US4264392A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming a peelable seal
Assignee: Pharmachem Corp
•
Filing: 1978-11-29
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Granted: 1981-04-28
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Expires: 1998-11-29
Abstract
Abstract A process for forming a peelable seal by heat sealing under combined application of heat and pressure at least two polyolefin film members having at least one oxidized surface therebetween, and the seal formed thereby.
Inventors
- 👤 William E. R. Watt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:32
CPC Classifications
C; C09; C09J; C09J5/00; C09J5/02; B; B29; B29C; B29C65/00; B29C65/76; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/1122; B29C66/40; B29C66/41; B29C66/43; B29C66/431; B29C66/4312; B29C66/43121; B29C66/432; B29C66/70; B29C66/71; B65; B65D; B65D53/00; B65D53/08; B65D75/00; B65D75/28; B65D75/30; B65D75/52; B65D75/58; B65D75/5855; B29L; B29L2031/00; B29L2031/712; B29L2031/7148; C09J2423/00; C09J2423/008; Y; Y10; Y10T; Y10T156/00; Y10T156/11; Y10T156/1153
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
In a process for forming a peelable seal with at least two extruded polyolefin film members by the simultaneous application of controlled heat and pressure to said film members at the portion to be sealed, the improvement which comprises oxidizing by corona discharge treatment at least one surface of at least one of the polyolefin film members at the portion to be sealed so as to modify by oxidation the structure of the surface crystals formed by extrusion and then simultaneously applying controlled heat and pressure to soften the modified crystals at the contacting surface to partially fuse the crystals at the contacting surface while maintaining the integrity of the crystals so that the modified crystals form an interface between the polyolefin film members at the seal portion and a peelable seal is thereby formed.
Claim 2
Dependent Claim
135 words
In a process for forming a peelable seal with at least two extruded polyolefin film members by the simultaneous application of controlled heat and pressure to said film members at the portion to be sealed, the improvement which comprises oxidizing by corona discharge treatment at least one surface of at least one of the polyolefin film members at the portion to be sealed so as to modify by oxidation the structure of the surface crystals formed by extrusion and then simultaneously applying controlled heat and pressure to soften the modified crystals at the contacting surface to partially fuse the crystals at the contacting surface while maintaining the integrity of the crystals so that the modified crystals form an interface between the polyolefin film members at the seal portion and a peelable seal is thereby formed.
Claim 3
Dependent Claim
37 words
A process according to claim 1 wherein at least two polyolefin film members having a surface oxidized by corona discharge treatment are sealed together so that the oxidized surface of each film member forms the interface therebetween.
Claim 4
Dependent Claim
11 words
The process according to claim 1 wherein said polyolefin is polyethylene.
Claim 5
Dependent Claim
20 words
The process according to claim 1 wherein said polyolefin film members are peelably sealed across the opening of a container.
Claim 6
Dependent Claim
45 words
The process according to claim 1, wherein a portion of said oxidized polyolefin film members are heat sealed to form a peelable seal and another portion of said oxidized polyolefin film members are heat sealed to said surface so as to form a weld seal.
Claim 7
Dependent Claim
33 words
The process according to claim 1, wherein said treated polyolefin film members are subjected to pressure between 500-1500 psi of sealing area and sealing is conducted at a temperature of about 200°-500° F.
Claim 8
Dependent Claim
23 words
The process according to claim 1, wherein said treated polyolefin film members are heat sealed at selective portions so as to form compartments.
References Cited (Backward Citations)
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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) | 1984-04-27 | 1984-10-27 | 1985-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-27 | 1988-10-27 | 1989-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-27 | 1992-10-27 | 1993-04-28 | $7700.00 | Window Closed / Lapsed |