US4318763A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing cross-linked thermoplastic materials
Assignee: WR Grace and Co Conn
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Filing: 1980-09-15
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Granted: 1982-03-09
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Expires: 2000-09-15
Abstract
Abstract A method of improving the high temperature strength of a heat seal which bonds cross-linkable thermoplastic material together by first forming the heat seal and then irradiating the seal area with ionizing radiation to increase the cross-linking in the material of the seal area by at least 2 MR.
Inventors
- 👤 Anne C. Bieler
- 👤 Milton A. Howe, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:06
CPC Classifications
B; B32; B32B; B32B7/00; B32B7/04; B29; B29C; B29C66/00; B29C66/70; B29C66/71; B29C65/00; B29C65/48; B29C65/4805; B29C65/483; B29C65/4845; B29C66/72; B29C66/723; B29C66/73; B29C66/737; B29C66/7371; B29C66/73711; B29C66/73715; B29C66/7375; B29C66/73755; B29C66/73756; B29C66/739; B29C66/7392; B29C66/73921; B29C66/7394; B29C66/73941; B32B27/00; B32B27/06; B32B27/08; C; C08; C08J; C08J5/00; C08J5/12; C08J5/121; B29C35/00; B29C35/02; B29C35/08; B29C35/0866; B29C2035/0877; B29C65/02; B29C65/14; B29C65/1403; B29C66/73751; B29C66/73752; B29C71/00; B29C71/04; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/08; B29K2023/083; B29K2023/10; B29K2023/12; B29K2031/00; B29K2031/04; B29K2105/00; B29K2105/0085; B29K2105/24; B29K2995/00; B29K2995/0037; B29K2995/0049; B29L; B29L2009/00; B29L2023/00; B29L2023/001; B32B2305/00; B32B2305/72; B32B2307/00; B32B2307/30; B32B2307/31; B32B2310/00; B32B2310/08; B32B2310/0875; B32B2310/0881; B32B2439/00; C08J2323/00; C08J2323/02; C08J2323/04; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1005; Y10T428/00; Y10T428/13; Y10T428/1328; Y10T428/1331; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/3192
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
138 words
A method of making a flexible, heat shrinkable receptacle from thermoplastic film having improved high temperature seal strength comprising the steps of: (a) selecting a thermoplastic film having at least one layer selected from the group consisting of polyethylenes and ethylene vinyl acetate copolymers which have been cross-linked by ionizing radiation, said film having a sealing surface wherein the material forming the surface is selected from the group consisting of polyethylenes and ethylene-vinyl acetate copolymers; (b) orienting said film to render it heat shrinkable; (c) placing said sealing surfaces in a face-to-face relationship; (d) heat sealing selected portions of said surface together to form a receptacle; (e) irradiating said sealed together surfaces with ionizing radiation to a dosage level of at least 2 MR thereby increasing the high temperature strength of the seals of said heat shrinkable receptacle.
Claim 2
Independent Claim
138 words
A method of making a flexible, heat shrinkable receptacle from thermoplastic film having improved high temperature seal strength comprising the steps of: (a) selecting a thermoplastic film having at least one layer selected from the group consisting of polyethylenes and ethylene vinyl acetate copolymers which have been cross-linked by ionizing radiation, said film having a sealing surface wherein the material forming the surface is selected from the group consisting of polyethylenes and ethylene-vinyl acetate copolymers; (b) orienting said film to render it heat shrinkable; (c) placing said sealing surfaces in a face-to-face relationship; (d) heat sealing selected portions of said surface together to form a receptacle; (e) irradiating said sealed together surfaces with ionizing radiation to a dosage level of at least 2 MR thereby increasing the high temperature strength of the seals of said heat shrinkable receptacle.
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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) | 1985-03-08 | 1985-09-07 | 1986-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-08 | 1989-09-07 | 1990-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-08 | 1993-09-07 | 1994-03-09 | $7700.00 | Window Closed / Lapsed |