US3880691A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing film and sheet materials from thermoplastic materials having hot tack by the blown film process and the film and sheet materials thereby obtained
Assignee: Individual
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Filing: 1972-03-20
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Granted: 1975-04-29
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Expires: 1992-03-20
Abstract
Abstract Thermoplastic materials which have hot tack and which are incapable of being independently processed by the blown film process due to the tack they show in hot state and especially in the as extruded state are processed to film and sheet by the blown film process by extruding and inflating in a manner known per se an at least two-ply tubular film or sheet of thermoplastic material, the inner ply being formed by a tack-free thermoplastic material and the outer ply superposed thereon being formed by said hot-tacky thermoplastic material; slitting the double-ply tubing for storage and after flattening at least at one edge, and arranging the film web, preferably with winding-up, together with the web of tack-free material in such a manner that one web having hot tack alternates with one tack-free web. The multi-ply film and sheet materials produced by the process are comprised by the invention.
Inventors
- 👤 Heinrich Pannenbecker
- 👤 Rudolf Plate
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 16:06
CPC Classifications
B; B32; B32B; B32B3/00; B32B3/02; B32B3/04; B29; B29C; B29C44/00; B29C44/20; B29C44/22; B29C48/00; B29C48/03; B29C48/09; B29C48/14; B29C48/147; B29C48/1472; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/32; B29C48/335; B32B1/00; B32B1/08; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B37/00; B32B37/28; B32B7/00; B32B7/02; B32B7/022; B29C2791/00; B29C2791/004; B29C2791/007; B29C48/001; B29C48/0017; B29C48/0018; B29C48/10; B32B2597/00; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
131 words
A PROCESS FOR PRODUCTION OF FILM OF HOT-TACKY THERMOPLASTIC MATERIAL BY THE BLOWN FILM PROCESS, WHICH MATERIAL IS TACKY TO THE EXTENT THAT IN PRODUCTION THEREOF BY THE BLOWN FILM PROCESS, WHEREIN A TUBE OF THE MATERIAL IS INDEPENDENTLY EXTRUDED, THE EXTRUDED TUBE IS INFLATED AND THEREAFTER FLATTENED WITH SQUEEZE ROLLER SO THAT WALLS OF THE TUBING ARE SUPERIMPOSED, THE SUPERIMPOSED WALLS BECOME BONDED TOGETHER, WHICH COMPRISES EXTRUDING TWO TUBES ONE, OUTSIDE THE OTHER TO PRODUCE A TWO PLY TUBE COMPRISING AN INNER PLY AND AN OUTER PLY, INFLATING THE TWO PLY TUBE, AND THEREAFTER FLATTENING THE TWO PLY TUBE WITH SQUEEZE ROLLERS, AND REMOVING THE FLATTENED TWO PLY TUBE FROM THE SQUEEZE ROLLERS, THE OUTER PLY BEING SAID HOT-TACKY THERMOPLASTIC MATERIAL, AND THE INNER PLY BEING A TACK-FREE THERMOPLASTIC MATERIAL.
Claim 2
Dependent Claim
131 words
A PROCESS FOR PRODUCTION OF FILM OF HOT-TACKY THERMOPLASTIC MATERIAL BY THE BLOWN FILM PROCESS, WHICH MATERIAL IS TACKY TO THE EXTENT THAT IN PRODUCTION THEREOF BY THE BLOWN FILM PROCESS, WHEREIN A TUBE OF THE MATERIAL IS INDEPENDENTLY EXTRUDED, THE EXTRUDED TUBE IS INFLATED AND THEREAFTER FLATTENED WITH SQUEEZE ROLLER SO THAT WALLS OF THE TUBING ARE SUPERIMPOSED, THE SUPERIMPOSED WALLS BECOME BONDED TOGETHER, WHICH COMPRISES EXTRUDING TWO TUBES ONE, OUTSIDE THE OTHER TO PRODUCE A TWO PLY TUBE COMPRISING AN INNER PLY AND AN OUTER PLY, INFLATING THE TWO PLY TUBE, AND THEREAFTER FLATTENING THE TWO PLY TUBE WITH SQUEEZE ROLLERS, AND REMOVING THE FLATTENED TWO PLY TUBE FROM THE SQUEEZE ROLLERS, THE OUTER PLY BEING SAID HOT-TACKY THERMOPLASTIC MATERIAL, AND THE INNER PLY BEING A TACK-FREE THERMOPLASTIC MATERIAL.
