Patent Publication Number: US-2016222555-A1

Title: Selvage portion gripping device for loom, loom, and method of manufacturing woven fabric

Description:
TECHNICAL FIELD 
     This disclosure relates to a selvage portion gripping device for a loom. More specifically, the disclosure relates to a selvage portion gripping device for a loom that effectively suppresses occurrence of warp yarn looseness in a base cloth selvage portion that occurs near a selvage portion when a high-density woven fabric is woven, a loom equipped with the device, and a method of manufacturing the woven fabric using the device. 
     BACKGROUND 
     Conventionally, there have been proposed a large number of high-density woven fabrics using a synthetic fiber multifilament including polyester and nylon. Due to diversification of uses, a woven fabric that is further made thin or is highly strengthened accompanying this diversification has been requested. 
     Generally, when the high-density woven fabric is woven, as a cover factor thereof becomes larger, an amount of movement of a cloth fell from a reed beating portion to a forwarding side of a warp yarn becomes larger. Because of this, the following inconveniences occur.
         It should be noted that the cover factor is a value expressed by (D1×0.9) 1/2 ×N1+(D2×0.9) 1/2 ×N2, wherein total fineness of a warp yarn is D1 (dtex), warp yarn density is N1 (yarns/2.54 cm), total fineness of a weft yarn is D2 (dtex), and weft yarn density is N2 (yarns/2.54 cm.   (a) The woven fabric near the reed beating portion undergoes a bumping phenomenon, and it becomes hard to obtain a woven fabric having a desirable weft yarn density.   (b) The warp yarn induces fluff and weaving cannot be stably performed.   (c) When a loom rotation speed is made high, a phenomenon in which the amount of movement of the cloth fell of the selvage portion from the reed beating portion to the forwarding side of the warp yarn becomes larger appears more conspicuously. Due to warp yarn looseness at the selvage portion, a cloth length difference between the selvage portion and a central portion occurs, and a waving phenomenon, that is, a so-called warp yarn looseness in a base cloth salvage portion (also referred to as “Mimitarumi” or “Mimitaburi” in Japanese) appears. The woven fabric is formed into a desirable product by cutting and sewing. To effectively utilize the woven fabric to the maximum for a target use, the woven fabric is usually used up to near an end portion of the woven fabric. Ends of a cut part easily unravel. Accordingly, when the warp yarn looseness in the base cloth selvage portion occurs near the selvage portion, poor cutting occurs, a shape as a product cannot be secured, or a function is not fulfilled.   (d) The warp yarn looseness in the base cloth selvage portion in a gray fabric not only hinders each processing passing property of a roll winding process, a scouring process, and a heat set process, but also becomes a cause for creating wrinkles on the obtained woven fabric.       

     As a technology to suppress occurrence of warp yarn looseness in the base cloth selvage portion, a method in which weaving density of a selvage portion is made higher than weaving density of a main body part of a woven fabric at the time of weaving (Japanese Patent Laid-open Publication No. H09-302549), a method in which additional yarns are beaten up into a selvage portion formed of ground yarns and binding yarns (Japanese Patent Laid-open Publication No. H09-302550), a method in which a binding yarn having a hetero-cross-section is used for a part of a plurality of additional yarns provided at an outside of the woven fabric (Japanese Patent Laid-open Publication No. 2001-355143), a method in which a section shape of a warp yarn at a selvage portion is made flat (Japanese Patent Laid-open Publication No. 2003-221749), and the like are known. However, it cannot be always said that these technologies are capable of sufficiently suppressing occurrence of the warp yarn looseness in the base cloth selvage portion. 
     Apart from the above-described technologies, a method in which, by an air jet loom or a water jet loom, a pair of grip rollers is provided at an arrival portion of a running weft yarn, tension for breaking the weft yarn running is applied to the weft yarn for a predetermined time until reed beating of a cloth fell is completed, and spring back of the warp yarn is held down (Japanese Patent Laid-open Publication No. H10-46445), and a method in which a device which tightens a weft yarn similarly provided at an arrival portion of a weft yarn is driven and controlled (Japanese Patent Laid-open Publication No. H10-298850) are known. 
     However, the above-described conventional technologies have a problem in that complicated control is required to grip the running weft yarn, which thereby leads to an increase in cost of manufacturing the woven fabric. 
     In consideration of the drawbacks of the above-described conventional technologies, it could be helpful to provide a selvage portion gripping device for a loom capable of effectively suppressing occurrence of cloth fell retreat at a selvage portion or warp yarn looseness in a base cloth selvage portion when a high-density woven fabric is woven at a high speed, a loom, and a method of manufacturing the woven fabric. 
     SUMMARY 
     We thus provide:
         (1) A selvage portion gripping device to be mounted on a loom, the selvage portion gripping device including: a space where a selvage portion can pass in which the selvage portion formed by weaving additional yarns and weft yarns can pass through in a woven fabric forwarding direction; a tiny space where the weft yarn can move in which the weft yarn can pass through; and a means for maintaining a woven condition of the selvage portion even when the weft yarn is cut with a weft yarn cutter of the loom.   (2) The selvage portion gripping device for the loom, wherein the means for maintaining the woven condition of the selvage portion is a flexible part which catches the selvage portion allocated in the space where the selvage portion can pass.   (3) The selvage portion gripping device for the loom according to claim  2 , wherein the flexible part which catches the selvage portion is a part formed of a plate spring or a flexible member and a plate material.   (4) A loom having any of the selvage portion gripping devices for the loom, wherein the selvage portion gripping device exists at a selvage portion of a woven fabric and at a position where a weft yarn is cut with a weft yarn cutter.   (5) A method of manufacturing a woven fabric where a predetermined number of warp yarns are parallelized, additional yarns are parallelized at an outside of the parallelized warp yarns, and a weft yarn is supplied to the warp yarns and the additional yarns, including: by using the loom, gripping a selvage portion by a selvage portion gripping device for a loom which exists on the loom at the time of cutting the weft yarn.   (6) The method of manufacturing the woven fabric, includes: gradually separating the additional yarns from the selvage portion discharged from the selvage portion gripping device for the loom.   (7) A method of manufacturing a woven fabric where a predetermined number of warp yarns are parallelized, additional yarns are parallelized at an outside of the parallelized warp yarns, and a weft yarn is supplied to the warp yarns and the additional yarns, including: after the weft yarn is supplied and the woven fabric is subjected to reed beating, gripping a selvage portion formed by weaving the additional yarns and the weft yarns at the time of cutting the weft yarn.       

     When weaving is performed by using the selvage portion gripping device for the loom, the selvage portion is disposed inside the selvage portion gripping device and configured to maintain the woven condition thereof. Accordingly, occurrence of crimp of the weft yarn can be prevented, looseness of the warp yarn can be prevented, and warp yarn looseness in a base cloth selvage portion can be effectively suppressed. Similarly, when weaving is performed by using the selvage portion gripping device for the loom, the selvage portion inside the selvage portion gripping device for the loom is flexibly caught by the flexible part which catches the selvage portion. Accordingly, forwarding of the selvage portion is performed more smoothly, and the woven condition between the additional yarns and the weft yarns are maintained more reliably. Consequently, occurrence of the crimp of the weft yarn can be prevented, the looseness of the warp yarn can be prevented, and the warp yarn looseness in the base cloth selvage portion can be effectively suppressed. 
     Further, when weaving is performed by using the selvage portion gripping device for the loom, the flexible part which catches the selvage portion is a part formed of a plate spring or a flexible member and a plate material. Accordingly, a structure is simple and inexpensive, forwarding of the selvage portion is performed more smoothly, and the woven condition between the additional yarns and the weft yarns is maintained further reliably. Consequently, occurrence of cloth fell retreat at the selvage portion of the woven fabric and the warp yarn looseness in the base cloth selvage portion can be suppressed more effectively and inexpensively. 
     When weaving is performed by using the loom, weaving can be performed while occurrence of cloth fell retreat at the selvage portion of the woven fabric or the warp yarn looseness in the base cloth selvage portion is suppressed more effectively. 
     Further, according to the weaving method, the selvage portion is disposed inside the selvage portion gripping device and is configured to maintain the woven condition thereof. Accordingly, it is possible to obtain a woven fabric in which occurrence of the crimp of the weft yarn can be prevented, the looseness of the warp yarn is prevented, and warp yarn looseness in the base cloth selvage portion is effectively suppressed. 
     The additional yarns are separated from the selvage portion discharged from the selvage portion gripping device together with the movement of the woven fabric. Accordingly, cutting work of the selvage portion is not required, and the selvage portion can be reused by winding the additional yarns separately. 
     Further, according to the weaving method, the selvage portion is configured to maintain the woven condition thereof. Accordingly, it is possible to obtain a woven fabric in which occurrence of the crimp of the weft yarn can be prevented, the looseness of the warp yarn is prevented, and the warp yarn looseness in the base cloth selvage portion is effectively suppressed. 
     In the weaving method, the weaving is performed by a loom which uses fluid to insert the weft yarn such as a water jet loom, the selvage portion gripping device for the loom is installed at a side of a weft yarn nozzle which is a nozzle for beating the weft yarn, and even when the weft yarn is cut between the weft yarn nozzle and the selvage portion gripping device for the loom with a weft yarn cutter, the selvage portion is disposed inside the selvage portion gripping device and is configured to maintain the woven condition thereof. Accordingly, occurrence of the crimp of the weft yarn can be prevented, the looseness of the warp yarn can be prevented, and the warp yarn looseness in the base cloth selvage portion can be effectively suppressed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic plan view showing a main part of a loom which includes a selvage portion gripping device for a loom. 
         FIG. 2  is a schematic perspective view showing the selvage portion gripping device for the loom. 
         FIG. 3  is a schematic sectional view of the selvage portion gripping device for the loom which uses a pair of plate springs as a flexible part which catches a selvage portion. 
         FIG. 4  is a schematic sectional view of the selvage portion gripping device for the loom which uses the pair of plate springs as the flexible part which catches the selvage portion. 
         FIG. 5  is a diagram showing an evaluation method of warp yarn looseness in a base cloth selvage portion. 
     
    
    
     DESCRIPTION OF REFERENCE SIGNS 
     
         
           1 : Warp yarn 
           2 : Additional yarn 
           3 : Reed 
           4 : Weft yarn nozzle 
           5 : Weft yarn 
           6 : Weft yarn cutter 
           7 : Selvage portion gripping device for loom 
           8 : Fringe 
           9 : Edge dent of reed 
           10 : Woven fabric 
           11 : Selvage portion 
           71 A: Inlet of space where selvage portion can pass 
           71 B: Outlet of space where selvage portion can pass 
           72 A: Tiny space where weft yarn can move and which is allocated at weft yarn nozzle side 
           72 B: Tiny space where weft yarn can move and which is allocated at woven fabric side 
           73 : Bolt 
           74 A,  74 B: Plate springs 
           75 A,  75 B: Plate spring supporting bodies 
           101 A: End portion allocated at weft yarn nozzle side of woven fabric 
           101 B: End portion allocated at side which is not weft yarn nozzle side of woven fabric 
           102 A,  102 B: Marks at central portions of woven fabric 
           103 A,  103 B: Lines along weft yarn 
           104 A,  104 B: Lines along warp yarn 
         L, R: Strips 
         X: Direction of weft yarn 
         Y: Direction of warp yarn 
       
    
     DETAILED DESCRIPTION 
     Hereinafter, examples will be described by using drawings and the like. 
     A selvage portion gripping device for a loom is a selvage portion gripping device for a loom which has a space where a selvage portion can pass in which the selvage portion formed by weaving an additional yarn and a weft yarn can pass through in a woven fabric forwarding direction and a tiny space where a weft yarn can move in which the weft yarn can move in the woven fabric forwarding direction. The selvage portion gripping device further has a means that maintains a woven condition of the selvage portion even when the weft yarn is cut with a weft yarn cutter. 
     It should be noted that a fringe is a weft yarn supplied from a weft yarn nozzle, and then cut and protruded from the woven fabric. The additional yarn is a yarn inserted into an outside of the woven fabric in a warp direction to catch the fringe apart from a ground yarn of the woven fabric. Since the weft yarns are weft-inserted into the additional yarns as with the warp yarns, a condition in which the additional yarns and the weft yarns are intersected by vertically changing their positions, i.e., a woven condition, is formed. The selvage portion is a portion where the fringes and the additional yarns are woven. 
       FIG. 1  is a schematic plan view showing an outline of weaving when the selvage portion gripping device for the loom is installed at a weft yarn nozzle side. “ 1 ” indicates a warp yarn, “ 2 ” indicates an additional yarn, “ 3 ” indicates a reed, “ 4 ” indicates a weft yarn nozzle, “ 5 ” indicates a weft yarn, “ 6 ” indicates a weft yarn cutter, “ 7 ” indicates a selvage portion gripping device for a loom, “ 8 ” indicates a fringe, and “ 9 ” indicates an edge dent of the reed. It should be noted that, in the weaving, a plurality of warp yarns further exists and the weft yarn  5  and the reed  3  are further extended at a right side in  FIG. 1 . However, the illustration is omitted. 
     The weft yarn  5  supplied from the weft yarn nozzle  4  is weft-inserted into the additional yarns  2  supplied from a device which supplies the additional yarns (not shown) and into the warp yarns  1  supplied from a device which supplies the warp yarns (not shown). The weft yarn  5  weft-inserted into the warp yarns  1  is beaten up by the reed  3  and the edge dent of the reed  9 , and a woven fabric  10  and a selvage portion  11  are formed. It should be noted that a tip of the beaten weft yarn  5  is normally caught by catch-cords (not shown) or the like, and weft yarn tension is maintained for a predetermined time. After that, the tip of the weft yarn  5  is cut between the woven fabric  10  and the catch-cords with a cutter allocated at an opposite side of the weft yarn nozzle (not shown), and the catch-cords are collected. 
     The selvage portion  11  where the additional yarns  2  and the weft yarns  5  are woven is supplied to the selvage portion gripping device for the loom  7  without being reed-beaten, and is moved inside the selvage portion gripping device synchronously with movements of the woven fabric  10  and the fringes  8 . At this time, the weft yarn  5  is cut with the weft yarn cutter  6  immediately after the reed beating. However, the selvage portion  11  after the weft yarn is cut is disposed inside the selvage portion gripping device, and the woven condition is maintained. Accordingly, occurrence of crimp of the weft yarn or occurrence of looseness of the warp yarn can be prevented. 
     The selvage portion  11  after the weft yarn have been cut is discharged from the selvage portion gripping device as it is, and is moved together with the woven fabric  10 . However, since the selvage portion  11  is discharged from the selvage portion gripping device for the loom, the woven condition of the additional yarns  2  and the fringes  8  is not maintained. The fringes  8  are gradually separated from the additional yarns  2  and move. The additional yarns  2  move independently. Further, the woven fabric  10  and the fringes  8  move together. The additional yarns  2  are collected in the same route as that of the catch-cords allocated at the opposite side of the weft yarn nozzle through a guide (not shown) or by another winding device. With this mechanism, the crimp of the weft yarn after the weft yarn is cut and looseness of the warp yarn are not generated, and occurrence of cloth fell retreat at the selvage of the woven fabric or warp yarn looseness in the base cloth selvage portion is effectively suppressed. 
     To make it difficult to generate the crimp of the weft yarn and the looseness of the warp yarn, a length for gripping the selvage portion (i.e., a length in a longitudinal direction of the woven fabric where the selvage portion is held down by the means that maintains the woven condition of the selvage portion of the woven fabric, and hereinafter referred to as “selvage portion gripping length”) is preferably 2 to 15 mm, and more preferably 3 to 10 mm. By having this range, high tension can be maintained even when the weft yarn is cut after the reed beating, and a woven fabric structure can be stabilized. 
     It is preferable that a width to grip the selvage portion (i.e., a length in a direction vertical to the longitudinal direction of the woven fabric where the selvage portion gripping device for the loom grips the selvage portion (a direction where the additional yarns which form the selvage portion are arranged), and hereinafter referred to as “selvage portion gripping width”) be a width capable of gripping the entire selvage portion. However, the width is not limited to the above-described width as long as the high tension can be maintained even when the weft yarn is cut after the reed beating to stabilize the woven fabric structure. 
     The selvage portion gripping device for the loom is only disposed at the weft yarn nozzle side of the woven fabric  10 . However, the device may be disposed at the opposite side of the weft yarn nozzle. When the selvage portion gripping device for the loom is disposed at the opposite side of the weft yarn nozzle, it is preferable that the device be provided between the woven fabric and the weft yarn cutter allocated at the opposite side of the weft yarn nozzle. At that time, similarly to the weft yarn nozzle side, it is preferable that the additional yarns be parallelized at the opposite side of the weft yarn nozzle of the woven fabric, that the selvage portion woven with the beaten weft yarns be formed, and that the selvage portion gripping device for the loom be disposed near a reed beating portion of the selvage portion. It is more preferable that the selvage portion gripping device for the loom allocated at the side of the weft yarn nozzle and the selvage portion gripping device for the loom allocated at the opposite side of the weft yarn nozzle be disposed opposite to each other via the warp yarns of the woven fabric to maintain weft yarn tension. 
       FIG. 2  is an enlarged schematic perspective view of when the selvage portion gripping device for the loom  7  is installed at the weft yarn nozzle  4  side. “ 1 ” indicates the warp yarn, “ 2 ” indicates the additional yarn, “ 4 ” indicates the weft yarn nozzle, “ 5 ” indicates the weft yarn, “ 8 ” indicates the fringe, “ 10 ” indicates the woven fabric, and “ 11 ” indicates the selvage portion. The woven fabric  10  is forwarded from a right upper side in the drawing to a left lower side in the drawing. Further, the plurality of warp yarns further exists and the weft yarn  5  is further extended at a right upper portion in the drawing. However, the illustration is omitted. 
     It is desirable that the selvage portion gripping device for the loom  7  be provided at least at the weft yarn nozzle side of the woven fabric  10 . In addition, it is preferable that the device  7  be further provided at the opposite side of the weft yarn nozzle. 
     The selvage portion gripping device for the loom  7  includes an outlet  71 B of the selvage portion of a space where the selvage portion can pass in which the selvage portion  11  formed by weaving the additional yarns  2  and the weft yarns  5  can pass through in the woven fabric forwarding direction and an inlet  71 A (not shown) of the selvage portion of the space where the selvage portion can pass formed at upper reaches of the additional yarns  2  of the selvage portion gripping device for the loom  7 . An outlet  72 B of the selvage portion is a tiny space portion where the weft yarn can move and which is at the woven fabric side for which the fringes  8  move parallel to the forwarding direction of the woven fabric  10 . A tiny space where the weft yarn can move and which is allocated at the weft yarn nozzle side  72 A (not shown) is formed at the weft yarn nozzle side of the selvage portion gripping device for the loom  7 . 
     The selvage portion  11  enters the space portion where the selvage portion can pass from the inlet  71 A of the space where the selvage portion can pass along the forwarding direction of the woven fabric  10 . The fringes  8  are gripped by a gripping means provided between the tiny space where the weft yarn can move and which is allocated at the weft yarn nozzle side  72 A and the tiny space where the selvage portion can move and which is allocated at the woven fabric side  72 B. The fringes  8  move inside the space where the selvage portion can pass parallel to the forwarding direction of the woven fabric  10 . Even when the weft yarn  5  is cut with the weft yarn cutter between the weft yarn nozzle  4  and the selvage portion gripping device for the loom  7 , the woven condition of the selvage portion is maintained. 
     As the means to maintain the woven condition of the selvage portion  11  within the selvage portion gripping device for the loom, a sliding member which does not prevent movement of the selvage portion in the space where the selvage portion can pass can be cited. A method in which a dimension of the space where the selvage portion can pass is appropriately set according to a dimension of the selvage portion to be capable of gripping the selvage portion  11  can be employed. However, a method in which a flexible part which catches a selvage portion which flexibly catches the selvage portion is arranged in the space where selvage portion can pass of the selvage portion gripping device for the loom is simpler and more reliable. 
     In this case, the flexible part which catches the selvage portion is provided inside the space where selvage portion can pass. As the flexible part which catches the selvage portion, a rubber plate or a resin plate can be used, or a member formed of a flexible member such as a coil spring or a rubber, and a plate material made of a metal or the like can be used. Further, it is advantageous to use a fixed plate spring in the space where the selvage portion can pass in terms of a structure and simplicity, i.e., cost. Also, it is preferable that a portion of the flexible part which catches the selvage portion which is in contact with the selvage portion have a surface having a low abrasion property. 
       FIG. 3  is a schematic sectional view of the selvage portion gripping device for the loom which uses a pair of plate springs  74 A,  74 B as the flexible part which catches the selvage portion.  FIG. 3  corresponds to a case where the device is taken along a surface orthogonal to the weft yarns  5  in  FIG. 2 . 
     The woven fabric is forcibly taken off by a winding roll in the weaving. Accordingly, in a condition where the additional yarns  2  and the weft yarns  5  are woven, the selvage portion  11  is moved from a right side to a left side in the drawing, i.e., from the inlet  71 A of the space where the selvage portion can pass to the outlet  71 B of the space where the selvage portion can pass. “ 74 A” and “ 74 B” indicate a pair of carbon steel catching parts such as plate springs, provided inside the space portion where the selvage portion can pass, and are respectively fixed to upper and lower wall surfaces of the space portion where the selvage portion can pass by two bolts  73 . There, the selvage portion  11  provided in the space portion where the selvage portion can pass is caught by the plate springs  74 A,  74 B serving as the flexible selvage portion parts from the upper and lower surfaces. Even when the weft yarn  5  is cut between the weft yarn nozzle  4  and the selvage portion gripping device for the loom  7 , the cut weft yarn  5  is prevented from slipping out from the selvage portion  11  or from loosening, and the woven condition of the selvage portion  11  is maintained inside the selvage portion gripping device for the loom  7 . The selvage portion  11  is moved inside the space portion where the selvage portion can pass and discharged from the selvage portion gripping device for the loom  7 . The woven fabric  10  is moved together with the fringes  8 . At this time, as described above, the woven condition between the additional yarns  2  and the cut fringes  8  are loosened, the cut fringes  8  are gradually separated from the additional yarns  2 , and the additional yarns  2  move independently and are separated from the woven fabric  10  and the fringes  8 . 
     It is not always necessary that the flexible part which catches the selvage portion is formed in a pair. One plate spring disposed on the upper (or the lower) wall surface and a lower side (or an upper side) thereof inside the selvage portion passage section may be provided. The plate spring can employ various shapes. However, to catch the selvage portion by uniform stress over a constant length, as in  FIG. 3 , it is preferable to use the pair of plate springs  74 A,  74 B which respectively has a planar shape and two arc shapes at both ends thereof. By considering the number of the additional yarns which configures the selvage portion and a thickness of each additional yarn, a thickness of the selvage portion, and the like, a length or a width of a portion having the planar shape, a thickness of the plate spring, and the like may be appropriately set. Accordingly, the woven condition of the selvage portion can be maintained in a degree that the crimp of the weft yarn after the weft yarn is cut or the looseness of the warp yarn is not generated at the selvage portion discharged from the selvage portion gripping device  7 . Further, as the material, stainless steel, phosphor bronze, beryllium copper, resin, or the like can be employed as well as the carbon steel. 
       FIG. 4  is a schematic sectional view of the selvage portion gripping device for the loom  7  shown in  FIG. 3  which is taken along a surface orthogonal to a forwarding direction of the additional yarns  2 . In this drawing, “ 72 A” indicates the tiny space where the weft yarn can move for the weft yarn at the weft yarn nozzle side (before cutting and after cutting) to move together with the selvage portion, and “ 72 B” indicates the tiny space where the weft yarn can move for the weft-inserted weft yarn  5  to move in the forwarding direction of the woven fabric  10 . These tiny space where the weft yarn can move  72 A,  72 B can adjust a clearance so that the weft yarn can pass through and a woven portion between the additional yarns and the weft yarns in the woven condition (i.e., the selvage portion) cannot pass through. Accordingly, even when the weft yarn is cut at the weft yarn nozzle side, the woven condition is maintained, and there is no occurrence of a crimp of the weft yarn caused by slipping-out or looseness of the cut weft yarn or no occurrence of a loosen fringe caused by the looseness of the warp yarn. Therefore, it is preferable that a height of the tiny space where the weft yarn can move be smaller than heights of the inlet and the outlet of the space portion where the selvage portion can pass. 
     Typically, the woven fabric woven by using the selvage portion gripping device for the loom is particularly useful when weaving a high-density woven fabric used for sportswear, industrial materials or the like. However, this disclosure is not limited to this. 
     The yarn for the warp yarn or the weft yarn used for weaving is not particularly limited, and a chemical fiber, a natural fiber or the like can be used. As the chemical fiber, for example, a polyamide-based fiber, a polyester-based fiber, an aramid-based fiber, a rayon-based fiber, a polysulfone-based fiber, a super high molecular weight polyethylene-based fiber or the like can be used. As the natural fiber, cotton, hemp, silk, wool, or the like can be used. In weaving the high-density woven fabric, the chemical fiber is preferable. Among these, the polyamide-based fiber and the polyester-based fiber which are excellent in mass productivity and economy are preferable. The polyamide-based fiber is further preferable from a viewpoint of heat resistance and less fluff of the fiber. 
     As the polyamide-based fiber, for example, fibers made of Nylon 6, Nylon 66, Nylon 12, Nylon 46, a copolymerized polyamide of the Nylon 6 and the Nylon 66, copolymerized polyamides formed by copolymerizing the Nylon 6 with polyalkylene glycol, dicarboxylic acid, amine and the like can be cited. Further, as the polyester-based fiber, for example, fibers made of polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and the like can be cited. A fiber formed by copolymerizing the polyethylene terephthalate or the polybutylene terephthalate with isophthalic acid, or 5-sodium sulfoisophthalic acid as an aromatic dicarboxylic acid component, or a fiber formed by copolymerizing the polyethylene terephthalate or the polybutylene terephthalate with aliphatic dicarboxylic acid such as adipic acid, may be used as well. 
     Further, to improve productivity in a spinning and stretching process and a processing process or to improve characteristics, these synthetic fibers may contain an additive such as a heat stabilizer, an antioxidant, a light stabilizer, a smoothing agent, an antistatic agent, a plasticizer, a thickener, a pigment, a flame retardant and the like. 
     Further, as a form of the fiber, a multifilament yarn is preferably used from a point of significantly achieving the desired effects. 
     Further, a sectional shape of a single yarn is not limited to a round shape and may be formed in any shape. For example, needless to say, the sectional shape may be a laterally symmetrical shape such as a flat shape, a rectangular shape, a rhomboid, or a cocoon shape, or a laterally asymmetrical shape. Alternatively, the sectional shape may be a shape combining any of these. Further, the sectional shape may have a protrusion or unevenness. The yarn may be a hollow yarn. 
     A plain weave, a twill weave, a satin weave, a variation of these weaves, and the like can be used for the woven fabric manufactured by using the selvage portion gripping device for the loom. However, this disclosure is not particularly limited to these weaves. 
     The woven fabric manufactured by using the selvage portion gripping device for the loom is woven using the warp yarn, the weft yarn, and the additional yarn as basic yarns. The additional yarn catches the weft yarn by utilizing its rigidity and prevents looseness of the weft yarn. The additional yarn forms the selvage portion by weaving with the weft yarn. 
     A predetermined number of the warp yarns are parallelized, and the additional yarns are further parallelized at the outside of the parallelized warp yarns. The weft yarn is supplied and beaten up, and the woven fabric is manufactured. As described above, after the woven condition between the supplied weft yarns and the additional yarns is maintained near the reed beating portion of the selvage portion by the selvage portion gripping device for the loom, the selvage portion is discharged from the selvage portion gripping device for the loom of the woven fabric. In other words, near the reed beating portion of the selvage portion, the selvage portion gripped by the selvage portion gripping device for the loom is moved synchronously with the movement of the woven fabric inside the selvage portion gripping device for the loom, and discharged thereafter. 
     The discharged selvage portion is moved together with the movement of the woven fabric. As mentioned above, since the additional yarns are gradually separated from the portion of the selvage portion where the weft yarn is cut, the finished woven fabric does not include the additional yarns. In other words, the additional yarn is supplied from a supply device different from the warp yarn. While the warp yarns are passed through healds and reeds, the additional yarns are not passed through the reeds. The additional yarns form the selvage portion together with the weft yarns woven by opening movements similar to the warp yarns, and are passed through the selvage portion gripping device for the loom. The additional yarns are supplied from the vicinity of a warp yarn beam, a load is applied to the additional yarns by a spring type tensioner, and the additional yarns are passed through the opened healds. After the weft yarn is run by high-pressure water or pressured air and the warp yarn and the weft yarn are beaten up by the reed, the weft yarn is cut with the weft yarn cutter. Since the selvage portion gripping device for the loom grips the selvage portion to maintain the woven condition of the selvage portion, slipping-out of the cut weft yarn from the selvage portion or looseness thereof is suppressed. With this configuration, compared with a case where the selvage portion gripping device for the loom is not installed, the crimp of the weft yarn of the selvage portion becomes small, and the crimp of the warp yarn becomes large. Due to this, warp yarn tension becomes high, gripping force for the weft yarn increases, and the cloth fell retreat at the selvage portion becomes small. Hence, since a cloth length difference between the selvage portion and a central portion of the woven fabric becomes small, an amount of a bow becomes small, and the warp yarn looseness in the base cloth selvage portion can improve. 
     When weaving is performed according to the conventional method, the cloth fell is expressed by a distance from a top of a temple to the cloth fell. When the weft yarn is run by the high-pressure water or the pressured air, high tension acts on the weft yarn. When the weft yarn is cut with the cutter after the weft yarn is beaten up by the reed, the free end portion of the weft yarn returns to a ground side of the woven fabric. Due to the decline in the weft yarn tension at the selvage portion of the woven fabric, the crimp of the weft yarn increases, and conversely the crimp of the warp yarn at the selvage portion decreases. Accordingly, the warp yarn tension at the selvage portion becomes low. As a result, the gripping force exerted on the weft yarn by the warp yarns disappears, and the cloth fell retreat becomes large. Also, the amount of a bow of the woven fabric increases, which thereby leads to occurrence of the warp yarn looseness in the base cloth selvage portion or deterioration of physical properties of the woven fabric. However, by performing weaving by using the selvage portion gripping device for the loom, the above-described problems are solved. 
     When weaving is performed by using the selvage portion gripping device for the loom, the additional yarns are normally supplied from a cone or a paper tube without using a leno yarn device or a bobbin. Particularly, it is preferable to use a spring washer to manage the tension when the additional yarns are supplied. 
     Since moderate crimping lessens fluctuations in tension of the additional yarns during weaving, it is preferable that the additional yarn be a multifilament and a crimped yarn. A material of the additional yarn is not particularly limited. However, polyester or nylon is easily available in general. It is preferable to select the material of the additional yarn similar in yarn characteristics to the warp yarn. 
     It is preferable that total fineness of the additional yarns be larger than total fineness of the weft yarns. By keeping woven strength between the additional yarns and the weft yarns at the selvage portion larger than woven strength between the warp yarns and the weft yarns, slipping-out of the cut weft yarn from the selvage portion or loosening thereof is prevented. 
     From a viewpoint of exhibiting the desired effects to the maximum, it is preferable that the number of additional yarns be four to eight yarns. 
     Since the woven fabric using the selvage portion gripping device for the loom can be subjected to high-speed operation, it is preferable that the woven fabric be woven by a jet loom. Particularly, a water jet loom is preferable from a point of conspicuously exhibiting the desired effects. The water jet loom runs the weft yarns by the high-pressure water, beats up the weft yarns, and then cuts the weft yarns at the weft yarn nozzle side. Because of this, compared to an air jet loom or a rapier loom, the water jet loom tends to have high running tension of the weft yarns, and further improvement of gripping force of the weft yarn at the selvage portion is requested. Accordingly, at the time of high-speed operation or a wide woven fabric in particular, the effect obtained by use of the added yarns (additional yarns) and by the selvage portion gripping device for the loom becomes more conspicuous. 
     When the high-density woven fabric is woven by using the selvage portion gripping device for the loom, it is preferable that, after the weaving by the water jet loom, scouring/heat set processing be performed to dry and/or remove an oil agent adhered to original yarns and remove wrinkles. 
     A width of the woven fabric is not particularly limited. However, since the warp yarn looseness in the base cloth selvage portion easily occurs as the woven fabric is wider, the device is particularly useful for the woven fabric having a region where only the warp yarns exist of 140 cm or more, and particularly of 180 cm or more. It is preferable that an upper limit of the width be 280 cm or less in manufacturing. 
     Next, a method of weaving using the selvage portion gripping device for the loom will be described. 
     The above-described yarns are used for the warp yarns, the additional yarns, and the weft yarns. The warp yarns and the additional yarns whose fineness is in proportion to woven fabric design are arranged for the warp and set in the loom. The weft yarns are prepared in the same manner. The additional yarn to be used is normally thicker than the warp yarn. As for the loom, it is preferable to use the water jet loom from a point of reducing occurrence of warp yarn fluff or improving productivity. 
     The tension of the warp yarn and the additional yarn is preferably 10 to 250 cN/yarn, and more preferably 20 to 200 cN/yarn. By setting the tension in such a range, a tiny space between single fibers in a yarn bundle of the yarns that configures the woven fabric can be reduced, and a dense woven fabric can be obtained. Further, after the weft yarn is inserted, the warp yarns tensioned as described above force the weft yarn to bend so that structure-restraining force of the woven fabric in the weft yarn direction is enhanced, an anti-yarn slippage property of the woven fabric improves, and a seam portion of a sewn product can be strengthened. If the warp yarn tension is small, a contact area between the warp yarns and the weft yarns in the woven fabric cannot be increased, and edge comb resistance cannot be obtained to a desirable extent. Further, an effect of reducing the tiny space between the single fibers is small. If the warp yarn tension is excessively great, the warp yarns tend to produce fluff due to abrasion at heald mails. 
     As a concrete method of adjusting the warp yarn tension within the above-described range, a method in which an inserting speed of the weft yarn is adjusted besides adjusting a forwarding speed of the warp yarn of the loom can be cited. Whether the warp yarn tension is actually within the above-described range during weaving can be checked by, for example, measuring the tension that acts per warp yarn at an intermediate point between the warp yarn beam and a back roller during operation of the loom. Further, it is preferable to provide a difference between tension of an upper sheet of the warp yarn and tension of a lower sheet of the warp yarn at the warp yarn opening. 
     As an adjustment method, there is, for example, a method in which a difference in a running line length between the upper yarns and the lower yarns is provided by installing a back roller level to, for example, about 10 to 30 mm higher than a horizontal position and the like. Further, as another method of providing a difference between the tension of the upper yarns and the tension of the lower yarns, there is, for example, a method in which a cam drive system is adopted in an opening device, and a dwell angle for the other side of the upper yarns/the lower yarns is made 100 degrees greater than that of the other. The tension of the warp yarn with the increased dwell angle is higher. 
     Next, if necessary, processing such as scouring, heat set, or the like is performed after the weaving process. 
     In the woven fabric woven by using the selvage portion gripping device for the loom, occurrence of cloth fell retreat at the selvage portion or occurrence of the warp yarn looseness in the base cloth selvage portion can be effectively prevented even in the high-speed weaving. For example, even when the loom is operated at high-speed rotation of about 400 to 900 rpm, occurrence of the warp yarn looseness in the base cloth selvage portion is extremely suppressed. Accordingly, the woven fabric can be cut into a shape as designed and also easy to sew. Further, since occurrence of the warp yarn looseness in the base cloth selvage portion is suppressed, waste of the woven fabric is small, and the woven fabric is advantageous in terms of cost. 
     Example 
     Hereinafter, a configuration and a desired effect will be described in detail by using the following examples. 
     Measurement Method 
     (1) Total Fineness 
     Total fineness was obtained by measuring fineness based on corrected mass with a predetermined load of 0.045 cN/dtex according to a JIS L 1013:2010 8.3.1 A method. 
     (2) Number of Single Fibers 
     Calculation was performed according to a method of JIS L 1013:2010 8.4. 
     (3) Fineness of Single Fiber 
     Calculation was performed by dividing the total fineness by the number of single fibers. 
     (4) Weaving Density of Warp Yarns/Weft Yarns 
     Measurement was performed based on JIS L 1096:2010 8.6.1. Each sample was placed on a flat table, and unnatural wrinkles and tension were removed. Then, at five different locations, the numbers of warp yarns and weft yarns in sections of 2.54 cm were counted, and average values for the warp yarn and the weft yarn were calculated. 
     (5) Strength/Elongation 
     Measurement was performed under a constant speed elongation condition shown in a JIS L 1013:2010 8.5.1 standard time test. Using “TENSILON” UCT-100 made by ORIENTEC Co., LTD, each sample was performed at a grip interval of 25 cm and a pulling speed of 30 cm/min. Elongation was obtained from elongation of a point showing the ultimate strength in an S-S curve. 
     (6) Warp Yarn Tension During Weaving 
     Using a “Check Master” (registered trademark) (type: CM-200FR) made by Kanai Kouki K.K., tension acting per warp yarn in an intermediate portion between the warp yarn beam and the back roller during operation of the loom was measured. 
     (7) Evaluation of Warp Yarn Looseness in Base Cloth Selvage Portion 
     As shown in  FIG. 5 , two marks ( 102 A,  102 B) are put on a central portion in a width direction of the woven fabric  10  at an interval of 500 mm. Two lines ( 103 A,  103 B) are drawn along the weft yarns from the marks  102 A,  102 B at the respective central portions of the woven fabric in a direction of an end portion  101 A at the weft yarn nozzle side of the woven fabric and in a direction of an end portion  102 B at the opposite side of the weft yarn nozzle of the woven fabric. The end portions  101 A,  102 B are width direction both ends. In this case, the woven condition of the woven fabric  10  tends to be loose at both the sides as compared with the central portion. Accordingly, as shown in  FIG. 5 , the two lines bend toward the cloth fell on both the sides, and an interval between the two lines, i.e., the lines  103 A,  103 B in the direction of the weft yarn, tends to be wider at peripheral portions than the central portion. Therefore, while a distance between the two lines  103 A,  103 B in the weft yarn direction at the central portion of the woven fabric is 500 mm, when the warp yarn looseness in the base cloth selvage portion becomes large, an interval between the two lines  103 A and  103 B in the direction of the weft yarn becomes wider at the end portion  101 A allocated at the weft yarn nozzle side of the woven fabric and the end portion  101 B allocated at a side which is not the weft yarn nozzle side of the woven fabric. The end portions  101 A,  101 B are the both sides. 
     Next, lines, i.e., lines  104 A,  104 B in the warp yarn direction, are drawn between the two lines  103 A,  103 B in the direction of the weft yarn at an interval of 20 mm from the end portion  101 A allocated at the weft yarn nozzle side of the woven fabric and from the end portion  101 B allocated at the opposite side of the weft yarn nozzle of the woven fabric. The end portions are the both sides of the woven fabric. The woven fabric is cut along the lines  103 A,  103 B in the direction of the weft yarn and the lines  104 A,  104 B in the direction of the warp yarn, thereby obtaining two strip-shaped bodies generated at the end portions of the woven fabric and having shapes close to rectangles. Lengths in the warp direction, (i.e., a length direction) of the strip-shaped bodies were measured, and the warp yarn looseness in the base cloth selvage portion was evaluated. 
     Example 
     Warp Yarns/Weft Yarns 
     Multifilament yarns formed of polyester and having a circular sectional shape, with single fiber fineness of 2.33 dtex, the number of filaments being 36, total fineness of 84 dtex, no twist provided, strength of 4.21 cN/dtex, and elongation of 40% were prepared. 
     Weaving 
     Employing the above-described yarns for warp yarns and weft yarns and by a water jet loom equipped with a selvage portion gripping device for a loom, which will be described below, a plain weave fabric was woven with warp yarn tension during weaving being 20 cN/yarn, loom rotation speed being 500 rpm, warp yarn density being 133 yarns/2.54 cm, weft yarn density being 133 yarns/2.54 cm, and a width (a width of a portion where the warp yarns exist) being 200 cm. 
     As for additional yarns, 3 ply textured yarns formed of polyester and having a circular sectional shape, with single fiber fineness of 3.44 dtex, the number of filaments being 96 f, and total fineness of 330 dtex were used. Four additional yarns were supplied and parallelized to each of the two outsides of the warp yarns where a predetermined number of yarns were parallelized, and supplied by setting additional yarn tension to 130 cN/yarn. A clearance of 5 mm was provided between the warp yarn and the additional yarn as a fringe. The fringes of the discharged selvage portion were gradually separated from the additional yarns, and the additional yarns were collected in the same route as the catch-cords at the opposite side of the weft yarn nozzle through a guide. 
     Selvage Portion Gripping Device for Loom 
     The selvage portion gripping device for the loom in  FIG. 3  includes the space portion where the selvage portion can pass in which the selvage portion formed by weaving the additional yarns and the weft yarns can pass through in the woven fabric forwarding direction and the tiny space portion where the weft yarn can move in which the weft yarn can move in the woven fabric forwarding direction, and further includes a pair of plate springs arranged at the space portion where the selvage portion can pass. The two selvage portion gripping devices for the loom were respectively installed at the end allocated at the weft yarn nozzle side and at the end allocated at the opposite side of the weft yarn nozzle near the reed beating portion of the loom. 
     A main body of the selvage portion gripping device for the loom  7  is made of stainless steel and has a rectangular parallelepiped shape (6 mm in width, 30 mm in height, 25 mm in length). As shown in  FIG. 3 , the selvage portion gripping device for the loom  7  includes the inlet  71 A of the space where the selvage portion can pass which has a width of 4 mm and a height of 10 mm and the outlet  72 A of the space where the selvage portion can pass. Also, the two flexible parts which catch the selvage portion are vertically provided in the space where the selvage portion can pass. The two flexible parts that catch the selvage portion are respectively configured by the plate springs  74 A,  74 B and plate spring supporting bodies  75 A,  75 B. The plate springs  74 A,  74 B are respectively made of stainless steel having a thickness of 0.3 mm, have the arc-shaped portions at both ends of the flat plate portion having a length of 20 mm, and are fixed to the plate spring supporting bodies  75 A,  75 B by bolts. As a result, a selvage portion gripping length was set to 20 mm, and a selvage portion gripping width was set to 4 mm. The selvage portion was configured to be caught so that the selvage portion passes between the flat plate portions of the pair of plate springs synchronizing with a flow of the woven fabric. Further, as shown in  FIG. 4 , the tiny space where the weft yarn can move and which is allocated at the weft yarn nozzle side  72 A and the tiny space portion where the selvage portion can move and which is allocated at the woven fabric side  72 B are formed on both the side surfaces of the selvage portion gripping device for the loom  7 . A widths of these tiny spaces are formed slightly larger than a diameter of the weft yarn and smaller than a thickness of the selvage portion where the weft yarns and the additional yarns are woven. As a result, the weft yarn moves parallel along the flow of the woven fabric, and the selvage portion is not slipped out from the tiny space where the weft yarn can move to the woven fabric side even after the weft yarn is cut with the weft yarn cutter. 
     Comparative Example 
     Except that the selvage portion gripping device for the loom and the additional yarns are not used, the weaving was performed according to a method similar to the method in Example. 
     Evaluation of Warp Yarn Looseness in Base Cloth Selvage Portion 
     Hereinafter, the woven fabrics obtained in the Example and Comparative Example were evaluated according to the above-described evaluation method of the warp yarn looseness in the base cloth selvage portion. Lengths of the strip-shaped bodies are shown. As is evident from this, occurrence of cloth fell retreat at the selvage portion of the woven fabric and the warp yarn looseness in the base cloth selvage portion were decreased in the woven fabric woven by using the selvage portion gripping device for the loom. 
     Warp Yarn Looseness at Base Cloth Selvage Portion in Example 
     L side: 510.5 mm 
     R side: 512.5 mm 
     Warp Yarn Looseness at Base Cloth Selvage Portion in Comparative Example 
     L side: 518.0 mm 
     R side: 520.0 mm