JP2013076193A - Device and method of opening fiber bundle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device of opening a fiber bundle capable of effectively opening in comparison with the conventional opening device, and to provide a method of opening the fiber bundle by use of the device.SOLUTION: A device of opening a fiber bundle, which is configured to widen a fiber bundle made of a plurality of single yarns in a width direction, comprises a plurality of means for retaining fiber bundle disposed in such a way that a thread guide of the transporting fiber bundle is retained to be bent. At least one of the plurality of means for retaining fiber bundle is means for changing bent angle of a thread guide for periodically changing a bent angle of the thread guide of the fiber bundle.

Description

  TECHNICAL FIELD The present invention relates to a fiber bundle opening device and a fiber opening method, and more particularly to a fiber opening device using carbon fibers and a carbon fiber continuous fiber opening method.

  In recent years, the use of carbon fibers has been developed, and fields in which aircraft materials, building materials, general industrial materials, sports, leisure goods, and the like are used are expanding. In general, when used for such applications, it often takes the form of a composite material in which carbon fibers are impregnated with a resin.

  As one of the forms of the carbon fiber composite material as described above, the carbon fiber is thinly spread in one direction in a planar shape and impregnated with a resin to obtain a planar composite material. In the case of such a process, it is necessary to spread the fiber bundle thinly and uniformly so as not to impair its quality.

  As a method for opening a fiber bundle, for example, as disclosed in Patent Document 1, a cylindrical base body that passes a fiber bundle being conveyed while being bent by a plurality of rollers and vibrates in an axial direction between the rollers. After the fiber bundle to be conveyed is vibrated in the vertical direction by a reciprocating body or a rotating body as disclosed in Patent Document 2, the curved surface is further formed. The fiber bundle to be transported, as disclosed in Patent Document 3, or the method of pressing on a substrate having a fiber opening, is opened by passing a roller group, a part of which is an eccentric rotating body. There has been proposed a method and a method of performing fiber opening by periodically repeating contact and separation with respect to a yarn as in Patent Document 4.

  However, even with these opening methods, a sufficient opening effect may not be obtained in the quality of the yarn. In such a case, in order to obtain a large fiber-opening effect, it is necessary to increase vibration and rubbing. As a result, fluff is generated, and in severe cases, the fiber bundle may be cut. This is particularly noticeable when the fiber bundle is a high modulus fiber or when the conveyance speed is increased, and the quality of the product obtained is also poor.

  In order to solve such problems, various ideas have been made such as reduction of the coefficient of friction of the base for opening the fiber bundle and use of ultrasonic waves. However, at present, no sufficient solution has been found.

JP 56-43435 A JP-A 61-275438 JP-A-7-268754 JP 2001-262443 A

  An object of the present invention is to provide a fiber bundle opening device that can be opened more efficiently than an existing opening method, and a fiber bundle opening method using the fiber opening device. is there.

In order to solve the above problems, a fiber bundle opening device according to the present invention has the following configuration.
(1) A fiber-spreading device for widening a fiber bundle formed from a plurality of single yarns in the width direction, and holding a plurality of fiber bundles arranged so that the yarn path of the conveyed fiber bundle is bent and held And a fiber bundle characterized in that at least one of the plurality of fiber bundle holding means is a yarn path bending angle changing means for periodically changing the bending angle of the yarn path of the bent fiber bundle. Opening device.
(2) The fiber bundle opening means according to (1), wherein the yarn path bending angle changing means periodically changes the holding point position of the fiber bundle holding means on the yarn path of the fiber bundle. Textile equipment.
(3) The fiber bundle opening device according to (1) or (2), wherein a bending angle θ when taking the minimum diameter is 90 ° or more in an arc-shaped portion formed by the bent fiber bundle.
(4) When the minimum value when the bending radius in the arcuate portion varies is r and the maximum value is R, r is a value 500 to 2000 times the average radius of the single yarn constituting the fiber bundle. The fiber bundle opening device according to any one of (1) to (3), wherein the value of R / r is twice or more.
(5) The fiber bundle opening device according to any one of (1) to (4), wherein a period of changing the bending angle is 1 to 60 Hz.
(6) The fiber bundle opening device according to any one of (1) to (5), wherein the tensile elastic modulus of the fiber bundle is 200 to 700 GPa.
(7) The fiber bundle opening device according to any one of (1) to (6), wherein carbon fiber is included in at least a part of the fiber bundle.
(8) A method of widening a fiber bundle formed of a plurality of single yarns in the width direction, wherein the fiber bundle to be conveyed is bent and held using a plurality of fiber bundle holding means, and at least one of the bending angles is set A method for opening a fiber bundle, which is performed by periodically changing the fiber bundle.
(9) The fiber bundle according to (8), wherein the bending angle is changed by periodically changing the fiber bundle tension by the movement of the fiber bundle holding means and elastically deforming the fiber bundle. Opening method.
That is, the fiber bundle is opened by periodically changing the bending rate while holding the fiber bundle in a bent state.

  According to the fiber bundle opening device and the fiber bundle opening method using the fiber opening device according to the present invention, when the fiber bundle is a so-called high-modulus fiber, the conveyance speed is increased in order to increase the fiber opening efficiency. Even if it is increased, the occurrence of fluff and the like in the fiber bundle can be reduced, the fiber bundle can be stably and efficiently opened, and a high-quality opened fiber bundle can be obtained.

  In addition, a composite material obtained by impregnating a resin into a fiber bundle that has been opened by such an opening method has a high quality with very little thickness unevenness despite its thin thickness.

It is a cross-sectional schematic diagram which shows an example of the shaping | molding apparatus which forms the carbon fiber composite material containing the war opening apparatus of this invention. It is a schematic diagram explaining the state which the fiber bundle opened. It is a schematic diagram explaining the continuous opening method It is a schematic diagram which shows the opening method used by this invention. It is a schematic diagram which shows one embodiment by this invention. It is a schematic diagram which shows another one embodiment by this invention. It is a schematic diagram which shows another one embodiment by this invention. It is a schematic diagram which shows another one embodiment by this invention. It is a schematic diagram which shows an example which applied to the fiber bundle combining multiple fiber-spreading methods by this invention. 1 is a schematic diagram illustrating an aspect described in Example 1. FIG. FIG. 6 is a schematic diagram showing an aspect described in Example 2. It is a schematic diagram which shows the embodiment by a prior art.

  A specific configuration of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to the apparatus structure etc. which were shown in the figure, It can change suitably.

  FIG. 1 is a schematic cross-sectional view showing an example of a molding apparatus for forming a carbon fiber composite material including the fiber opening device of the present invention. A plurality of bobbins 110 of fiber bundles of reinforcing fibers are installed in the creel device 100, and after a certain amount of fiber bundles fed out from the bobbin 110 are converged, fibers are opened by the fiber opening device 120 to facilitate impregnation with the resin. Open the bundle. The opened fiber bundle passes through the impregnation die 130 to impregnate (matrix) resin supplied from the resin supply means between the fibers. The fiber bundle that has passed through the impregnation die is solidified by the cooling device 140 and then taken up by the take-up device 160 via the take-up device 150.

  In describing the fiber-spreading device 120 that is the subject of the present invention, first, fiber-fiber opening will be described with reference to FIG. The term “opening” means that the fiber bundle composed of a plurality of single yarns 6 is loosened, the intervals between the single yarns are opened, and the entire fiber bundle is deformed into a flat shape in the width direction. Various methods for loosening and moving the fiber bundle single yarn have been considered, and as shown in FIG. 3, the fiber opening mechanism 8 is generally operated while the fiber bundle 7b to be opened is running. In many cases, a continuous processing form such as a fiber bundle 7a that is introduced into the fiber and is opened is taken, and the present invention also falls under this form. Examples of the specific mechanism of the fiber opening mechanism 8 include a mechanism for pressing a guide and imparting vibration. In the present invention, a mechanism for imparting bending and stretching to a fiber bundle is provided as the mechanism. And

  FIG. 4 schematically shows the bending and stretching of a part of the fiber bundle. The bending radius that the fiber bundle takes when bending is given is represented by r, and the maximum bending radius that is the curvature radius when the bending is most loose (close to a straight line) is represented by R. Further, the bending angle in the bent state is represented by θ (°).

  The mechanism of the opening effect is shown below. When the fiber bundle is bent, tensile stress is applied to the outer side fiber and compressive stress is applied to the inner side fiber due to the path length difference between the inside and outside of the bent part. In this state, if the bending radius is changed and these stresses are applied dynamically, the force acts in the direction of releasing the stress, the outer side fibers are on the inner side, and the inner side fibers are on the outer side. A force acts in the direction of moving to. As a result, all the fibers gather near the center line of the assumed yarn path, resulting in density increase and interference. As a result, each other's fibers are intertwined and spread laterally so as to eliminate the interference. This opens the fiber bundle.

  As a method of expressing this effect, specifically, by having fiber bundle holding means for bending and holding the yarn, by periodically moving this, the tension and relaxation of the fiber bundle is repeated, It is conceivable to change the bending radius by utilizing elastic deformation of the fiber bundle.

  As the fiber bundle holding means 3a, specifically, as shown in FIG. 5, a yarn path is formed by a guide having a sufficiently small curvature that can bend the yarn, a roller, or the like. A method of periodically generating tension and relaxation in the fiber bundle by periodically operating the fiber bundle holding means 3a can be adopted. According to these methods, when the fiber bundle is tensioned, the fiber is pressed against the fiber bundle holding means 3a, and the bending is strengthened. At the time of relaxation, the yarn returns by the elasticity of the yarn and the movement of the bending is repeated. As a result, the fiber bundle is periodically bent and stretched, and the opening effect as described above can be obtained. Specifically, a rod-like fixed bar, a roller that can rotate around an axis, and the like are mentioned as the fiber bundle holding means 3a. When the fiber bundle holding means 3a is a roller, it may be a driving roller that is rotated by driving force transmitted thereto, or may be a so-called free rotating roller that does not transmit driving force.

  In addition, the fiber bundle holding means 3a needs to have a small-diameter curved surface that can sufficiently bend the fiber bundle during tension at the fiber bundle contact portion. Specifically, the average radius of the single yarn constituting the fiber bundle is 500 to 2000 times, more preferably 1000 to 1500 times. The other parts may have any shape. In particular, when the contact portion with the fiber bundle is limited to a part such as a fixed bar, the cross section may be asymmetric.

  Since the movement of the fiber bundle holding means 3a is intended to repeatedly apply tension / relaxation to the fiber bundle, it is preferable to reciprocate the member along the fiber bundle traveling direction. In addition, the embodiment is not particularly limited to this, and even in other motions such as a rotational motion and an eccentric motion, tension / relaxation may be applied to the fiber bundle as long as the yarn path length changes as a result. Since it can be given repeatedly, an opening effect can be obtained.

  As the material constituting the fiber bundle holding means 3a, stainless steel, ceramics, general carbon steel or the like can be preferably used, and other materials can be used as long as the amount of bending is small and the strength is not insufficient. be able to. Further, the surface roughness of the portion where the substrate and the fiber bundle come into contact is 0.4 to 3.2 μm, preferably 0.8 to 1.6 μm in terms of arithmetic average roughness Ra measured by JIS B0601 (2001). .

  Another possible form may be that the fiber bundle is held using the fiber bundle holding means 3a and the holding points are periodically changed on the yarn. After forming the yarn path by a plurality of holding points, the yarn path is changed by moving the contact point, and the curvature of the fiber bundle can be changed. As a result, periodic bending and stretching of the fiber bundle occurs, and an opening effect can be obtained.

  Specifically, a method of holding the yarn with a plurality of bars, rollers, guides or the like (3b) as shown in FIG. By periodically changing these positions, it is possible to change the curvature of the yarn path to be formed, change the curvature of the fiber bundle traveling as a result, and perform bending and stretching. At this time, the fiber bundle holding means 3b may move independently, or the fiber bundle holding means may be arranged on the base and rotated or reciprocated together with the base. In addition, the method is not particularly limited.

  As the material constituting the fiber bundle holding means 3a, 3b, stainless steel, ceramics, general carbon steel and the like can be preferably used. However, other materials can be used as long as the amount of bending is small and the strength is not insufficient. But it can be used. Further, the surface roughness of the portion where the substrate and the fiber bundle come into contact is 0.4 to 3.2 μm, preferably 0.8 to 1.6 μm in terms of arithmetic average roughness Ra measured by JIS B0601 (2001). .

  Further, as other possible forms, the fiber bundle holding means 3c as shown in FIG. 7 periodically changes the contact surface by its rotation or the like, or by its own deformation (3d) as shown in FIG. Methods such as changing the contact surface curvature are conceivable, and any shape can be used as long as the bending radius of the fiber bundle can be periodically changed. In any case, a good fiber opening effect can be obtained by the fiber bundle opening effect described above.

  In the fiber bundle opening device according to the present invention, two or more fiber bundle holding means 3a may be provided as shown in FIG. Further, a plurality of similar methods may be arranged, or a combination of different formats may be used. Further, the installation pattern is not limited to the horizontal staggered arrangement as shown in FIG. 9, but can be implemented in various arrangements such as the vertical direction or other patterns.

  Also, as shown in FIGS. 10 and 11, guide rollers 4 are provided on the upstream side and the downstream side of the fiber bundle holding means 3a to 3c to align the fiber bundles and send them to each roller of the fiber bundle holding means. It has been. The guide roller 4 is not particularly limited. However, even when the fiber bundle holding means 3a to 3c are periodically moved and the like, the form of the fiber bundle to be supplied / discharged is fixed. It has a role to hold.

  In any method, the minimum value r of the bending radius given to the fiber bundle shown in FIG. 4 varies depending on the type of fiber bundle and the conveying speed, but the average diameter of the single yarns constituting the fiber bundle The value may be 500 to 20000 times, preferably 1000 to 1500 times d (μm). If it is less than 500 times, the fiber bundle is excessively bent with respect to the bendability of the fiber bundle, and there is a possibility that thread breakage or the like may occur in the case where the yarn is painful or severe at the bent portion. Further, although depending on the method, the movement of the yarn itself tends to increase, and fluffing due to rubbing or the like easily occurs with the fiber bundle holding means 3a. On the other hand, if it exceeds 2000 times, the bending of the yarn is insufficient with respect to the ease of bending of the fiber bundle, and the yarn fluctuation itself tends to be small depending on the method. It tends to be smaller.

  Also, the rate of change of the bending rate is important. Specifically, it is desirable that the maximum bending radius value R is 2 times or more, more preferably 3 times or more the minimum bending radius value r. When this rate of change is small, the dynamic force applied to the fiber bundle at the time of bending becomes insufficient, and the fiber opening effect cannot be obtained satisfactorily.

  Similarly, in any method, the bending angle θ shown in FIG. 4 is 90 ° to 180 °, preferably 120 ° to 180 °, and more preferably 150 ° to 180 °. By taking a large bending angle, the above-mentioned opening effect can be strongly expressed. When the bending angle θ exceeds 180 °, among the fiber bundle holding means 3a arranged in a staggered manner as shown in FIG. 9, for example, the adjacent fiber bundle holding means 3a approach each other at the end in the same direction. Can be considered. Although there is no immediate inconvenience when it exceeds 180 °, in order to avoid contact between the fiber bundles opened between the fiber bundle holding means 3a, the bending angle θ is 180 ° at the maximum (fiber bundles Are preferably held in a substantially parallel state).

  As the fiber bundle to be opened, carbon fibers and graphite fibers are suitable, and particularly when the tensile elastic modulus of these reinforcing fibers is 200 to 700 GPa, preferably 350 to 700 GPa, the effect is great. The method can also be applied to other reinforcing fibers such as glass fibers and organic high elastic modulus fibers such as polyaramid fibers. The number of single fibers constituting the fiber bundle may be 1,000 to 100,000, preferably 3,000 to 18,000.

  Such fiber bundles may be provided with an oil agent for improving the bundle property of the fiber bundle, or may be provided with a so-called sizing agent in order to improve adhesion with a resin or the like. In such a case, before opening the fiber bundle, using an infrared heater or the like, the surface of at least one roller of the roller group, the surface of at least one roller in the opening device, or fiber By preheating the bundle itself to 70 to 250 ° C., preferably 100 to 200 ° C., more preferably 100 to 180 ° C., the oil agent and sizing agent on the surface of the fiber bundle are softened, and the fiber bundle is opened more efficiently. This is preferable. The oil agent and sizing agent applied to the fiber bundle can be reduced or removed by passing the fiber bundle through a bathtub in which an organic solvent or a cleaning solution is stored.

  In the fiber bundle opening method according to the present invention, the conveying speed of the fiber bundle to be opened is 0.1 to 20 m / min, preferably 1 to 10 m / min. If it is less than 0.1 m / min, the bending and stretching of the fiber bundle is concentrated at the same location, and there is a possibility that the yarn becomes fuzzy or painful. On the other hand, if it exceeds 20 m / min, the bending and stretching of the fiber bundle becomes sparse, and the spread efficiency may decrease.

  In the fiber bundle opening method according to the present invention, the frequency of the reciprocating motion of the substrate depends on the type of fiber bundle and the conveying speed, but it is preferably 1 to 50 Hz, preferably 5 to 30 Hz. If it exceeds 50 Hz, fluff may occur in the fiber bundle. The frequency is preferably increased as the fiber bundle conveying speed is increased from the viewpoint of stabilizing the fiber bundle opening. When the fiber bundle conveying speed is 0.1 to 10 m / min, the frequency is 5 to 20 Hz. When the speed exceeds 10 m / min, the frequency is preferably 20 to 50 Hz.

  Furthermore, in the fiber bundle opening method according to the present invention, in order to further enhance the fiber bundle opening effect, gas can be injected into the fiber bundle to be opened. The gas injection may be performed on the upstream side with respect to the conveyance direction of the fiber bundle from the roller, or may be performed on the downstream side, but from the viewpoint of further enhancing the fiber bundle opening effect, it is performed on the upstream side. Is preferred. Thereby, even if an oil agent or a sizing agent is applied to the fiber bundle and the fiber bundle is strongly bundled, the fiber bundle is opened with higher efficiency. Here, from the viewpoint of further enhancing the fiber bundle opening effect, the gas temperature is 70 to 250 ° C, preferably 100 to 200 ° C, and the gas injection pressure is 0.1 to 0.5 MPa, preferably 0.2 to 0.5 MPa is good. Moreover, air is usually used as the gas because of production costs. In this case, air supplied from factory compressed air can be used.

  In the fiber bundle opening method according to the present invention, in order to further enhance the fiber bundle opening effect, the fiber bundle that is opened and conveyed downstream from the roller in the fiber opening device with respect to the fiber bundle conveying direction It can also be supported on a belt having a width wider than the entire width of the fiber bundle and curved so as to be convex on the side in contact with the fiber bundle.

  In the present invention, in the creel device 100 that unwinds the fiber bundle, the opening of the fiber bundle can be stabilized by appropriately changing the resistance of the yarn feeding mechanism that holds the bobbin 110.

  As an application of the present invention, it can be considered that the fiber bundle opened by the fiber bundle opening method of the present invention is impregnated with a resin to obtain a planar composite material. Thereby, although the thickness is small, there are few thickness spots, and a high quality product in which the resin is sufficiently impregnated in the fiber can be manufactured.

  The resin or resin impregnation method used here is not particularly limited, and examples of the resin include thermosetting resins such as epoxy resins, vinyl ester resins, unsaturated polyester resins, and phenol resins, polyester resins, and polyethylene. Examples thereof include thermoplastic resins such as resins, polycarbonate resins, polyether resins, and polyamide resins.

  Examples of the epoxy resin include bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, urethane-modified epoxy resin, brominated bisphenol A type epoxy resin, etc. Can be used.

  These epoxy resins are not limited to being used alone, and two or more types can be used in combination, and further, liquid to solid can be used. Usually, a curing agent is added to an epoxy resin.

  In addition, as the impregnation method, a method of directly impregnating a fiber bundle with a resin whose viscosity has been reduced by heating, the above resin is thinly and uniformly applied to a sheet such as paper or a resin film subjected to a release treatment. Examples thereof include a method in which a fiber bundle is sandwiched between two resin sheets, and this is pressurized with, for example, a heating roller, or a method in which the fiber bundle is impregnated with a resin that has been dissolved in an organic solvent or the like to reduce the viscosity.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to the aspect mentioned later. Moreover, in each Example, the measurement of a physical-property value etc. was performed as follows.

  <Spreading width> A standard ruler was used, applied to the fiber bundle to be conveyed, and measured visually.

  <Degree of fluff generation> The state of the fluff of the fiber bundle was observed by visual inspection.

Example 1
As a fiber bundle to be opened, a carbon fiber bundle having an average single fiber diameter of 7 μm, the number of single fibers of 12,000, a tensile strength of 4,900 MPa, and a tensile elastic modulus of 230 GPa was used.

  The fiber bundle was unwound from the bobbin 110 provided in the creel device 100 while the fiber bundle was taken up by the take-up device 150. Here, the conveying speed was 2 m / min.

  In the fiber opening device 120, the fiber bundle holding means repeated the tension / relaxation of the fiber bundle while reciprocating at a frequency of 10 Hz in the vertical direction, that is, the direction substantially perpendicular to the direction in which the fiber bundle is conveyed. Thereby, the fiber bundle to be conveyed was opened. Here, the amplitude of the fiber bundle holding means was 10 mm, and the bending angle of the fiber bundle was 120 degrees.

  The fiber bundle holding means used at this time was a φ10 mm fixing bar, and the yarn bending radius r during yarn tension was 5 mm, which was 1428.5 times the average single yarn radius. Further, the yarn bending radius R at the time of relaxation was 15 mm, and the value of R / r was 3.0.

  The fiber bundle was uniformly opened with an average of 25 mm in the fiber bundle direction with respect to the width of 7 mm before opening, and the opening effect was sufficient. Generation | occurrence | production of the fluff was not seen and the cutting | disconnection of the fiber bundle was not observed.

(Comparative Example 1)
In Example 1, fiber opening was performed under the same conditions as in Example 1 except that the φ10 mm fixing bar of the fiber bundle holding means was replaced with a φ30 mm fixing bar. The yarn bending radius at the time of yarn tension was 15 mm, which was 4285.7 times the average single yarn radius. Further, the yarn bending radius R at the time of relaxation was 15 mm, and the value of R / r was 1.0.

  The fiber bundle opened only an average of 15 mm in the fiber bundle direction with respect to the width of 7 mm before opening, and the opening effect was not sufficient. Generation | occurrence | production of the fluff was not seen and the cutting | disconnection of the fiber bundle was not observed.

(Comparative Example 2)
In Comparative Example 1, fiber opening was performed under the same conditions as Comparative Example 1 except that the frequency was increased to 100 Hz.

  The fiber bundle was opened in an average of 25 mm in the fiber bundle direction with respect to the width of 7 mm before opening, and the opening effect was obtained, but fluff was generated and the fiber bundle was partially cut.

(Example 2)
As a fiber bundle to be opened, a carbon fiber bundle having an average single fiber diameter of 7 μm, the number of single fibers of 12,000, a tensile strength of 4,900 MPa, and a tensile elastic modulus of 230 GPa was used.

  The fiber bundle was unwound from the bobbin 110 provided in the creel device 100 while the fiber bundle was taken up by the take-up device 150. Here, the conveying speed was 2 m / min.

  In the fiber opening device 2, the fiber bundle holding means was constituted by two rollers, and they moved periodically and repeated bending and stretching of the fiber bundle at a frequency of 20 Hz. Thereby, the fiber bundle to be conveyed was opened. Here, the bending angle of the fiber bundle at the contact portion of the fiber bundle holding means was 180 degrees at the maximum.

  The roller diameter used at this time was φ10 mm, and the minimum bending radius r of the yarn at the roller contact portion was 5 mm, which was 1428.5 times the average single yarn radius. Further, the yarn bending at the non-contact portion of the roller was almost zero, the value of the maximum bending radius R was infinite, and the value of R / r was twice or more.

  The fiber bundle was uniformly opened with an average of 2 2 mm in the fiber bundle direction with respect to the width of 7 mm before opening, and the opening effect was sufficient. Generation | occurrence | production of the fluff was not seen and the cutting | disconnection of the fiber bundle was not observed.

(Comparative Example 3)
In Example 2, fiber opening was performed with the movement of the fiber bundle holding means stopped.

  The fiber bundle opened only an average of 15 mm in the fiber bundle direction with respect to the width of 7 mm before opening, and the opening effect was not sufficient. Generation | occurrence | production of the fluff was not seen and the cutting | disconnection of the fiber bundle was not observed.

(Comparative Example 4)
In Example 2, fiber opening was performed under the condition that the φ10 mm roller of the fiber bundle holding means was replaced with a φ30 mm roller. The minimum bending radius r of the yarn in the roller contact portion was 15 mm, which was 4285.7 times the average single yarn radius.

  The fiber bundle opened only an average of 18 mm in the fiber bundle direction with respect to the width of 7 mm before opening, and the opening effect was not sufficient. Generation | occurrence | production of the fluff was not seen and the cutting | disconnection of the fiber bundle was not observed.

1: Fiber bundle yarn path (at maximum bending)
2: Fiber bundle yarn path (when relaxed)
3a to 3d: Fiber bundle holding means 4: Guide roller 5: Yarn support (conventional technology)
6: Single yarn 7a: Fiber bundle (after opening)
7b: Fiber bundle (before opening)
8: opening mechanism 100: creel device 110: bobbin 120: opening device 130: impregnation die 140: cooling device 150: take-up device 160: winding device

Claims (9)

An opening device that widens a fiber bundle formed of a plurality of single yarns in the width direction, and has a plurality of fiber bundle holding means arranged so that the yarn path of the conveyed fiber bundle is bent and held. And at least one of the plurality of fiber bundle holding means is yarn path bending angle changing means for periodically changing the bending angle of the yarn path of the bent fiber bundle. apparatus. The fiber bundle opening device according to claim 1, wherein the yarn path bending angle changing means periodically changes the holding point position of the fiber bundle holding means on the yarn path of the fiber bundle. The fiber bundle opening device according to claim 1 or 2, wherein a bending angle θ at the time of taking a minimum diameter is 90 ° or more in an arc-shaped portion formed by the bent fiber bundle. When r is the minimum value and R is the maximum value when the bending radius of the arcuate portion varies, r is a value that is 500 to 2000 times the average radius of the single yarn constituting the fiber bundle, and R The fiber bundle opening device according to any one of claims 1 to 3, wherein the value of / r is twice or more. The fiber bundle opening device according to any one of claims 1 to 4, wherein a period of changing the bending angle is 1 to 60 Hz. The fiber bundle opening device according to any one of claims 1 to 5, wherein a tensile elastic modulus of the fiber bundle is 200 to 700 GPa. The fiber bundle opening device according to any one of claims 1 to 6, wherein carbon fiber is included in at least a part of the fiber bundle. A method of widening a fiber bundle formed of a plurality of single yarns in a width direction, wherein the fiber bundle to be conveyed is bent and held using a plurality of fiber bundle holding means, and at least one of the bending angles is periodically A method for opening a fiber bundle, which is performed by changing. The fiber bundle opening method according to claim 8, wherein the bending angle is changed by periodically changing the fiber bundle tension by the movement of the fiber bundle holding means and elastically deforming the fiber bundle. .

Images