Weaving method and reed for weaving

Abstract: A weaving method for weaving woven fabric (2) and a reed (5) used in such a weaving method are disclosed by means of which woven fabrics can be produced having a comfortable feel similar to that of hand-woven products wherein yarn spun by hand is used. For this purpose, the density of the warp yarns (21) of a woven fabric (2) is used which has a 1/f fluctuation. Also, a reed (5) is used in such a weaving method wherein the spacing between the dents (52) of the reed (5) has a 1/f fluctuation.

Description: The invention relates to a method for weaving woven fabric and a reed used in such a weaving method. In conventional weaving processes, a reed is used which has a uniform spacing between the dents in order to weave goods with uniform spacing between warp yarns which are guided through the reed. Uneven or irregular weaves are woven with randomly-spaced warp yarns by randomly removing warp yarns from the plurality of warp yarns passing through the reed or by using yarns which are different in their coarseness. Hence, conventional weaving machines and weaving methods produce woven fabric in which the warp yarns have a uniform spacing or in which the warp yarns vary at random. However, compared to woven fabric which has a natural, irregular feel as a result of hand-weaving using yarns spun by hand, this randomness produces an artificial texture with very little natural feel. Therefore it is not particularly comfortable for a wearer. The German Patent DE-C 54 92 64 discloses a reed in which the spacings between the dents increase linearly from one end of the reed to the other. The achieved woven fabric has a density which gradually increases from one edge to the other. The dent spacings are provided by wrapping the support bars of the reed with a binding cord, which has an increasing diameter. The object underlying the present invention is to provide a weaving method and a reed for weaving by means of which woven fabric is made available that provides a natural feeling of comfort to human beings. In order to resolve these problems, the invention provides a reed and a weaving method for weaving a woven fabric as defined in claims 1 and 3, respectively. One advantage of the present invention resides in that woven fabric is provided in which the density of the warp yarns does not vary randomly, rather the variations have a specific correlation, in particular a 1/f fluctuation. Using the weaving method and the reed for weaving according to one embodiment, a woven fabric is provided in which the 1/f fluctuation of the warp yarns corresponds to and expresses a melody or sound. Thus, the weaving method and the reed for weaving are capable of weaving a woven fabric having a natural, irregular feel on an industrial scale. In the present application, the expression "1/f fluctuation" is defined and understood as a power spectrum, with a frequency component f, which is proportional to 1/f k , wherein k is approximately 1. According to the method for weaving woven fabric, warp yarns are guided through a reed having dents which are spaced from each other at a spacing having a 1/f fluctuation, wherein the warp yarns are separated into two sets so that a shed is formed between the two sets, wherein weft yarns are passed transversely through the shed, causing the warp yarns and the weft yarns to intersect, thereby weaving a woven fabric in which the density of the warp yarns varies with a 1/f fluctuation. The reed used in weaving has a plurality of dents extending adjacent to one another, wherein the spacing between the dents is varying having a 1/f fluctuation. According to a further embodiment, the reed used in weaving is provided, which reed has a pair of bars mounted opposite to each other and holding a plurality of dents which extend transversely to the bars, wherein a yarn having a varying diameter with a 1/f fluctuation is wound around the bars disposing the dents in an arrangement in which the spacing between the dents provided by the yarns is varying with a 1/f fluctuation. The invention will be explained in more detail below by means of preferred embodiments and with reference to the accompanying drawings, wherein Fig. 1 shows an overview diagram of the principal components of a weaving machine used to perform the invention; Fig. 2 is a diagram of a reed for weaving according to one embodiment; Fig. 3 shows a portion of a melody with a 1/f fluctuation used in the method and the reed according to another embodiment; Fig. 4 shows an overview diagram of the principal components of a spinning frame producing yarns to be used with the reed; and Fig. 5 shows an enlarged view of woven fabric produced with the method, wherein the density of the warp yarns has a 1/f fluctuation. Weaving Machine An overview diagram of the principle components of a weaving machine 1 used to carry out the weaving method according to the invention is shown in Fig. 1 of the drawings. The weaving machine 1 weaves spun yarn into woven fabric 2 through the primary movements of opening a shed formed by two sets of warp yarns 21, inserting a weft yarn 22 transversely through the shed, and beating the weft yarn 22, and the secondary movements of letting off warp yarns 21 from a let-off device 3, and taking up woven fabric 2 by means of a take-up device 7. The construction is shown in a diagrammatic manner in Fig. 1. The action of opening the shed between the warp yarns 21 divides all the warp yarns into two sets, forming an opening through which the weft yarn 22 passes transversely, and the warp yarns 21 and the weft yarns 22 are intersecting. For this purpose, the warp yarns 21 are threaded through two sets of heddles 4 in a prescribed order, and the up and down action of these heddles 4 separates the warp yarns 21 vertically from each other. The insertion movement of the weft yarn 22 involves, for example, passing a shuttle 6, in which a weft yarn 22 is wound around a wooden tube, through the inside of the shed formed by the warp yarns 21, thereby shooting the weft yarn 22 across the warp yarns 21. In addition or as an alternative to a shuttle 6, other methods and devices for inserting the weft yarn 22 may be used, including air flow, fluid flow, rapiers or grippers. The weft beating motion causes the warp yarns 21 and the weft yarn 22 to intersect by using a reed 5 in order to apply pressure to the weft yarn 22 after the weft yarn 22 has passed through the inside of the shed formed by the warp yarns, and forces the yarns into a predetermined position. In such a weaving machine, the let-off device 3 for warp yarns 21 gradually feeds the warp yarns 21, from right to left in the weaving machine 1 shown in Fig. 1, and the take-up device 7 rolls up the woven fabric 2 produced in the weaving machine 1. The take-up speed for the woven fabric 2 can be set at a constant rate or can also be controlled so that the speed varies. Reed An embodiment of the reed 5 according to the invention is shown diagrammatically in Fig. 2 of the drawings. The reed 5 determines the spacing between the warp yarns 21, and it is constructed in such a manner that a plurality of reed wires or dents 52 is arranged between two bars 51 as shown, for example, in Fig. 2. These bars 51 or the reed 5 are provided with slots into which the dents 52 are inserted, and have a diameter of 1 cm, for example. The dents 52 are fabricated of steel, for example, and may have a width of 2.8 mm and a thickness of 0.2 mm. In this context, it is essential that the dents 52 have a spacing between each other which spacing varies with a 1/f fluctuation which in turn will cause that the density of the warp yarns 51 varies with a 1/f fluctuation, too. In order to set the spacing between the dents 52 in the desired manner having the 1/f fluctuation, a yarn 93 may be used for example, wherein the diameter of the yarn 93 varies with a 1/f fluctuation. This yarn 93 is closely wound onto the bars 51 of the reed 5, and by interposing the dents 52 between the coils or windings of the yarn 93, the desired 1/f fluctuation will be imparted to the spacing between the dents. The gaps between the dents 52 can be made parallel by winding two such yarns 93, each having the same 1/f fluctuation, onto the two bars 51 in the same manner. Also, when the reed 5 is fabricated by winding the yarn 93 having a 1/f fluctuation only onto one bar 51, the dents 52 can also be arranged in parallel. 1/f Fluctuation The present inventor was the first in the world to discover that a 1/f fluctuation would impart a particularly comfortable feel to human beings. The results were published in a paper entitled "Bioinformation and 1/f Fluctuation", Applied Physics, 1985, pp. 429 to 435, and in another paper entitled "Biocontrol and 1/f Fluctuation", Journal of Japan. Soc. of Precision Machinery, 1984, Vol. 50, No. 6. The abstract of these papers reads as follows: "The 1/f fluctuation provides a comfortable feeling to human beings; the reason is that the variations in the basic rhythm of the human body have a 1/f spectrum. From another perspective, the human body eventually becomes tired of a constant stimulation from the same source, but conversely, the body feels uncomfortable if the stimulations were to change too suddenly. Therefore, a 1/f fluctuation is a fluctuation of the right proportion between these two extremes." In addition, an excerpt from "The World of Fluctuations", published by Kodansha Publishers, 1980, reads as follows: "For example, the rhythms exhibited by the human body such as heart beats, hand-clapping to music, impulse-release period of neurons, and alpha rhythms observed in the brain, are all basically 1/f fluctuations, and it has been shown experimentally that if a body is stimulated by a fluctuation like these biorhythmic 1/f fluctuations, it would feel comfortable." Fluctuations or variations exist in various forms throughout the nature, but the murmur of a brook, a breeze of wind, and other phenomena that impart a comfortable feeling to humans have a 1/f fluctuation, while typhoons and other strong winds that impart and evoke a sense of uneasiness do not have this 1/f fluctuation. 1/f Fluctuation Signal A 1/f fluctuation signal is determined from y 1 , y 2 , y 3, ..... generated by multiplying n coefficients a 1 , a 2 , a 3 , ....., a n in a sequence of random numbers x 1 , x 2 , x 3 , ...... Generally, y j can be expressed by equation (1) indicated below. It should be noted herein that the sequence of numerical values forming y 1 , y 2 , y 3 , ..... has a 1/f spectrum. For further details, reference is made to Seitai shingô (Biological Signaling), Chapter 10, "Biological Rhythms and Fluctuations", published by Corona Publishers, Ltd.. The 1/f fluctuation signal is obtained in two steps. In a first step, a computer, for example, generates a sequence of random numbers. In a second step, this sequence of random numbers is stored in a storage device, wherein a certain number n of coefficients is successively multiplied on the random numbers, and then, by a linear transformation, a sequence of numerical values y is obtained. This numerical sequence of y values has a 1/f spectrum and can be used as a 1/f fluctuation signal. In this context, a melody having a 1/f fluctuation can be generated from this sequence of numerical values y having a 1/f sequence. For this purpose, at first the scale and the range with a lowest frequency fL and a highest frequency fU are determined. Then, a 1/f sequence of y values is derived, and a linear transformation is performed so that the upper and the lower limits become the lowest frequency fL and the highest frequency fU, respectively. The values of the sequence y so derived are regarded as acoustic frequencies, and are substituted for the frequency of the scale they most closely approximate. In other words, they are arranged, for example, as quarter notes, between or on the lines of a staff on music paper. Fig. 3 of the drawings shows a portion of a melody derived using this method. The pitch and duration of the notes of the melody arranged in such a manner are set to correspond, for example, to the rotational speed of motors and the duration of that speed, respectively, when spinning yarn to be used in the weaving method according to the invention. In this manner it is possible to control the respective motors in a spinning frame, and upon drafting a fiber bundle during spinning, the melody is expressed in the variations in the diameter of the yarn. Spinning Frame Fig. 4 of the drawings discloses a simplified diagram of a spinning frame 8 used for producing yarn 93 used in the method of the invention. The spinning frame 8 is a device to draft rovings 91 and, by imparting twist, spin it into yarn 93. As shown in Fig. 4, the spinning frame 8 comprises a plurality of motors, for example a back motor 81, an apron motor 82, a front motor 83 and a spindle motor 84 each of which can be independently controlled. The back motor 81 is used to drive a back roller 85. The rotational speed of the back roller 85 can be determined, for example, by imparting a prescribed rotational speed to the back roller 85 via belts and gears (which are only diagrammatically shown), and by adjusting the size and the number of the gears. Moreover, the rotational speed of the back roller 85 can be adjusted arbitrarily by controlling the back motor 81. In a similar manner, the apron roller 86 and the front roller 88 can be independently controlled, and the rotational speed of the apron roller 86 and the front roller 88 can be adjusted arbitrarily. In this case, too, the rotational speed of the apron roller 86 and the front roller 88 can be adjusted by using belts and gears which are only shown diagrammatically in Fig. 4. Moreover, an arbitrary rotational speed can be imparted to spindles 89 by rotating a tin roller 90 using the spindle motor 84. These motors can also be used in common, where necessary, and the rotational speed of the rollers can be adjusted using speed converters such as belts and/or gears. In the spinning frame according to Fig. 4, the back roller 85 has a prescribed rotational speed and pinches the rovings 91 to draw them out. The drawing speed of the rovings 91 is determined by the diameter and the rotational speed of the back roller 85. In a similar manner, the apron roller 85 draws out a fiber bundle 92 fed from the back roller 85. A rubber apron can be arranged to rotate on the periphery of the apron roller 86, and by applying pressure to the fiber bundle 92 over a large surface area and holding the fiber bundle 92 stable, draws it out. By adopting a drawing speed for the apron roller 86 that is larger than the drawing speed of the back roller 85, the rovings 91 are drafted or attenuated by a predetermined factor. In other words, by drafting the rovings 91 between the back roller 85 and the apron roller 86, the fibers of the rovings 91 slide and rub against each other and are formed into a fiber bundle 92 which is finer than the rovings 91 being made longer by the predetermined factor. In a similar manner, the front roller 88 also draws out the fiber bundle fed from the apron roller 86. Its drawing speed is set to be greater than the drawing speed of the apron roller 86. By setting the drawing speed, for example, to be 20 times faster than that of the apron roller 86, the drafting will form a fiber bundle that is 20 times longer than the original. In other words, the diameter of the fiber bundle 92 will become thinner. Over the entire spinning frame 8, by the time the rovings 91 are drawn out from the back roller 85 and the fiber bundle 92 is brought out from the front roller 88, the degree of attenuation could be 30- to 40-fold. In order to impart a 1/f fluctuation to the yarn 93, drafting of the fiber bundle 92 can be varied by controlling the back motor 81, the apron motor 82, the front motor 83 and/or the spindle motor 84, respectively. For example, the speed at which the fiber bundle 92 is taken up by the apron roller 86 can be kept constant, and the speed at which the fiber bundle 92 is taken up by the front roller 88 can be varied with a 1/f fluctuation, wherein the diameter of the drafted fiber bundle 92 will vary from thick to thin with a 1/f fluctuation. The take-up speed of the front roller 88 can be adjusted by controlling the rotational speed of the front motor 83. Accordingly, in order to impart a 1/f fluctuation to the diameter of the yarn 93, a 1/f fluctuation signal is applied to control the rotation of the front motor 83, wherein drafting between the apron roller 86 and the front roller 88 will cause the diameter of the yarn 93 to vary. Alternatively, rather than controlling the front motor 83, the apron motor 82 can be controlled, or both motors 82 and 83 can be controlled concurrently. The spindle 89 applies a twist to the fiber bundle fed from the front roller 88 driven by the front motor 83 forming the yarn 93 of suitable strength. In applying a twist, using the spindle 89, to a fiber bundle of uniform thickness, the strength of the twist can be controlled to have a 1/f fluctuation by applying the 1/f fluctuation signal to the rotational speed of the spindle motor 84. A similar effect can be achieved by keeping the rotation of the spindle 89 constant and keeping the rotational frequencies of the back motor 81, the apron motor 82 and the front motor 83 at a constant ratio, and then applying the same 1/f fluctuation signal concurrently to the three motors 81, 82 and 83. If, on the other hand, the fiber bundle 92 is drafted with the 1/f fluctuation, the rotation of the spindle 89 can be controlled to apply a stronger twist to sections of the yarn 93 of thin diameter and a weaker twist to sections of the yarn 93 of thick diameter in order to provide a uniform twist coefficient over the length of the yarn 93. In addition, since the apparent thickness of the yarn 93 varies as a function of the degree of twist, a 1/f fluctuation can be applied that will take this variation into account. In this case, both the drafting motors 81, 82 and 83 and the spindle motor 84 of the spindle 89 are controlled to impart a 1/f fluctuation over the entire drafting and twisting process. For this purpose, when applying a draft having a 1/f fluctuation between the respective rollers, the rotational speed of the respective motors is controlled in such a manner as to incorporate the melody shown in Fig. 3 of the drawings which has a 1/f fluctuation, thereby imparting this 1/f fluctuation to the diameter of the yarn 93. Therefore, the motor control is set so that the pitch and duration of the notes of the melody correspond, respectively, to the rotational speed of the front motor 83 and the running time at that speed. For example, in the motor control the duration of one note in the melody was set to be equivalent to 1 meter of the yarn 93, the "la" note at 440 Hz was set to be equivalent to a thickness of yarn count 30, and the difference between the respective adjacent notes on the "do, re, mi, fa, so, la, ti, do" scale was set to be equivalent to a yarn count of 5. Under these conditions, the yarn 93 became finer with higher frequencies. In this case, the length of variable thickness of the yarn 93 between notes will be on the order of several centimeters. Woven Fabric In order to produce a woven fabric in which the density of the warp yarns 21 has 1/f fluctuation, a reed 5 is made in which a yarn 93 having a 1/f fluctuation is used and wound around each of a pair of bars 51 of the reed 5. Such a yarn 93 can be made as explained above using the melody in Fig. 3 in order to achieve the desired 1/f fluctuation. If the number of the dents 52 of such a reed 5 averages 72 dents/2 inches (wherein two warp yarns 21 will pass through each dent) and a woven fabric 2 is woven using 30-count cotton yarn both for the warp yarns 21 and the weft yarns 22, the warp yarn density of the woven fabric 2 will turn out to average 77 threads/inch, whereas the weft yarn density will average 70 threads/inch in the raw cloth. An example of such a woven fabric 2 is shown in the enlarged diagram in Fig. 5 of the drawings. The density of the warp yarns 21 in this woven fabric 2 has a 1/f fluctuation. It should be noted that in Fig. 5 the warp yarns 21 lie along a line perpendicular to the side indicated by the leader line (a line parallel to the direction extending from the leader line of the warp yarn 21) and that the weft yarns 22 are perpendicular to the warp yarns 21 and lie along a line perpendicular to the side indicated by the leader line of the weft yarns 22 (a line parallel to the direction extending from the leader line 22).

Claims: A reed for use in weaving comprising: a plurality of dents (52) arranged adjacent to one another with variable spacing, characterized in that the spacing between the dents (52) varies with a distribution defined by a 1/f fluctuation. The reed of Claim 1, further comprising a pair of support bars (51) being mounted opposite to one another and holding said plurality of dents (52) extended transversely therebetween, wherein a winding yarn (93) having a diameter varying with a 1/f fluctuation is wound around the support bars (51), the dents (52) being interposed between coils of the winding yarn (93) and the 1/f spacing of the dents (52) being provided by the diameter variation of the winding yarn (93). A weaving method for weaving a woven fabric comprising: a) guiding warp yarns (21) through a reed (5) having dents (52) spaced from one another, b) separating the warp yarns (21) into two sets so as to form a shed between the sets, c) passing weft yarns (22) transversely through the shed, causing the warp yarns (21) and the weft yarns (22) to intersect, thereby weaving a woven fabric, characterized in that said guiding step (a) includes spacing the warp yarns (21) with the reed (5) of Claim 1 or 2 having dents (52) variably spaced with a 1/f fluctuation, whereby the woven fabric has a warp density which varies with a 1/f fluctuation.

Inventors: MUSHA TOSHIMITSU, NIWA YUKI, TAKAGI SHOJI, YANAI YUICHI, MUSHA, TOSHIMITSU, NIWA, YUKI, TAKAGI, SHOJI, YANAI, YUICHI, NIWA, YUKI, C/O NISSHINBO IND. INC. MIAI, TAKAGI, SHOJI, C/O NISSHINBO IND. INC. MIAI, YANAI, YUICHI, C/O NISSHINBO IND. INC. MIAI
Applicants: MUSHA TOSHIMITSU, NISSHIN SPINNING, MUSHA, TOSHIMITSU, NISSHINBO INDUSTRIES INC.
Application year: 1995
Main classification: D03D49
IPC codes: D03D49, D03D13