US4018860A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Injection blow molding with improved cooling
Assignee: Farrell Patent Co
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Filing: 1975-07-07
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Granted: 1977-04-19
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Expires: 1995-07-07
Abstract
Abstract This invention cools the blowing mold and the plastic article blown therein to shorten the time that a core rod must remain at a blowing station of a blow molding machine for making plastic articles. The cooling is performed by conditioned air that is dried to lower its dew point. An air curtain is used to prevent other air from contacting with and depositing moisture on the mold. In order to take advantage of the shorter time at the blowing station, an auxiliary injection device is used to also shorten the time required for the injection operation; and auxiliary cooling is supplied to the core rod at the stripper station.
Inventors
- 👤 John J. Farrell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:15
CPC Classifications
B; B29; B29C; B29C49/00; B29C49/42; B29C49/64; B29C49/6409; B29C49/6463; B29C49/02; B29C49/06; B29C49/48; B29C49/4823; B29C2049/023; B29C49/46; B29C2049/4673; B29C2049/4676; B29C2791/00; B29C2791/004; B29C2791/005; B29C35/00; B29C35/16
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
178 words
A method of blow molding a plastic parison comprising blowing the parison to form a blown article, cooling a blow mold to cool the article blown in the blow mold, opening the blow mold to remove the article therefrom, and preventing sweating of the confronting cooled surfaces of the blow mold sections that move toward and away from one another by circulating dry air around the space between the open sections of the mold, said air having a dew point lower than the temperature of the confronting surfaces of the blow mold sections including the surface of the wall forming the blow mold cavity, characterized by projecting the dried air as a curtain surrounding the periphery of the mold sections to prevent any air, except air from the curtain, from entering the space between the mold sections during opening of the mold and while the mold is open, wherein said curtain is formed as a continuous curtain around the entire periphery of the space between the blow mold sections and is transversely disposed to the blow mold sections.
Claim 2
Independent Claim
178 words
A method of blow molding a plastic parison comprising blowing the parison to form a blown article, cooling a blow mold to cool the article blown in the blow mold, opening the blow mold to remove the article therefrom, and preventing sweating of the confronting cooled surfaces of the blow mold sections that move toward and away from one another by circulating dry air around the space between the open sections of the mold, said air having a dew point lower than the temperature of the confronting surfaces of the blow mold sections including the surface of the wall forming the blow mold cavity, characterized by projecting the dried air as a curtain surrounding the periphery of the mold sections to prevent any air, except air from the curtain, from entering the space between the mold sections during opening of the mold and while the mold is open, wherein said curtain is formed as a continuous curtain around the entire periphery of the space between the blow mold sections and is transversely disposed to the blow mold sections.
Claim 3
Dependent Claim
38 words
The method described in claim 1 characterized by drying the air by refrigeration to condense water therefrom, and supplying some heat to the dry air to reduce its relative humidity before using the air in the air curtain.
Claim 4
Independent Claim
227 words
A method of injection blow molding comprising injection molding a plastic parison on a core rod, transferring said parison and core rod to a blow mold, blow molding said parison to form a blown article, cooling the blow mold to cool an article blown in the blow mold, opening the blow mold to remove the article therefrom, and preventing sweating of the confronting cooled surfaces of the blow mold sections that move toward and away from one another by circulating dry air around the space between the open sections of the mold, characterized by projecting the dried air as a curtain surrounding the periphery of the mold sections to prevent any air, except air from the curtain, from entering the space between the mold sections during opening of the mold and while the mold is open, wherein said curtain is formed as a curtain aroung the periphery of the space between the blow mold sections and is transversely disposed to the blow mold sections, said air having a dew point lower than the temperature of the confronting surfaces of the blow mold sections including the surface of the wall forming the blow mold cavity, and stripping the blown article from the core rod while cooling the core rod, whereby the time for the blow mold cooling operation is less than the time for the injection molding operation.
Claim 5
Independent Claim
227 words
A method of injection blow molding comprising injection molding a plastic parison on a core rod, transferring said parison and core rod to a blow mold, blow molding said parison to form a blown article, cooling the blow mold to cool an article blown in the blow mold, opening the blow mold to remove the article therefrom, and preventing sweating of the confronting cooled surfaces of the blow mold sections that move toward and away from one another by circulating dry air around the space between the open sections of the mold, characterized by projecting the dried air as a curtain surrounding the periphery of the mold sections to prevent any air, except air from the curtain, from entering the space between the mold sections during opening of the mold and while the mold is open, wherein said curtain is formed as a curtain aroung the periphery of the space between the blow mold sections and is transversely disposed to the blow mold sections, said air having a dew point lower than the temperature of the confronting surfaces of the blow mold sections including the surface of the wall forming the blow mold cavity, and stripping the blown article from the core rod while cooling the core rod, whereby the time for the blow mold cooling operation is less than the time for the injection molding operation.
Claim 6
Dependent Claim
37 words
The method of claim 3, characterized by drying the air by refrigeration to condense water therefrom, and supplying some heat to the dry air to reduce its relative humidity before using the air in the air curtain.
Claim 7
Dependent Claim
35 words
The method of claim 3, wherein said curtain is formed as a continuous curtain around the entire periphery of the space between the blow mold sections and is transversely disposed to the blow mold sections.
Claim 8
Dependent Claim
41 words
The method of claim 3, further comprising varying the amount of cooling the core rod with different parts of the core rod along the length of the core rod, and in accordance with different sections of material of the core rod.
Claim 9
Independent Claim
261 words
A method of injection blow molding in an injection blow molding machine having an injection molding station, a blow molding station, a stripping station and core rods transferrable from station to station, said method comprises injection molding a plastic parison on a core rod by means of a plasticizer in cooperation with means exerting pressure on the injected thermoplastic during recovery of the plasticizer, transferring the parison to a blow mold at the blow molding station, blow molding said parison to form a blown article, cooling the blow mold to cool an article blown in the blow mold, opening the blow mold to remove the article therefrom, and preventing sweating of the confronting cooled surfaces at the blow mold sections that move toward and away from one another by circulating dry air around the space between the open sections of the mold, characterized by projecting the dried air as a curtain surrounding the periphery of the mold sections to prevent any air, except air from the curtain, from entering the space between the mold sections during opening of the mold and while the mold is open, wherein said curtain is formed as a curtain aroung the periphery of the space between the blow mold sections and is transversely disposed to the blow mold sections, said air having a dew point lower than the temperature of the confronting surfaces of the blow mold sections including the surface of the wall forming the blow mold cavity, transferring the blown article to the stripping station, stripping the blown article with cooling the core rod.
Claim 10
Independent Claim
261 words
A method of injection blow molding in an injection blow molding machine having an injection molding station, a blow molding station, a stripping station and core rods transferrable from station to station, said method comprises injection molding a plastic parison on a core rod by means of a plasticizer in cooperation with means exerting pressure on the injected thermoplastic during recovery of the plasticizer, transferring the parison to a blow mold at the blow molding station, blow molding said parison to form a blown article, cooling the blow mold to cool an article blown in the blow mold, opening the blow mold to remove the article therefrom, and preventing sweating of the confronting cooled surfaces at the blow mold sections that move toward and away from one another by circulating dry air around the space between the open sections of the mold, characterized by projecting the dried air as a curtain surrounding the periphery of the mold sections to prevent any air, except air from the curtain, from entering the space between the mold sections during opening of the mold and while the mold is open, wherein said curtain is formed as a curtain aroung the periphery of the space between the blow mold sections and is transversely disposed to the blow mold sections, said air having a dew point lower than the temperature of the confronting surfaces of the blow mold sections including the surface of the wall forming the blow mold cavity, transferring the blown article to the stripping station, stripping the blown article with cooling the core rod.
Claim 11
Dependent Claim
59 words
The method of claim 7, wherein the step of injection molding further comprises operating the plasticizer to inject molten thermoplastic into the injection mold, and wherein said means to maintain pressure on the plastic in the mold comprises a pump, said pump displacing thermoplastic to compensate for shrinkage in the mold as it cools down from the injection temperature.
Claim 12
Dependent Claim
24 words
The method of claim 8, reversing the plastic pump so as to draw back thermoplastic to break the thermoplastic between the parison and runner.
Claim 13
Dependent Claim
18 words
The method of claim 9, wherein the injection molded parison is transferred after the drawback of the thermoplastic.
Claim 14
Dependent Claim
26 words
The method of claim 7, further comprising conditioning the parison to its orientation temperature during transfer from the injection molding station to the blow molding station.
Claim 15
Dependent Claim
37 words
The method of claim 7, characterized by drying the air by refrigeration to condense water therefrom, and supplying some heat to the dry air to reduce its relative humidity before using the air in the air curtain.
Claim 16
Dependent Claim
35 words
The method of claim 7, wherein said curtain is formed as a continuous curtain around the entire periphery of the space between the blow mold sections and is transversely disposed to the blow mold sections.
Claim 17
Dependent Claim
25 words
The method of claim 7, wherein the step of cooling the core rod comprising blowing a fluid along the entire length of the core rod.
Claim 18
Dependent Claim
17 words
The method of claim 14, further comprising blowing a fluid around the periphery of the core rod.
Claim 19
Dependent Claim
21 words
The method of claim 15, varying the amount of blown fluid at different points along the length of the core rod.
Claim 20
Dependent Claim
38 words
The method of claim 7, wherein the stripper comprises means to cool the core rod and the steps of stripping the blown article and cooling the core rod are performed concurrently along the length of the core rod.
Claim 21
Dependent Claim
16 words
The method of claim 17, further comprising blowing air around the periphery of the core rod.
Claim 22
Dependent Claim
21 words
The method of claim 18, varying the amount of blown air at different points along the length of the core rod.
References Cited (Backward Citations)
US3078508A
Cited
US3321564A
Cited
US3233416A
Cited
US3665063A
Cited
US3709644A
Cited
JPS473548U
Cited
US3707591A
Cited
US3789093A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-18 | 1980-10-18 | 1981-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-18 | 1984-10-18 | 1985-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-18 | 1988-10-18 | 1989-04-19 | $7700.00 | Window Closed / Lapsed |