US3789093A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for accelerating the molding cycle by blanketing with dry carbon dioxide gas
Assignee: Individual
•
Filing: 1971-12-08
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Granted: 1974-01-29
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Expires: 1991-12-08
Abstract
Abstract Process of accelerating the molding cycle when using blow molding or injection molding machines including providing an enclosure around the molding area and supplying to said enclosure an atmosphere for blanketing the mold area with carbon dioxide gas to reduce the dew point in the mold cavities whereby the molds may be operated at a lower temperature without causing surface imperfections on the molded part. In other embodiments multi-station blow molding and injection molding machines include an enclosed mold area into which exhaust carbon dioxide from the molded articles is vented to maintain the dew point at a value below that of the ambient.
Inventors
- 👤 R Bose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:44
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/02; B29C33/04; B29C33/046; B29C45/00; B29C45/17; B29C45/1701; B29C45/72; B29C45/73; B29C49/00; B29C49/02; B29C49/04; B29C49/42; B29C49/46; B29C49/48; B29C49/4823; B29C49/64; B29C49/66; B29C35/00; B29C35/16; B29C2035/1658; B29C2049/4825
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
127 words
A method of accelerating the molding cycle in a plastic molding operation wherein a hot plastic material is placed in a mold cavity defined by a plurality of relatively movable mold parts and forced against the interior mold surfaces to form a plastic part, which mold parts are then moved apart to permit removal of the part, comprising the steps of substantially enclosing the space immediately around said mold parts, and supplying dry carbon dioxide gas to the enclosed area to maintain an atmosphere of dry carbon dioxide gas within said area so as to reduce the dew point of the atmosphere in said cavity and permit cooling of the mold parts to temperatures lower than the ambient temperature without causing water marks on the plastic part.
Claim 2
Independent Claim
127 words
A method of accelerating the molding cycle in a plastic molding operation wherein a hot plastic material is placed in a mold cavity defined by a plurality of relatively movable mold parts and forced against the interior mold surfaces to form a plastic part, which mold parts are then moved apart to permit removal of the part, comprising the steps of substantially enclosing the space immediately around said mold parts, and supplying dry carbon dioxide gas to the enclosed area to maintain an atmosphere of dry carbon dioxide gas within said area so as to reduce the dew point of the atmosphere in said cavity and permit cooling of the mold parts to temperatures lower than the ambient temperature without causing water marks on the plastic part.
Claim 3
Dependent Claim
52 words
A method according to claim 1 wherein carbon dioxide is supplied to the interior of said plastic part during the molding operation, comprising the further step of returning at least a portion of the carbon dioxide gas exhausted from the interior of said part to the enclosed space around said mold parts.
Claim 4
Dependent Claim
59 words
A method according to claim 1 wherein the hot plastic is injected into said mold cavity and carbon dioxide is supplied to passageways within the mold parts to cool said mold parts and the plastic part, comprising the step of returning at least a portion of the carbon dioxide gas exhausted from the mold passageways to said enclosed area.
Claim 5
Independent Claim
89 words
A method of blow molding a plastic part comprising the steps of providing an enclosure around a plurality of relatively movable mold parts defining a mold cavity therein, forming a plastic parison, positioning said mold parts over said parison so that said parison is located within said mold cavity, injecting carbon dioxide into said parison, and thereafter venting the gas from the molded part into the space within said enclosure exteriorly of the mold parts to reduce the dew point in said mold cavity during the subsequent molding operation.
Claim 6
Independent Claim
89 words
A method of blow molding a plastic part comprising the steps of providing an enclosure around a plurality of relatively movable mold parts defining a mold cavity therein, forming a plastic parison, positioning said mold parts over said parison so that said parison is located within said mold cavity, injecting carbon dioxide into said parison, and thereafter venting the gas from the molded part into the space within said enclosure exteriorly of the mold parts to reduce the dew point in said mold cavity during the subsequent molding operation.
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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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |