US3819345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of fibers from thermoplastic materials, particularly glass fibers
Assignee: Compagnie de Saint Gobain SA
•
Filing: 1972-03-29
•
Granted: 1974-06-25
•
Expires: 1992-03-29
Abstract
Abstract The production of fibers from thermoplastic materials, particularly glass fibers, by feeding a molten stream of the material into the interior of a hollow centrifuge body of enlarged diameter rotating rapidly around a vertical axis, which body is provided with a peripheral wall of substantial height which is pierced with a large number of rows of orifices through which the molten material is projected by centrifugal force in the form of filaments, which are then attenuated into fibrous form by hot gaseous blasts acting in a direction transverse to the planes of emission of the filaments. The deformation of the centrifuge body is reduced and its operating life is extended by critically controlling the temperature of the molten material which is projected through the orifices by first directing the incoming stream of molten material onto an annular supporting element or flange which is integral with the lower edge of said peripheral wall and extending inwardly therefrom, wherefrom the molten material is distributed in an upward direction along the interior face of said peripheral wall in position to be projected through the orifices therein. The introduction of the molten material upwardly from the annular flange or support element enables the accurate control of the temperature of the molten material by heating the latter or the support element so that the temperature of the peripheral wall is substantially constant along the entire height thereof, resulting in the production of fibers of uniform characteristics.
Inventors
- 👤 J Battigelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:39
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/04; C03B37/045; C03B37/048
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
239 words
The method of producing fibers from molten thermoplastic material by projecting by centrifugal force, the molten material which is fed to the interior of a rapidly rotating hollow body having an annular surface at the lower end thereof, through a large number of rows of orifices in the high peripheral wall of said body, and thereafter attenuating the filaments projected from said orifices, which comprises a. dropping a stream of the molten material to the lower end of said hollow body, b. causing the molten material within the hollow body to flow laterally on said annular surface at said lower end by centrifugal force, towards the lower part of the peripheral wall in the shape of a thin sheet, preparatory to the travel of the material upwardly adjacent to the inner surface of said peripheral wall with the orifices therein, to scatter the molten material therearound, c. maintaining the temperature of said annular surface close to the temperature of said peripheral wall, with a permissible low temperature gradient in said annular surface in the radial direction, so that the temperature of the thermoplastic material when it reaches said inner surface is sufficiently high for projection through the orifices therein, and d. distributing the material upwardly therefrom along the entire height of the peripheral wall to present a layer of the material behind all the orifices therein at a substantially uniform temperature for projection by centrifugal force through said orifices.
Claim 2
Independent Claim
239 words
The method of producing fibers from molten thermoplastic material by projecting by centrifugal force, the molten material which is fed to the interior of a rapidly rotating hollow body having an annular surface at the lower end thereof, through a large number of rows of orifices in the high peripheral wall of said body, and thereafter attenuating the filaments projected from said orifices, which comprises a. dropping a stream of the molten material to the lower end of said hollow body, b. causing the molten material within the hollow body to flow laterally on said annular surface at said lower end by centrifugal force, towards the lower part of the peripheral wall in the shape of a thin sheet, preparatory to the travel of the material upwardly adjacent to the inner surface of said peripheral wall with the orifices therein, to scatter the molten material therearound, c. maintaining the temperature of said annular surface close to the temperature of said peripheral wall, with a permissible low temperature gradient in said annular surface in the radial direction, so that the temperature of the thermoplastic material when it reaches said inner surface is sufficiently high for projection through the orifices therein, and d. distributing the material upwardly therefrom along the entire height of the peripheral wall to present a layer of the material behind all the orifices therein at a substantially uniform temperature for projection by centrifugal force through said orifices.
Claim 3
Dependent Claim
28 words
The method set forth in claim 1, wherein said temperature gradient is lower than 15*C. per cm. from the inner edge of said surface to said peripheral wall.
Claim 4
Dependent Claim
17 words
The method set forth in claim 2, wherein the diminishing temperature gradient is approximately 5*C. per cm.
Claim 5
Dependent Claim
39 words
The method set forth in claim 1, wherein the stream of molten material is dropped into said hollow body along the rotary axis thereof onto a distributing member, wherefrom it is projected by centrifugal force onto said annular surface.
Claim 6
Dependent Claim
38 words
The method set forth in claim 1, wherein the stream of molten material is dropped into said hollow body at a point displaced from the rotary axis thereof and adjacent to the inner boundry of said annular surface.
Claim 7
Dependent Claim
39 words
The method set forth in claim 4, including the step of inductively heating the molten material in the course of its lateral flow on said annular surface towards the bottom edge of the internal surface of said lateral wall.
Claim 8
Dependent Claim
34 words
The method set forth in claim 5, wherein the displacement of the dropping stream of molten material from the rotary axis of the hollow body is greater than one-fourth the diameter of the latter.
Claim 9
Dependent Claim
39 words
The method set forth in claim 1, including the step of heating the molten material in the course of its travel to the lower end of said hollow body by applying heat directly to the stream of molten material.
Claim 10
Dependent Claim
35 words
The method set forth in claim 1, wherein the layer of material distributed upwardly along the entire height of the peripheral wall diminishes in depth from the lower to the upper part of said layer.
Claim 11
Dependent Claim
44 words
The method set forth in claim 1, wherein the layer of material distributed upwardly along the entire height of the peripheral wall is of substantially uniform depth to subject the molten material adapted to be discharged from the orifices to substantially the same pressure.
Claim 12
Dependent Claim
22 words
The method set forth in claim 1, wherein the molten thermoplastic material is a vitreous composition for The production of glass fibers.
