US3864186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for induction sealing packaging material
Assignee: Tetra Pak AB
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Filing: 1973-01-12
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Granted: 1975-02-04
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Expires: 1993-01-12
Abstract
Abstract A method of producing separate packages by sealing a continuous tube of a packaging material, the packaging material having a layer of metal foil and a layer of thermoplastic material on one side thereof in which opposed portions of the packaging material are juxtaposed with the layers of thermoplastic material facing each other. The two portions are pressed together along a transverse area by means including a coil supplied with a high frequency alternating current to produce a high frequency electromagnetic alternating field to induce heat producing eddy currents in the metal foil and said heat is transmitted to the thermoplastic material to fuse same and form two spaced tight, mechanically durable seals and cutting between the seals.
Inventors
- 👤 Gyula Balla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:32
CPC Classifications
B; B65; B65B; B65B51/00; B65B51/10; B65B51/22; B65B51/227; B29; B29C; B29C65/00; B29C65/02; B29C65/34; B29C65/36; B29C65/3604; B29C65/3656; B29C65/3668; B29C65/3672; B29C65/3676; B29C65/368; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/11; B29C66/112; B29C66/1122; B29C66/40; B29C66/41; B29C66/43; B29C66/70; B29C66/72; B29C66/723; B29C66/7232; B29C66/72321; B29C66/72327; B29C66/72328; B29C66/73; B29C66/739; B29C66/7392; B29C66/73921; B29C66/80; B29C66/81; B29C66/812; B29C66/8122; B29C66/8126; B29C66/818; B29C66/8187; B29C66/81871; B29C66/431; B29C66/4312; B29C66/71; B29C66/83; B29C66/832; B29K; B29K2995/00; B29K2995/0003; B29K2995/0008; B29L; B29L2009/00; B29L2009/003; B29L2023/00; B29L2023/20
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
154 words
A METHOD OF PRODUCING SEPARATE PACKAGES FROM A CONTINUOUS TUBE HAVING AN INNER LAYER OF THERMOPLASTIC MATERIAL AND A LAYER OF METAL FOIL DISPOSED ON THE OUTSIDE THEREOF BY FORMING SIMULTANEOUSLY, TWO LONGITUDINALLY SPACED, ADJACENT, TRANSVERSE SEALS ACROSS THE TUBE COMPRISING, PRESSING OPPOSED PORTIONS OF THE TUBE TOGETHER ALONG A TRANSVERSE AREA SO THAT THE LAYERS OF THERMOPLSTIC MATERIAL OF EACH PORTION ARE FLATTENED TOGETHER AND ARE JUXTAPOSED, INDUCING SIMULTANEOUSLY A FLOW OF TWO SETS OF SPACED, ADJACENT, HEAT-PRODUCING EDDY CURRENTS IN THE LAYERS OF THE METAL FOIL TO HEAT SAID METAL LAYERS TO A TEMPERATURE SUFFICIENT TO HEAT SAID THERMOPLASTIC MATERIAL, BY CONDUCTION, TO FUSION TEMPERATURES AT TWO LONGITUDINALLY SPACED, PARALLEL, ADJACENT, TRANSVERSE ZONES IN SAID TRANSVERSE AREA TO THEREBY FORM SIMULTANEOUSLY TWO TIGHT, MECHANICALLY DURABLE, PARALLEL, LONGITUDINALLY SPACED, ADJACENT, TRANSVERSE SEALS, ACROSS THE TUBE AND, CUTTING THE TUBE TRANSVERSELY BETWEEN THE TWO, ADJACENT SEALS TO SEPARATE THE CONTINUOUS TUBE INTO SEPARATE PACKAGES.
Claim 2
Independent Claim
154 words
A METHOD OF PRODUCING SEPARATE PACKAGES FROM A CONTINUOUS TUBE HAVING AN INNER LAYER OF THERMOPLASTIC MATERIAL AND A LAYER OF METAL FOIL DISPOSED ON THE OUTSIDE THEREOF BY FORMING SIMULTANEOUSLY, TWO LONGITUDINALLY SPACED, ADJACENT, TRANSVERSE SEALS ACROSS THE TUBE COMPRISING, PRESSING OPPOSED PORTIONS OF THE TUBE TOGETHER ALONG A TRANSVERSE AREA SO THAT THE LAYERS OF THERMOPLSTIC MATERIAL OF EACH PORTION ARE FLATTENED TOGETHER AND ARE JUXTAPOSED, INDUCING SIMULTANEOUSLY A FLOW OF TWO SETS OF SPACED, ADJACENT, HEAT-PRODUCING EDDY CURRENTS IN THE LAYERS OF THE METAL FOIL TO HEAT SAID METAL LAYERS TO A TEMPERATURE SUFFICIENT TO HEAT SAID THERMOPLASTIC MATERIAL, BY CONDUCTION, TO FUSION TEMPERATURES AT TWO LONGITUDINALLY SPACED, PARALLEL, ADJACENT, TRANSVERSE ZONES IN SAID TRANSVERSE AREA TO THEREBY FORM SIMULTANEOUSLY TWO TIGHT, MECHANICALLY DURABLE, PARALLEL, LONGITUDINALLY SPACED, ADJACENT, TRANSVERSE SEALS, ACROSS THE TUBE AND, CUTTING THE TUBE TRANSVERSELY BETWEEN THE TWO, ADJACENT SEALS TO SEPARATE THE CONTINUOUS TUBE INTO SEPARATE PACKAGES.
Claim 3
Dependent Claim
17 words
A method as claimed in claim 1 wherein the layer of metal foil consists of aluminum foil.
Claim 4
Dependent Claim
14 words
a method as claimed in claim 1 wherein the thermoplastic material consists of polyethylene.
Claim 5
Dependent Claim
35 words
A method as claimed in claim 1 wherein the two sets of heat producing eddy currents are produced by a high frequency electromagnetic alternating field having a frequency of between about 0.5 and 2.0 MHz.
Claim 6
Dependent Claim
25 words
A method as claimed in claim 1 wherein the tube has a layer of carton material bonded to the outside of the metal foil layer.
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) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |