US3125847A - Means for and method of collecting - Google Patents

Description

March 24, 1964 B. LINDER ETAL 3,125,847 MEANS FOR AND METHOD OF COLLECTING STAPLE FIBERS Filed Feb.- 18, 1959 24 l4 3 24 o I 9 |9 7 2l8 4 l2 22 i I I III .LFJ 1 BERND LINDER EDWARD L.AHLSTROM INVENTORS BY wiw M ATT ORNEYS United States Patent 3,125,847 MEANS FOR AND METHOD OF COLLECTING STAPLE FIBERS Bernd Linder, Belmont, and Edward L. Ahlstrom, Reading, Mass., assignors to Avco Manufacturing Corporation, Cincinnati, Ohio, a corporation of Delaware Filed Feb. 18, 1959, Ser. No. 794,026 20 Claims. (Cl. 5758.89)

This invention relates to a method of and apparatus for collecting staple fibers. While the invention is par ticularly suited for converting silica fibers into rovings, its application is not limited thereto and the process may be applied to glass, other thermoplastic materials, and mineral compositions, for example. The term roving is used herein as it is used in the textile field and describes a yarn-like product in which the fibers are substantially parallel to each other.

Heretofore silica rovings were produced by combining a plurality of extruded monofilaments of the basic silica material. Extruding silica monofilaments is an extremely delicate operation requiring a high degree of skill, and the production yield of the monofilaments is low, partly due to the nature of the extrusion process and partly due to the careful handling required by the inherently brittle filaments.

It was found in practice that the techniques developed in making glass fibers and rovings could not be applied to silica because of its extremely high melting temperature, as compared to that of glass. Materials suitable for containing molten silica, or working it in a plastic state, are not available.

In addition, the conventional methods of making both fibers and rovings, whether of silica or glass, are slow. In contrast, the novel invention set forth herein produces both the fibers and the rovings at an extremely high rate beyond the capabilities of the prior art.

The fibers produced by the present process diifer from monofilaments in that they have short finite lengths, in the order of two to four inches. Immediately after formation, the fibers are supported in a high velocity stream. Early attempts to collect these fibers from the stream and to convert them into rovings by conventional textile carding techniques failed. Being inherently brittle, the silica fibers were destroyed during carding by the attrition of the fibers rubbing together. Through use of the present invention it is possible to collect the short silica fibers from the stream and to transform them into an integrating roving in a simple and inexpensive manner.

It is an object of the invention to provide a method of collecting staple fibers which avoids one or more of the limitations and disadvantages of prior methods.

It is another object of the invention to provide a method of and apparatus for converting staple fibers, as they are produced, directly into a roving.

It is still another object of the invention to provide an inexpensive and efficient method of collecting staple fibers.

Other objects of the invention are:

(1) Utilization of a roving as a fiber collection medium for accumulating staple fibers.

(2) Provision of means for coating the staple fibers prior to their conversion into a roving.

(3) Provision of a method of making a roving in which the quantity of roving produced is balanced against the quantity of fibers produced.

(4) Provision of a fiber collection method which makes use of the mutual adhesion between staple fibers.

(5) Provision of a fiber collection method particularly suited for collecting staple fibers produced at a high rate.

(6) Provision of a method of producing a roving the cross section of which may be varied and regulated.

The novel method of collecting staple fibers as a roving comprises suspending the staple fibers in a fluid stream, preferably a high velocity air stream, and spraying a lubricant into the stream for coating the fibers. The fibers are then intercepted, causing them to adhere to one another to form an accumulation suspended in the fluid stream and extending in the direction of flow of the stream. Finally, a portion of the accumulation is continuously removed from the fluid stream without interrupting the collecting function of the accumulation that remains within the fluid stream. The process is a continuous one wherein the accumulation acts as a collecting medium for newly formed fibers.

The novel features that are considered characteristic of the invention are set forth in the appended claims; the invention itself, however, both as to its organization and method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specific embodiment when read in conjunction with the accompanying drawings, in which:

FIGURE 1 is a top view of an apparatus for the making and collecting of staple fibers embodying the principles of this invention;

FIGURE 2 is a side view of the device shown in FIGURE 1; and

FIGURE 3 is a fragmentary enlarged view of a roving showing the alignment of the staple fibers therein.

Referring to FIGURES 1 and 2 of the drawings, there is shown an apparatus for making and collecting silica fibers. Shown is a fiber producing means, comprising a ceramic metallizing gun 10, available as a commercial apparatus under the name of Mogul Turbo-jet Type R-l, made by the Metallizing Company of America. The metallizing gun 10 softens silica rod 11 and delivers the molten silica to a high velocity fluid stream, preferably a stream of air although steam is also suitable. The high velocity fluid stream draws and attenuates the molten silica into fine staple fibers 9, in the order of two to four inches in length. The drawn staple fibers 9 emerge from nozzle 12 at the front of the metallizing gun along with the fluid stream. The staple fibers 9 are thus floated, or suspended, in the fluid stream and together with the fluid stream comprise a high velocity fiber stream 13. The metallizing gun 10 constitutes one means for producing a fiber stream and is not exhaustive of the devices available. For example, silica rod may be melted and blown in a high temperature plasma are instead of metallizing gun 10.

As seen in FIGURES 1 and 2, the fiber stream 13 is directed outwardly from the metallizing gun 10 and at a slightly elevated angle. Shortly after the fiber stream 13 leaves the metallizing gun 10, it passes through transverse lubricant sprays 14 in which the staple fibers are coated with a suitable lubricant, a polyvinyl alcohol-oil emulsion for example. The lubricant encourages adhesion between the staple fibers and also tends to reduce abrasive breakage during collection when the fibers are moved relative to one another. The lubricant sprays comprise a mixture of air and lubricant, and are formed by a pair of nozzles 16 located adjacent to and pointing into the fiber stream. The lubricant sprays also tend to prevent the fiber stream 13 from dispersing laterally.

After passing through the lubricant sprays 14, the fiber stream 13 is intercepted by a generally elongated body extending in the direction of the fiber stream 13. This horizontal body, hereinafter called accumulation 17, is suspended Within the air stream and extends through a funnel 18. The accumulation functions as a collection medium for the fibers suspended within the fiber stream 13. It intercepts these fibers, causing them to adhere to it and to one another. The adhesion is effected partly by the natural aifinity the fibers have for one another and partly by the adhesive properties of the lubricant coating.

As seen in FIGURES l and 2 the accumulation buildup is nonuniform in cross section. It is maximum at or near the funnel 18 and gradually tapers away to a vanishing point at an end 19 remote from the funnel 18. The fibers comprising the accumulation 17 are generally aligned in the direction of the fluid stream. As a fiber 9 in the fluid stream 13 comes, contacts and adheres to the accumulation, the fluid stream aligns it in the direction of the fluid flow. In the course of forming the accumulation 17, a staple fiber in the fluid stream 13 first adheres to one or more fibers making up the accumulation 17 and then to newly arrived fibers. The adhesion between fibers is manifestly great enough to overcome the force of the high velocity fluid stream, and the result is a selfsupporting build-up of aligned fibers which eventually form a roving.

The accumulation 17 at the mouth of the funnel 18 is outside of the fiber stream 113 and, therefore, no longer collects newly blown fibers. At this time, the accumulation may be considered to be a roving, designated for distinguishing purposes by the numeral 21. The roving 21 passes from the funnel to a take-up means comprising a spool 22 which is rotated at a uniform rate by a motor assembly 25.

The take-up spool 22 exerts a constant force tending to withdraw the accumulation 17 from the fiber stream 13- at a uniform rate. The withdrawal rate is adjusted so that the accumulation 17 collects fibers as fast as they are produced. It is obvious, that the cross section of the roving is a function of the withdrawal rate. In other words, if the rotational speed of the take-up spool 22 is high, the accumulation 17 passes through the fiber stream 13- in a small interval of time thus enabling it to collect only a small number of fibers. On the other hand, if the takeup velocity is low, the accumulation 17 is in contact with the fiber stream for a greater length of time thus enabling it to intercept and collect a greater quantity of fibers. For the reasons just discussed the gauge, or width of the accumulation 17, and consequently the roving 21 is easily varied. It has also been found that when the Withdrawal velocity is kept constant, a roving having a uniform gauge is produced.

The apparatus also includes auxiliary jets 23 which provide auxiliary fluid streams 24 for maintaining the accumulation 17 in a substantially horizontal position. Generally, the number of auxiliary jets employed and their location relative to the fluid stream 13 will vary with the apparatus employed to practice the invention and the nature of the fluid available. Both of these considerations are easily handled by a skilled practitioner. The auxiliary fluid streams 24 also have the effect of focusing the fiber stream 13 in a horizontal direction and preventing it from dispersing. T hus auxiliary fluid streams 24, in conjunction with the previously described lubricating sprays "14, tend to prevent the fiber stream 13 from dispersing and to channel it, and the fibers 9= suspended therein in particular, into contact with accumulation 17. The auxiliary fluid streams 24 merge with the fiber stream 13 to form a composite stream in which the staple fibers are suspended and in which the accumulation is suspended and its position stabilized.

The accumulation 17 responds to the dominant forces in the composite stream of fluid and assumes a cantilevered construction extending in the direction of the composite stream. In FIGURE 2 it is apparent that the composite stream and accumulation extend in a horizontal direction.

The direction of the composite stream diifers from the fiber stream 13 due to the placement of the auxiliary jets 23, as indicated in FIGURES 1 and 2, and interaction of the auxiliary fluid streams 24 and the fiber stream 13 4 whether turbulence exists in the composite stream is immaterial so long as the dominant force develops a composite stream moving linearly.

The apparatus for and method of collecting fibers just described comprises a simple, inexpensive system for collecting staple silica fibers into a roving. In FIGURE 3 of the drawings, there is shown a greatly enlarged representation of a section of roving. It will be noted that the staple fibers therein are longitudinally aligned. In converting the blown fibers directly into a roving the normal intermediate carding step is eliminated.

This is particularly significant when working with silica because of the abrasive nature of the material. In a carding operation, a random accumulation of fibers is converted to a generally aligned accumulation. The process involves a great deal of relative movement between contiguous fibers, much of which occurs in a transverse direction. The fine fibers act as cutting edges tending to weaken or cut through the fibers. In the process disclosed herein the relative movement occurs between substantially parallel fibers, a condition which minimizes the cutting effect between fibers.

It has also been found that the process is operable and effective if the fibers are not lubricated prior to their collection. However, a roving comprising nonlubricated fibers has been found to be somewhat weaker in tensile strength than one containing lubricated fibers.

It is clear from the foregoing description and operation that the process is a balanced and continuous one. The fibers are collected as they are formed and the accumulatfiion 17 acts as a collecting medium for the newly blown 1 bers.

To complete this discussion it is merely necessary to indicate how the process is initiated. To initiate the process, the metallizing gun, the lubricant spray and the auxiliary spray are first activated. A rod, not shown, is then inserted through the large opening of the funnel 18 and out of the small opening and into the fiber stream 13. The rod acts, at this time, as the collection medium and the fibers in the fiber stream 13 adhere to it and to themselves to form an accumulation 17. The rod is then slowly withdrawn from the fiber stream without removing the formed accumulation 17 from the fiber stream 13 and without interrupting its collecting function. After the rod is removed from the funnel 18, the roving connected to it is removed and wound on the take-up spool 22. Thereafter the process becomes a self-supporting and contmuous one.

The various features and advantages of the invention are thought to be clear from the foregoing description. Various other features and advantages not specifically enumerated will undoubtedly occur to those versed in the art, as likewise will many variations and modifications of the preferred embodiment illustrated, all of which may be achieved without departing from the spirit and scope of the invention as defined by the following claims.

We claim:

1. A method of collecting staple fibers as a roving compr1s1ng: suspending the fibers in a linearly directed nonrotational fluid stream; intercepting the fibers in the stream; and causing them to adhere to one another in a substantially linear parallel relationship and to form an accumulation suspended by the fluid stream.

2. A method of collecting staple fibers as a roving as described in claim 1 in which said fluid stream is a high velocity gas.

3. A method of collecting staple fibers as a roving comprising: suspending the fibers in a linearly directed nondirection Opposite to the direction of the fluid is formed whereby a roving is produced.

4. A method of collecting staple fibers as a roving comprising: suspending the fibers in a linearly directed nonrotational fluid stream; injecting a lubricant into the fluid stream for coating the fibers; intercepting the fibers in the fluid stream causing them to adhere to one another in a substantially linear parallel relationship and to form an elongated accumulation suspended in the fluid stream; supporting one end of said accumulation to maintain it in a fixed position in the fluid stream and suspended thereby; directing auxiliary fluid streams into the first mentioned fluid stream for focusing the fibers against said accumulation; and continuously withdrawing a portion of the accumulation in a direction opposite to the direction of flow of the first mentioned fluid stream at a preselected rate for forming a roving having a predetermined gauge.

5. A method of making and collecting silica fibers as a roving comprising; supplying silica to a metallizing gun for melting the silica and attenuating the molten silica into staple fibers by spraying the melt out of the gun in a high velocity nonrotational air stream, the fibers being suspended in the air stream; spraying a mixture of air and lubricant into the air stream for coating the fibers; intercepting the fibers causing them to adhere to one another in a substantially linear parallel relationship to form an accumulation; supporting the accumulation by the air stream to continuously intercept silica fibers; and continuously withdrawing a portion of the accumulation in a direction opposite to the direction of flow of the air stream to form a continuous roving.

6. A method of making and collecting silica fibers as a roving as described in claim 5 which includes, in addition, directing an auxiliary fluid stream into the air stream for focusing the silica fibers on the accumulation.

7. A method of collecting staple fibers as a roving comprising: forming a jet of fluid; suspending staple fibers in said jet of fluid; and intercepting said staple fibers in said jet of fluid as a continuous accumulation.

8. A method of collecting staple fibers as a roving comprising: forming a jet of fluid; suspending staple fibers in said jet of fluid; and inserting means in said jet of fluid for intercepting said fibers causing them to adhere to said means as a continuous accumulation suspended in the jet of fluid.

9. A method of collecting staple fibers as a roving comprising: forming a jet of fluid; suspending staple fibers in said jet of fluid; intercepting said staple fibers in said jet of fluid causing them to adhere to one another and to form an accumulation; and slowly withdrawing said accumulation in a direction opposite to the direction of flow of said jet of fluid without interrupting the collection of fibers.

10. A method of collecting staple fibers as a roving comprising: forming a first nonrotational stream of fluid; suspending staple fibers in said first nonrotational stream of fluid; directing a second nonrotational stream of fluid against said first stream of fluid to reduce dispersion of said staple fibers; and intercepting said staple fibers and collecting them in an accumulation.

11. A method of collecting staple fibers comprising: forming a first nonrotational stream of fluid; suspending staple fibers in said first nonrotational stream of fluid; directing a second nonrotational stream of fluid against said first nonrotational stream of fluid to linearly collimate said staple fibers; intercepting said staple fibers causing them to form an accumulation; and removing the accumulation from said first nonrotational stream of fluid in a direction opposite to the direction of flow of said first nonrotational stream of fluid without interrupting the accumulation of fibers.

12. A method of collecting staple fibers as a roving comprising: suspending staple fibers in a substantially laminar stream of fluid; intercepting said staple fibers and collecting them in an accumulation; and directing a sec- 0nd stream of fluid against said laminar stream of fluid tending to move said suspended fibers into contact with said accumulation.

13. A method of making and collecting silica fibers as a roving comprising: melting silica and attenuating the molten silica into staple fibers by the interaction of the molten silica and a high velocity, nonrotational .fluid stream, the fibers formed thereby being suspended within said fluid stream; directing auxiliary streams of fluid on said fiber stream for preventing the dispersion of the fibers, said fiber stream and said auxiliary stream of fluid merging into a composite stream of fluid; inserting means in the composite stream of fluid for intercepting the silica fibers, causing them to adhere to the means and to one another; withdrawing the collecting medium from the composite stream of fluid at a rate which permits newly formed fibers to be intercepted by the previously collected fibers to form an accumulation suspended by and stabilized in position by said composite stream of fluid; continuously withdrawing a portion of the accumulation from the composite stream of fluid in a direction opposite to the direction of flow of the composite stream of fluid while the remaining portion of the accumulation in the composite stream of fluid continues to collect newly formed fibers; and winding the accumulation on a collection spool.

14. A method of collecting staple fibers as a roving comprising: forming a first jet of fluid; suspending staple fibers in said first jet of fluid directing a second jet of fluid against the said first jet of fluid for reducing dispersion of said staple fibers, said first and second jets of fluid forming a composite jet of fluid having said staple fibers suspended therein; intercepting said staple fibers in said composite jet of fluid causing them to form a continuous accumulation; and slowly withdrawing said accumulation in a direction opposite to the direction of flow of the composite jet of fluid without interrupting the accumulation of fibers.

15. A method of collecting staple fibers as a roving comprising: suspending staple fibers in a first jet of fluid; directing a second jet of fluid against said first jet of fluid to reduce dispersion of said suspended fibers, said first and second jets of fluid merging into a composite jet of fluid; and intercepting said staple fibers in said composite stream of fluid causing them to form an accumulation.

16. An apparatus utilizing a fiber accumulation for collecting staple fibers as a roving comprising: means for forming a stable fiber suspension in a jet fluid stream,

guide means for supporting the fiber accumulation in suspension Within the jet fluid stream for intercepting the suspended fibers in a substantially parallel relationship; and take-up means adapted to continuously withdraw a portion of the fiber accumulation from the jet fluid stream in a direction opposite to the direction of flow of jet fluid stream without interrupting the fiber intercepting function of the remaining portion.

17. An apparatus utilizing a fiber accumulation for collecting staple fibers as a roving comprising: means for forming a staple fiber suspension in a jet of fluid; guide means for slidably supporting one end of the fiber accumulation, said other end being in suspension within the jet of fluid and supported thereby for intercepting the suspended fibers; and take-up means adapted to continuously withdraw a portion of the fiber accumulation from the jet of fluid in a direction opposite to the direction of flow of the jet of fluid without interrupting the fiber intercepting function of the remaining portion.

18 An apparatus utilizing a fiber accumulation for collecting staple fibers as a roving comprising: means for forming a stable fiber suspension in a first jet of fluid; means for directing a second jet of fluid against the first jet of fluid for preventing the dispersion of the fibers suspended in the latter, said first and second jets of fluid merging into a composite jet of fluid; and guide means for slidably supporting one end of the fiber accumulation,

said other end being suspended in said composite jet of fluid and supported thereby, for intercepting the suspended fibers.

19. An apparatus as described in claim 18 in which said second jet of fluid is directed laterally into said first stream of fluid, and includes a component of velocity in the direction of flow of said first stream of fluid.

20. An apparatus for collecting staple fibers as a roving comprising: means for forming a stable fiber suspension in a nonrotational stream of fluid; auxiliary fluid means interacting with said nonrotational stream of fluid to form a composite nonrotational stream of fluid for reducing dispersion of said fibers suspended in said nonrotational stream of fluid; and guide means for slidably supporting one end of the fiber accumulation, said other end being inserted in said composite stream of fluid for intercepting fibers therein forming an accumulation.

References Cited in the file of this patent UNITED STATES PATENTS 2,451,504 Mayo Oct. 19, 1948 2,686,954 Parker Aug. 24, 1954 2,787,314 Anderson Apr. 2, 1957 2,801,189 Collier July 30, 1957 2,911,783 Gotzfried Nov. 10, 1959 2,931,421 Schuller Apr. 5, 1960 FOREIGN PATENTS 536,990 Canada Feb. 12, 1957 536,991 Canada Feb. 12, 1957

Claims (1)

13. A METHOD OF MAKING AND COLLECTING SILICA FIBERS AS A ROVING COMPRISING: MELTING SILICA AND ATTENUATING THE MOLTEN SILICA INTO STAPLE FIBERS BY THE INTERACTION OF THE MOLTEN SILICA AND A HIGH VELOCITY, NONROTATIONAL FLUID STREAM, THE FIBERS FORMED THEREBY BEING SUSPENDED WITHIN SAID FLUID STREAM; DIRECTING AUXLIARY STREAMS OF FLUID ON SAID FIBER STREAM FOR PREVENTING THE DISPERSION OF THE FIBERS, SAID FIBER STREAM AND SAID AUXILIARY STREAM OF FLUID MERGING INTO A COMPOSITE STREAM OF FLUID; INSERTING MEANS IN THE COMPOSITE STREAM OF FLUID FOR INTERCEPTING THE SILICA FIBERS, CAUSING THEM TO ADHERE TO THE MEANS AND TO ONE ANOTHER; WITHDRAWING THE COLLECTING MEDIUM FROM THE COMPOSITE STREAM OF FLUID AT A RATE WHICH PERMITS NEWLY FORMED FIBERS TO BE INTERCEPTED BY THE PREVIOUSLY COLLECTED FIBERS TO FORM AN ACCUMULATION SUSPENDED BY AND STABILIZED IN POSITION BY SAID COMPOSITE STREAM OF FLUID; CONTINUOUSLY WITHDRAWING A PORTION OF THE ACCUMULATION FROM THE COMPOSITE STEAM OF FLUID IN A DIRECTION OPPOSITE TO THE DIRECTION OF FLOW OF THE COMPOSITE STREAM OF FLUID WHILE THE REMAINING PORTION OF THE ACCUMULATION IN THE COMPOSITE STREAM OF FLUID CONTINUES TO COLLECT NEWLY FORMED FIBERS; AND WINDING THE ACCUMULATION ON A COLLECTION SPOOL.

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