US2605500A - Method and apparatus for forming fibers - Google Patents

Description

Aug. 5, 1952 E..R. POWELL METHOD AND APPARATUS FOR FORMING IBER-S BY/U 0 Filed Sept. 50. 1949 IT' ENT R ATTORNEY Patented Aug. 5, 1952 liiETHOD AND APPARATUS FOR FORMING FIBERS Edward R. Powell, North Plainfield, N. J., as-

signor to Johns-Manville Corporation, New York, N. Y., a corporation of New York Application September 30, 1949, Serial No. 118,815

18 Claims.

The instant invention relates to a method and apparatus for producin fine fibers and, although it is particularly directed to, and will be described in connection with the manufacture of fibers from glass and similar thermoplastic or meltable materials, it is not to be considered as limited to such materials. Other plastic materials, such as polystyrene and melamine resins, and the like, from which fibers may be drawn can also be employed. The term glass is used herein in a generic sense to include glass compositions, synthetic low alkali glass, natural glass, mineral wool compositions, and the like.

A principal object of the invention is the provision of an economical method and apparatus for the production of extremely fine and shot-free fibers.

The methods previously proposed for the production of fine glass fibers have, for the most part, required the formation of relatively fine glass rods and their reduction to a multiplicity of fibers by feeding them into a high speed, high temperature, gaseous blast by which they are remelted and drawn or blown into fibrous form. An object of the instant invention is th provision of a method and apparatus which, in contrast to th prior methods referred to above, employs the operations of drawing preferably a plurality of filaments from a relatively viscous body of glass and further attenuating the individual filaments into fine filaments or fibers Without reheating. The method permits the use of more viscous melts than the prior methods and produces longer, more shot-free fibers.

A further object of the invention is the provision of a fiber forming apparatus which is economical in performance and operation and which is compactly arranged to require a minimum of space.

Briefly stated, the invention resides in a process comprising the steps of forming a layer of molten glass, moving a series of pins or projections into contact with and then away from the layer to draw filaments from the layer, and attenuating such filaments into long fine fibers by applying a drawing force transversely to the lengths of the filaments and while they are, at least during the major portion of th drawing operation, still attached to atleast one of the elements. The invention also resides in the apparatus for carrying out such method.

My invention will be mor fully understood and further objects and advantages will become apparent when reference is made to the mor detailed description of a preferred embodiment of 2 the invention which is to follow and to the accompanying drawings in which:

Fig. 1 is a View, partially in section and partially in elevation, illustrating an apparatus embodying the instant invention;

Fig. 2 is a sectional view taken on the line 2--2 of Fig. 1;

Fig. 3 is a sectional view, on an enlarged scale, taken on the line 3-3 of Fig. 2;

Fig. 4 is a sectional view, on an enlargedscal taken on the line 4-4 of Fig. 1; and,

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 2.

Referring now to the drawings, the apparatus includes a rotor Ill mounted on a shaft l2 for rotation in the direction indicated by arrow l3. Rotor I0 is of a construction to resist Warpage and excessive deterioration and wearunder the temperatures involved which for conventional glasses may run as high, for example, as 1900 F. to 2100 F. Suitably for this purpos it includes-a tire It made of a heat-resistant metal, such as non-ferrous nichrome, connected to a hub [6 by spokes [8, the intervals between the spokes being filled with a high temperature insulating mate-'- rial 20. The tire can also be of a suitable ceramic material. A second rotor 22 is mounted on a shaft 24 lying in parallelism with shaft I2. Rotorsv I0 and 22 are in alignment and portions of their peripheral surfaces lie in adjacent parallel, but noncontacting relationship, as will be later more fully explained. The peripheralsurface of rotor I0 is smooth whil that of rotor 22 is provided with a multiplicity of protuberances, specifically pins or projections 26, suitably equally spaced at relatively close intervals over the peripheral surface of the rotor. For example, the protuberances may be placed from 64. to 400 per sq. in. Rotor 22, except for the protuberances, is of similar construction to rotor l0 and is mounted for rotation in the direction indicated by arrow 27; that is, in a direction opposite to rotor ID. The rotors are driven by any suitabl means subject to speed control, the drive being diagrammaticallyillustrated at 28. l

A glass melting furnace 29 of any conventional or suitable type is mounted above the rotors with an outlet orifice 30. positioned to discharge a stream of glass 32 onto rotor mat a point on: a downturning arc of its peripheral surface.

A rockable shaft 34, mounted in suitable bearings, 36, carries a wiper blade 38 fixed to the shaft for movementwith the shaft, whereby the Wiping edge of the blade'may be adjusted toward and away from the surface of rotor ID to spread the a movement of the stretching disc.

material of stream 32 to a layer of predetermined thickness on the surface of the rotor. Suitable means may be employed for rocking shaft 3 3 to provide the desired adjustment within close tolerances. Such means is diagrammatically illustrated as a micrometer adjustment it.

