US3795474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Molten thermoplastic web quenching apparatus
Assignee: EIDP Inc
•
Filing: 1972-03-08
•
Granted: 1974-03-05
•
Expires: 1992-03-08
Abstract
Abstract In the casting of molten thermoplastic web onto a moving quenching surface, the improved apparatus which comprises a bearing having a lubricating fluid on the surface thereof and over which the freshly extruded web is passed.
Inventors
- 👤 D Heyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:39
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/915; B29C48/917; B29C48/03; B29C48/07; B29C48/08; B29C48/914; B29C48/9155; B29C48/9165
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
140 words
An apparatus for quenching a molten thermoplastic web which comprises a movable quenching surface, an extrusion die positioned above the quenching surface and a bearing positioned between and spaced from the extrusion die and the touchdown point of a polymeric web extruded from the die onto the quenching surface and means for providing a layer of fluid on the outer surface of the bearing and for maintaining the fluid at a distributed pressure equal to the pressure exerted toward the bearing surface as a result of the tension of the web and at a pressure sufficient to maintain the freshly extruded web out of contact with the surface of the bearing, the bearing being so positioned as to displace an extruded web from its normally caternary path to a more vertical path from the extrusion die to the quenching surface.
Claim 2
Independent Claim
140 words
An apparatus for quenching a molten thermoplastic web which comprises a movable quenching surface, an extrusion die positioned above the quenching surface and a bearing positioned between and spaced from the extrusion die and the touchdown point of a polymeric web extruded from the die onto the quenching surface and means for providing a layer of fluid on the outer surface of the bearing and for maintaining the fluid at a distributed pressure equal to the pressure exerted toward the bearing surface as a result of the tension of the web and at a pressure sufficient to maintain the freshly extruded web out of contact with the surface of the bearing, the bearing being so positioned as to displace an extruded web from its normally caternary path to a more vertical path from the extrusion die to the quenching surface.
Claim 3
Dependent Claim
47 words
An apparatus of claim 1 wherein the bearing is porous and the means for providing a layer of fluid comprises a pressurized fluid source connected to the interior of the bearing whereby the fluid passes through the porous surface of the bearing to form a layer thereon.
Claim 4
Dependent Claim
16 words
An apparatus of claim 2 wherein the surface of the porous bearing consists essentially of metal.
Claim 5
Dependent Claim
25 words
An apparatus of claim 3 wherein the surface of the porous bearing consists essentially of sintered metal selected from bronze, copper, stainless steel and aluminum.
Claim 6
Dependent Claim
16 words
An apparatus of claim 2 wherein the surface of th porous bearing consists essentially of ceramic.
Claim 7
Dependent Claim
17 words
An apparatus of claim 1 further comprising means for pinning the polymeric web to thE quenching surface.
Claim 8
Dependent Claim
23 words
An apparatus of claim 6 wherein the means for pinning the web is apparatus for imparting an electrostatic charge to the polymeric web.
Claim 9
Dependent Claim
32 words
An apparatus of claim 6 wherein the pinning means comprises an air knife positioned above the touchdown point of the polymeric web and extending substantially the full width of the extruded web.
Claim 10
Dependent Claim
35 words
An apparatus of claim 6 wherein the pinning means comprises a pressure box for applying a uniform field of air pressure onto the surface of the polymeric web after its touchdown onto the quenching surface.
Claim 11
Dependent Claim
112 words
An apparatus of claim 6 wherein the bearing is stationary and porous and the means for providing a layer of fluid comprises a pressurized fluid source connected to the interior of the bearing whereby the fluid passes through the porous surface of the bearing to form a layer thereon and wherein the means for pinning the polymeric web to the quenching surface includes: electrostatic edge probes for imparting an electrostatic charge to the polymeric web thereby causing the edges to closely adhere to the quenching surface, and a pressure chamber for applying a uniform field of air pressure onto the surface of the polymeric web after its touchdown onto the quenching surface.
Claim 12
Dependent Claim
40 words
An apparatus of claim 1 in which the fluid is a gas and the pressure of the gas is adjusted to provide a layer on the surface of the bearing having a thickness of about from 0.1 to 15 mils.
Claim 13
Dependent Claim
10 words
An apparatus of claim 1 wherein the bearing is rotatable.
Claim 14
Dependent Claim
12 words
An apparatus of claim 1 wherein the bearing is stationary and porous.
Claim 15
Dependent Claim
13 words
An apparatus of claim 13 wherein the bearing has a substantially tubular configuration.
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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) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |