GB1598560A - Apparatus for forming twisted slubby strand - Google Patents

Description

(54) APPARATUS FOR FORMING TWISTED SLUBBY STRAND PATENTS ACT 1949 SPECIFICATION NO 1598560 The following corrections were allowed under Section 76 on 8 lune 1982: Page 3, line 16, after 51271/77 insert Serial No. 1598558 Page 3, line 53, after strand insert, the Strand Page 3, line l, for 5-8read 5 and 6 Page 3, line 78, after turn, insert is Attention is also directed to the following Printers Errors: Page 1, Heading, (62) for 1598588 read 1598558 Page 1, Heading (32) for 9 Mar 1976 read 9 Dec 1976 Page 1, line 1, (71) forPPGreadPPG Page 1, line 46, for bulkiing read bulking Page J, line 89, for coninuous read continuous Page I, line 12, for protion read portion Page 1, line 50, for consitute read constitute Page 1, line 54, for elngth read THE PATENT OFFICE 9 August 1982 Bas 91727/2 speeas as mey are passea tnrougn an air jet device to filamentize the fibers of the faster travelling strands and entangle them within the core yarn. A typical process of this type is illustrated in U. S. Patent No. 3 262 177.

Another process for producing a bulky yarn having intermittent bulkiing along its length is shown in U. S. Patent No. 3 410 077.

While all of the above processes are useful in producing novel textile strands, a need still or a comnuous strana.

Slubby strand produced using the apparatus of the present invention is characteristically twisted on either end of the slubs produced and this greatly assists in locking the slubs in place so that they cannot be inadvertently removed by subsequent tension placed on either end of a slub during processing of ihe strands on which they are positioned. It has also been observed that strands produced using the apparatus of (54) APPARATUS FOR FORMING TWISTED SLUBBY STRAND (71) We, PPG INDUSTRIES, INC., a Corporation organized and existing under the laws of the State of Pennysylvania, United States of America, of One Gateway Center, Pittsburgh, State of Pennsylvania 15222, United States of America, (Assignees of HERBERT WILLIAM BARCH, AUGUST GEORGE BOHY and WARREN WENDELL DRUMMOND), do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to an apparatus for producing slubby yarn.

Novel yarns or strands are produced by a variety of processes in the textile field and find utility for many specific textile purposes, for example, in the manufacture of draperies, industrial cloths used as reinforcement for resin articles and the like. Yarn, as referred to in this specification, includes twisted yams, untwisted strands, rovings of strands and the like. Many processes have been designed, especially in processing glass fiber strands, to produce decorative effects on textile strands to render them useful in providing bulk for cloth to be woven for decorative purposes as well as cloth woven for industrial purposes such as resin reinforcement.

Thus, in U. S. Patent No. 3 388 444 a process is described in which glass fiber strands are passed through a texturizing jet at various rates of speed and air under pressure is introduced into the jet to entangle the yarns passing therethrough to produce a bulking effect on the yarn issuing from the jet. In another process, bulky textile yarn is produced by providing a core and effect yarn, each of which travels at different speeds as they are passed through an air jet device to filamentize the fibers of the faster travelling strands and entangle them within the core yarn. A typical process of this type is illustrated in U. S. Patent No. 3 262 177.

Another process for producing a bulky yarn having intermittent bulkiing along its length is shown in U. S. Patent No. 3 410 077.

While all of the above processes are useful in producing novel textile strands, a need still exists in the art for a process which will produce efficiently a slubby textile strand in which slubs of good integrity are present.

Minimized filament damage caused by breaking filaments during the processing of a strand is also a desired goal in producing slubby strands.

Filament damage to strands using the procedures of the prior art often reduces strand strength below an acceptable value. Further, in producing textile strands having slubs thereon, it is a desired goal to produce slubs randomly so that the cloth woven therefrom does not develop a fixed pattern.

By means of the present invention it is possible to produce at high speed a textile strand having slubs, which may be random or inter mittent, along the length thereof. The slubs have extremely good integrity in that, once provided on the textile strand, they cannot easily be pulled out of the strand by pulling the strand at either end of the slub. This feature is important in that the strands provided using the apparatus in accordance with the present invention can bc woven and otherwise physically handled in various textile finishing operations when they are utilized to produce cloth without losing slub integrity. When glass fibers are used as the textile strand, it has been found that a slubby strand having very few filament breaks therein can be produced. In addition, slubs of varying size can be produced on the same strand and in random locations. By varying yarn tension, it is also possible using the apparatus herein described to-produce texturized yarns. The apparatus of the present invention for producing slubs along a textile strand is simple in construction and permits considerable versatility in the production of slubs as to their size and their location along a given length of a coninuous strand.

Slubby strand produced using the apparatus of the present invention is characteristically twisted on either end of the slubs produced and this greatly assists in locking the slubs in place so that they cannot be inadvertently removed by subsequent tension placed on either end of a slub during processing of the strands on which they are positioned. It has also been observed that strands produced using the apparatus of this invention, especially those produced from glass fiber strands, have little or no fiber breaks therein, thus producing a slubby glass fiber strand having extremely high tensile strength.

According to the present invention there is provided a slubbing tool for forming twisted slubby strand, which comprises a hollow body having an interior surface for passing strand through said tool, and a fluid jet approximately normal to the interior surface for directing fluid approximately normal to the interior surface, said fluid jet including an end protion comprising a slot having a circular portion at each end of the slot.

In order to produce a twisted slubby strand using the apparatus of the present invention a consolidated textile strand containing a plurality of fibers therein is passed through the slubbing tool. Fluid under pressure, e. g. air, impinges on the surface of the strand. As the fluid, e. g. at a pressure of from 20 to 80 psig (137, 895 to 551,580 pascal), passes through the strand, the fluid twists and bulks the strand along its length. The bulked strand is removed from the slubbing tool thereby producing a slub at various points on the strand and the strand with the slubs thereon may be transported to a collection zone where it is wound or collected in any suitable manner for ultimate distribution to the customer. By varying the speed of travel of the strand through the slubbing tool, varying the pressure of the fluid, or varying the total available fluid space in the slubbing tool, variations in slub size for a given strand can be readily realized.

In the production of slubs on textile strands using apparatus in accordance with the present invention, any conventional textile strand can be employed, provided it is capable of being opened up by the passage therethrough of fluid under pressure, such as air, oxygen, steam, water, nitrogen or carbon dioxide. Preferably, gaseous fluids are employed and most preferably air is employed as the gaseous fluid. The invention has particular utility in the production of slubs on consolidated strands containing a plurality of glass fibers and can produce these slubs with little or no breakage of the fibers during the formation thereof. This is an important consideration in the preparation of glass strands because glass filaments, in general, have little or no elasticity and often the prior art processes involving the bulking of glass strands produce strands which may have many broken filaments therein.

The apparatus of the present invention may be used to produce slubs on any synthetic or natural textile strand containing a plurality of filaments in the strand, e. g., nylon, polyester, glass, acetate, or cotton.

In the production of slubby glass fiber textile strands, the source of the strand can be varied. Thus, for example, by recourse to special processing techniques, glass fiber strands can be processed using as the strand source a forming package, i. e. wound strand on a tube produced by winding as the glass fiber strand is prepared form a molten source of glass. Form- ing packages can be employed either wet or dry.

The glass fiber strands may also be processed -directly from bobbins which are normally pro duced by placing a forming package on a con ventional twist frame and twisting the strand to any desired twist value as it is removed from the forming packages and wound on the bobbin.

In addition, the strands may be slubbed directly as they are formed from a bushing.

It is also contemplated, utilizing the present invention, to apply the slubs to the glass fiber strand on a conventional textile twist frame by feeding the strand contained on forming packages through the slubbing tool of the pre sent invention prior to collecting them on the bobbins of the twist frame. While two glass fiber strands may be utilised to produce the final strand product, it will be readily under stood that more than two strands can be fed to the system and slubbed in the same manner to produce a final slubbed strand. Obviously, it is also contemplated that a single strand feed be employed to produce slubbed yarns.

The present invention will now be further described by reference to the accompanying drawings, in : Figure 1 is an illustration of a slubbing tool in accordance with the present invention show ing the location and configuration of the fluid jet within the tool; Figure 2 is a sectional view along line 12-12 of Figure 1 illustrating the relation between the interior surface and the fluid jet; Figure 3 is a sectional view of another slubb ing tool in accordance with the present invention illustrating the means employed for varying the entrance diameter to the slubbing tool and the means employed to vary the total fluid volume within the tube; Figure 4 illustrates a wheel which may be used to vafy the diameter of the entrance to the slubbing tool of Figure 3; Figure 5 illustrates a suitable fluid jet which may be employed in the present invention; Figure 6 illustrates the nozzle configuration for the fluid jet of Figure 5.

Figure 1 illustrates a slu6bing tool 51 in accordance with the present invention. The tool comprises a hollow body 52 having an interior surface and having a fluid jet 53 embedded therein and approximately normal to the in terior surface of the hollow body 52. The shape of the interior of the tool may take any desired form, such as round, elliptical, square, etc. The exact location of the nozzle with respect to the hollow body 52 is seen in more detail in Figure 2. The vertical distance between the nozzle 63 and the bottom of the surface of the hollow body 52 is adjustable to give varied effects to the slubs produced in the yarn undergoing treatment in this tool. The fiber strand to be treated is pulled through this tool and is sub jected to the fluid under pressure at nozzle 63 thus resulting in the production of the slubbed fiber.

Figure 3 illustrates another slubbing tool according to the present invention. In this Figure, the hollow body 52, the fluid jet 53 and the nozzle 63 are identical to those shown in Figure 1. In addition, there is employed an air chamber 61 having a device, such as a screw or baffle 62, adjustment of which increases or decreases the total volumetric area of the fluid space within the hollow body 52. In addition, there is illustrated in Figure 4 a wheel 64, similar to wheels 15 in Figures I and 5 of our copending British Patent Application No.

51271/77, which is employed at the entrance of the hollow body 52. This wheel varies the diameter of the entrance to the body 52 by means of holes 68 of varying diameter. It has been found that when decreasing the size of the entrance, the flow pattern of the fluid within the hollow body tends to aid in pulling the strand through the hollow body 52. This, of course, will change the characteristic of the thus formed slub.

Figure 5 illustrates a typical fluid jet for supplying fluid under pressure to the working surfaces of any of the slubbing apparatus of the present invention. The jet comprises a hollow tube 80 having an end portion 81. The end portion 81 has an opening therein, the shape of which is illustrated in Figure 6. The opening (Figure 6) comprises a slot having circular portions at each end of the slot, giving a"dog bone"shape. Preferably the slot has a length of about 0.094 inch (2.38 millimeters), a width of about. 005 inch (. 127 millimeter) and the circular holes have diameters of about. 042 inch (1.067 millimeter).

The exact mechanism which results in the formation of the slubs in the yarn treated using the apparatus of this invention is not completely understood. Several theories have been advanced to explain formation of slubs on the strand.

The first theory is that, as the strands are passed through the slubbing tool, and fluid under pressure is applied to them, the entire strand is bulked by expanding the fibers which consitute the strand. At the same time, due to the low (i. e. substantially zero) tension in the strand and the turbulent air flow around the strand is twisted along its length. The slubs form at the areas along the strand elngth where the direction of the twist changes. This forms a bulked, twisted strand followed by an area of untwisted, bulked strand, followed by a reverse twisted, bulked strand.

Another theory is that the fluid stream twists the strand along its length and does not bulk the entire strand. Only at the locations along the strand where the direction to twist is about to reverse is there an area of untwisted strand. At these points the fluid bulks the strand forming the slubs between areas of opposite direction twist.

A third theory states that the slubbing effect produced by the apparatus of the present inven tion is the result of a"double vortex"effect.

Thus, the fluid passing through the nozzle 80 '6f Figures 5-8 is directed into a pair of counter current streams rotating generally as circles around approximately one-half of the surface.

As the strand is passed through the tool, it is alternately caught within one of the counter current fluid streams which will twist the strand in the direction of that stream. When the strand, in turn, caught up by the opposing fluid stream, the strand is twisted in the oppo site direction. Between these counter-directiona twists are null points where there is no twist in the strand. At these points, the fluid within the tool will bulk the yarn, thus producing slubs which, due to the counter-directional twists on either side will not readily pull out.

Regardless of the theory used to explain the phenomenon occurring using the apparatus of the present invention, it remains clear that the final resulting strand consists of highly bulked slubs having twisted strand surrounding the slubs, the twist on each side of a given slub being in opposing direction. The thus produced strand has slubs which cannot easily be pulled out and is a highly desirable commercial product It is within the purview of this invention to provide intermittent fluid flow to thereby per mit intermittent contact of the fluid with the strand undergoing treatment. Other means for varying the slub treatment include varying the fluid pressure to the nozzle, the fluid space within the slubbing tool, the height of the nozzle above the bottom of the surface of the tool, the entrance size to the slubbing tool, and the tension of the strand as it passes through the slubbing tool.

Considerable versatility is provided by the present apparatus in that strand effect can be changed considerably with small changes in the system. Thus, at lower speeds, 300 to 1,000 feet (91.44 to 304.8 meters) per minute and air pressures in the 30 to 75 pounds per square inch gauge (206, 842 to 517, 106 pascal), the slubs produced on a strand tend to be more clearly defined with little strand disturbance in between slubs. At similar air pressures and higher speeds, over 1,000 feet (304. 8 meters) per minute, the effect on the strand is to pro vide for more texturing of the strand between slubs.

In general, the speed of strand travel can be varied between 200 and 5,000 feet (60.96 to 1,524 meters) per minute or more, with speeds of 300 to 3,000 feet (91.44 to 914.4 meters) per minute being those typically used. Air pressure, where air is used as the fluid, generally ranges from 20 to 80 pounds per square inch gauge (137,895 to 551,580 pascal), with pressures of 30 to 75 pounds per square inch gauge (206,842 to 517,106 pascal) being typical of those employed.

From the foregoing, it is obvious that the slubbing tool of the present invention can be utilized in numerous textile yarn treating operations to provide textile yarns having numerous and varied characteristics.

Claims (8)

WHAT WE CLAIM IS:

1. A slubbing tool for forming twisted slubby strand, which comprises a hollow body having an interior surface for passing strand through said tool, and a fluid jet approximately normal to the interior surface for directing fluid approximately normal to the interior surface, said fluid jet including an end portion comprising a slot having a circular portion at each end of the slot.

2. A slubbing tool as claimed in Claim 1 wherein the width of the slot is about 0.005 inch (0.127 millimeter) and the length is about 0.094 inch (2.38 millimeters).

3. A slubbing tool as claimed in Claim 2, wherein the circular portions are about 0.042 inch (1.067 millimeter) in diameter.

4. A slubbing tool as claimed in any of Claims 1 to 3, further comprising means for adjusting the diameter of the entrance to the hollow body.

< S. A slubbing tool as claimed in Claim 4, wherein said means comprises a wheel having a plurality of differing diameter holes therein.

6. A slubbing tool as claimed in any of Claims 1 to 5, further comprising means for adjusting the total fluid volume of the hollow body.

7. A slubbing tool as claimed in any of Claims 1 to 6, wherein the fluid jet is located within the hollow body.

8. A slubbing tool substantially as herein before described with reference to the accom panying drawings.