US3694424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of internally cooling a blow molded article
Assignee: HUNKAR LAB Inc
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Filing: 1970-10-13
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Granted: 1972-09-26
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Expires: 1990-10-13
Abstract
Abstract A method of blow molding a hollow article of thermoplastic material in which the newly formed article is cooled internally by explosively injecting into the article a charge of a highly pressurized and chilled mixture of air and water.
Inventors
- 👤 Denes B Hunkar
- 👤 Jeno Peter Bercz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:34
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/64; B29C49/66; B29C49/46; B29C2049/4602; B29C2049/4647; B29C49/48; B29C49/4823; B29C2049/4825; B29C49/6604; B29C2049/6606; B29C2049/6607; B29C2049/6615
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
143 words
In the method of blow molding hollow plastic articles wherein molten plastic is extruded in the form of a parison, pinched between mold parts and then expanded outwardly into contact with the inner surfaces of said mold parts, said mold parts being chilled to effect external cooling of the newly formed article therein, the improvement for cooling the newly formed article internally that comprises providing a contained mixture of water supersaturated with air and air, which mixture is chilled to a point above but close to the freezing point of water and is pressurized to at least about 500 pounds per square inch, and explosively injecting said mixture into said article while the air of said mixture is in the state of adiabatic expansion to cause an instantaneous dispersion of the water component of the mixture to all internal surfaces of the article.
Claim 2
Dependent Claim
143 words
In the method of blow molding hollow plastic articles wherein molten plastic is extruded in the form of a parison, pinched between mold parts and then expanded outwardly into contact with the inner surfaces of said mold parts, said mold parts being chilled to effect external cooling of the newly formed article therein, the improvement for cooling the newly formed article internally that comprises providing a contained mixture of water supersaturated with air and air, which mixture is chilled to a point above but close to the freezing point of water and is pressurized to at least about 500 pounds per square inch, and explosively injecting said mixture into said article while the air of said mixture is in the state of adiabatic expansion to cause an instantaneous dispersion of the water component of the mixture to all internal surfaces of the article.
Claim 3
Dependent Claim
42 words
The improvement as set forth in claim 1 in which said mixture is pressurized and chilled to an extent such that rapid release of the mixture to an atmosphere at a substantially lower pressure results in the formation of fine ice crystals.
Claim 4
Dependent Claim
28 words
The improvement as set forth in claim 1 in which said mixture is pressurized to within a range of from about 500 to 5,000 pounds per square inch.
Claim 5
Dependent Claim
44 words
The improvement as set forth in claim 1 in which said mixture is pressurized above approximately 1,000 pounds per square inch and injected into said article while said article is closed and pressured with air at approximately 70 to 100 pounds per square inch.
Claim 6
Dependent Claim
27 words
The improvement as set forth in claim 1 in which the explosive injection of said mixture results in a three phase system comprising solids, liquids and gases.
Claim 7
Dependent Claim
43 words
The improvement as set forth in claim 5 in which said solids are in the form of fine ice crystals, the liquids are in the form of fine droplets of water, and the gases are in the form of water vapor and air.
Claim 8
Dependent Claim
125 words
In the method of blow molding hollow plastic articles wherein molten plastic is extruded in the form of a parison, pinched between mold parts and then expanded outwardly into contact with the inner surfaces of said mold parts, said mold parts being chilled to effect external cooling of the newly formed article therein, the improvement for cooling the newly formed article internally that comprises explosively injecting into said article a chilled mixture of water supersaturated with air and air, which mixture is initially pressurized to at least about 500 pounds per square inch, while the air of said mixture is in the state of adiabatic expansion to cause an instantaneous dispersion of the water component of the mixture to all internal surfaces of the article.
Claim 9
Dependent Claim
125 words
In the method of blow molding hollow plastic articles wherein molten plastic is extruded in the form of a parison, pinched between mold parts and then expanded outwardly into contact with the inner surfaces of said mold parts, said mold parts being chilled to effect external cooling of the newly formed article therein, the improvement for cooling the newly formed article internally that comprises explosively injecting into said article a chilled mixture of water supersaturated with air and air, which mixture is initially pressurized to at least about 500 pounds per square inch, while the air of said mixture is in the state of adiabatic expansion to cause an instantaneous dispersion of the water component of the mixture to all internal surfaces of the article.
Claim 10
Dependent Claim
37 words
In the method set forth in claim 7, the step of providing a mixing chamber and introducing said air and said water into said chamber with the water initially pressurized to a greater extent than said air.
Claim 11
Dependent Claim
22 words
In the method set forth in claim 8 in which the water of said mixture is initially chilled to approximately 34* F.
Claim 12
Dependent Claim
39 words
In the method set forth in claim 8 in which said air and water are initially pressurized to within the range of from 500 to 2,000 pounds per square inch and said water is chilled to approximately 34* F.
Claim 13
Dependent Claim
37 words
In the method set forth in claim 8 in which said article is pressurized to a substantially lesser extent than said mixture and said article is vented to atmospheric pressure following the injection of said mixture thereinto.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |