shape or parison, prior to blow molding, so that a subsequent blowing operation can be carried out under conditions conducive to bi-axial orientation in the final blown article. More specifically, the parison is formed by conventional techniques, such as free extrusion or injection molding. The parison is then enclosed in a heat exchange chamber and exposed to a fluid heat transfer agent, so that the parison temperature is adjusted to that temperature at which the parison, upon expansion, will become bi-axially oriented. The fluid agent can either heat or cool the parison to the desired temperature.
Inventors
- 👤 Albert R Uhlig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:26
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/64; B29C49/6409; B29C49/48; B29C49/4823; B29C49/58; B29C49/02; B29C2049/023; B29C2949/00; B29C2949/07; B29C2949/0715; B29C35/00; B29C35/02; B29C35/04; B29C49/06; B29C49/6427; B29C49/643; B29C49/6435
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
113 words
In a method of making a blown thermoplastic article, the steps of forming a parison of thermoplastic material, enclosing said parison in an individual heat exchange chamber having opposed openable and closeable sections, the sections having interior walls spaced substantially uniformly from the exterior of said parison, flowing a fluid heat transfer medium through the space between said parison and said interior section walls, terminating the flow of heat transfer medium when the average wall temperature of the parison is conducive to orientation during subsequent blowing of the parison, opening said opposed heat chamber sections, transferring the parison at said temperature to a blow mold, and blowing said parison at said orientation temperature.
Claim 2
Dependent Claim
113 words
In a method of making a blown thermoplastic article, the steps of forming a parison of thermoplastic material, enclosing said parison in an individual heat exchange chamber having opposed openable and closeable sections, the sections having interior walls spaced substantially uniformly from the exterior of said parison, flowing a fluid heat transfer medium through the space between said parison and said interior section walls, terminating the flow of heat transfer medium when the average wall temperature of the parison is conducive to orientation during subsequent blowing of the parison, opening said opposed heat chamber sections, transferring the parison at said temperature to a blow mold, and blowing said parison at said orientation temperature.
Claim 3
Dependent Claim
50 words
In a method as defined in claim 1, the further steps of forming the parison by injection molding about a core, supporting the parison on the core in the heat exchange chamber and varying the temperature of the core to aid in the attainment of orientation temperature by the parison.
Claim 4
Dependent Claim
64 words
In a method as defined in claim 1, wherein the step of enclosing said parison pinches shut a tubular extrusion, the further step of simultaneously circulating additional heat transfer medium interiorly of the parison while flowing fluid heat transfer medium through said space, the pressures and volumes of the heat transfer media being correlated to avoid distortion of the parison from its formed configuration.
Claim 5
Independent Claim
135 words
A method of making a blown thermoplastic article comprising the steps of forming a parison of thermoplastic material, enclosing said parison in an individual heat exchange chamber by closing opposed chamber sections, the sections generally conforming to the shape of the parison and having inner walls uniformly spaced from the exterior of the parison, simultaneously directing a first fluid heat transfer medium in a fixed path between the exterior of the parison and said chamber sections, and directing a second fluid heat transfer medium interiorly of said parison, terminating the flow of heat transfer media when said parison has obtained a desired temperature, opening said opposed chamber sections, removing the parison from the heat exchange chamber and placing it in a blow mold, and expanding said parison at the desired temperature, in the blow mold.
Claim 6
Independent Claim
135 words
A method of making a blown thermoplastic article comprising the steps of forming a parison of thermoplastic material, enclosing said parison in an individual heat exchange chamber by closing opposed chamber sections, the sections generally conforming to the shape of the parison and having inner walls uniformly spaced from the exterior of the parison, simultaneously directing a first fluid heat transfer medium in a fixed path between the exterior of the parison and said chamber sections, and directing a second fluid heat transfer medium interiorly of said parison, terminating the flow of heat transfer media when said parison has obtained a desired temperature, opening said opposed chamber sections, removing the parison from the heat exchange chamber and placing it in a blow mold, and expanding said parison at the desired temperature, in the blow mold.
Claim 7
Dependent Claim
19 words
The method as defined in claim 4 wherein said first fluid medium is directed in a generally spiral configuration.
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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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |