JP2010001597A - Method for producing winding of plurality of carbon fiber bundles - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a winding of a plurality of carbon fiber bundles in production of carbon fibers bundles through baking a bundle of carbon precursor fibers, suppressing a new equipment investment, raising a fiber bundle density in the equipment in the baking process, effectively producing carbon fiber bundles with reduced filaments, obtaining a high-quality carbon fiber bundles with rare development of fluff. <P>SOLUTION: The method includes the process of imparting convergence to the bundle of carbon precursor fibers by subjecting to an air entangling treatment, the process of producing carbon fiber bundle by subjecting the bundle of carbon precursor fibers to a flameproof treatment and a carbonizing treatment, and the process of winding at least the two carbon fiber bundles on a single bobbin without arranging the carbon fiber bundles, or parallelly disposing each other and winding on a single bobbin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plurality of carbon fiber bundle wound bodies, an apparatus and a method for dividing each carbon fiber bundle from the plurality of carbon fiber bundle wound bodies, and more specifically, efficiently produces a carbon fiber bundle having a small number of filaments. It is related with the manufacturing method of the multiple carbon fiber bundle winding body suitable for this.

Carbon fibers are widely used for aerospace applications, sports applications, general industrial applications and the like as reinforcing fibers for composite materials.
The carbon fiber is a oxidized fiber obtained by heating the precursor fiber in an oxidizing atmosphere such as air or nitrogen oxide at a temperature of 200 to 300 ° C. for spinning the precursor fiber such as polyacrylonitrile which is the precursor yarn. It is manufactured through a flameproofing process that converts to, and a carbonization process in which it is carbonized by heating to 300 to 3000 ° C. in an inert atmosphere such as nitrogen, argon, and helium.
Among them, the firing process such as the flameproofing process and the carbonization process requires a long time for the firing treatment, and therefore the traveling speed of the carbon fiber bundle is slower than the other spinning processes. Therefore, in order to produce carbon fiber with high efficiency, the firing process has been rate-limiting. Therefore, in order to efficiently produce carbon fiber bundles with a small number of filaments, attempts have been made to increase the number of carbon fiber bundles that are run on one manufacturing facility.
For example, as a method for efficiently producing a carbon fiber bundle with a small number of filaments without adding additional equipment in the firing process of the precursor fiber bundle, a thick carbon fiber is obtained by combining a plurality of carbon fiber precursor bundles. There are methods in which precursor yarns are combined and introduced into one firing step (Japanese Patent Publication No. 62-3246, Japanese Patent Laid-Open No. 9-273032, etc.).
However, the carbon fiber yarn obtained by combining and firing a plurality of carbon fiber precursor bundles has a structure in which each carbon fiber bundle is partially parallel or overlapped vertically and the constituent filaments are entangled between the carbon fiber bundles. Therefore, when it is attempted to divide into the original carbon fiber bundles at a high speed, fluffing, fiber cutting, and the like occur, causing the quality of the carbon fiber bundle to deteriorate. In addition, the carbon fiber yarn obtained by firing can be once wound up on a single bobbin and divided using a device that separates fibers separately. Was needed and was not efficient. In particular, since the fibers become fluffy and the quality decreases as the number of handling increases, the carbon fiber yarn is not wound on a single bobbin, but is divided into individual carbon fiber bundles on the spot after firing. Each carbon fiber bundle was wound around a bobbin.
On the other hand, if it can be divided into each carbon fiber bundle at high speed without causing fuzzing or fiber cutting, a large number of fiber separation devices are required even if a plurality of carbon fiber bundles are directly wound around a bobbin. The above disadvantages do not occur. Further, if the fired carbon fiber bundle can be directly wound around the bobbin, the number of winders for winding the carbon fiber bundle can be reduced.
Further, as a method for improving the splitting property from the carbon fiber yarns into a plurality of carbon fiber bundles, there is a method of increasing the convergence of each fiber bundle by twisting in a spinning process. However, in that case, the carbon fiber bundle must be untwisted after the firing step, which requires capital investment for that purpose, which is not preferable.

  An object of the present invention is to eliminate the above-described conventional problems. Specifically, in producing a carbon fiber bundle by firing a precursor fiber bundle, while suppressing new equipment investment, the fiber bundle density in the apparatus in the firing process is increased to reduce the number of filaments. A multi-carbon fiber bundle wound body that can produce a high-quality carbon fiber bundle with extremely low generation of fluff, and an apparatus and method for dividing each carbon fiber bundle from the multi-carbon fiber bundle wound body It is intended to provide.

As a result of diligent research to solve the above-mentioned problems, the present inventors have found that a plurality of carbon fiber bundles are wound around a single bobbin without arranging a plurality of carbon fiber bundles in parallel with each other. It has been found that by splitting the carbon fiber bundles into individual carbon fiber bundles while giving a constant tension fluctuation under a constant tension, the fibers can be split at any speed while suppressing fuzz and fiber cutting.
Accordingly, the present invention provides a multi-carbon fiber bundle wound body in which at least two carbon fiber bundles to which convergence is imparted are wound on a single bobbin without being aligned. .
Further, the present invention provides a plurality of carbon fiber bundle windings, wherein the carbon fiber bundles to which at least two convergence properties are imparted are arranged in parallel to each other and wound on a single bobbin. Provide the body.
The present invention also provides a multiple carbon fiber bundle wound body in which the carbon fiber bundles adjacent to each other are bonded together by a sizing agent.
Further, the present invention is a fiber separation device that divides a plurality of carbon fiber bundles of the plurality of carbon fiber bundle wound bodies into each carbon fiber bundle, and supports the plurality of carbon fiber bundle wound bodies rotatably. Means, a separating means for dividing the plurality of carbon fiber bundles wound around the plurality of carbon fiber bundle wound bodies supported by the supporting means for each carbon fiber bundle, and each divided by the separating means Provided is a fiber separation device having a drawing means for pulling out a carbon fiber bundle by tension and a tension changing means for changing the tension in a predetermined cycle.
Furthermore, the present invention is characterized in that when the plurality of carbon fiber bundles of the plurality of carbon fiber bundle winding bodies are divided for each carbon fiber bundle, the plurality of carbon fiber bundles are pulled out while giving a variation in tension. A method for separating carbon fiber bundles is provided.

It is a perspective view which shows the one aspect | mode of the multiple carbon fiber bundle winding body of this invention. It is a perspective view which shows the one aspect | mode of the multiple carbon fiber bundle winding body of this invention. It is an enlarged view of the multiple carbon fiber bundle shown in FIG. It is the schematic which shows the one aspect | mode of the fiber separation apparatus of this invention. It is the schematic which shows the one aspect | mode of the fiber separation apparatus of this invention. It is the schematic of the splitting guide used by this invention.

Hereinafter, the present invention will be described in detail.
<Multi-carbon fiber bundle winder>
An embodiment of a multiple carbon fiber bundle wound body in the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, the multiple carbon fiber bundle wound body 1 in the present embodiment is obtained by winding a carbon fiber bundle 4 around a single bobbin 2.
The carbon fiber bundle 4 is composed of 500 to 12000, preferably 1000 to 8000 carbon fiber filaments. As the carbon fiber bundle in the present invention, an existing carbon fiber bundle obtained by firing a carbon fiber precursor bundle such as polyacrylonitrile, pitch and cellulose can be used.
Furthermore, the carbon fiber bundle 4 of this embodiment is provided with convergence. Here, “convergence is imparted” refers to a state in which the carbon fiber bundle is bundled without being scattered for each filament constituting the bundle. For example, by giving convergence to 3000 carbon fibers, one unitary fiber form is formed. By imparting convergence, there is an advantage that generation of fluff, winding around a roll, and the like are prevented, and the passage through the firing process and the passage through the separation process described later are improved. As means for imparting convergence, for example, known means such as means for entanglement of filaments such as gas entanglement treatment and needle punch treatment, and means by false twisting can be used. Preferably, performing the gas entanglement treatment at a gas pressure of 80 to 650 kPa is suitable for imparting sufficient convergence and preventing the fluff generation of the carbon fiber bundle.

As an embodiment of the multiple carbon fiber bundle wound body in the present invention, as shown in FIG. 1, a single bobbin 2 without aligning at least two, preferably 2 to 6 carbon fiber bundles 4. It may be wound around. Here, “without aligning” means that the carbon fiber bundles do not overlap each other and exist independently in parallel as shown in FIG. Therefore, a plurality of carbon fiber bundles are stacked in parallel or vertically and are arbitrarily twisted or entangled to make these carbon fiber bundles a single unitary carbon fiber yarn in a different state. is there.
By winding a plurality of carbon fiber bundles in this way, when dividing into carbon fiber bundles by a separating apparatus described later, the carbon fiber bundles can be divided at an arbitrary speed while suppressing fuzz and fiber cutting.
Moreover, as embodiment of the multiple carbon fiber winding body in this invention, as shown in FIG. 2, the state which has arrange | positioned the carbon fiber bundle 4 of at least 2 pieces, Preferably 2-6 pieces in parallel mutually is maintained. It may be wound around a single bobbin 2 as it is. Here, “arranged in parallel with each other” means that the carbon fiber bundles are adjacent to each other in parallel without overlapping each other, as shown in FIG. For example, the two carbon fiber bundles 4 are arranged in parallel with no gap between each other without overlapping each other. By winding a plurality of carbon fiber bundles in this way, when dividing into carbon fiber bundles by a separating apparatus described later, the carbon fiber bundles can be divided at an arbitrary speed while suppressing fuzz and fiber cutting.

Further, as shown in FIG. 3 which is an enlarged view of the front end portion of the plurality of carbon fiber bundles 3 in FIG. 2, the carbon fiber bundles 4 are bonded to each other by adjoining surfaces 5 with a sizing agent. It is preferable. This is because simply winding a plurality of carbon fiber bundles causes the carbon fiber bundles wound around the plurality of carbon fiber bundle winding bodies to be scattered, which is inconvenient to handle. Bonding with the sizing agent is performed by, for example, firing two carbon fiber bundle precursors arranged in parallel to each other and drying, and maintaining the obtained two carbon fiber bundles arranged in parallel. It is carried out by immersing in a sizing solution while being dried. Thereby, the filaments contained in the carbon fiber bundle 4 are bonded to each other by the sizing agent, and the adjacent carbon fiber bundles 4 are also bonded to each other on the adjacent surface 5.
The sizing agent used here is not particularly limited, but for example, those mainly composed of epoxy, urethane, ester and mixed systems thereof can be used. When preparing a sizing agent solution composed of a compound insoluble in water, it is preferable to use a surfactant for dispersion stability. As the surfactant used here, any of nonionic, cationic, anionic and the like can be used. Further, by blending a softener such as an adduct of fatty acid ethylene oxide, it is possible to obtain a carbon fiber that is more excellent in terms of fineness. In addition, as a softening agent added at this time, it is preferable to select a water-soluble type.
The multiple carbon fiber bundle wound body 1 according to an embodiment of the present invention is obtained by winding the multiple carbon fiber bundles 3 around the bobbin 2 while maintaining the state in which the multiple carbon fiber bundles 3 are arranged in parallel.

  As a winding method around the bobbin 2, for example, a known winding method such as so-called cheese winding, parn winding, cone winding or the like can be used. The bobbin 2 may be formed of any material, but is preferably paper, plastic, or metal. The shape of the bobbin 2 may be any known shape as long as it is suitable for winding the carbon fiber bundle 4. For example, a bobbin shaped like a cylinder may be used. For example, in the case of a cylindrical bobbin, the size of the bobbin 2 is 60 to 210 mm in outer diameter, 50 to 200 mm in inner diameter, and 150 to 1000 mm in length. A plurality of carbon fiber bundles are wound on such a bobbin, for example, 500 to 20000 m, preferably 800 to 12000 m. Although the magnitude | size of the obtained multiple carbon fiber bundle winding body is based also on the frequency | count of winding and the shape of a bobbin, it is 70-1000 mm in diameter and 150-1000 mm in width, for example.

<Separation device>
An embodiment of the fiber separation device of the present invention will be described with reference to the accompanying drawings. As shown in FIGS. 4 and 5, the splitting device according to the present embodiment includes a supporting unit that rotatably supports the multiple carbon fiber bundle winding body 1, and a multiple carbon fiber bundle winding supported by the supporting unit. A separating means for dividing the plurality of carbon fiber bundles 3 wound around the body 1 into each carbon fiber bundle, a drawing means for pulling out each carbon fiber bundle 4 divided by the separating means by tension, and this tension. Tension changing means for changing at a predetermined cycle.
The multiple carbon fiber bundle wound body 1 of the present embodiment is supported by a support means that rotatably supports the multiple carbon fiber bundle wound body (not shown). Here, as long as this support means supports so that the multiple carbon fiber bundle winding body 1 can rotate, the kind will not be ask | required, but generally a creel etc. are used.
The multiple carbon fiber bundle wound body 3 is pulled out from the multiple carbon fiber bundle wound body 1 supported by the support means, and is divided into the carbon fiber bundles 4 by the separating means. As the splitting means, first, as shown in FIG. 4, the angle θ formed by the flow direction of the carbon fiber bundle 4 and the flow direction of the plurality of carbon fiber bundles 3 around the splitting position 6 is, for example, 1 to 1. A means for pulling out each carbon fiber bundle 4 so as to be 30 °, preferably 2 to 15 ° can be mentioned. Here, the splitting position 6 may move back and forth during the division operation, but in this case, it is set as an average splitting position. By pulling out each carbon fiber bundle in this way, for example, even when the carbon fiber bundles are bonded by a sizing agent, or even when fuzz generated from the carbon fiber bundles are intertwined, the adhesion and the like are easily peeled off. And the division | segmentation for every carbon fiber bundle can be performed smoothly and continuously. For example, when two carbon fiber bundles are included in a plurality of carbon fiber bundles, it is preferable to draw each carbon fiber bundle so that θ is 1 to 30 °, preferably 2 to 15 °. When a plurality of carbon fiber bundles are included in a plurality of carbon fiber bundles, the carbon fiber bundles may be drawn in three directions at the same time to be divided into three carbon fiber bundles. You may divide | segment sequentially for every carbon fiber bundle. Further, the drawing direction of the carbon fiber bundle 4 may be any direction such as drawing in a spatially different direction in addition to the same plane direction.

  Further, for example, a splitting guide 8 as shown in FIG. 6 may be used as the splitting means. By passing the divided carbon fiber bundles through the fiber splitting guide, the carbon fiber bundles 4 can always be pulled out in a certain direction, and the plurality of carbon fiber bundles 3 can be divided stably and reliably. Examples of the fiber separation guide include an eye guide having an opening at the center of a flat plate (FIG. 6A), a snail guide having a shape in which a wire or the like is wound once or more (FIG. 6B), a rod-shaped guide ( Fig. 6C) and a roll-shaped guide such as a roller (Fig. 6D). In the eye guide (FIG. 6A), the carbon fiber bundle passes through the opening at the center of the eye guide. In the snail guide (FIG. 6B), the carbon fiber bundle passes through the opening at the center of the snail guide. In the rod-shaped guide (FIG. 6C), the carbon fiber bundle passes through one side surface of the rod-shaped guide. In the roll-shaped guide (FIG. 6D), the carbon fiber bundle passes through the upper (lower) groove of the roll-shaped guide. These fiber-splitting guides may be formed of any material such as ceramic, plastic, and metal, but ceramic or metal is preferable from the viewpoint of fluffing of the carbon fiber bundle and prevention of yarn breakage. The position of the splitting guide may be a position where the divided carbon fiber bundle can be pulled out in a desired direction. For example, as shown in FIG. 5, the split carbon fiber bundle is behind the splitting position 6 and divided. 4 is arranged at an arbitrary position where it passes. Preferably, along the flow direction of the carbon fiber bundle, a position 2 m or more, preferably 3 m or more behind the plurality of carbon fiber bundle wound bodies 1, or a position 1 m or more, preferably 2 m or more behind the splitting position 6 Installed. Furthermore, the splitting guide of the present invention may be used in combination. For example, using an eye guide or a snail guide in front of the roll-shaped guide prevents the carbon fiber bundle from falling off the roll-shaped guide. This is preferable.

Each carbon fiber bundle 4 divided by the separating means is drawn out by the drawing means drawn out by tension. 4 and FIG. 5, for example, a winder 7 that winds up each carbon fiber bundle 4, a driving means such as a goded roll, a nip roll, and a Nelson roll installed on the plurality of carbon fiber bundles 3 or the carbon fiber bundle 4 ( (Not shown). In particular, it is preferable to use a driving means such as a godd roll, a nip roll, or a Nelson roll because each carbon fiber bundle can be pulled out without transmitting tension fluctuation to the winder 7.
The drawing speed is, for example, 10 to 200 m / s, preferably 30 to 120 m / s. At this time, it is preferable that the carbon fiber bundles 4 divided from the plurality of carbon fiber bundles 3 are simultaneously drawn out at the same speed. By pulling out in this way, the multiple carbon fiber bundles 3 can be pulled out from the multiple carbon fiber bundle winder 1 so as to exist as one bundle.

Furthermore, when each carbon fiber bundle is pulled out, tension variation is given to the carbon fiber bundle by a tension variation means that varies the tension applied to the carbon fiber bundle at a predetermined period.
For example, in FIG. 5, the tension fluctuation is applied at least between the plurality of carbon fiber bundle wound bodies 1 and the winder 7, preferably in front of the splitting guide 8 and before and after the splitting position 6. By giving a tension variation immediately after the multiple carbon fiber bundle wound body 1, problems such as ringer, fluffing and thread breakage that can occur when the multiple carbon fiber bundle 3 is pulled out from the multiple carbon fiber bundle wound body 1 can be avoided. . Further, by giving tension fluctuations before and after the splitting position 6, it is possible to avoid problems such as fuzz and yarn breakage that may occur when dividing a plurality of carbon fiber bundles, and to divide the plurality of carbon fiber bundles stably and reliably. It can be carried out.
Examples of the tension changing means include a tension changing means using a tension changing apparatus, a supporting means for supporting a plurality of carbon fiber bundle winding bodies so as to be eccentrically rotatable, a drawing means capable of changing the drawing speed of the carbon fiber bundle, and the like. The tension variation can be given using.
For example, in FIG. 5, the tension fluctuation device is placed at any position on the multiple carbon fiber bundle wound body 1, on the multiple carbon fiber bundle 3 drawn out from the multiple carbon fiber bundle wound body 1, or on the carbon fiber bundle 4. It can be installed, and is preferably installed in front of the separation position 6.
Further, as a support means for supporting the multiple carbon fiber bundle wound body so as to be eccentrically rotatable, means for eccentrically rotating using a bobbin having an eccentric shaft, means for rotating eccentrically by revolving the bobbin itself around the shaft, There are also means for providing a gap between the bobbin bearing and the shaft to decenter the rotation of the bobbin.
Examples of the drawing means capable of changing the drawing speed of the carbon fiber bundle include the above-described winder, goded roll, nip roll, and Nelson roll capable of periodically changing the drawing speed.
The tension applied to the carbon fiber bundle is, for example, 0.25 to 2.5 mN / dtex, preferably 0.5 to 1.5 mN / dtex. A tension of 2.5 mN / dtex or less is preferable because there is little possibility that the winding of the multiple carbon fiber bundle wound body 1 is broken and thread breakage occurs. Moreover, if it is 0.25 mN / dtex or more, since sufficient tension | tensile_strength acts on a carbon fiber bundle and favorable splitting property is obtained, it is preferable. On the other hand, the fluctuation in tension is, for example, 0.05 to 2 seconds, preferably 0.1 to 0.5 seconds, and ± 0.12 to 1.25 mN / dtex, preferably ± 0.25 to 0. It is preferable to apply with a tension fluctuation amplitude of .75 mN / dtex. If the period is 0.05 seconds or more or 2 seconds or less and the tension fluctuation amplitude is ± 0.12 mN / dtex or more or ± 1.25 mN / dtex or less, sufficient tension fluctuation can be given, which is preferable.

<Dividing method of multiple carbon fiber bundles>
One embodiment of the present invention divides a plurality of carbon fiber bundles wound around a plurality of carbon fiber bundle winding bodies into each carbon fiber bundle, and draws out each divided carbon fiber bundle while giving a tension variation. Provided is a splitting method for a plurality of carbon fiber bundles.
As a method of dividing the plurality of carbon fiber bundles for each carbon fiber bundle, as shown in FIG. 4, the flow direction of the plurality of carbon fiber bundles 3 and the flow direction of the carbon fiber bundles 4 around the splitting position 6 There is a method of pulling out each carbon fiber bundle 4 such that the angle θ formed by is 1 to 30 °, preferably 2 to 15 °. For example, when two carbon fiber bundles are included in a plurality of carbon fiber bundles, it is preferable to draw each carbon fiber bundle so that θ = 1 to 30 °, preferably 2 to 15 °. When a plurality of carbon fiber bundles are included in a plurality of carbon fiber bundles, the carbon fiber bundles may be drawn in three directions at the same time to be divided into three carbon fiber bundles. You may divide | segment sequentially for every carbon fiber bundle. The drawing direction of the carbon fiber bundle may be the same plane direction or a spatially different direction. In order to stably and reliably divide a plurality of carbon fiber bundles, the above-described splitting guide (FIGS. 6A to 6D) may be used.

Each of the carbon fiber bundles divided as described above is drawn out while giving a variation in tension.
As a method for pulling out the carbon fiber bundle, for example, a winder 7 for winding the divided carbon fiber bundle is driven at a constant speed, and a goded roll, nip roll, Nelson roll, etc. are pulled out from the multiple carbon fiber bundle winder 1. For example, there is a method of installing at an arbitrary position on the plurality of carbon fiber bundles 3 or the carbon fiber bundle 4 and driving at a constant speed.
Moreover, it is preferable to pull out each carbon fiber bundle 4 divided | segmented from the multiple carbon fiber bundle 3 simultaneously at the same speed. By pulling out in this way, the multiple carbon fiber bundles 3 can be pulled out from the multiple carbon fiber bundle winder 1 so as to exist as one bundle.
The tension fluctuation may be given by any method, for example, a method of eccentrically rotating a plurality of carbon fiber bundle winding bodies, a method of changing the drawing speed of the carbon fiber bundle by the above-described winder, etc., and the above tension fluctuation device There is a method of changing the tension by using. As a method of eccentrically rotating a multi-carbon fiber bundle winding body, a method of eccentrically rotating using a bobbin having an eccentric shaft, a method of rotating the bobbin itself around the shaft and rotating eccentrically, and a bobbin bearing and shaft There is a method in which a bobbin is rotated eccentrically by providing a gap therebetween.

Hereinafter, the effects of the present invention will be specifically described with reference to examples.
<Multi-carbon fiber bundle winder>
(Example 1)
Convergence was imparted to 3000 carbon fiber precursors made of polyacrylonitrile using an air entanglement processor to obtain a carbon fiber precursor bundle. This carbon fiber precursor bundle was subjected to flame resistance treatment in air at 230 to 270 ° C. for 45 minutes, and subsequently subjected to carbonization treatment at 1400 ° C. for 1 minute. The obtained carbon fiber bundle was immersed in an epoxy sizing agent solution obtained by emulsifying 80 parts of an epoxy resin (Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.) with 20 parts of a nonionic emulsifier, and then dried. At this time, although the carbon fiber bundles are not bonded to each other by the sizing agent, the carbon fiber bundles are in a state where the carbon fiber bundles are partially entangled with the fluff generated from the carbon fiber bundle. The basis weight of this carbon fiber bundle was 2000 dtex. The obtained multi-carbon fiber bundle 5000 m is wound around a cylindrical bobbin having an inner diameter of 76 mm, an outer diameter of 82 mm, and a length of 280 mm, independently and without pulling out at the same speed (100 m / s). A multiple carbon fiber bundle wound body of 260 mm was obtained.

(Example 2)
Using the same carbon fiber precursor bundle as in Example 1, a carbon fiber bundle was obtained in the same manner as in Example 1. The obtained two carbon fiber bundles 5000m are wound around the same cylindrical bobbin as in Example 1 while maintaining the state in which the two carbon fiber bundles 5000m are arranged in parallel with each other without being stacked one above the other. A carbon fiber bundle wound body was obtained. At this time, the plurality of carbon fiber bundles are in a state where the carbon fiber bundles are partially entangled with each other by the fluff generated from the carbon fiber bundle.
Example 3
Using the same carbon fiber precursor bundle as in Example 1 above, the two carbon fiber precursor bundles were arranged in parallel without overlapping each other, and subjected to flameproofing treatment in air at 230 to 270 ° C. for 45 minutes. Subsequently, carbonization was performed at 1400 ° C. for 1 minute. The obtained two carbon fiber bundles were immersed in the epoxy sizing agent solution while maintaining a state in which they were arranged in parallel, and then dried. At this time, the plurality of carbon fiber bundles are in a state where carbon fiber bundles adjacent to each other are bonded to each other by a sizing agent. The obtained two carbon fiber bundles 5000 m were wound around the same cylindrical bobbin as in Example 1 to obtain a multiple carbon fiber bundle wound body having a diameter of 130 mm and a width of 260 mm.

(Comparative Example 1)
Using the same carbon fiber precursor bundle as in Example 1 above, these two carbon fiber precursor bundles were combined using a groove roll, and subjected to a flameproofing treatment in air at 230 to 270 ° C. for 45 minutes. At 1400 ° C. for 1 minute. The obtained multiple carbon fiber bundles were immersed in the epoxy sizing agent solution and then dried. At this time, when the obtained multiple carbon fiber bundle is viewed in the longitudinal direction, a certain portion is in parallel and a certain portion is overlapped with each other. Then, it wound around the same cylindrical bobbin as Example 1, and obtained the multiple carbon fiber bundle winding body of diameter 130mm and width 260mm.

<Multi-carbon fiber bundle splitting method and splitting device>
Hereinafter, a description will be given with reference to FIG. The multiple carbon fiber bundle wound body 1 obtained in Example 3 was attached to a creel (not shown). Since this creel supports the bobbin 2 itself so as to revolve around an axis and rotate eccentrically, the multiple carbon fiber bundle wound body 1 can be rotated eccentrically.
Next, the two carbon fiber bundles 4 drawn out from the multiple carbon fiber bundle wound body 1 were passed through a fiber separation guide 8. The splitting guide was installed at a position 3 m behind the creel. As the splitting guide, a ceramic roll guide having a diameter of 50 mm (Yuasa Yodomichi Co., Ltd., product number: A01060) is used, and the center distance of the splitting guide is 50 mm. Further, an eye guide (Yuasa Yodo Co., Ltd., product number: A411007) was placed 10 mm before the fiber separation guide 8, and the carbon fiber bundle 4 was passed through the opening. As a result, the angle θ formed by the flow direction of the plurality of carbon fiber bundles 3 and the flow direction of the carbon fiber bundles 4 with the splitting position 6 as the center is about 3 °.
The two carbon fiber bundles 4 that passed through the splitting guide 8 were further wound up by a winder 7.
Here, the speed of the winder and the carbon fiber when splitting as described above using the multiple carbon fiber bundle wound body of Examples 1 to 3 and the multiple carbon fiber bundle wound body of Comparative Example 1 Table 1 shows the tension applied to the bundle and the tension fluctuation.

＊試験１は、実施例１の複数炭素繊維束巻取体を使用。試験２は、実施例２の複数炭素繊維束巻取体を使用。試験３〜５は、実施例３の複数炭素繊維束巻取体を使用（但し試験５は、張力変動を行っていないので比較例）。試験６〜８は、比較例１の複数炭素繊維束巻取体を使用。 Table 1

* Test 1 uses the multiple carbon fiber bundle wound body of Example 1. Test 2 uses the multiple carbon fiber bundle wound body of Example 2. Tests 3 to 5 use the multiple carbon fiber bundle wound body of Example 3 (however, test 5 is a comparative example because no tension fluctuation is performed). Tests 6-8 use the multiple carbon fiber bundle wound body of Comparative Example 1.

<Evaluation>
(1) Splitting position The distance d from the splitting position 6 to the splitting guide 8 was measured. The farther the separation position 6 is from the separation guide, the more stable and reliable the division of the plurality of carbon fiber bundles is. Here, the splitting position 6 may move back and forth during the division operation, but in this case, it is set as an average splitting position. Evaluation of the position of separation was in accordance with the criteria of ◎: 2 m or more, ◯: 1 m or more and less than 2 m, Δ: 50 cm or more and less than 1 m, ×: less than 50 cm.
(2) Product quality The carbon fiber bundle wound with a winder was visually checked for fluff and thread breakage. The evaluation is performed by measuring the locations where the fluff is generated in the carbon fiber bundle wound body 1 with respect to the fluff, and ◎: less than 5 locations, ○: 5 locations to less than 20 locations, x: 20 locations or more. The standard was followed. Regarding thread breakage, the criteria of ○: no thread breakage and x: thread breakage were observed.
Table 2 shows the results of the evaluations performed for tests 1 to 8.

試験１〜４で分割された炭素繊維束は、毛羽立ちや糸切れの問題がなく、良質な炭素繊維束が得られた。特に、試験１〜３は、製品品質の観点から、良好な炭素繊維束が得られた。
一方、試験５〜８で分割された炭素繊維束は、分繊の安定性及び製品品質において問題があった。 Table 2

The carbon fiber bundles divided in Tests 1 to 4 were free from problems of fuzz and yarn breakage, and good quality carbon fiber bundles were obtained. In particular, in Tests 1 to 3, good carbon fiber bundles were obtained from the viewpoint of product quality.
On the other hand, the carbon fiber bundles divided in tests 5 to 8 have problems in the stability of splitting and the product quality.

  By selecting a specific multi-carbon fiber bundle wound body according to the present invention, high-speed splitting from a multi-carbon fiber bundle to each carbon fiber bundle is possible. Thereby, a plurality of carbon fiber bundles obtained by firing a plurality of carbon fiber precursor fiber bundles can be wound as they are on a single bobbin, and new winders, bobbins and the like for winding the carbon fiber bundles can be obtained. No capital investment is required. In particular, by using the winding body of the carbon fiber precursor fiber bundle described in Japanese Patent Application No. 2000-209111 related to the prior application of the present applicant, the "precursor fiber bundle wound around a single bobbin" In order to form a series of flow of “→ firing step → carbon fiber bundle wound around a single bobbin”, a conventional firing apparatus can be used as it is. In addition, it is possible to draw a large number of carbon fiber bundles from a single bobbin at an arbitrary speed and use them as they are in the weaving process, etc. In addition, the process can be omitted and the equipment cost can be reduced. Even when a separate carbon fiber splitting device is used, splitting can be performed at high speed. Therefore, it is possible to split efficiently by using several splitting devices effectively. Furthermore, since the number of steps can be reduced as a whole, quality improvement of the carbon fiber bundle can be expected.

1: Multiple carbon fiber bundle wound body 2: Bobbin 3: Multiple carbon fiber bundles 4: Carbon fiber bundle 5: Adjacent surface 6: Split position 7: Winder 8: Split guide

Claims (3)

A step of applying air entanglement treatment to the carbon fiber precursor fiber bundle to impart convergence;
Flame proofing the carbon fiber precursor fiber bundle, applying carbonization treatment to obtain a carbon fiber bundle,
Winding at least two of the carbon fiber bundles onto a single bobbin without being aligned;
The manufacturing method of the multiple carbon fiber bundle winding body characterized by having. A step of applying air entanglement treatment to the carbon fiber precursor fiber bundle to impart convergence;
Flame proofing the carbon fiber precursor fiber bundle, applying carbonization treatment to obtain a carbon fiber bundle,
Arranging at least two of the carbon fiber bundles in parallel with each other and winding them on a single bobbin;
The manufacturing method of the multiple carbon fiber bundle winding body characterized by having.   The method for producing a multiple carbon fiber bundle wound body according to claim 2, wherein the carbon fiber bundles adjacent to each other are bonded together by a sizing agent.

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