Patent US3754372A successfully refreshed from Google Patents.
US3754372A
Expired / Lapsed
US
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Apparatus for making thermoplastic vacuum packages
Assignee: WR Grace and Co
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Filing: 1971-10-26
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Granted: 1973-08-28
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Expires: 1991-10-26
Abstract
Abstract A vacuum package is prepared by placing a product between two webs at least one of which is heat softenable, applying differential air pressure to draw the heat softenable web against a heated surface, evacuating the space between the webs, and then releasing the web and using air or gas pressure to drive the softened web onto the product and at the same time contact the other web around the periphery of the product, thus enabling the two webs to be sealed together. A heated platen having vacuum ports therein is used to apply suction and heat to the softenable web. In the resulting package the heated web conforms closely to the shape of the product it contacts.
Inventors
- 👤 R Perdue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:18
CPC Classifications
B; B65; B65B; B65B11/00; B65B11/50; B65B11/52
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
107 words
Apparatus for preparing an evacuated package from heat sealable and softenable sheet material comprising: a. a mold having a cavity suitable for vacuum forming, said mold having a peripheral horizontal surface surrounding said cavity; b. a platen disposed for reciprocal Vertical motion above said mold cavity; said platen contacting said peripheral horizontal surface at the lower extreme of its motion and covering said mold cavity; c. means for drawing a vacuum through said platen to hold said sheet of material thereagainst; d. means for uniformly heating said platen; and, e. means for evacuating the mold cavity through the space between the platen and said peripheral horizontal surface.
Claim 2
Dependent Claim
107 words
Apparatus for preparing an evacuated package from heat sealable and softenable sheet material comprising: a. a mold having a cavity suitable for vacuum forming, said mold having a peripheral horizontal surface surrounding said cavity; b. a platen disposed for reciprocal Vertical motion above said mold cavity; said platen contacting said peripheral horizontal surface at the lower extreme of its motion and covering said mold cavity; c. means for drawing a vacuum through said platen to hold said sheet of material thereagainst; d. means for uniformly heating said platen; and, e. means for evacuating the mold cavity through the space between the platen and said peripheral horizontal surface.
Claim 3
Dependent Claim
148 words
Apparatus for preparing vacuumized thermoplastic packages from heat sealable thermoplastic web materials comprising: a. a mold having a forming cavity, said mold having a horizontal surface surrounding the upper periphery of said cavity; b. means for drawing a vacuum through said cavity whereby formable sheet material may be drawn into said cavity to conform to the shape of the cavity; c. a vacuum head for sealing the mold cavity region from the atmosphere; d. a platen associated with said vacuum head, said platen being disposed for reciprocal vertical motion within the region sealed by the vacuum head, said platen covering the mold cavity and contacting said horizontal surface at its extreme descent; e. means for drawing a vacuum through said platen to hold a portion of said materials thereagainst; f. means for uniformly heating said platen; and, g. means for evacuating the region sealed by said vacuum head.
Claim 4
Dependent Claim
148 words
Apparatus for preparing vacuumized thermoplastic packages from heat sealable thermoplastic web materials comprising: a. a mold having a forming cavity, said mold having a horizontal surface surrounding the upper periphery of said cavity; b. means for drawing a vacuum through said cavity whereby formable sheet material may be drawn into said cavity to conform to the shape of the cavity; c. a vacuum head for sealing the mold cavity region from the atmosphere; d. a platen associated with said vacuum head, said platen being disposed for reciprocal vertical motion within the region sealed by the vacuum head, said platen covering the mold cavity and contacting said horizontal surface at its extreme descent; e. means for drawing a vacuum through said platen to hold a portion of said materials thereagainst; f. means for uniformly heating said platen; and, g. means for evacuating the region sealed by said vacuum head.
Claim 5
Dependent Claim
22 words
The apparatus of claim 2 wherein means for drawing a vacuum through said platen includes a plurality of passageways in the platen.
Claim 6
Dependent Claim
20 words
The apparatus of claim 3 wherein the means for heating said platen includes additional passageways through which steam is circulated.
Claim 7
Dependent Claim
16 words
The apparatus of claim 2 wherein the means for heating said platen is electrical resistance means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |