US 2863208 A
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W.W. DRUMMOND ETAL 2,863,208 METHOD FOR PACKAGING A CONTINUOUS STRAND Filed Dec. 29. 1953 Dec. 9, 1958 2 Sheets-Sheet 1 M/MVW ATTORNEYS 1958 v w. w. DRUMMOND ET AL 2,863,208
METHOD FOR PACKAGING A commuous STRAND Filed Dec. 29, 1953 2 Sheets-Sheet 2 INVENTOR. l Vaq'rep W Drum/pond By VV/fl/am A; fife/f ATTORNEY-5 METHOD non PACKAGING A CONTINUOUS STRAND Warren Wendell Drummond, Anderson, S. C., and
William R. Steitz, fiebron, Ohio, assignors to Owens- Corning Fiberglas Corporation, Toledo, 01110, a corporation of Delaware Application December 29, 1953, Serial No. 400,932
2 Claims. (CI. 28-72) This invention relates to a method for packaging a continuous strand and to the package of strand produced by the practice of the method.
The method of the invention is particularly applicable to the packaging of a strand simultaneously with its formation and it has advantages for the packaging of a glass fiber strand at the time of its forming by attenuation from molten streams of glass. Textile glass fiber strands are formed by attenuating fibers of glass which are pulled from a plurality of minute streams of molten glass at a high rate of speed, say in the order of 10,000 feet per minute, the strand being formed by associating a group of individual fibers in the order of from 100 to 200 per strand, and then packaging the strand in or on some form of container from which it can subsequently be longitudinally removed.
Most commercial strand forming operations are performed with rotary spools on which the strand is wound and the force created by the rotary spool applies the tension which pulls the strand, both to associate the fibers and to attenuate the fibers from their respective streams of molten glass. Strand packaging on a rotary device has a number of disadvantages. Among them is the fact that as the package size increases the constrictive tension of the superposed loops and layers of strand binds the strands more and more tightly together. The force, in fact, is so great as to crush any suitable lightweight, tubular, package on which the strand is wound and, consequently, complex and cumbersome expandable collets are employed to support the package tube during the winding. This increasing constrictive force also tends to adhere the strands one to the other where their lays cross, particularly if the strand is coated with some coating substance that is tacky in nature.
These results of rotary tension winding interfere with the unwinding of the strand by causing snarls and loops and by snagging the strand, sometimes snapping it or so severely snarling it as to require that a substantial number of turns of strand be stripped from the tube in order to reach a free end. Under the best conditions it is diificult for an operator to find the free end of a tightly wound spool type package. Consequently, it is conventional for the operator to strip off handfuls of strand seeking to find the free end and wasting all of the stripped material.
Various suggestions have been made that a continuously produced strand of continuous fibers could be packaged merely by being deposited in a large container and later pulled from the container in the inverse order of its deposition. Most of these suggested processes have been less desirable even than the tension winding because, among other objections, merely depositing the strand in a container does not insure that later deposited sections of the strand shall always be on top of previously deposited sections of strand. In these previous processes many loops and swirls of strand are tucked under previously deposited loops and when the strand is being removed these previously deposited loops are pulled out of the package in inverse order; again causing substantial snags and snarls. Another objection to these suggestions arises from the fact that rripst coating substances which are applied to a strand during formation are tacky, at least until they have been adequately dried. When a strand thus coated engages, say a wall of a can, coating substance on the strand tends to hang up the engaging portion of the strand so that subsequent portions of the strand may get underneath it or become tangled with it. v
The problems in handling a fine strand, for example, a glass fiber strand of, say, .003 inch in diameter, and comprising as many as 200 extremely fine fibers, are substantially different from those encountered in looping or coiling a rope or a roving in an open topped barrel or tub. Not only is the size of the object handled entirely different but economical production of glass fiber strands requires their manufacture at the extremely high rate mentioned above and this introduces further problems.
It is the principal object of this invention to provide a process for the packaging of a continuously produced continuous fiber glass strand that is performed simultaneously with the forming of the strand and which produces a package of strand of lightweight without any tension on the strand, with very little opportunity for the strand to become entangled with itself, and with further advantages such as case of drying, ease of impregnating or coating the strand after formation and reduction of the likelihood of wastage of the strand when seeking a free end to remove the strand from the package. 7
These and other advantages will be better understood from the specification which follows and from the drawings in which:
Fig. 1 is a schematic view in elevation of a strand forming and packaging process according to the invention.
Fig. 2 is a greatly enlarged diagrammatic illustration of the manner of accumulation of a strand in a package according to the invention.
Fig. 3 is a view similar to Fig. 1 but showing the packaging of a strand according to the invention in a package embodying a preferred form of the invention.
Fig. 4 is a fragmentary further enlarged view illustrating the simplicity of the initiation of removal of the strand from a package produced according to the invennon.
Fig. 5 is a fragmentary view of a portion of a package produced according to the invention and illustrating the removal of a strand therefrom.
In the co-pending application of Drummond Serial No. 400,691 filed December 28, 1953, now U. S. Patent 2,719,351, a method and apparatus for packaging a continuous strand in various manners is disclosed. The present invention consists of an improvement over 'the method disclosed in the mentioned Drummond application wherein the process is employed for the production of a particularly advantageous package and of the package itself.
A strand produced and packaged according to the in-. vention comprises a large number of individual fibers 10 which are drawn or attenuated from individual streams of molten glass flowing through orifices in a bushing generally indicated at 11 that is located on the bottom of a molten glass tank 12. The fibers 10 are associated together into a strand 13 by being led over a guide 14 where they usually are also coated with a suitable coating or lubricating material supplied to the guide 14 from a tank 15 through a valve controlled drip line 16.
Longitudinal movement of the strand 13 to provide the fiber attenuating force is produced by engaging the strand 13 between the peripheries of a pair of pulling wheels 17 which are rotated on parallel spaced axes, with their peripheries in engagement, at a speed sufficient to produce a linear speed of the strand in the order of 10,000 feet per minute. The pulling wheels 17 as shown in Fig. 1 are provided with slotted peripheries which cause the strand 13 to be projected freely from the bite of the wheels 17, downwardly along a lineal path.
At a level below the pulling Wheels 17 but close enough thereto so that resistance of air to the passage of the strand 13 does not yet appreciably slow the strand 13 to produce Wave configurations therein, there is located a pin traverse generally indicated at 18 and consisting of a vertical rotary shaft 19, a disk 20 or similar structure and a plurality of pins 21 mounted near the perimeters of the disk 20 and rotated thereby across the path of movement of the strand 13 as it leaves the pulling wheels 17.
The speed of rotation of the pin traverse 18 is selected so that the pins 21 cross the path of movement of the strand 13 at intervals of time appropriate to allow the strand to flow between successive ones of the pins 21 to form depending loops 22, 23, etc., as shown in Fig. 1. At the point of the process of the invention illustrated in Fig. 1 the loop 22 is supported between two successive ones of the pins 21 and the loop 23 has just been released by the advanced one of the pair of pins 21 on which it was formed. A succeeding loop 24 is shown with one of its ends hooked over a pin 21 which has just passed the path of movement of the strand 13 but the next one of the pins 21 has notyet reached the strand 13. Because of the constant speed of generation and projection of the strand 13 and the constant speed of rotation of the pin traverse 18, the loops 22 and 23 and the successive loops formed have the same amplitude and wave length and thus the same lineal length of strand depends between successive ones of the pins 21.
As the pin traverse rotates centrifugal force acting on the loops 22, 23, etc., slides them off the ends of the pins on which they were originally looped in the same order as that in which they were originally engaged thereby and upon departure from the pin traverse 18 the loops of strand form what might be termed a travelling wave extending away and downwardly from the pin traverse 18 and lying substantially in a plane which is generally tangential to the path of movement of the ends of the pins 22 at the point of departure of the strand loops, for example the loop 23 from the pin 21. The strand in the loops 22, 23, etc., moves across this new path at a rate of progression determined by the lineal speed of the strand 13 from the pulling wheels 17 divided by the length of strand depending between succssive ones of the pins 21. Therefore the size of the loops and their speed are subject to precise control.
The shape and direction of movement of the loops also is controllable by modifying the shape of the pins 21 to provide more or less resistance to centrifugal force. If, for example, the pins 21 extend upwardly from the plane of engagement with the strand 13, greater centrifugal force is necessary to throw the loops off the pins 21 and the point of departure of the travelling wave is moved around the pin traverse 18 from the place of engagement with the strand 13. Conversely, if the pins 21 are inclined downwardly at a sharp angle the loops caught thereon may be almost instantaneously released.
Having determined the path of movement of the travelling wave in accordance with the explanation just set forth, the process of the invention then contemplates the positioning of an appropriately shaped receptacle of calculated size in the path of movement of the waves of strand to catch such waves. In Fig. 1 this receptacle is illustrated asa fabric'bag 25, the mouth of which is directed upwardly and held open by a pair of cooperating rings 26 and 27 mounted upon arms 28 and 29, respec tively, that are supported by the bracket 30. The diameter of the bag 25 is determined by the amplitude of the waves of strand to be caught therein and should be only 4 slightly larger so that each successive wave of strand enters and lies flat in the bag 25.
In actual operation, of course, ambient air currents, "slight variations in operating conditions, etc., produce slight variations in the wave form of the strand as thrown off the pin traverse 18 and may cause a slightly helical formation in addition or in combination with the general wave form of the strand. Therefore, as the waves of strand enter the bag 25 the axes of the waves are more or less randomly disposed within the bag, contact with the bag walls and with other loops of strand causing infinite variations in the final shapes of the loops of strand as they fall one upon the other and accumulate in the bag 25. This random disposition of the strand in the bag 25 is highly desirable in that it results in most of the contacting portions of strand lying across each other at relatively large angles and thus providing but slight surfaces for interloop adhesion.
The selection of fabric as the material from which to construct the bag 25 constitutes an important feature of the present invention. Because fabric is quick to absorb any excessive lubricant on the strand rather than having the lubricant spread out on the surface of the bag and retain the strand by its surface tension, such strand loops as may encounter the walls of a textile bag are not hung up but only mementarily delayed in their travel into the bag 25. Therefore, each successively formed loop lies on top of all previously formed loops and the tucking in of a loop portion beneath lengths of strand previously introduced into the bag 25 is very unlikely.
The superposed relationship of the various strand loops can possibly be better understood by reference to Fig. 2 where a bag 31 is shown in broken lines and a strand 32 in greatly enlarged disproportion as shown lying therein in a number of open loops. By following the strand 32 from its upper end indicated at 33, downwardly into the bag 31 it will be seen that each successive loop of strand lies beneath the subsequently introduced loop of strand. Conversely, by following the strand upwardly from its lower end indicated at 34 it can similarly be seen that as each loop of strand is introduced it lies on top of previously introduced loops of strand.
When it is desired to remove the strand 32 from the bag 31 the end 33 is led out of the bag. Each of the loops of strand successively i unlooped and the strand pulled out of the bag 25 or 31 with no fear of loop entanglement.
Operation according to the invention also is illustrated in Fig. 3, in particular this figure showing a process for packaging acontinuous strand in a package which is the preferred form. In Fig. 3 a strand 35 is projected downwardly by a pair of cooperating pulling wheels 36 into the path of movement of a multiple pin traverse 37 having a considerable number of pins 38. The traverse 37 is rotated at a substantial speed and the combination of its high speed rotation and large number of pins 38 causes frequent interruption of the strand 35 and thus formation of small loops 39, 40, 41, etc., of strand.
In common with the showing of Fig. 1, the loops 39, 40, 41, etc., are thrown off the pin traverse 37 but, because of its higher speed of rotation, may be thrown 011 at a point closer to the point of engagement of the pins 38 with the strand 35. The travelling wave formed by the small amplitude and wave length waves of strand 39, 40, 41, etc., moves through a controlled pathway leading to the open upper end of an elongated bag 42 of small diameter. The bag 42 is supported in appropriate wave receiving position by cooperating hanger loop mechanism 43 similar to that shown in Fig. l.
The advantage of an elongated small diameter bag 42 as shown in Fig. 3 is understood when it is realized that the number of loops of strand accumulated one upon the other vertically has no effect upon either the ease of packaging or removal of the strand. It is preferable therefore that the package should be elongated with .respect to its diameter in order to provide a substantial total length of strand and to permit the more precise control of the loop size and the reduction in size of the loops for reasons to be later explained. The bag 42 also is made of fabric and has, therefore, all of the advantages already outlined for the fabric bag.
In addition, because of the small diameter of this form of package as compared to its length, it is simpler to locate the free end at the top of the package to initiate removal of the strand. Fig. 4 illustrates how an operators hand can reach into the top of the bag 42 and, taking hold of the top one or two loops indicated generally at 44, remove them from the bag 42 to start the end flowing. Because the loops 44 are of short length only a small length of strand may be lost at the time of starting the removal. In contrast, on a wound package where each loop may be, say, 15 or more inches in length and where it is diflicult to ascertain which of the loops is the free end, an operator may waste a substantial number of feet before finding the actual end of the strand. To a lesser extent, but still the cause of some wastage, is the removal of the strand from a wide open topped receptacle where each loop across the receptacle might be, say, 2 to 3 feet in length.
After the strand is started out of the bag 42, because the loops are of such small size, they unfold quite freely and with little resistance to the movement of the strand as a whole. In Fig. 5 the strand 35 is shown being pulled longitudinally out of a bag 42 embodying the invention and it will be seen that even when a loop such as the loops generally indicated at 45 does become tangled only a slight length of strand is involved and the entanglement is less likely to become snagged tightly enough to interfere with the progressive pulling of the strand from the bag.
The elongated, fabric bag, type package formed by the process of the invention has additional advantages because of its small cross section. It is frequently necessary in treating a continuous strand to coat the strand with some form of a coating or lubricating medium, for example, the lubrication of strand at the time of formation according to Fig. 1 of these drawings. Some of the lubricating or coating materials which are placed on such strands during their formation comprise volatiles which must be driven off the strand before it is put through the next operation or before it is used. If the package containing the strand is very dense and has a substantial cross section it requires a far greater period of heating or storage time to either drive off the volatiles or to allow them to escape. Since the elongated narrow package contains a length of strand equal to a package having the same volume but short and wide, no storage space problem is created by the shape of the bag for a given length of strand, but the heat treatment or drying processes are greatly facilitated.
Passage of fluids in the reverse direction, i. e., from without the package to its interior, for example, the wax coating of a strand after formation is greatly simplified 6 in a package embodying the invention. In order to ade quately coat a strand with wax the wax must penetrate into the very interior of the package of strand. Where the package diameter is smaller in accordance with the instant invention the penetration of the wax is facilitated since it may approach a larger mass of strand from a shorter distance. These advantages of simplicity in aftertreatment of the strand, whether to drive material out of the package or to place material in the package, result from the combination of fabric which permits penetration, and the decrease in mass penetration distance resulting from the narrower, elongated shape of the package.
It is, of course, within the scope of the invention and contemplated thereby that packages of different lengths and diameters may be employed for different purposes. The heart of the combination lies in two factors. The first is the use of a permeable substance, preferably a fabric material for the bag itself. The second is the process of creating the travelling wave of strand of such amplitude that it will neatly fit into the open end of the bag so that the waves of strand as they are laid down in the bag extend substantially across the bag but do not lie against the sides of the bag in any appreciable numbers or to any appreciable extent. The control of the size of waves and their projection cleanly into the bag as performed according to the process of the invention, results in the virtual elomination of snags and snarls caused by underlapping or tucking in of the strand.
1. A method for accumulating a mass of a continuous flexible strand that comprises feeding said strand longitudinally along a substantially linear path, interrupting the longitudinal movement of said strand by laterally displacing progressively spaced portions of said strand while continuing the feeding of said strand along such path beyond the point of displacement thereby forming serially connected loops, moving said serially connected loops along a new path and depositing said loops in substantially the order of their formation in a fluid permeable, fabric container having a diameter substantially equal to the maximum dimension of one of said loops.
2. A method according to claim 1 that is characterized by forming the loops of strand with small amplitude and feeding the loops into a fluid permeable, fabric bag having a generally tubular shape, a diameter only slightly larger than the maximum lateral dimension of said loops and a length at least several times its diameter.
References Cited in the file of this patent UNITED STATES PATENTS 1,937,544 Cameron et al. Dec. 5, 1933 2,719,351 Drummond Oct. 4, 1955 2,721,371 Hodkinson et al Oct. 25, 1955, 2,741,009 Slayter et al. Apr. 10, 1956