JP2006274497A - Carbon fiber package and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon fiber package excellent in processability to higher-order-processed fabrics, prepregs, etc., and capable of supplying stable filament yarn width at low cost, and to provide a method for producing the package. <P>SOLUTION: The carbon fiber package is characterized by meeting the following relationships: W2/W1≥0.95 (wherein, W1 (mm) is an average yarn width on the wound package of carbon fiber bundles, and W2 (mm) is an average yarn width after laterally unreeled) and W2≥0.225×D<SP>1/2</SP>(wherein, W2 is the same, and D is the total fineness (tex) of the unreeled yarn). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a carbon fiber package having a stable yarn width and a method for producing the same, and more particularly, a carbon fiber package excellent in processability to a high-order woven fabric or prepreg using a carbon fiber bundle, and the method thereof. It relates to a manufacturing method.

Carbon fiber bundles are processed in the form of woven fabrics and prepregs as reinforced fibers for composite materials due to their high specific strength, specific elastic modulus and excellent heat resistance. It's being used.
However, in recent years, with the increasing demand for weight reduction of fiber reinforced composite material products, the absolute amount of reinforcing fibers in the composite material tends to be reduced as much as possible, and the reinforcing fiber content tends to be increased. Therefore, in order to express excellent properties with a small amount of reinforcing fibers, the reinforcing fibers themselves are required to have a high elastic modulus and high strength, but when subjected to a high-order processing step such as woven fabric or prepreg, It is necessary to make the carbon fiber bundles, which are fibers, uniform and easy to spread, or to be thin and wide, and to be uniformly spread, which is a particularly important element, so as not to impair the quality of the carbon fiber bundles. In particular, the yarn width of the reinforcing fiber unwound from the bobbin tends to affect the quality, i.e., the yarn width of the unraveled yarn before it is unwound from the bobbin and enters the high-order processing step is expanded as much as possible. Such demands are particularly high in high-order machining, where a smaller variation is advantageous.

  As a method for solving such a problem, there are a method of widening the yarn width at the stage of high-order processing and a method of forming a carbon fiber bundle as a raw material into a package that is easy to expand.

  2. Description of the Related Art Conventionally, with respect to a method for manufacturing a reinforced fabric made of reinforcing fibers, a technique has been proposed in which a cylindrical object is reciprocated while rolling in a pressurized state to widen the warp yarn width in the weft direction. (See Patent Document 1). However, this proposal is based on a process after weaving the reinforcing fibers into a woven fabric, and no proposal has been made about the widening of the yarn width before weaving and the content of widening the fiber bundle itself as the raw material.

Furthermore, as another widening method, a method has been proposed in which a sheet previously opened with an air stream before weaving is produced (see Patent Document 2). However, similar to the proposal of Patent Document 1, there is no proposal for the contents of the widened fiber bundle itself, which is the raw material width of the yarn, and it is expensive to incorporate the device, which may lead to an increase in cost. is there.
In general, in order to improve the spreadability and spreadability of the carbon fiber bundle, a sizing agent is added to the carbon fiber bundle to improve convergence, scratch resistance and mechanical properties, and then dried with a hot roller. Thus, the carbon fiber bundle is flattened to some extent, wound around a bobbin, and then unwound and used in a high-order processing step. There, a carbon fiber bundle in which the drape value and the flatness are regulated is proposed as a carbon fiber bundle (see Patent Document 3). However, in general, a drape value is low, that is, a soft carbon fiber bundle has a low form retainability, so that it has good spreadability in high-order processability. However, the guide roller twill when the carbon fiber bundle is wound as a package is good. As a result of the swinging motion, it is partially bent, particularly at both ends of the bobbin, twisted, and the carbon fiber bundle is instantaneously narrowed. Therefore, even if the carbon fiber bundle is easy to widen, when a plurality of carbon fiber bundles are aligned and subjected to high-order processing, the narrowed portion does not sufficiently expand, and carbon in the high-order processed product is partially carbonized. There is a possibility that a defect portion called so-called cracking occurs in which no fiber is present.
In addition, what is important for stable widening when winding a carbon fiber bundle is a roller immediately before winding with a winder, and by defining the contact length between the final guide roller, the roller and the yarn. A guide device that can obtain a stable spread yarn width has been proposed (see Patent Document 4). However, in this guide device, there is no provision for the process before entering the final roller, and in particular, the drape value is low, i.e., the soft yarn has a low shape retention, so sizing and drying are performed. After that, it may meander with the yarn path roller until it enters the final guide roller of the winder, twisting may occur, and the spreadability may be inferior due to the narrowing of the yarn width.

  In addition, there has been proposed a method for reducing the variation in the fiber yarn width when unwound with a yarn path roller that hardly affects the shape of the yarn (see Patent Document 5). However, in this method, because the force that tries to converge in a state where the roller and the yarn are always in contact with each other at an angle, the absolute spread width of the fiber bundle may be reduced even if the variation can be reduced. There is a possibility that the spreadability is inferior.

  In addition, a method has been proposed in which, after a sizing agent is applied to a carbon fiber bundle, the ratio of the groove bottom flat portion to the carbon fiber bundle yarn width is defined in the yarn path (see Patent Document 6). In this method, since the drape value is low, that is, the soft yarn has low shape retention, it becomes easy to meander on the yarn path roller from sizing and drying until it enters the final guide roller of the winder. If the edge is in continuous contact, the carbon fiber bundle will be folded and twisted, etc., so that it does not spread during high-order processing, that is, there is a possibility that a defect part called crack will occur, in which there are no fibers in part. There is.

For the reasons described above, various proposals have been made for devices having excellent spreadability and widening devices, but the unfolded yarn bundle width, which is advantageous for spreadability, is widened, and at the same time homogeneity. It is an unsolved problem that it is difficult to achieve both of obtaining excellent carbon fiber bundles. In addition, with respect to soft carbon fiber bundles that are particularly advantageous in terms of spreadability, no sufficiently satisfactory solution has been found.
JP 2003-268669 A JP 2002-227053 A JP 2004-76246 A JP 2004-155590 A JP 2004-142945 A No. 2004-232133

  An object of the present invention is to provide a carbon fiber package that is excellent in processability to higher-order processed woven fabrics, prepregs, and the like, and that can supply a cheap and stable yarn width, and a method for producing the same.

  In order to achieve the above object, the present invention adopts the following configuration.

In the carbon fiber package of the present invention, the relationship between the average yarn width W1 [mm] on the take-up package of the carbon fiber bundle and the average yarn width W2 [mm] of the unwinding yarn after the transverse winding is W2 / W1 ≧ A carbon fiber package characterized in that the relationship between the average yarn width W2 [mm] and the total fineness D [tex] of the unwinding yarn is 0.95 and W2 ≧ 0.225 × D ^1/2 is there.

Furthermore, the carbon fiber package of the present invention has the following preferred embodiments.
(1) The CV value of the average yarn width W2 of the unwinding yarn is 10% or less.
(2) The unwinding tension at the time of the unwinding is 0.2 × (D / 2) ^1/2 [N] or less, and the carbon fiber bundle is substantially free of twist.
(3) The carbon fiber bundle has a drape value at a temperature of 23 ° C. of 9 cm or less and substantially no twist.

  Further, in the method for producing a carbon fiber package of the present invention, when the carbon fiber bundle is wound up and the carbon fiber package is produced, the groove ratio of the guide roller when the carbon fiber bundle is conveyed to the traverse guide roller is 5 to 40%. And a contact length between the traverse guide roller and the carbon fiber bundle is set to 15 mm or more.

  According to a preferred aspect of the method for producing a carbon fiber package of the present invention, a guide roller having a curved radius R of a guide roller in which the yarn running surface is curved concavely and has no wrinkles is in the range of 20 to 40 mm is used.

  According to the present invention, the winding yarn width of the carbon fiber bundle per fineness is widened, and the soft shape retention is small. A carbon fiber package can be obtained in which the shape change of the immediately preceding yarn bundle and the variation in the yarn width are small. By using such a carbon fiber package, it is possible to produce an inexpensive high-order processed product that is excellent in widening stability at the time of high-order workability such as prepreg and woven fabric and has good quality.

  In the present invention, the carbon fiber bundle constituting the carbon fiber package includes the average yarn width W1 [mm] on the winding package and the average yarn width W2 [mm] of the unwinding yarn after the side unwinding and the total The carbon fiber bundle is characterized in that the relationship with the fineness D [tex] is in the range of the following formula.

W2 / W1 ≧ 0.95 and W2 ≧ 0.225 × D ^1/2
That is, the carbon fiber bundle in the present invention is unraveled while maintaining a spread width of a certain level or more, with the yarn width after being unwound almost not narrowed with respect to the yarn width on the winding package. That is.

As the package here, a carbon fiber bundle is wound around a core bobbin that is generally inexpensive and easy to manufacture, and the shape is preferably a general cylindrical shape, and the material of the core bobbin is not particularly limited. Inexpensive paper and relatively inexpensive paper that can be reused are preferable, and the form of the take-up package may be a cylindrical type or a tapered end type. A cylindrical shape is a preferred embodiment in that it is not slippery and has excellent package shape retention.
Here, the average yarn width W1 on the winding package is obtained as follows. The average yarn width W1 is a carbon fiber bundle width value when a carbon fiber bundle is wound around a bobbin to form a package state. For the yarn to be measured for the yarn width on the package surface, The width of the carbon fiber bundle can be measured by applying a ruler vertically and measuring 10 points per traverse (0.5 traverse 5 points) with the take-up package standing on a flat surface. Is measured evenly and the average value is obtained.

  Further, the average yarn width W2 of the unwinding yarn after the further side unwinding can be measured as follows. Rotate 3cm from the carbon fiber package so that the winding package is creeled and the running yarn always runs on the yarn width reading sensor (for example, manufacturer name: OMRON, model: Z4LC-S2840, etc.). A guide is attached so that the yarn path is regulated in the vertical (vertical) direction. Install a thread width reading sensor at a distance of 1 m from there, so that it is perpendicular to the running yarn, and further, a satin-finished fixed guide that is less likely to get fuzz and dirt at a distance of 20 cm. The contact is made within a range of 0 to 0.5 ° which is hardly scratched, and measurement is performed while unwinding with a take-up machine at a pulling speed of 5 m / min.

  As the data at this time, data collected for 5 minutes at a cycle of times / second is used. Here, the satin-finished fixed guide means a surface obtained by roughening the guide surface by blasting or the like and then performing surface processing by plating (hard chrome plating). The outer peripheral surface roughness is JIS B The arithmetic average height Ra measured at 0601 (2001) is preferably 0.4 or more and 3.2 or less.

When the relationship between the average yarn width W1 [mm] on the package of carbon fiber bundles and the average yarn width W2 [mm] of the unwinding yarn after the side unwinding is less than 0.95, This means that the yarn width is narrowed. As a result, the carbon fiber bundles are not sufficiently expanded during the high-order workability. Further, when the relationship W2 ≧ 0.225 × D ^1/2 between the average yarn width W2 [mm] and the fineness D [tex] of the unwinding yarn after the weft unwinding is not satisfied, This means that the spread width per unit is narrow, and the expansion of the carbon fiber bundle at the time of high-order processing, especially at the time of production of thin high-order processed products, becomes insufficient. As a result, it is difficult to obtain a high-quality and high-quality composite material such as a high fiber content.
The relationship W2 / W1 between the average yarn width W1 [mm] on the winding package and the average yarn width W2 [mm] after the side unwinding yields a high-quality and high-quality composite material such as a high fiber content. However, the upper limit is about 1.50 from the viewpoint of shape retention as a fiber bundle and restrictions on equipment.
Moreover, the preferable range of the average yarn width W1 [mm] on the winding package is preferably 1.5 to 20 mm. If the average yarn width W1 is less than 1.5 mm, the yarn may be too thin, resulting in poor handling when pulling the yarn from the carbon fiber bundle package, and the average yarn width W1 may be 20 mm. When it exceeds, it becomes difficult to wind up as a package with a stable yarn width.

The preferred range of the relationship (W2 ≧ 0.225 × D ^1/2 ) between the average yarn width W2 [mm] and the fineness D [tex] of the unwinding yarn after the side unwinding is the average yarn on the winding package. From the upper limit value of the width W1, it is preferable that the following relationship is satisfied.

D ^1/2 ≧ W2 ≧ 0.225 × D ^1/2
Further, the average yarn width W2 of the unwinding yarn after the weft unwinding is preferably 10% or less, more preferably 8% or less, as a CV value as an index of variation. When the CV value exceeds 10%, the yarn width in the longitudinal direction is not stable, and as a result, in the high-order processability of prepregs and fabrics, cracking defects such as gaps can be generated and the quality is stable. It can happen.
The CV value here means the average value X and the standard deviation S of the data using N = 300 obtained when the average yarn width W2 of the unwinding yarn after unwinding is sampled at a cycle of times / second for 5 minutes. Calculated by the following formula.
CV value = S / X × 100 [%]
In addition, the range of the transverse unraveling tension at that time is preferably 0.3 × (D / 2) ^1/2 [N] or less, more preferably 0.25 × (D / 2) ^1/2. [N] or less. When the unraveling tension exceeds 0.3 × (D / 2) ^1/2 [N], the tension is high, so that the quality of the carbon fiber bundle is deteriorated due to rubbing between the carbon fiber bundle and the package surface. Since the yarn width is narrowed, the quality of the high-order workability is deteriorated, and it is sometimes difficult to accurately measure the average yarn width of the weft unwinding. In addition, the lower the side unraveling tension, the better from the viewpoint of not deteriorating the quality, but the lower limit is about 0.05 × (D / 2) ^1/2 [N] from the viewpoint of handleability.

  In addition, the carbon fiber bundle in the present invention preferably has a drape value at a temperature of 23 ° C. of 9 cm or less, that is, the carbon fiber bundle is more effective with respect to a relatively soft yarn bundle. The drape value represents the hardness of the yarn bundle, and it can be said that the smaller the value is, the softer the shape is and the less the shape retention is. A sizing agent is attached to the carbon fiber bundle due to improvement in mechanical characteristics and handling properties, and the drape value varies depending on the amount and characteristics of the sizing agent attached. In general, even when a flat yarn bundle with a soft carbon fiber bundle is used to improve spreadability, mechanical properties, or spreadability, a stable yarn with a wide unwinding yarn width can be obtained. The lower limit of the drape value is about 4 cm from the relationship with the sizing agent adhesion amount and the sizing agent characteristics.

  The drape value here will be described with reference to FIG. FIG. 1 is a schematic side view showing a drape value measuring method used in the present invention. As shown in FIG. 1A, a carbon fiber bundle cut to 50 cm is hung with a weight of 0.0375 [g / tex] in an atmosphere of a temperature of 23 ° C. and a humidity of 60%, and left for 30 minutes or more. Untwist and twist to form. It is cut into a length of 30 cm and, as shown in FIG. 1 (b), one end thereof is fixed to the upper surface of the quadrangular column so as to be parallel to the floor surface so as not to hang down in a cantilevered state. At this time, the carbon fiber bundle is fixed so that the carbon fiber bundle is perpendicular to the side surface of the square column and the length from the side surface of the square column to the tip of the suspended carbon fiber bundle is 25 cm. Thereafter, the closest distance [cm] formed by the tip of the carbon fiber bundle that hangs down due to gravity and the side surface of the quadrangular column is measured. At this time, the distance after 1 second from the start of drooping of the carbon fiber bundle is taken as the drape value. The sizing agent adhesion amount is generally preferably in the range of 0.2 to 3.0% by weight, and more preferably in the range of 0.2 to 2.0% by weight. When the amount of sizing agent adhering exceeds 3.0% by weight, the converging property is improved, so that the shape retention and handling properties are improved. The high-order workability tends to be inferior due to insufficient spreading due to too high convergence. On the other hand, if the amount of sizing agent attached is 0.2% by weight or less, fluff and thread trimming occur at the time of unwinding due to a decrease in scratch resistance and insufficient convergence, and the handleability tends to deteriorate.

In the present invention, the meaning that the carbon fiber bundle is not substantially twisted means that, even if there is a twist, the number of remaining twists is preferably 0.1 turns or less per meter. That the number of remaining twists exceeds 0.1 turns / m means that the yarn width is partially narrowed, and the spreadability tends to be inferior.
The number of remaining twists here can be measured by the following method. The carbon fiber bundle is unrolled in a horizontal direction while tearing the carbon fiber bundle about half from the carbon fiber package. When the twist enters, unwind the twist and record the value. This is repeated 20 m, and the value obtained by adding the absolute values is divided by 20 m to obtain the number of remaining twists per 1 m.