A stretching disc 42 is mounted for rotation in the direction indicated by the arrow on a shaft 44, the disc being positioned to have a downturning are of its peripheral surface intercept fibers formed between the rotors. Opposite the stretching disc is a pusher wheel 45, mounted on a shaft 48 for rotation in a direction opposite to that of the stretching disc, as indicated by the arrow and at preferably the same peripheral speed. The periphery of the pushing wheel intercepts the fibers which are beyond the path of The shafts of the stretching disc and pusher wheel may be driven by any suitable mechanism indicated diagrammatically at 50. The periphery of disc d2 carries a continuous series of forwardly slanting pins 52 adapted to hook the fibers and carry them downwardly upon rotation of the disc. Pusher wheel 46 is suitably centrally grooved (see Fig. 3) and mounted relatively to the disc to receive the tips of the pins in the groove. The peripheral flanges defining the groove are preferably notched, as indicated, to prevent slipping of the fibers.

Means are provided for stripping fibers from the, stretching disc and for further drawing the fibers. Such means comprise gaseous jets directed downwardly adjacent the periphery of the disc and substantially at the point where the pins 52 point approximately downwardly. Suitably the jets are issued from a V-shaped nozzle 54 (see particularly Fig. having a series of orifices 56 pointing inwardly and downwardly to direct the jets in converging paths. The nozzle is connected by a line .58 to a supply of any suitable gas under pressure, such as compressed air or superheated steam. As will be appreciated, in lieu of asingle V-shaped nozzle, separate nozzles on opposite sides of the stretching disc may be used. Also, a nozzle located only on one side of the disc is operable but does not have the efficiency of other types which deliver converging jets.

The apparatus described above, with the exception of furnace 29, that is, rotors It and 22, the working portions of thestretching disc and the pusher wheel, and nozzle 54, are substantially enclosed by a casing 59. The casing is cut away at the bottom to points approximately beneath the rotor shafts, the cut away portions extending up the side walls sufficiently to provide clearance for the stretching disc, pusher wheel, nozzle, etc. An opening 60 is also provided in the upper Walls of the casingfor the entry of stream 32. The casing may consist of a steel shell 62 lined with a refractory material 64 of a character to resist the temperatures involved. The casing is .of a Width to closely embrace the rotors, as illustrated particularly in Fig. 2, and is of such length and height that the refractory lining is relatively close to the rotor peripheries. Burners 66 are mountedin apertures in the upper corners at the opposite ends of the casing. Each of the burners is positioned to direct its flame along the refractory walls of the casing. The flames extend completely along the walls, and tongues of flame issue from between the rotors and lower walls of the casing. The rotors andthe'air spaces between thewalls and the rotors are thus principallyheated by radiation-from the refractory d walls. The burners, which may be of conven tional type, are connected by lines 6'! to a supply (not shown) of a fuel such as a mixture of gas and air.

Suitable means are provided below the casing for collection of the fibers produced by the apparatus described above. This may comprise a foraminous or openwork conveyor 68 on which the fibers settle from an aeriform suspension to be continuously carried from the place of formation. A suction box (not shown) may be located below the upper reach of the conveyor to aid in the fiber collecting and felting operation.

In the operation of the apparatus and in carrying out the method of the instant invention for the formation of glass fibers, a suitable glass composition, which may be any of those available for fiber drawing, is melted in furnace 29 and is discharged as a continuous stream or a succession of drops or wads, both being referred to as stream 32, through orifice 30, the stream falling onto a downturning arc of the peripheral surface of rotor It. The body of material collected on the rotor is carried beneath blade 38 where it is spread width-wise of the rotor surface and leveled off to a layer of predetermined thickness by the blade. The blade is adjusted to leave a layer of such thickness that projections 36 on rotor 22 dip into the layer, but the layer is not squeezed or placed under pressure between the rotors. Rotors it and 22 are driven at the same, or substantially the same speed, and in opposite directions, as previously mentioned.

Burners 65 direct their flames along the walls of the casing, as explained above, and are adjusted to such intensity that the spaces inside the casing and the surfaces of the rotors, including pins 26, are maintained at temperatures sufficiently above the melting point of the particular glass used that the glass carried by the rotors is in a molten but viscous state.

As the surfaces of the rotors move apart, each of the projections 25 which contacts or dips into the layer of glass draws a fiber whereby a multiplicity of parallel fibers extend from the ends of the projections to the layer, the fibers being stretched, elongated, and further drawn as the surfaces of the rotors separate. Due to the fact that the pins are maintained at temperatures above the melting point of the glass, as mentioned above, the projections do not tend to accumulate glass on successive rotation of the rotors, an equilibrium point being quickly reached at which the amount of glass on the projections is substantially constant. The parallel fibers are carried into a position where they are picked up by the pins 52 of the stretching disc or are pushed by the pusher wheel into positions where they will be picked up by the pins. The stretching disc draws the fibers into extended Vs with the ends of the fibers still connected t the projections and to the glass layer.

The stretching disc carries the Vs into the convergence of the gaseous jets issuing from nozzle 5d, the blast of the jets impinging on the filaments and sliding them off the pins of the stretching disc and elongating them by drawing additional glass from the rotors. of the filaments to the pins 26 and to the layer of glass, or at least to one of them, continues until the connected end or ends of the fibers reach the points where they are impinged by the flame tips issuing from between the rotors and the bottom Walls of the casing. Particularly since the fibers are still under the tensionof the blast, they are immediately burned off. The fibers thus The connection aeoasoo formed are carried downwardly in the blast as velocity of, the steam blast may, of course, be

varied in relatively wide limits, depending on the glass melt and the character of the fibers to be obtained; In operation it has, been found that the rotors may be driven from 500 to 800 feet per minute for successful fiber drawing with conventional glasses. The blast issuing from nozzle 54 is maintained at a relatively high velocity, say, between 6,000 and 20,000 feet per minutein order to draw long fine fibers. Either high temperature steam or compressed air may be employed for the blast as itexerts only a pulling, and not a melting function. The stretching disc 42 is preferably driven at surface speed substantially twice or three times that of the rotors. say speeds of the order of 1,000 to 1,500 feet per minute. The apparatus is compact and highly efficient. A plurality of the devices may be placed side by side and supplied with streams of glass from a line of orifices 30 in the glass melting furnace 28. The heating system illustrated is highly efficient as the rotors are heated by directimpingement of the burner flames to some extent but mostly by the heat radiated from the refractory walls of the casing. The flame tips issuing from between the rotors and lower wall of the casing also cut off the fibers;, as explained above, and insure that they will not be drawn into the casing.

Fiber diameter may be controlled by adjustment of the rate of. flow of glass in relation to the rest of the equipment,- orby relative adjuststyrene and melamine resins, may be reduced to fiber by the instant method and apparatus. 7

Having thus described my invention in rather full detail, it will be understood that these details need not be strictly adhered to and that various changes and modifications may suggest themselves to one skilled in the art, all falling Much longer fibers are:

within the scope of the invention as defined by 1 the subjoined claims.

What I claim is:

1. A method of making fibers from molten material comprising forming a body of the molten material, contacting said body at a plurality of points by drawing means and drawing fibers from said body at said point by moving said drawing means relatively to said body,-intercepting said fibers during the fiber drawing operation by means moving in a direction transverse to the fibers to elongate the same, and subjecting said elongated fibers to the action of a gaseous blast to further elongate them.

2. A method of making fibers from fiber forming material comprising forming a layer of the material on a moving surface, contacting the layer with a plurality of elements, moving the elements in a path diverging from that of the surface to draw fibers from said layer, grasping said fibers during thefiber drawing operation by means moving in a path transverse to the length of said fibers and carrying-theminto the path of a gaseous blast.

3. A method ofunaking fibers from molten terial comprising forming a layer of the molten material on the peripheral surface of a rotor,

contacting said layer by a succession of pins the fibers to the action of the blast to elongate them.

4; In an apparatus for producing fibers, means for forming a body of fiber forming material,

means movable relatively away from said body for contacting said body ata plurality of points and drawing fibers therefrom, means for grasping said fibers at a point intermediate the ends thereof and stretching them into Vs, and means for setting up afluid blast directed to elongate the fibers. 5. In an apparatus for producing fibers, amovtoward said Vs able member, means for forming a layer of fiber forming material on the surfaceof the member, a second member carrying a plurality of elements and mounted for movement of said elements into contact with said layer and then away from said layer whereby fibers are drawn by the elements from the layenmeans for grasping said fibers intermediate the length thereof and stretching them into Vs, and means for setting up a fluid blast moving toward said Vs.

6. In an apparatus for producing fibers, a'rotor having a peripheral surface, means for forming a layer of fiber forming material thereon, asec- 0nd rotor having a plurality of elements projecting from the peripheral surface thereof, means for imounting said second rotor for contact of said elements with the layer on said first rotor whereby, upon rotation of said rotors, fibers are drawn from said layer by said elements, means including a plurality of elements moving in a direction transverse to the lengthof said fibers to contact said fibers and stretch the same into Vs, and means for projecting a gaseous blast against said Vs to elongate the fibers. I

7. In an apparatus for producing fibers, a rotor having a peripheral surface, means for forming a layer of fiber forming material thereon, means for controlling the thickness of said layer, a sec,- ond rotor mounted adjacent said first rotor and having a plurality of elements projecting from the peripheral surface thereof for contacting the layer on said first rotor whereby, upon rotation of said rotors, fibers are drawn from said layer, and means for applying forces to said fibers during the drawing operation and in a direction transverse to the length thereof to elongate said fibers.

8. In an apparatus for producing fibers, a rotor having a peripheral surface, means for forming a layer of molten material on said surface, a sec- 0nd rotor, fiber drawing means projecting from 9. In an apparatus for producing fibers, a rotor havinga peripheral surface, means for formin a layer of molten material on said surface, a second rotor, fiber drawing means projecting from the periphery of the second rotor, means mounting said second rotor for rotation with said fiber drawing means moving into and out of contact with said layer to draw fibers therefrom, means projecting between said rotors for applying elongating forces to said fibers in directions transverse to the lengths thereof, means partially enclosing said rotors to leave an opening adjacent the bottoms of the rotors, and burners directed to set up flames extending along the walls of said enclosure and into said opening whereby said walls radiate heat toward said molten layer and said flames burn ofi the ends of the fibers from the rotors. v

10. In an apparatus for producing fibers, a rotor having a peripheral surface, means for forming a layer of molten material on said surface, a second rotor, elements projecting from the periphery of the second rotor, means mounting said second rotor for rotation with said elements moving into and out of contact with said layer to draw fibers therefrom, a stretching disc having a succession of extending elements, means mounting said disc for rotation with said extending'elements moving in a path transverse to the directions of said fibers and to intercept fibers whereby the intercepted fibers are hooked by said extending elements and stretched into Vs,.and means for removing said fibers from said extending elements and further elongating the fibers.

11. In an apparatus for producing fibers, means for forming a continuous succession of fibers, a stretching disc having a succession of extending elements, means mounting said disc for rotation with said extending elements moving in a path transverse to the directions of said fibers and to intercept fibers, whereby the intercepted fibers are booked by said extending elements and stretched into Vs, and means for removing said fibers from said extending elements and further elongating the fibers.

12. In an apparatus for producing fibers, means for forming a continuous succession of fibers, a stretching disc having a succession of extending elements moving in a path transverse to the directions of said fibers and to intercept fibers, a pusher wheel mounted for rotation opposite said disc to push fibers into position for interception by saidelements, whereby the fibers are hooked by said extending elements and drawn into Vs and means for removing said fibers from said exfrom saidbody to draw fibers therefrom, applying a force to each fiber in a direction generally transversely of the length thereof, and elongating said fibers by continued application of said forces while the respective ends of said fibers are connected to said elements and said body.

15. A method of making fibersfrom fiber forming material comprising forming a layer of the material on a moving surface, contacting the layer with aplurality of elements, moving the elements in a path diverging from that of the surface to draw fibers from said layer, applying a force to each fiber in a direction generally transversely of the length thereof, and elongating said fibers by continued application of said forces while the respectiveends of said fibers are connected to said elements and said body.

16. Aimethod of making fibers from molten material comprising forming a layer of the molten material on the peripheral surface of a rotor, contacting said layer by a succession of projections extending from the periphery of a second rotor, maintaining said projections at temperatures above the melting point of the material, rotating said rotors in opposite directions whereby said projections draw fibers from said layer, applying a force to each fiber in a direction generally transversely of the. length thereof, and elongating said fibers by continued application of said forces while the respective ends of said fibers are connected to said elements and said body.

17. An apparatus for producing fibers comprising, means for forming a body offiber forming material, a plurality of elements, means for moving said elements into contact with and then relatively away from said body to. drawfibers therefrom, a plurality of members relatively movable into contact with intermediate portions of said fibers, and means for moving said members While in contact with said fibers in directions generally transversely of the fiber lengths to elongate said fibers."

18. An apparatus .for producing fibers comprising a first rotor having a peripheral surface, means for forming a layer of fiber forming material on said surface, a second rotor positioned adjacent said first rotor, projection means on said second rotor arranged to contact 'said layer, means for rotating said rotors whereby said projection means contact and then move relatively tending elements and further elongating the 13. A method of making fibers comprising forming a body of fiber forming material, contacting said body at a plurality of points, drawing fibers from the body at said points, applying a force to each fiberin a direction generally transversely of the length thereof, and elongating said fibers by continued application of away from said layer;to draw fibers therefrom, a plurality of members relatively movable into contact with intermediate portions of said fibers, and means for moving said members while in contact with said fibers in directions generally transversely of the fiber length to elongate said fibers.

EDWARD R. POWELL.

REFERENCES mm) The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,126,411 Powell a Aug. 9, 1938 2,385,358 Hanson Sept. 25, 1945 2,450,914 Powell Oct. 12, 1948 2,522,526 Manning Sept. 19, 1950

Images