Claim 13
Independent Claim
226 words
An apparatus for the production of fine fibers from molten thermoplastic material, particularly molten glass, which comprises a. a hollow centrifuge rotatable about a vertical axis and having a peripheral wall of substantial height provided with a large number of superposed rows of orifices therein through which are adapted to be projected filaments by centrifugal force, with an annular metallic reenforcing support extending inwardly from the lower end of said peripheral wall, b. a hollow rotary shaft supporting said centrifuge at the lower end thereof, c. means for rapidly rotating said shaft and centrifuge, d. an annular combustion chamber above said rotary centrifuge and fitted with an annularly-shaped blower slot immediately beyond said peripheral wall to direct downwardly combustion gases at high temperature and velocity beyond said peripheral wall for attenuating said filaments into thin fibers, e. means for feeding a stream of the molten material to the interior of said centrifuge and directing it laterally by centrifugal force onto said annular support towards the lower edge of the internal surface of said peripheral wall, wherefrom it spreads upwardly to present a layer of the material behind all the orifices therein at a substantially uniform temperature for projection by centrifugal force through said orifices, and f. heating means for said molten material to maintain the temperature thereof substantially constant at all the superposed rows of orifices.
Claim 14
Independent Claim
226 words
An apparatus for the production of fine fibers from molten thermoplastic material, particularly molten glass, which comprises a. a hollow centrifuge rotatable about a vertical axis and having a peripheral wall of substantial height provided with a large number of superposed rows of orifices therein through which are adapted to be projected filaments by centrifugal force, with an annular metallic reenforcing support extending inwardly from the lower end of said peripheral wall, b. a hollow rotary shaft supporting said centrifuge at the lower end thereof, c. means for rapidly rotating said shaft and centrifuge, d. an annular combustion chamber above said rotary centrifuge and fitted with an annularly-shaped blower slot immediately beyond said peripheral wall to direct downwardly combustion gases at high temperature and velocity beyond said peripheral wall for attenuating said filaments into thin fibers, e. means for feeding a stream of the molten material to the interior of said centrifuge and directing it laterally by centrifugal force onto said annular support towards the lower edge of the internal surface of said peripheral wall, wherefrom it spreads upwardly to present a layer of the material behind all the orifices therein at a substantially uniform temperature for projection by centrifugal force through said orifices, and f. heating means for said molten material to maintain the temperature thereof substantially constant at all the superposed rows of orifices.
Claim 15
Dependent Claim
24 words
An apparatus as set forth in claim 12, wherein said annular support is formed of the same metal as that of said peripheral wall.
Claim 16
Dependent Claim
29 words
An apparatus as set forth in claim 12, wherein said annular metallic support is of a radial width which is less than one-fourth the diameter of said peripheral wall.
Claim 17
Dependent Claim
37 words
An apparatus as set forth in claim 12, wherein said hollow centrifuge has a diameter ranging from 300mm. to 400mm. and the peripheral wall of which is provided with 10 to 20 superposed rows of orifices therein.
Claim 18
Dependent Claim
45 words
An apparatus as set forth in claim 12, wherein said last-mentioned heating means comprises an electric inductive heating coil in a substantially horizontal plane perpendicular to the rotary axis of the centrifuge and below said annular metallic support for inducing heating effects in the latter.
Claim 19
Dependent Claim
29 words
An apparatus as set forth in claim 16, including means for energizing said heating coil with alternating electrical currents of medium frequency ranging from 6 kc. to 20 kc.
Claim 20
Dependent Claim
29 words
An apparatus as set forth in claim 16, including means for energizing said heating coil with alternating electrical currents of high frequency ranging from 100 kc. to 300 kc.
Claim 21
Dependent Claim
38 words
The method set forth in claim 1, including the step of heating the molten material in the course of its lateral flow on said annular surface towards the bottom edge of the internal surface of said lateral wall.
Claim 22
Dependent Claim
60 words
An apparatus as set forth in claim 12, wherein said feeding means comprises a circular member at the bottom of said rotary shaft concentric with said annular metallic support for receiving a stream of the molten material dropping downwardly through said hollow shaft and throwing said material centrifugally therefrom onto said annular metallic support for travel towards said peripheral wall.
Claim 23
Dependent Claim
67 words
An apparatus as set forth in claim 12, wherein said feeding means comprises an annular channel member supporting the bottom of said rotary shaft inwardly of said annular metallic support, said channel member adapted to receive the stream of molten material along a line displaced from the rotary axis of said centrifuge and scatter it centrifugally onto said annular metallic support for travel towards said peripheral wall.
Claim 24
Dependent Claim
33 words
An apparatus as set forth in claim 21, wherein said annular channel member comprises an upstanding annular partition along its inner boundary for preventing the molten material From contacting said hollow rotary shaft.
Claim 25
Dependent Claim
21 words
An apparatus as set forth in claim 21, wherein said annular channel member is formed integrally with said annular metallic support.
Claim 26
Dependent Claim
27 words
An apparatus as set forth in claim 15, wherein the diameters of the orifices in the peripheral wall diminish from the upper rows to the lower rows.
Claim 27
Dependent Claim
58 words
An apparatus as set forth in claim 12, including a partition wall in said centrifuge above said annular metallic support and laterally displaced from said peripheral wall for defining an annular chamber of substantially uniform cross-section for permitting a reserve supply of the molten material to constitute the layer thereof behind all the orifices in said peripheral wall.
Claim 28
Dependent Claim
25 words
An apparatus as set forth in claim 25, wherein the spacing of said partition wall from said annular metallic support ranges from 5mm. to 10mm.
Claim 29
Dependent Claim
28 words
An apparatus as set forth in claim 25, including an annular lining of insulating material for said partition wall on the face thereof remote from said annular chamber.
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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |