US3715855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for automatically venting plastic bags
Assignee: Basic Packaging Systems Inc
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Filing: 1970-12-21
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Granted: 1973-02-13
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Expires: 1990-12-21
Abstract
Abstract Method and apparatus for automatically closing plastic film bags while simultaneously venting the bag in a manner so that the bag is essentially ''''leak proof,'''' but yet is able to breathe to avoid expansion of ''''pillowing'''' when stored at high temperature. The invention contemplates folding over the top portion of the bag, applying heating along the fold line sufficient to heat plastify the film and while cooperatively shielding short increments of the film; and thereafter squeezing and cooling the film to pressure set the seal. Each shielded increment forms an air vent to the above-noted quality.
Inventors
- 👤 W Armstrong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:24
CPC Classifications
B; B65; B65B; B65B7/00; B65B7/02; B65B7/06; B65B7/08
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
179 words
In a method of venting heat sealable plastic bag material while simultaneously closing the same, the material being generally of a type having opposed walls defining therebetween an opening, said method comprising the steps of: a. folding said walls over said opening while moving said material forward, defining a fold line extending generally in the direction of movement of said material; b. moving said material past radiant heating means to radiantly heat plastify the material along a select region thereof extending along said fold line. c. providing a plurality of heat shielding means moving simultaneously with said material shielding at least partially from said radiantly applied heat, a plurality of discrete increments of material along said fold line as said material is moving past said radiant heating means, said shielding providing a plurality of weakened seals along said discrete increments of material, said weakened seals being sufficient to form vent means in said seal upon the formation of internal pressures, pressing said heated layers together to form a continuous seal along said fold line thereby sealing closed said opening.
Claim 2
Dependent Claim
179 words
In a method of venting heat sealable plastic bag material while simultaneously closing the same, the material being generally of a type having opposed walls defining therebetween an opening, said method comprising the steps of: a. folding said walls over said opening while moving said material forward, defining a fold line extending generally in the direction of movement of said material; b. moving said material past radiant heating means to radiantly heat plastify the material along a select region thereof extending along said fold line. c. providing a plurality of heat shielding means moving simultaneously with said material shielding at least partially from said radiantly applied heat, a plurality of discrete increments of material along said fold line as said material is moving past said radiant heating means, said shielding providing a plurality of weakened seals along said discrete increments of material, said weakened seals being sufficient to form vent means in said seal upon the formation of internal pressures, pressing said heated layers together to form a continuous seal along said fold line thereby sealing closed said opening.
Claim 3
Dependent Claim
179 words
In a method of venting heat sealable plastic bag material while simultaneously closing the same, the material being generally of a type having opposed walls defining therebetween an opening, said method comprising the steps of: a. folding said walls over said opening while moving said material forward, defining a fold line extending generally in the direction of movement of said material; b. moving said material past radiant heating means to radiantly heat plastify the material along a select region thereof extending along said fold line. c. providing a plurality of heat shielding means moving simultaneously with said material shielding at least partially from said radiantly applied heat, a plurality of discrete increments of material along said fold line as said material is moving past said radiant heating means, said shielding providing a plurality of weakened seals along said discrete increments of material, said weakened seals being sufficient to form vent means in said seal upon the formation of internal pressures, pressing said heated layers together to form a continuous seal along said fold line thereby sealing closed said opening.
Claim 4
Dependent Claim
179 words
In a method of venting heat sealable plastic bag material while simultaneously closing the same, the material being generally of a type having opposed walls defining therebetween an opening, said method comprising the steps of: a. folding said walls over said opening while moving said material forward, defining a fold line extending generally in the direction of movement of said material; b. moving said material past radiant heating means to radiantly heat plastify the material along a select region thereof extending along said fold line. c. providing a plurality of heat shielding means moving simultaneously with said material shielding at least partially from said radiantly applied heat, a plurality of discrete increments of material along said fold line as said material is moving past said radiant heating means, said shielding providing a plurality of weakened seals along said discrete increments of material, said weakened seals being sufficient to form vent means in said seal upon the formation of internal pressures, pressing said heated layers together to form a continuous seal along said fold line thereby sealing closed said opening.
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) | 1976-02-13 | 1976-08-14 | 1977-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-13 | 1980-08-14 | 1981-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-13 | 1984-08-14 | 1985-02-13 | $7700.00 | Window Closed / Lapsed |