Claim 3
Dependent Claim
29 words
A process according to claim 1, and slitting the flattened two ply tube, and winding the split two ply tube into a roll wherein hot-tacky and tack-free turns alternate.
Claim 4
Dependent Claim
14 words
A process according to claim 1, wherein said tack-free thermoplastic material is a polyolefin.
Claim 5
Dependent Claim
13 words
A process according to claim 3, wherein the polyolefin is polyethylene or polypropylene.
Claim 6
Dependent Claim
67 words
A process according to claim 1, which comprises extruding a third tube to produce a three-ply tube comprising an inner ply, intermediate ply and an outer ply, in which the inner ply is said ply of tack-free thermoplastic material, the intermediate ply is said ply of hot-tacky material and the outer ply is a hot-tacky thermoplastic material different from the intermediate layer or a tack-free thermoplastic material.
Claim 7
Dependent Claim
29 words
A process according to claim 1, in which the softening temperature of the tack-free material is not substantially in excess of the softening temperature of said hot-tacky thermoplastic material.
Claim 8
Dependent Claim
27 words
A process according to claim 6, wherein said tack-free material has a softening temperature which is about 10* to 80*C lower than that of the hot-tacky material.
Claim 9
Dependent Claim
27 words
A process according to claim 6, wherein said tack-free material has a softening temperature which is about 10* to 40*C lower than that of the hot-tacky material.
Claim 10
Dependent Claim
83 words
A process according to claim 1, which comprises extruding the hot-tacky material to form film having a thickness of about 10 to 300 microns while operating, within the following ratios of film thicknesses of the hot-tacky material to tack-free material: hot-tacky material about 50 to 100 microns/tack-free material having about the same film thickness: hot-tacky material less tha 50 microns/tack-free material having greater film thickness; hot-tacky material in excess of 100 microns/tack-free material having not more than the same or lower film thickness.
Claim 11
Dependent Claim
92 words
A process according to claim 1, which comprises extruding the hot-tacky material to form film having a thickness of about 10 to 300 microns while operating, within the following ratios of film thicknesses of the hot-tacky material to tack-free material: hot-tacky material about 50 to 100 microns/tack-free material having about the same film thickness; hot-tacky material less than 50 microns/tack-free material having a greater film thickness in a ratio oif 1:1.5 to 1:2.5; hot-tacky material in excess of 100 microns/tack-free material having a lower thickness in a ratio of 1:0.8 to 1:0.6.
Claim 12
Dependent Claim
20 words
A process according to claim 5, the inner ply and the outer ply having thicknesses not exceeding about 100 microns.
Claim 13
Dependent Claim
19 words
A process according to claim 5, the inner ply and outer ply having thicknesses of 20 to 50 microns.
Claim 14
Dependent Claim
18 words
A process according to claim 5, wherein the intermediate ply and the outer ply are undetachably bonded together.
Claim 15
Dependent Claim
19 words
A process according to claim 1, wherein a blowing agent is incorporated in the hot-tacky material prior to extrusion.
Claim 16
Dependent Claim
70 words
A process according to claim 1, which comprises extruding a third tube to produce a three-ply tube comprising an inner ply, intermediate ply and an outer ply in which the inner ply is said ply of tack-free thermoplastic material, the intermediate ply is said ply of hot-tacky material and the outer Ply is a thermoplastic material having a blowing agent incorporated therein and is undetachably bonded to the intermediate ply.
Claim 17
Dependent Claim
18 words
A process according to claim 1, wherein the hot-tacky material has a softening temperature of up to 280*C.
Claim 18
Dependent Claim
18 words
A process according to claim 1, wherein the hot-tacky material has a softening temperature of up to 220*C.
Claim 19
Dependent Claim
59 words
A process according to claim 1, wherein the tack free thermoplastic material does not substantially adhere to the hot-tacky thermoplastic material and the inner ply of tack free thermoplastic material is a release ply which can be detached from the outer ply of hot-tacky thermoplastic material, the outer ply, after detachment from the inner ply being a self-supporting film.
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) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |