Fiber bundle opening method and device

Abstract

To solve problems of opening efficiency and large oscillation of a device in a method to open a fiber bundle while making a fluid pass through the fiber bundle and bending the fiber bundle, which are caused by a significant change in flow of the fluid acting on the fiber bundle in a short time due to a member when opening is executed by disposing the member for forming a bending on an opening processing part and applying tension and relaxation alternately to the fiber bundle in a short time.SOLUTION: Tension and relaxation are applied to a fiber bundle by a bending formation member on which an opening for making fluid pass through is formed. The fluid passed through the opening passes a neighboring area at a maximum push-in position of the fiber bundle and opens the fiber bundle by moving fibers in a width direction while bending the fibers in a passage direction of the fluid.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a fiber bundle spreading method and device which comprises pulling out and conveying a fiber bundle formed by aligning and bundling a large number of fibers from a yarn supplier, and spreading the fiber bundle by passing a fluid through the conveyed fiber bundle to move the fibers in the width direction while bending them. [Background technology]

[0002] Fiber-reinforced composite materials, which are made of reinforcing fibers such as carbon fiber or glass fiber and a base material (matrix) of thermosetting resins such as epoxy resin, or thermoplastic resins such as PA6, PPS, and PEEK, are lightweight and have excellent mechanical properties and corrosion resistance, and therefore are being used widely in products in a variety of fields, including the transportation field such as aircraft and automobiles, industrial applications such as machine tool parts and robot arms, and sports fields such as fishing rods and golf shafts.

[0003] As a method for forming a molded body of this fiber-reinforced composite material, a method using a sheet-shaped intermediate material called a prepreg sheet, which is made by impregnating the spaces between the single fibers of the reinforcing fiber bundles with a resin that serves as a matrix, is often used. For example, there is a method in which prepreg sheets are laminated in various directions and then heated and pressurized to form a molded body, and the molded body obtained by this method is a molded body with high elasticity and high strength that makes use of the characteristics of the long fibers. In addition, a molding method in which a prepreg sheet is processed into a rectangular chopped tape, and then the chopped tape is spread in a mold and heated and pressurized, can obtain a molded body with a complex shape that is lightweight and has excellent mechanical properties.

[0004] In recent years, there has been an increasing need for thin prepreg sheets with good fiber dispersion. Thin prepreg sheets are not only useful for obtaining thin molded bodies, but also for enabling a variety of designs that take advantage of the anisotropic characteristics of excellent physical properties in the long fiber direction. They are also known to improve the mechanical properties of molded bodies made by laminating prepreg sheets or chopped tapes, and are expected to further expand the uses of fiber-reinforced composite materials. In order to meet the demand for such uniform and thin prepreg sheets, a technology for opening reinforcing fiber bundles is also required.

[0005] In addition, in the manufacture of prepreg sheets, spreading reinforcing fiber bundles is also necessary to reduce material costs. In order to make a uniform and thin prepreg sheet, it is common to make it by arranging reinforcing fiber bundles with a small number of fibers (filaments) in one direction. However, since reinforcing fiber bundles with a small number of filaments are expensive, it is desirable to use reinforcing fiber bundles with as many filaments as possible. For this reason, a method in which a reinforcing fiber bundle with a large number of filaments is spread to produce a spread fiber sheet of thin reinforcing fiber bundles and then made into a prepreg sheet makes it possible to make a uniform and thin prepreg sheet with reduced material costs.

[0006] As a method for spreading a plurality of fiber bundles, the present inventors have proposed methods such as those described in Patent Documents 1 and 2. These methods involve applying a fluid to the conveyed fiber bundle in a direction intersecting the conveying direction, bending the fiber bundle while moving each fiber in the width direction, and spreading the fiber bundle. In order to impart bending to the plurality of conveyed fiber bundles, a method is disclosed in which an action of pushing the fiber bundle in a direction intersecting the conveying direction by a member that comes into contact with the fiber bundle (referred to as a contact member) and an action of moving the contact member away from the pushed-in fiber bundle are repeatedly performed.

[0007] These methods make it possible to widely spread a plurality of fiber bundles with good fiber distribution. In the method of Patent Document 2, the contact member rotates to repeatedly push the fiber bundles in and separate them from the fiber bundles at high speed, making it possible to quickly spread wide fibers with good quality. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 4740131 [Patent Document 2] Patent No. 5553074 Summary of the Invention [Problem to be solved by the invention]

[0009] These methods can be performed by an apparatus equipped with a fluctuation imparting unit that repeatedly applies an action of pushing the fiber bundle with the contact member and an action of moving the contact member away from the fiber bundle in the pushed-in state, and a fiber-spreading processing unit that applies a fluid to the fiber bundle to bend it into a curved shape and move each fiber in the width direction.Then, by using an apparatus in which the contact member of the fluctuation imparting unit is disposed in the upper part of an air cavity tube (the upper part is open, and the lower part is connected to a suction pump that sucks in a fluid) that constitutes the fiber-spreading processing unit, the fiber bundle is transported to the downstream side where the fluid of the contact member is sucked in, and fiber-spreading is performed, thereby making it possible to realize wide and high-quality fiber-spreading.

[0010] However, when the fiber bundle bends inside the cavity tube, the fluid acting on the fiber bundle is sucked into the cavity tube so as to go around the contact member and then acts on the fiber bundle, and it is thought that the sucked in fluid does not act on the fiber bundle efficiently.

[0011] Furthermore, these methods cause large vibrations in the entire fiber-spreading processing section, resulting in problems such as shaking of the device, loosening of screws, damage to components, and loud noise. This is believed to be caused by the fact that when the contact member rotates or vibrates vertically in the fiber-spreading processing section, the area of ​​the region into which the fluid flows in the fiber-spreading processing section varies greatly between when the contact member pushes the fiber bundle and when it separates from the fiber bundle. In particular, the vibration increases as the fiber-spreading processing speed increases, and device durability and noise when high-speed fiber-spreading processing is performed continuously become an issue.

[0012] Therefore, an object of the present invention is to provide a fiber bundle spreading method and device capable of performing fiber spreading in which a fluid acts efficiently on the fiber bundle. [Means for solving the problem]

[0013] The fiber-spreading method of the present invention includes: drawing out a fiber bundle formed by aligning and bundling a large number of fibers from a yarn supplier, transporting the fiber bundle, pushing a part of the fiber bundle in a direction intersecting the transport direction while contacting a deflection forming member to tension the fiber bundle, and then moving the deflection forming member away from the fiber bundle in the tensioned state to relax the fiber bundle in a region where a fluctuating operation is repeatedly performed, and spreading the fiber bundle by moving the fibers in the width direction while bending the fibers in the passing direction of the fluid, in which an opening is formed in the deflection forming member through which the fluid passes, and the fluid that has passed through the opening passes through a region in the vicinity of a maximum pushing position of the fiber bundle by the operation of the deflection forming member, and moving the fibers in the width direction while bending the fibers in the passing direction of the fluid, thereby spreading the fiber bundle. Furthermore, the deflection forming member rotates to repeatedly apply fluctuating operations of tension and relaxation to the fiber bundle. Furthermore, the bend forming member vibrates in a direction intersecting the feeding direction of the fiber bundle, and repeatedly applies fluctuating motions of tension and relaxation to the fiber bundle. Furthermore, the relationship between the bending section length, which is the length in the feeding direction of the region where the fiber bundle is bent, and the fluid action section length, which is the length in the feeding direction of the region where a fluid acts on the bent fiber bundle and passes through, is such that the bending section length>the fluid action section length. Furthermore, a region in which a fluid acts on the fed fiber bundle to bend the fibers and move them in the width direction to spread them is set at a plurality of locations in the feeding path of the fiber bundle. Furthermore, the bend forming member is provided with a width regulating guide that regulates the spread width of the fed fiber bundle, and the fiber bundle is spread while gradually expanding the spread width. Furthermore, a plurality of the fiber bundles are lined up in the width direction and fed, and each of the fiber bundles is spread.

[0014] The fiber spreading device according to the present invention includes a fiber spreading processing section that spreads the fiber bundle by applying a fluid to the fiber bundle being fed and moving the fibers in the width direction while bending the fibers, and a bend forming section that arranges a bend forming member having an opening through which the fluid passes within the fiber spreading processing section and repeatedly performs a fluctuating operation in which the bend forming member pushes the fiber bundle in a direction intersecting the feeding direction to make the fiber bundle tense and moves the bend forming member away from the fiber bundle in the tense state to make the fiber bundle relaxed. Furthermore, the bend forming member includes a plurality of pushing members that push the fiber bundle being fed in a direction intersecting the feeding direction, and an attachment member that is attached to the pushing members so as to form the openings at intervals that allow the fluid to pass through. Furthermore, the pushing members are formed in a roll shape. Effect of the Invention

[0015] By having the above-mentioned configuration, the present invention can reduce the fluctuation of the fluid passing through the fiber bundle and perform the fiber-spreading action efficiently. In addition, by reducing the fluctuation of the fluid passing through the fiber bundle, it is possible to reduce the vibration generated in the entire fiber-spreading processing section, thereby reducing problems such as shaking of the device, loosening of screws, damage to the shafts of members, and high noise.

[0016] Here, the conveying direction of the fiber bundle means the direction of the conveying path of the conveyed fiber bundle, and in the case where the conveying path is defined by a guide member such as a guide roll, means the direction in which the fiber bundle is stretched on the conveying path. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic side view of a fiber spreading device according to the present invention. [Diagram 2] FIG. 2 is a schematic diagram of a pivoting deflection forming member according to the present invention; [Diagram 3] 4 is a schematic diagram showing a state in which a plurality of fiber bundles are spread by a rotating deflection forming member according to the present invention. FIG. [Figure 4] 6A and 6B are explanatory diagrams regarding air flow caused by a rotating deflection forming member according to the present invention. [Diagram 5] 11 is a schematic diagram of another embodiment of a pivoting flexure forming member according to the present invention; FIG. [Figure 6] 1 is a schematic diagram of a deflection forming member that vertically vibrates in a direction intersecting with the feeding direction of the fiber bundle according to the present invention. FIG. [Figure 7] FIG. 4 is an explanatory diagram relating to the length of a section in which the fiber bundle according to the present invention is bent and the length of a section in which a fluid acts on and passes through the fiber bundle. [Figure 8] FIG. 4 is a schematic plan view of a fiber spreading device according to another embodiment of the present invention. [Figure 9] FIG. 4 is a schematic side view of a fiber spreading device according to another embodiment of the present invention. [Figure 10] 13 is an explanatory diagram regarding fiber spreading when a rotating contact member according to a conventional example is used. FIG. [Figure 11A] FIG. 11 is an explanatory diagram regarding dimensional settings of a fiber-spreading processing section and a bend forming section in the embodiment. [Figure 11B] FIG. 11 is an explanatory diagram regarding dimensional settings of a fiber-spreading processing section and a bend forming section in the embodiment. [Figure 12A] 13 is a result showing a vibration state during fiber spreading at a processing speed of 15 m / min in the air cavity tube portion of the fiber spreading device according to the present invention. [Figure 12B] 13 is a result showing a vibration state during fiber spreading at a processing speed of 40 m / min in the air cavity tube portion of the fiber spreading device according to the present invention. [Figure 13A] 13 is a result showing a vibration state during fiber spreading at a processing speed of 15 m / min in a wind tunnel tube part of a fiber spreading device according to the prior art. [Figure 13B] 13 is a result showing a vibration state during fiber spreading at a processing speed of 40 m / min in a wind tunnel tube part of a fiber spreading device according to the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are preferred examples for carrying out the present invention, and therefore various technical limitations are imposed thereon, but the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited thereto.

[0019] 1 is a schematic side view of a fiber-spreading device according to the present invention. This device example includes a yarn supplying section 1 that supplies a plurality of fiber bundles Tm, a guide section 2 that guides each of the supplied fiber bundles Tm, a bend forming section 3 that performs a varying operation to bend and temporarily relax each of the fed fiber bundles Tm, a fiber-spreading processing section 4 that spreads each of the fed fiber bundles Tm, a heating section 5 that blows hot air onto each of the fiber bundles Tm to heat them, and a take-up section 6 that clamps and transports the spread yarn Ts obtained by spreading each of the fiber bundles.

[0020] The fiber bundle Tm obtained by bundling a plurality of long fibers is wound around a bobbin-type yarn supplier 11, and as the spread yarn Ts is drawn in by the take-up unit 6, the yarn supplier 11 rotates to unwind the fiber bundle Tm. Note that, although five yarn suppliers are set in Fig. 1, the number of supplied fiber bundles Tm may be one, or five or more may be set to produce a wide spread fiber sheet.

[0021] Examples of fiber materials used for the fiber bundle Tm include reinforced fiber bundles made of high-strength fibers such as carbon fiber bundles, glass fiber bundles, aramid fiber bundles, and ceramic fiber bundles, and thermoplastic resin fiber bundles made of thermoplastic synthetic fibers such as polyethylene, polypropylene, nylon 6, nylon 66, nylon 12, polyethylene terephthalate, polyphenylene sulfide, and polyether ether ketone. For example, the number of fibers in a carbon fiber bundle is generally 12,000 to 24,000, but in the present invention, a fiber bundle having a number of fibers exceeding 24,000 (for example, 50,000) can also be used.

[0022] In the example of Fig. 1, a yarn supplying motor (not shown in Fig. 1) is attached to the yarn supplier 11, and the amount of fiber to be paid out from the yarn supplier 11 can be adjusted by rotating the yarn supplying motor. The fiber bundle Tm paid out from the yarn supplier 11 is fed to the guide section 2, where it is conveyed with a constant tension. In the guide section 2, the fiber bundle Tm is first paid out in a predetermined payout direction by the rotating guide roll 21.

[0023] The fiber bundle Tm drawn out in a predetermined direction by the guide roll 21 is transported to the tensioning section 22. The tensioning section 22 includes a pair of support rolls 221 arranged at a predetermined interval in the transport direction D of the fiber bundle Tm, and a tensioning roll 222 that applies tension to the fiber bundle Tm between the pair of support rolls 221. The fiber bundle Tm is set and transported so as to wrap around from the upper side of the support rolls 221 to the lower side of the tensioning roll 222. When the length of the fiber bundle Tm passing between the support rolls 221 changes, the tensioning roll 222 rises and falls accordingly. The rising and lowering operation of the tensioning roll 222 is detected by an upper limit position detection sensor 223 and a lower limit position detection sensor 224.

[0024] When the tension-giving roll 222 rises and is detected by the upper limit position detection sensor 223, the payout amount of the yarn supplying motor connected to the yarn supplier 11 increases, and the feed amount of the fiber bundle Tm increases. When the tension-giving roll 222 falls and is detected by the lower limit position detection sensor 224, the payout amount of the yarn supplying motor connected to the yarn supplier 11 decreases, and the feed amount of the fiber bundle Tm decreases.

[0025] In this way, the feed amount of the fiber bundle Tm is adjusted so that the tension-applying roll 222 is positioned within a predetermined range based on detection signals from the upper limit position detection sensor 223 and the lower limit position detection sensor 224, and the tension of the fiber bundle Tm is stabilized by the own weight of the tension-applying roll 222. The tension applied to the fiber bundle Tm can be appropriately determined by adjusting the weight of the tension-applying roll 222.

[0026] A vibration elimination section 23 is provided on the downstream side of the tension imparting section 22 in the transport direction as a mechanism for reducing vibrations generated in the fiber bundle Tm. The vibration elimination section 23 is provided with a pair of support rolls 231 and a swing roll 232. The swing roll 232 is arranged between the pair of support rolls 231, and is set so that the fiber bundle Tm passing below the support roll 231 passes above the swing roll 232. A spring member 233 is provided to bias the swing roll 232 so as to move it upward, and the swing roll 232 is biased upward. With this configuration, vibrations generated in the fiber bundle Tm are reduced.

[0027] A reverse-back prevention unit 24 is provided downstream of the vibration removal unit 23 in the conveying direction to prevent the conveyance of the fiber bundle Tm from reverse. The reverse-back prevention unit 24 is composed of a one-way rotating roll 241 and a support roll 242. The one-way rotating roll 241 is equipped with a one-way clutch (not shown) so that it rotates only in the direction in which the fiber bundle Tm is conveyed and does not rotate in the direction in which it is pulled back. The fiber bundle Tm is nipped and conveyed by the one-way rotating roll 241 and the support roll 242 to prevent the fiber bundle Tm from traveling in the reverse direction.

[0028] A predetermined tension is applied to the fiber bundle Tm unwound from each yarn supplier 11, and the fiber bundle Tm is sent out through the vibration elimination section 23 and the reverse return prevention section 24, and is transported toward the alignment roll 26 by the guide roll 25. The alignment roll 26 aligns the transported fiber bundles Tm so that they are arranged at equal intervals on the same plane, and delivers the fiber bundles Tm.

[0029] The fiber bundle Tm, which has been set to a tension within a predetermined range, passes through the fiber-spreading processing section 3 installed in the conveying direction D. The fiber-spreading processing section supports the fiber bundle Tm with a pair of guide rolls 31 arranged in the conveying direction D. Between the guide rolls 31, a cavity tube 32 is provided, and an upper opening of the cavity tube 32 is formed with a predetermined length between the guide rolls 31. A flow rate control valve 33 and an intake pump 34 are attached to the lower side of the cavity tube 32, and the intake pump 34 is operated to suck air from within the cavity tube 32, thereby generating a downward air current due to suction at the upper opening between the guide rolls 31. In the present invention, the downward air current due to suction is called a suction air current. The flow rate of the suction air current can be adjusted by adjusting the flow rate control valve 33.

[0030] When the suction airflow passes through the fiber bundle Tm being transported between the guide rolls 31 and the fiber bundle Tm becomes bent in the direction of the airflow, the air passes between the fibers of the bent fiber bundle Tm, and a force that moves the fibers in the width direction of the fiber bundle Tm is generated, and the fiber bundle Tm is spread. Such a fiber-spreading action is well known. In this example, the fiber-spreading process is performed using an air flow, but the fiber-spreading process can also be performed using a liquid such as water as the fluid.

[0031] The bend forming unit 4 is disposed between a pair of guide rolls 31 in the fiber-spreading unit 3. In this example, the bend forming unit 4 is configured as shown in the explanatory diagram of Fig. 2. It is composed of a bend forming member 41 that rotates to give the fiber bundle Tm a tense state and a relaxed state, a support rod 43 that is disposed along a central axis O that is set in the longitudinal direction of the bend forming member, and a rotary motor 44 that rotates the bend forming member 41 around the central axis O.

[0032] The rotating deflection forming member 41 in Fig. 2 is formed into a plate-like body having a predetermined thickness, and the length in the longitudinal direction is set to be longer than the length that can contact the entire width of the spread fiber bundles Tm in the width direction. A pair of contact surfaces 41a is formed on both side edges set parallel to the central axis O set in the longitudinal direction at a predetermined interval. Since the contact surface 41a is the surface that comes into contact with the fiber bundles Tm, it is formed into a curved shape in a cut surface in a direction perpendicular to the central axis O. The curved shape makes it possible to prevent the fiber bundles that come into contact from being damaged. Specifically, it is desirable for the cross-sectional shape to be an arc shape or the like.

[0033] The deflection forming member 41 is provided with an opening M through which the suction airflow passes. In the rotating deflection forming member 41 in Fig. 2, the opening M is open in the thickness direction of the plate-like body, the opening width is set to a predetermined width through which a fluid can pass within a range in which the fiber bundles Tm can be spread symmetrically about the central axis O, and the opening length is set to be equal to or longer than the length through which the suction airflow acts over the entire width in the width direction of the plurality of spread fiber bundles Tm.

[0034] 3 is a schematic diagram showing the state of multiple fiber bundles spread by a rotating bend forming member. The bend forming member 41 is disposed on the opposite side of the guide roll 31 with respect to the fiber bundle Tm being fed, and is set to a length that allows contact across the entire width of the multiple fiber bundles Tm being spread. The bend forming member 41 rotates by the rotation drive of the rotation motor 44, and the contact surface 41a of the bend forming member 41 moves in a direction inclined to the feeding direction D while alternately contacting the fiber bundle Tm, and rotates to stroke the surface of the fiber bundle Tm, pushing the fiber bundle Tm between the guide rolls 31 and putting it in a tensed state. The fiber bundle Tm is temporarily relaxed at the moment when the contact surface 41a further rotates upward and separates from the tensed fiber bundle Tm.

[0035] 3, the deflection forming member 41 is attached to a pair of wall surfaces arranged on the width direction side of the fiber bundle Tm of the cavity tube 32. In this case, disk-shaped wall members 42 are attached to both longitudinal ends of the deflection forming member 41, and the wall members 42 are attached with a circular opening provided in the wall surfaces so that they fit within the wall surfaces of the cavity tube 32. A ball bearing or the like is disposed between the opening in the wall surface and the outer periphery of the wall member 42, so that the deflection forming member 41 can rotate.

[0036] Immediately after the contact surface 41a of the deflection forming member 41 pushes the fiber bundle Tm between the pair of guide rolls 31 and then rotates to separate from the fiber bundle Tm, the air flow (suction airflow) sucked into the air cavity tube 32 from the opening M of the deflection forming member 41 directly acts on the fiber bundle, causing the fiber bundle Tm to bend in a curved shape in the direction of the suction airflow, and at the same time, air passes between the fibers to spread the fiber bundle Tm in the width direction with good dispersion.

[0037] In a method in which a fiber bundle is spread while bending in a curved shape by passing a fluid between each fiber, when the fiber bundle is bent in the fluid flow direction, each fiber can be moved in the width direction most efficiently by passing the fluid through a region (hereinafter referred to as the "maximum bending region") adjacent to the position where the fiber bundle is most bent downstream in the fluid flow direction, and fiber spreading with good fiber distribution can be achieved.

[0038] 4 is an explanatory diagram regarding the air flow when a rotating flexure forming member 41 having an opening M is disposed at approximately the center position between the guide rolls 31. By providing the opening M in the flexure forming member 41, immediately after the contact surface 41a of the flexure forming member 41 separates from the fiber bundle Tm, the air that has passed through the opening flows directly into and passes through the maximum deflection region N of the fiber bundle Tm, which is a method for efficiently spreading fiber. In this case, the region near the position (maximum push-in position P) where the flexure forming member 41 pushes the fiber bundle Tm to the maximum becomes the maximum deflection region N when the fiber bundle Tm is curved in the fluid flow direction.

[0039] 10 is an explanatory diagram of fiber-spreading using a rotating contact member according to a conventional example. In the conventional example, a fluctuation imparting section 8 is provided between guide rolls 31 arranged at the upper opening of the cavity tube 32 of the fiber-spreading processing section 3. The fluctuation imparting section 8 corresponds to the deflection forming section 4 of the present invention. The contact member 81, which corresponds to the deflection forming member 41 of the present invention, alternately pushes the fiber bundle Tm into the cavity tube 32 to make it tense and moves it away from the fiber bundle Tm to make it relaxed. Since the contact member 81 in the conventional example has a solid plate-like structure, after the contact surface 81a of the contact member 81 moves away from the fiber bundle Tm, the suction airflow flows around the contact member 81 and enters, and it is considered that the suction airflow does not efficiently pass through the maximum deflection region of the fiber bundle Tm during fiber-spreading.

[0040] In the conventional example, the area through which the suction airflow passes at the upper opening of the cavity tube 32 when the contact surface 81a of the contact member 81 pushes the fiber bundle Tm to the most downstream side varies greatly from the area through which the suction airflow passes at the upper opening when the contact surface 81a is separated from the fiber bundle Tm and becomes substantially parallel to the conveying direction D. It is considered that the large variation in the area causes the flow of the fluid to also vary greatly, which is also a cause of vibration occurring in the entire fiber-spreading processing section. In particular, it is considered that the vibration becomes larger as the fiber-spreading processing speed increases because the area width varies in a short period of time.

[0041] 4, in the present invention, by providing the opening M in the deflection forming member 41, the difference in area between the area through which the suction airflow passes at the upper opening of the cavity tube 32 when the contact surface 41a of the deflection forming member 41 pushes the fiber bundle Tm to the most downstream side and the area through which the suction airflow passes at the upper opening when the contact surface 41a is separated from the fiber bundle Tm and becomes substantially parallel to the conveying direction D is smaller than in the conventional example. Therefore, compared to the conventional example, vibrations, noise, and the like generated in the entire fiber-spreading processing section are reduced, and stable fiber-spreading can be performed even in high-speed processing.

[0042] The rotatable deflection forming member 41 in FIG. 2 has an opening M of a predetermined width and length in the thickness direction of a plate-like body having a predetermined thickness, and the opening is formed by drilling or the like. The deflection forming member 41 only needs to have an opening through which airflow can pass in the maximum deflection region during rotation, and the shape of the opening is not particularly limited. For example, the deflection forming member can be formed by combining a plurality of members. In FIG. 5, the deflection forming member is composed of two pushing members 411 and two mounting members 412.

[0043] The pushing member 411 is a member that pushes the fiber bundle Tm in a direction perpendicular to the conveying direction. The cross-sectional shape in the direction perpendicular to the central axis O is approximately rectangular, and the contact surface 41a that comes into contact with the fiber bundle Tm is curved so as not to damage the fiber bundle. The attachment member 411 is disk-shaped with a predetermined thickness, and has holes that allow the pushing member 411 to be fixed.

[0044] Two pushing members 411 are disposed at positions symmetrical about the central axis O, and both ends of the pushing members 411 are fitted and fixed into the respective mounting members 412. Then, by fitting the pushing members 411 into the mounting members 412 at a certain distance from the central axis O, a certain gap is formed between the two pushing members, and the gap is formed as an opening M. The length of the pushing members along the central axis O is set to be equal to or greater than the length that allows contact with the multiple spread fiber bundles Tm over the entire width in the width direction.

[0045] A support rod 43 is attached to the center of one of the disk-shaped mounting members 412 and connected to a rotary motor 44, while the other disk-shaped mounting member 412 is attached so as to fit inside a circular opening provided in the wall of the cavity tube. A ball bearing or the like is disposed between the opening in the wall and the outer periphery of the mounting member 412. With this configuration, the deflection forming member 41 can rotate at the upper opening of the cavity tube.

[0046] The shape of the pushing member 411 may be a roll shape or an ellipse shape in the cross section in the direction perpendicular to the central axis O. It is sufficient that the surface in contact with the fiber bundle Tm has a curved shape. The number of pushing members 411 may be more than two. By arranging a plurality of pushing members so that the tips of the contact surfaces 41a of the pushing members 411 are equally spaced on one circumference, the rotation of the deflection forming member 41 is stabilized and the deflection of the fiber bundle Tm is also stably formed, which is desirable. As a result of the study by the present inventors, the number of pushing members 411 is preferably up to four. If the number of pushing members 411 is more than that, the pushing members 411 do not separate from the fiber bundle Tm, or even if they do separate, it is instantaneous, and the deflection of the fiber bundle is not formed, and wide spreading cannot be performed.

[0047] 6 is a schematic diagram of a deflection forming member that vertically vibrates in a direction intersecting with the feeding direction of the fiber bundle according to the present invention. In the present invention, a deflection forming member having an opening M for efficiently spreading the fiber bundle is disposed at the upper opening of the cavity tube. The deflection forming member may be rotated to apply tension and relaxation to the fiber bundle, or may be vibrated up and down to apply tension and relaxation to the fiber bundle.

[0048] The deflection forming member 41 in Fig. 6 vibrates up and down with respect to the feeding direction of the fiber bundle to cause deflection in the multiple fiber bundles. The cross-sectional shape of the deflection forming member 41 in the direction perpendicular to the central axis O is, for example, semicircular as shown in Fig. 6, and the curved surface portion is the portion that comes into contact with the fiber bundle. The opening M is set in a direction in which the suction airflow can pass, with a predetermined width through which the suction airflow can pass within a range in which the fiber bundles can be spread symmetrically about the central axis O, and with a predetermined length through which the suction airflow acts over the entire width in the width direction of the multiple spread fiber bundles.

[0049] 6 has a support rod 43 protruding along a central axis O, and one of the support rods 43 is connected to a lifting rod 453, a connecting rod 452, and a rotating plate 451. When the rotating plate 451 is rotated by a rotation drive transmitted from a rotating motor 44, the support rod is moved up and down by a crank mechanism of the connecting rod 452 and the lifting rod 453. The other support rod 43 is attached to the wall surface of the cavity tube by a mechanism such as a linear slide that makes the support rod move up and down smoothly. With this configuration, the deflection forming member 41 can move up and down quickly and smoothly.

[0050] 6 is placed at the upper opening of the cavity tube, and the bend forming member 41 is vibrated up and down taking into account the transport speed of the fiber bundle, so that the fiber bundle is bent immediately after the bend forming member 41 is separated from the fiber bundle. At this time, the fluid passing through the opening M provided in the bend forming member 41 acts on the maximum bend region of the bent fiber bundle, and the fiber bundle can be opened.

[0051] 7 is an explanatory diagram relating to the length of the section in which the fiber bundle according to the present invention is bent and the length of the section through which the fluid acts on and passes through the fiber bundle. In the present invention, the bend forming member 41 is disposed between a pair of guide rolls 31 to push the fiber bundle Tm in a direction perpendicular to the conveying direction D, so that the length of the fiber bundle Tm conveyed between the pair of guide rolls 31 is equal to or longer than the linear distance between the guide rolls 31. Therefore, when the fiber bundle Tm separates from the bend forming member 41, it can bend between the guide rolls 31 in the passing direction of the fluid.

[0052] In the method of passing a fluid through a fiber bundle to bend the fiber bundle into a curved shape and spread the fiber bundle, the fluid is made to act on and pass through the maximum deflection region of the bent fiber bundle, thereby enabling efficient fiber spreading. Therefore, it is desirable to make the fluid act on an area centered on the neighboring region and pass between the fibers. In the present invention, since the deflection forming member 41 is provided with an opening, the fluid that has passed through the opening can flow directly into the neighboring region and pass between the fibers, enabling efficient fiber spreading.

[0053] In a fiber bundle bent between a pair of guide rolls 31, when the length of a linear section from a point where the fiber bundle leaves contact with the guide roll 31 to the point where the fiber bundle comes into contact with the other guide roll 31 is defined as the bending section length L, and the length in the conveying direction D of the region where a fluid acts on the fiber bundle Tm and passes between each fiber is defined as the fluid action section length W, in the present invention, since the openings M are provided in the bending forming member 41, it is possible to set L>W, and the fluid can be passed through the maximum bending region of the fiber bundle bent in the fluid passing direction, and efficient fiber-spreading can be performed. Since it is possible to narrow the fluid action section length W, the amount of fluid consumed can be reduced, and therefore an effect of reducing energy consumption can be obtained. Furthermore, by reducing the amount of fluid sucked into the cavity tube, there is also an effect of reducing vibration of the entire fiber-spreading processing section.

[0054] In FIG. 1, the fiber bundle Tm is subjected to the action of a fluid passing through an opening M formed in the deflection forming member 41 while repeatedly undergoing the fluctuating action of the deflection forming member 41, and is efficiently opened while being deflected. At this time, the fiber bundle Tm is bundled with a plurality of fibers by a sizing agent or the like, but when a sizing agent with high bundling properties is used as the sizing agent, or when the amount of the sizing agent attached is large, the bundling property of each fiber becomes strong, and each fiber becomes difficult to spread. In such a case, it is preferable to heat the fiber bundle Tm by blowing hot air onto the fiber bundle Tm using the heating unit 5. The sizing agent is softened by heating, and each fiber becomes easy to spread. The heating temperature depends on the type and amount of the sizing agent, the conveying speed of the fiber bundle Tm, and the like, and it is preferable to find and set a temperature at which the sizing agent used is softened and the fiber bundle becomes easy to spread. The inventors set the non-atmosphere temperature to a range of 60 degrees to 120 degrees.

[0055] The fiber bundle Tm that has passed through the fiber-spreading processing section 3 is processed into a spread yarn Ts that has been spread with good fiber distribution. In FIG. 1, a plurality of spread yarns Ts are sandwiched between a pair of take-up rolls 61 in the take-up section 6 and transported. The take-up roll 61 is rotated by a take-up motor (not shown in FIG. 1) and transports the spread yarn Ts. A plurality of spread yarns Ts transported by the take-up roll 61 are wound by a winding device (not shown) or transported directly to a resin impregnation device or the like and processed into a prepreg sheet. Note that a prepreg sheet manufacturing device that manufactures a prepreg sheet is usually provided with a mechanism for transporting a sheet in many cases, and in this case, the take-up section 6 in FIG. 1 is not provided.

[0056] 8 and 9 are a schematic plan view and a schematic side view of a fiber-spreading device according to another embodiment of the present invention. In this fiber-spreading device, three fiber-spreading processing sections 3 are arranged along the feeding path of the fiber bundle Tm. A heating section 5 is provided corresponding to each fiber-spreading processing section 3, and the spread width of each fiber-spreading processing section 3 is set to be gradually wider from the upstream side to the downstream side in the feeding direction. A rotating deflection forming member 41 having an opening M is arranged at the upper opening of each fiber-spreading processing section 3. A support rod 43 is attached to one side of the deflection forming member 41, and a drive pulley 46 is fixed to each support rod 43, and each drive pulley 46 is connected to a rotary motor 44 via a drive transmission belt 47. By driving and rotating the rotary motor 44, each drive pulley 46 rotates, and the deflection forming members 41 rotate in synchronization with each other. In this embodiment, three fiber-spreading processing units are provided, but the number of fiber-spreading processing units may be two or four or more, and the number of units to be used may be determined depending on the fiber bundle to be used, the width to be spread, the conveying speed, etc.

[0057] In the above-mentioned example of the fiber-spreading device, a drive transmission belt is used, but a drive transmission chain may be used. In addition, although the plurality of sag forming members 41 are rotated synchronously, the rotation timing of the sag forming members 41 can be easily varied, and it is desirable to adjust the rotation timing according to the characteristics such as the type, fineness, and number of fiber bundles and the spread width, and perform the fluctuating operation at the optimal timing.

[0058] A plurality of bend forming members 41 synchronously push the fiber bundle Tm in a direction intersecting the feeding direction to place it in a tensed state, and then the bend forming members 41 move away from the tensed fiber bundle Tm to place it in a relaxed state, and this fluctuating operation is repeated, whereby the fiber bundle Tm can be bent in the fluid flow direction in the cavity tube of each fiber-spreading processing unit 3. Since the bend forming members 41 are formed with openings M, the suction airflow that has passed through the openings acts on the vicinity of the most downstream side of the bent fiber bundle, and the fluid passes between the fibers, thereby achieving wide spreading with good fiber distribution.

[0059] The width of the spread of each fiber bundle Tm can be restricted by providing the width restriction guide 48 to the bend forming member 41. In the embodiment of Fig. 8 and Fig. 9, three spread processing sections are arranged, but the most upstream bend forming member 41 is provided with a wide width restriction guide 48, the next bend forming member 41 is provided with a narrow width restriction guide 48, and the last bend forming member 48 is provided with no width restriction guide. With this configuration, wider spread can be performed in sequence starting from the fiber spread processing section 3 arranged upstream in the conveying direction.

[0060] The width restriction guide may be a disk-shaped plate that is directly inserted into the deflection forming guide 41 as shown in Fig. 8, or the upper opening of the cavity tube may be formed into a rectangular shape and the side wall may be used as it is. Also, a plurality of wires or the like may be erected inside the cavity tube and used as the width restriction guide.

[0061] On the downstream side in the feeding direction of the fiber-spreading processing unit 3, a width direction fluctuation imparting unit 7 that comes into sliding contact in the width direction with the spread yarn Ts obtained by spreading each fiber bundle is provided. The width direction fluctuation imparting unit 7 has a horizontal vibration roll 71 arranged over the entire width on the upper side of the plurality of spread yarns Ts, and a support roll 72 is arranged under the plurality of spread yarns Ts. The horizontal vibration roll 71 is connected to a crank mechanism 74, and the crank mechanism 74 is driven by a crank motor 73 to move the horizontal vibration roll 71 back and forth in the width direction of the plurality of spread yarns Ts. The horizontal vibration roll 71 moves back and forth to come into sliding contact with the fibers of the plurality of spread yarns Ts, thereby softly untangling the portions where the fibers are adhered to each other and filling the gaps between the fibers by the horizontal movement of the fibers, and the entire plurality of spread yarns Ts are finished into a spread fiber sheet S in a state where the fibers are uniformly distributed.

[0062] The spread fiber sheet S is sandwiched and transported by take-up rolls 61. The take-up rolls 61 are rotationally driven by a rotary motor 62 to transport the spread fiber sheet S. The spread fiber sheet S carried out by the take-up rolls 61 is taken up by a take-up device (not shown), or is carried as it is into a resin impregnation device or the like and processed into a prepreg sheet. EXAMPLES

[0063] <Example 1> The experiment was carried out with a device configuration equipped with one set of a fiber spreading section such as the fiber spreading device shown in Figure 1 and a deflection forming section using a rotating deflection forming member. A carbon fiber bundle (manufactured by Toray Industries, Inc., product number T700SC-60E-12K, fiber diameter approximately 7 μm, number of fibers 12,000) was used as the fiber bundle. The original width of the fiber bundle was approximately 6 mm.

[0064] The dimensions of each member in the device in the fiber-spreading section and the bend forming section shown in Figs. 11A and 11B were set as follows. Deflection forming member 41; width X1 = 48 mm, thickness X2 = 20 mm Contact surface 41a: cross-sectional shape curvature radius X3 = 10 mm Opening width at opening M; X4 = 20 mm Guide roll 31; outer diameter X5=20mm · Air cavity tube 32; length in the conveying direction, that is, length of the fluid action section X6 = 52 mm Height difference X7 between the central axis O of the deflection forming member 41 and the top point of the guide roll 31 = 2 mm Distance X8 between the central axis O of the deflection forming member 41 and the central axis of the guide roll 31 = 36 mm Distance between the central axes of the guide rolls 31 X9 = 72 mm The height difference X10 between the lowest point of the contact surface 41a during rotation and the highest point of the guide roll 31 is 22 mm.

[0065] The heating temperature by the heating mechanism 5 was set to about 80°C near where the blown hot air hit the fiber bundle, and the flow rate of the suction airflow of the cavity tube 32 was 20 m / sec when there was no fiber bundle. The number of fiber bundles transported to the fiber-spreading processing section 3 was eight, and they were transported at intervals of 25 mm in the width direction. The initial tension of the fiber bundle was set to 150 g, and the transport speed was set to 15 m / min and 40 m / min. The rotation speed of the deflection forming member 41 was set to 250 rpm when the transport speed was 15 m / min and 450 rpm when the transport speed was 40 m / min, and the fluctuating operation was performed 500 times and 900 times per minute, respectively.

[0066] The fiber-spreading state during fiber-spreading was visually confirmed after passing through the fiber-spreading section. The vibration of the device during fiber-spreading was confirmed as follows.

[0067] A micro accelerometer (model number NP-3211, manufactured by Ono Sokki Co., Ltd.) was attached to the bottom of the cavity tube 32, and the micro accelerometer was connected to a sensor amplifier (model number PS-1300, manufactured by Ono Sokki Co., Ltd.). The output data from the sensor amplifier was input to a personal computer, and the relationship between time and acceleration was graphed to confirm the vibration of the device during fiber-spreading.

[0068] When the fiber-spreading process was performed as described above, the fiber bundles were processed into spread yarns in which they were uniformly distributed in a width of 25 mm at both the processing speeds of 15 m / min and 40 m / min, and a spread fiber sheet with a width of 200 mm could be finished. Regarding the continuity of fiber-spreading, stable fiber-spreading was possible for 10 minutes or more without generating large gaps between the spread yarns.

[0069] Regarding the vibration state of the fiber spreading device, Fig. 12A shows the result of processing speed 15m / min, and Fig. 12B shows the result of processing speed 40m / min. The fiber spreading process was carried out for more than 10 minutes, and the results of 30 seconds are shown. At the processing speed of 15m / min, the acceleration was 50m / s 2 Below, at a processing speed of 40 m / min, the acceleration is 75 m / s 2 The vibration results were as follows. In all cases, the vibration was stable and no irregular vibration occurred. Comparative Example

[0070] <Comparative Example 1> The experiment was carried out with a fiber spreading device having a configuration similar to that shown in Fig. 1, with one fiber spreading section and a rotating contact member that gives a deflection to the fiber bundle within the fiber spreading section. As in Example 1, a carbon fiber bundle (manufactured by Toray Industries, Inc., product number T700SC-60E-12K, fiber diameter approximately 7 μm, number of fibers 12,000) was used as the fiber bundle. The original width of the fiber bundle was approximately 6 mm.

[0071] The device configuration of the fiber-spreading section and the contact member was the same as in Example 1, and a solid member without an opening of the deflection forming member of Example 1 was used as the contact member. Each dimension was the same as in Example 1.

[0072] The heating mechanism for heating the fiber bundle was also the same as in Example 1. The number of fibers to be fed, the flow velocity of the suction airflow flowing into the cavity tube, the set spread width, the initial tension of the fiber bundle, and the rotation speed of the contact member corresponding to the processing speed were also the same as in Example 1. The feeding speeds were also set to 15 m / min and 40 m / min, as in Example 1.

[0073] The fiber-spreading state during fiber-spreading was visually confirmed after passing through the fiber-spreading section. The vibration of the device during fiber-spreading was also measured by attaching a miniature accelerometer to the bottom of the cavity tube, as in Example 1. The relationship between time and acceleration was plotted in a graph and confirmed as the vibration of the device during fiber-spreading.

[0074] As described above, the prior art spread process was performed, and a spread fiber in which each fiber bundle was distributed to a width of 25 mm was obtained at both the processing speeds of 15 m / min and 40 m / min. Under the processing conditions this time, gaps were observed in the fiber bundles at a conveying speed of 40 m / min. At a conveying speed of 40 m / min, the rotation speed of the contact member was set to 550 rpm, and the fluctuating operation was performed 1,100 times per minute, and a spread fiber sheet with good fiber distribution and a width of 200 mm could be finished.

[0075] Regarding the vibration state of the fiber-spreading device, Fig. 13A shows the results for a processing speed of 15 m / min, and Fig. 13B shows the results for a processing speed of 40 m / min. Fiber-spreading was performed for more than 10 minutes, and the results for 30 seconds of that are shown. At processing speeds of 15 m / min and 40 m / min, the acceleration was greater than in Example 1, indicating that the device vibration was greater. When a contact member was used, when the contact member was nearly parallel to the feeding direction of the fiber bundle, the area through which the suction airflow could pass through the cavity tube was very narrow. It is believed that the large change in the area through which the suction airflow could pass also increased the vibration generated in the cavity tube.

[0076] From the examples and comparative examples, it was found that the present invention allows the suction airflow that has passed through the openings in the deflection forming member to flow directly through the maximum deflection region of the fiber bundle, thereby enabling efficient fiber spreading. It was also confirmed that the vibration frequency during fiber spreading processing for devices such as air cavity tubes is reduced, and it is expected that the durability of the devices will be improved. [Explanation of symbols]

[0077] 1 yarn supplying section, 11 yarn supply body, 12 yarn supplying motor, 2 guide section, 21 guide roll, 22 tension applying section, 221 support roll, 222 tension applying roll, 223 upper limit position detection sensor, 224 lower limit position detection sensor, 23 vibration elimination section, 231 support roll, 232 swing roll, 233 spring member, 24 reverse return prevention section, 241 one-way rotation roll, 242 support roll, 25 guide roll, 26 alignment roll, 3 fiber spreading section, 31 Guide roll, 32...air cavity tube, 33...flow rate control valve, 34...suction pump, 4...deflection forming section, 41...deflection forming member, 41a...contact surface, 411...pushing member, 412...mounting member, 42...wall member, 43...support rod, 44...rotation motor, 45...crank mechanism, 451...rotating plate, 452...connecting rod, 453...lifting rod, 46...driving pulley, 47...drive transmission belt, 48...width regulating guide, 5...heating section, 6...take-up section, 61...take-up roll, 62 Rotation motor, 7 Width direction fluctuation imparting section, 71 Lateral vibration roll, 72 Support roll, 73 Crank motor, 74 Crank mechanism, 8 Fluctuation imparting section, 81 Contact member, 81a Contact surface, Tm Fiber bundle, Ts Spread yarn, S Spread yarn sheet, O Central axis, M Opening, P Maximum push-in position, N Maximum deflection area, L Deflection section length, W Fluid action section length, D Conveying direction, X1 Width of deflection forming member 41, X2 Thickness of deflection forming member 41 X3: radius of curvature of the cross-sectional shape of the contact surface 41a, X4: opening width at the opening of the deflection forming member 41, X5: diameter of the guide roll 31, X6: length of the cavity tube 32 in the conveying direction, i.e., length of the fluid action section, X7: height difference between the central axis O of the deflection forming member 41 and the uppermost point of the guide roll 31, X8: distance between the central axis O of the deflection forming member 41 and the central axis of the guide roll 31, X9: distance between the central axes of the guide rolls 31, X10: height difference between the lowest point of the contact surface 41a when rotating and the uppermost point of the guide roll 31

Claims

1. A fiber-spreading method in which a fiber bundle formed by aligning and bundling a large number of fibers is pulled out from a yarn supplier and transported, a deflection-forming member is brought into contact with a part of the fiber bundle and pushed in a direction intersecting a transport direction to bring the fiber bundle into a tensioned state, and then the deflection-forming member is moved away from the tensioned fiber bundle to bring the fiber bundle into a relaxed state in a region where a fluctuating operation is repeatedly performed, in which a fluid is passed through the fiber bundle and the fibers are moved in a width direction while being deflected in the passing direction of the fluid, thereby spreading the fiber bundle, the deflection-forming member having an opening through which the fluid passes, passes through a region in the vicinity of a maximum push-in position of the fiber bundle caused by the operation of the deflection-forming member, and the fibers are moved in the width direction while being deflected in the passing direction of the fluid, thereby spreading the fiber bundle,

2. 2. The method for spreading fiber bundles according to claim 1, wherein the sag forming member rotates to repeatedly apply fluctuating motions of tension and relaxation to the fiber bundle.

3. 2. The method for spreading fiber bundles according to claim 1, wherein the sag forming member vibrates in a direction intersecting a feeding direction of the fiber bundle, and repeatedly applies fluctuating motions of tension and relaxation to the fiber bundle.

4. 2. The method for spreading fiber bundles according to claim 1, wherein a bending section length, which is a length in the feeding direction of a region where the fiber bundle is bent, and a fluid action section length, which is a length in the feeding direction of a region through which a fluid acts on and passes through the bent fiber bundle, have a relationship of bending section length > fluid action section length.

5. The method for spreading fiber bundles according to claim 1, wherein a region in which a fluid is applied to the transported fiber bundle to bend the fibers and move them in the width direction to spread them is set at a plurality of positions in a transport path of the fiber bundle.

6. The method for spreading fiber bundles according to claim 5, wherein the bend forming member is provided with a width regulating guide that regulates a spread width of the transported fiber bundle, and the fiber bundle is spread while gradually expanding its spread width.

7. The method for spreading fiber bundles according to claim 1 , further comprising the steps of: feeding a plurality of the fiber bundles arranged in a width direction; and spreading each of the fiber bundles.

8. a fiber-spreading device comprising: a fiber-spreading processing section that applies a fluid to a transported fiber bundle to move the fibers in a width direction while bending the fibers and spread the fiber bundle; and a bend forming section that arranges a bend forming member having an opening through which the fluid passes within the fiber-spreading processing section, and repeatedly performs a fluctuating operation in which the bend forming member pushes the fiber bundle in a direction intersecting a transport direction to bring the fiber bundle into a tensioned state, and separates the bend forming member from the fiber bundle in the tensioned state to bring the fiber bundle into a relaxed state.

9. 9. The fiber spreading device according to claim 8, wherein the deflection forming member includes a plurality of pushing members which push the transported fiber bundle in a direction intersecting a transport direction, and an attachment member which is attached to the pushing members so as to form the opening at intervals allowing the fluid to pass through.

10. The fiber spreading device according to claim 9 , wherein the pushing member is formed in a roll shape.

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