US5679306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of molding preform in injection stretch blow molding
Assignee: Aoki Technical Laboratory Inc
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Filing: 1994-10-14
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Granted: 1997-10-21
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Expires: 2014-10-14
Abstract
Abstract A method of molding a preform in an injection stretch blow molding, wherein a gas is entered into the boundary between the preform and an injection core so that the gas pressure causes the preform in an injection mold to be insulated from the injection core, thereby allowing a high-temperature releasing of the preform.
Inventors
- 👤 Hisashi Nakajima
- 👤 Hideaki Koda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:43
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/02; B29C49/06; B29C45/00; B29C45/17; B29C45/1703; B29C45/174; B29C45/72; B29C45/73; B29C2049/023; B29C2949/00; B29C2949/07; B29C2949/0861; B29C2949/0872; B29K; B29K2105/00; B29K2105/25; B29K2105/253
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
162 words
In a method of injection stretch blow molding wherein an injection molded preform is released in a high temperature state from an injection mold and an injection core while being held by a neck mold, and the released preform is stretch blow molded to a molded product immediately after the injection molded preform is released the improvement which comprises the steps of forcing a gas having a predetermined pressure into the boundary between the preform formed by injecting a resin in an injection cavity and the injection core so that the gas pressure causes an inner surface of the preform to be insulated from a surface of the injection core and the preform to be urged against the cavity surface, thereby performing a cooling step for producing a skin layer on the high temperature preform; and releasing the preform from the injection mold in a state where the inner surface of the preform is insulated from the surface of the injection core.
Claim 2
Dependent Claim
162 words
In a method of injection stretch blow molding wherein an injection molded preform is released in a high temperature state from an injection mold and an injection core while being held by a neck mold, and the released preform is stretch blow molded to a molded product immediately after the injection molded preform is released the improvement which comprises the steps of forcing a gas having a predetermined pressure into the boundary between the preform formed by injecting a resin in an injection cavity and the injection core so that the gas pressure causes an inner surface of the preform to be insulated from a surface of the injection core and the preform to be urged against the cavity surface, thereby performing a cooling step for producing a skin layer on the high temperature preform; and releasing the preform from the injection mold in a state where the inner surface of the preform is insulated from the surface of the injection core.
Claim 3
Dependent Claim
60 words
A method of injection stretch blow molding as set forth in claim 1 wherein the forcing of the gas into the boundary between the preform and the injection core is started after injection pressure holding step is completed, and stopped before the preform is released but after the cooling step for producing the skin layer of the preform is completed.
Claim 4
Dependent Claim
62 words
A method of injection stretch blow molding as set forth in claim 1 wherein the forcing of the gas into the boundary between the resin and the injection core is started when the cooling step for producing the skin layer of the preform is started and is stopped when the cooling step for producing the skin layer of the preform is completed.
Claim 5
Dependent Claim
18 words
A method of injection stretch blow molding as set forth in claim 1 wherein the preform is polypropylene.
Claim 6
Dependent Claim
18 words
A method of injection stretch blow molding as set forth in claim 1 wherein the preform is polycarbonate.
Claim 7
Dependent Claim
18 words
A method of injection stretch blow molding as set forth in claim 1 wherein the preform is polyethylene.
Claim 8
Independent Claim
176 words
A method of injection stretch blow molding comprising the steps of: injection molding a predetermined preform by filling an injection mold comprising a cavity die, a core die and a neck mold with molten molding resin, forcing a gas having a predetermined pressure into the boundary between the preform and the injection core so that the gas pressure causes the inner surface of the preform to be insulated from the surface of the injection core and the preform to be urged against the cavity surface, thereby performing a cooling step for producing a skin layer on the high temperature preform, releasing the preform in a high temperature state from the injection mold while the preform is in a state where the inner surface of the preform is insulated from the surface of the injection core, and while the preform is being held by the neck mold, and immediately after the injection molded preform is released, biaxially stretching and expanding the preform employing a stretching rod and blowing air into the form of a hollow thin-walled product.
Claim 9
Independent Claim
176 words
A method of injection stretch blow molding comprising the steps of: injection molding a predetermined preform by filling an injection mold comprising a cavity die, a core die and a neck mold with molten molding resin, forcing a gas having a predetermined pressure into the boundary between the preform and the injection core so that the gas pressure causes the inner surface of the preform to be insulated from the surface of the injection core and the preform to be urged against the cavity surface, thereby performing a cooling step for producing a skin layer on the high temperature preform, releasing the preform in a high temperature state from the injection mold while the preform is in a state where the inner surface of the preform is insulated from the surface of the injection core, and while the preform is being held by the neck mold, and immediately after the injection molded preform is released, biaxially stretching and expanding the preform employing a stretching rod and blowing air into the form of a hollow thin-walled product.
Claim 10
Dependent Claim
60 words
A method of injection stretch blow molding as set forth in claim 7 wherein the forcing of the gas into the boundary between the resin and the injection core is started when cooling for producing the skin layer of the preform is started and is stopped when the cooling step for producing the skin layer of the preform is completed.
Claim 11
Dependent Claim
18 words
A method of injection stretch blow molding as set forth in claim 7 wherein the preform is polypropylene.
Claim 12
Dependent Claim
18 words
A method of injection stretch blow molding as set forth in claim 7 wherein the preform is polycarbonate.
Claim 13
Dependent Claim
20 words
A method of injection stretch blow molding as preform as set forth in claim 7 wherein the preform is polyethylene.
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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) | 2000-10-20 | 2001-04-21 | 2001-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-20 | 2005-04-21 | 2005-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-20 | 2009-04-21 | 2009-10-21 | $7700.00 | Window Closed / Lapsed |