US2795926A - Method for producing a continuous roving - Google Patents

Description

June 18, 1957 w. w. DRUMMOND METHOD FOR PRODUCING A CONTINUOUS ROVING 2 Sheets-Sheet 1 Filed Feb. 23, 1954 m T m m June 18, 1957 w. DRUMMOND 2,

METHOD FOR PRODUCING A CONTINUOUS ROVING Filed Feb. 23, 1954' 2 Sheets-Sheet 2 A TT RNE Y5 ited States Patent O METHOD FOR PRODUCING A CONTINUOUS ROVING Warren Wendell Drummond, Anderson, S. C., assignor to Owens-Coming Fiberglas Corporation, a corporation of Delaware Application February 23, 1954, Serial No. 411,778 Claims. (Cl. 57--164) This invention relates to a method for the production of a continuous multifilament roving comprising both continuous filaments and staple fibers intermatted and intertwisted together to produce a product having a high bulk factor and substantial tensile strength.

A product produced according to the invention will have the high tensile strength characteristic of the continuous fibers incorporated within it and a bulk factor resulting from the selected proportion of staple fibers which are intermatted and intertwisted with the continuous filaments. For example, if the product is a glass fiber product the high tensile strength of the continuous filaments will give the finished roving high tensile strength and the presence of the staple fibers intertwisted with the continuous filaments will bulk up the continuous filament both to protect them from interfilament abrasion and to provide for larger turning radii when the product is knotted.

The finished roving-like mass may be treated with suitable adhesives, binders, coatings or other resins to adhere the continuous and staple fibers together and to each other and to further provide protective coatings for both the continuous filaments and staple fibers. Such a product may be twisted tightly when manufactured according to the invention and when so twisted has utility as a tough twine of the type employed in binding and baling machines.

The process of the invention comprises the use of con tinuously operating means for producing both the continuous filaments and the staple fibers and for intertwisting them at high lineal speeds with the principle of random deposition being relied upon toproduce a continuous roving-like structure of constant average characteristics.

It is, therefore, the principal object of this invention to provide a method for continuously producing a tough strong twisted product in the nature of a strong cord, twine or roving.

It is yet another object of this invention to provide a process for the production of an all glass fiber twine which makes use of the high tensile strength characteristics of glass fibers to provide strength and wherein the glass fibers are protected against self-abrasion during subsequent use.

Other objects and advantages accruing from the process and apparatus of the invention will be better understood from the specification which follows and from the drawings in which:

Fig. l is a diagrammatic drawing of apparatus on which the process of the invention may be carried out, certain parts being shown fragmentarily and certain other parts being shown in section.

Fig. 2 is a view similar to Fig. l but showing only a portion of the apparatus shown in Fig. 1 illustrating a slight modification of the process of the invention for further increasing the bulk factor of the material being made.

Patented June 18, 1957 'ice Fig. 3 is a fragmentary view partly in elevation taken generally along the line 3-3 at the left side of Fig. 2.

Fig. 4 is a view similar to Fig. 1 but of a modified form of apparatus for carrying out the process of the invention.

The process of the invention comprises the production of both continuous filaments of glass and staple fibers of glass and the combination of the two types of fibers in controlled proportions for the fabrication of a rovinglike or twine-like article having the characteristics and qualities derivable from both forms of fibers. In Fig. 1 there is shown a conventional glass fiber forming apparatus generally indicated at 10 comprising a molten glass tank 11 and a bushing 12 through which streams of molten glass flow to form continuous glass fibers 13. The continuous fibers 13 are grouped together by being led over a gathering eye 14 and then directed downwardly between the contacting peripheries of a pair of high speed pulling wheels 15. The pulling wheels 15 apply tractive force to the mass of fibers 13 in the form of a glass fiber strand 16. The pulling force applied by the wheels 15 attenuates the fibers 13 from the glass streams flowing from the bushing 12 at a high lineal speed in the order, say of 10,000 feet per minute, and projects the strandv 16 downwardly along a substantially lineal path.

A rotary spinner generally indicated at 17 is so positioned that a plurality of axially extending pegs 18 mounted near the edge of a rotating disk 19 are repeatedly swung across the path of projection of the strand 16 so that the strand successively is engaged by each of the pegs 18 causing it to be formed into loops, for example, the loops indicated at 20 and 21 in Fig. 1, which are rotated around with the pegs 13 on which they hang. The disk 19 is mounted on a hollow axle 22 which is supported for rotation in bearings 23 on a bracket 24 and the axle 22 is driven by an electric motor 25 through a belt and pulley generally indicated at 26.

By controlling the speed of rotation of the spinner 17 with respect to the lineal speed of the strand 16 the degree of doubling up of the strand 16 on the pegs 18 can be precisely controlled.

By reaching up through the hollow axle 22 with a hooked instrument an operator succeeds in engaging one or more of the portions of the'strand 16 or the loops 20 being formed on the pegs 18 and spinning around with the spinner 17, and draws the engaged portions inwardly and axially through the hollow axle 22. The engaged end of the intertwisted mass is carried downwardly and through a guide 27 of a conventional balling machine generally indicated at 28 and then around a spool 22 of the machine. A driving roller 30 of the balling machine 28 is driven so that its peripheral speed is proportional to the lineal speed of the strand 16 by a factor equal to the degree of doubling up" desired so that a roving-like continuous mass 31 is formed comprising a number of generally parallel staggered loops 20 and 21 of the continuous strand 16 intertwisted together.

If the roving 31 is cut at any point along its length it will be found to have a cross section of the same number of sections of strand 16 and that number will be equal to the ratio between the lineal speeds of the strand 16 and the roving 31.

Rotation of the spinner 17 not only throws the loops 20 and 21 outwardly, distributing the continuous strand 16 over the entire surface of the spinner 17, but it also twists the loops 20 and 21 and similar loops together so that the roving 31 has a true twist. The degree of twist ing is determined by the ratios already mentioned between the speed of rotation of the spinner 17 and the lineal speed of the roving 31.

Staple glass fibers are added to the roving-like article 31 during the time of intertwistin-g of the loops 20 and 21.

of continuous strand 16. The staple fibers are formed by feeding a group of so-called primary filaments 32 firom larger orifices in a secondary bushing 33 fed from a molten glass tank 34. The large diameter filaments 32 are .fed at slow speed, say in the order of a few hundred feet per minute, by a pair of slow speed rotating drums 35 downwardly through a suitable guide mechanism 36 and into a narrow high speed blast 37 from a jet or burner 38. The speed of the blast 37 which may, for example, be a flame or a steam jet, is such that it rapidly shreds and attenuates the primary filaments 32 into a mass of very fine diameter staple fibers generally indicated at 39 in Fig. 1.

One or more sprays 40 may be so positioned adjacent the blast 37 as to coat the staple fibers with suitable adhesives or other coating means during their flight with the blast ,37 across the space between :the burner or jet 38 and the rotary spinner 17.

The blast 37 is so aimed and of such size that it impinges upon the disk 19 at a point where it does not interfere with the lineal projection of the continuous strand 16 but where it will be crossed by portions of the strand 16 forming the loops 20 and 21 and similar loops on the remaining ones of the pegs 18 particularly Where they are drawn radially inward to the hollow axle 22.

Fig. 2 illustrates a further increase in the bulk factor of the finished roving, in this case a roving 41, which results from a slight modification of the process embodying the invention wherein a continuous strand 42 isso directed as to strike a rotary disk 43 of a peg spinner 44 so Ithat it is shattered," i, e., its filaments are separated one kfrom the other, and they are deflected slightly outwardly land into engagement with pegs 45. By thus impinging the continuous strand .42 against the disk 43 and separating its individual filaments from each other they are opened up so that each filament of the strand 42 can be engaged by and intermatted with some of :the staple fibers projected by a blast 46 into the area of engagement therewith.

Fig. 3 similarly shows the strand 42 impinging against the surface of the rotary disk 43 and illustrates how loops generally indicated at 47, 48 and 49, for example, are caught on and carried around by each of the pegs 45. In Fig. 3 a mass of staple fibers 50 carried by the blast 46 is shown impinging against the disk 43 in position to be engaged by the whirling lengths of separated fibers being drawn inwardly and through an axial opening 51 in the disk 43 to form the roving 41.

It will be appreciated that with respect to the showing of the configurations of both the continuous strands 16 or 42 and the staple fibers 39 or 50 in the figures of the drawings, it is impossible to draw or to illustrate the exact shapes assumed. In general the strand and fibers involved, both during their lineal and rotary movements, assume the shapes shown in the drawings and these drawings are intended merely as illustrative of the operation which takes place according to the invention.

Fig. 4 illustrates a different form of apparatus upon which the process of the invention can be carried out. In the illustration of Fig. 4 a continuous strand 52 is projected along a lineal path intersected by a plurality of bent pegs 53 which mounted around the periphery of a rotating disk 54. The disk 54 is mounted on an inclined axis 55 and its central portion is foranrinous as is general- 13 indicated by screen-like cross sectioning at 56. A hood 57 is mounted behind the disk 54 and a vacuum pump 58 connected to the hood 57 to draw air inwardly through the forarninous central portion of the disk 54. In com-' men with the showings of Figs, l-3 the continuous filament strand 52 is repeatedly engaged by the rotating pegs 53 and formed into a plurality of loops 59 which whirl around with the disk 54. In this instance, however, rather than being drawn radially inward and through a hollow axle fOIIh61dlSk'i54, the inner ends of the loops 69, i. e., those ends engaged with the pegs 53, are drawn inwardly 4 and away trom the disk 59 through a gathering eye 60 and thence in the form of a [twisted roving 61 to suitable Winding or other mechanism, for example, a machine similar to the winder 28 of Fig. 1.

In common with the showing of Figs. l-3 a mass of staple fibers 62 is blown inwardly against the disk 54 by a blast 63 from a burner or jet 64 which shreds a plurality of primary "fibers.6 5 fed into'theblast 63,. The air drawn through the foraminous center portion of the disk 54 causes -the .staple fibers 62 to all be drawn inwardly and insures their engagement with and capture by the spinning mass of lengths of continuous strand being simultaneously drawn radially inwardly from the pegs 53 and up throughithe eye 60.

If desired, the continuous strand52 may be shattered to increase the bulk factor of the roving 61 by directing it into impingement upon the rotating disk 54 of Fig. 4 in the manner illustrated in Figs. 2 and 3.

By variations in the relative speeds of lineal feeding of the continuous strand and the blast carrying the staple fibers, proportions between the continuous filaments and staple fibers in the finished product may be controlled with nicety. Therdegree of"doubl,i-ng up of the continuous strand in the finished product and thus the number'of adjacent parallel portions of continuous strand present at any cross section in the finished roving-like product may also be controlled by properly proporti-oning the relative speeds involved.

The correct selection of material to be sprayed either .ontothe parti-culate-or-staple fibers as shown in Fig. 1 or into the general mass being formed as for example, 'bya -spray'66 (Fig. 4), determines the characteristics of the finis-hed product with respect to the degree of adherence between the two types of fibers involved both to maintain integrity, tor-example, in the case of a tightly twisted, tough twine, and to establish degree offlexibility orability to-be-further treated, as in the case of the preparation of-roving'to be further processed as by chopping to form reinforcing media for molding resinous products.

Although the preceding description has spoken of the utilization of continuous and staple fibers of the same material, i. e., glass fibers, it will, of course, be appreciated that the process of the invention is not restricted to the combination of staple glass fibers with continuous glass fibers but fibers of different materials may be combined in asimilar manner by projecting :a continuous filament or strand into .the engagementarea .of a rotary peg spinner and then projecting .a. mass of staple fibers into the working area in which the continuous fibers are being doubled up andpulled into intertwisted and intermatted relationhip.

I claim:

1. A me thod for forming a composite roving from staple fibersand a strand of continuous filaments that comprises feeding said continuous strand longitudinally along a linear path, diverting spaced portions of said strand into a circular path while continuing feeding said strand between such spaced portions thereby forming connected loops in said strand, moving said loops through such circular path, feeding a controlled mass of staple fibers along a path leading into such circular path at a controlled rate, and concomitantly and progressively drawing said loops radially inward across the path of said staple fibers and .along a second linear path extending axially away from such circular path.

2. A method for forming a composite roving from staple fibers and a strand of continuous filaments that comprises rotating a plurality of evenly spaced pins through a circular path, longitudinally projecting a continuous strand along a linear path extending across the path of movement of said pins, .whereby serially connected loops ofcontinuous strand are engaged on said pins and rotated therewith, progressively moving said loops radially inward from said pins and then serially into and along a second linear path extending axially away from such circular path, entraining a controlled mass of staple fibers in a controlled blast of gas and directing said blast along a path crossing the path of movement of said loops while moving radially inward from and circularly with said pins.

- 3. A method according to claim 2 in which the pins are mounted around the periphery of a rotating disk and the continuous strand is moved along a first linear path impinging against said disk at a point radially inward from said pins at an angle such that said strand is deflected therefrom outwardly into engagement with said pins and its filaments are separated by the impact against said disk.

4. A method according to claim 2 in which a binder is placed on said fibers and filaments.

6 5. A method according to claim 2 in which the mass of fibers and filaments is pulled longitudinally along the second linear path and twisted together by reaction to the rotation of the loops of continuous strand around the circular path.

References Cited in the file of this patent UNITED STATES PATENTS 2,208,897 Dockerty et a1. July 23, 1940 2,719,350 Slayter et a1 Oct. 4, 1955 2,719,352 Slayter et a1. Oct. 4, 1955 2,743,573 Hiensch May 1, 1956

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