  In the present invention, the carbon fiber bundle can be obtained as follows. The raw fiber may be any of polyacrylonitrile fiber, pitch fiber, rayon fiber, etc., but for the reason that a carbon fiber bundle excellent in scratch resistance can be obtained, polyacrylonitrile fiber is used as the raw fiber. It is preferable to do.

  The number of single fibers constituting the carbon fiber bundle is suitably in the range of 3,000 to 48,000 from the viewpoint of productivity and resin impregnation.

  The carbon fiber bundle used in the present invention is flame resistant by heating the precursor fiber, preferably a polyacrylonitrile fiber, in an oxidizing atmosphere (usually in air) at a temperature in the range of 200 to 300 ° C. Thereafter, it can be produced by heating in an inert atmosphere at a temperature in the range of 300 to 2,000 ° C. and carbonizing and stretching in a range of 0.9 to 1.0 times. Prior to the carbonization treatment, a so-called preliminary carbonization treatment in which the flameproof fiber is heated at 200 to 800 ° C. in an inert atmosphere may be performed. When the flameproofing temperature is less than 200 ° C., burnt spots occur, which may cause deterioration in properties such as a decrease in tensile strength, and deterioration in quality such as generation of yarn scratches and fluff. On the other hand, when the flameproof temperature exceeds 300 ° C., heat storage of reaction heat occurs and production becomes unstable. A preferable range of the flameproofing temperature is 200 to 270 ° C, and a more preferable range is 230 to 270 ° C.

  Moreover, when carbonization temperature is lower than 300 degreeC, the tensile strength and tensile elasticity modulus of the carbon fiber obtained will fall. On the other hand, when the carbonization temperature exceeds 2,000 ° C., the compression strength in the 0 ° direction of the carbon fiber obtained by promoting crystallization is lowered, and the twist strength when the fiber reinforced composite material is formed into a cylinder is reduced. There is a tendency to become damaged. A preferable range of the carbonization temperature is 300 to 2,000 ° C, and a more preferable range is 300 to 1,950 ° C.

  Furthermore, when the draw ratio in the carbonization treatment is less than 0.9 times, the tensile strength and tensile elastic modulus of the obtained carbon fiber may be lowered. On the other hand, when the draw ratio exceeds 1.1 times, there are cases in which fluffing occurs due to yarn breakage at the time of release or rubbing with a roller. A preferable range of the draw ratio is 0.9 to 1.0 times, and a more preferable range is 0.92 to 0.98 times.

  When obtaining a so-called graphitized fiber bundle, the carbonized fiber bundle is graphitized at a maximum firing temperature higher than 2,000 ° C. in an inert atmosphere (for example, in a nitrogen atmosphere) and 0.9 to It is preferable to produce by stretching in a range of 1.2 times. At this time, the maximum firing temperature is preferably 2,000 to 3,000 ° C, more preferably 2,000 to 2,900 ° C, and further preferably 2,000 to 2,700 ° C. To do. If the maximum firing temperature is less than 2,000 ° C, the tensile modulus may be insufficient, and if it exceeds 3,000 ° C, crystallization of carbon is promoted and compression in the 0 ° direction when a fiber reinforced composite material is obtained. It may cause quality deterioration such as strength reduction.

  In addition, if the draw ratio in the graphitization treatment is less than 0.9 times, the tensile modulus and tensile strength may decrease. If the draw ratio exceeds 1.2 times, yarn breakage at the time of release or fluffing due to rubbing with the roller may occur. It may become like this. A more preferable range for the stretch ratio is 1.0 to 1.2 times, and a further preferable range is 1.0 to 1.1 times.

Further, a method is preferably applied in which the surface of the obtained carbon fiber bundle is subjected to electrolytic treatment in an aqueous solution, a sizing agent is adhered, the yarn is dried to some extent by preliminary drying, and dried at a higher temperature. For the preliminary drying, it is preferable to use a hot roller capable of flattening and opening the carbon fiber bundle to some extent. Here, the preliminary drying temperature is preferably 100 to 200 ° C. The contact time between the yarn and the roller is preferably 5 to 30 seconds. If the contact time is 5 seconds or less, sufficient drying cannot be obtained, and a sufficiently flat yarn bundle may not be kept. In addition, when the contact time is 30 seconds or more, the equipment cost is increased due to the deterioration of productivity due to a reduction in production speed and the fact that the equipment becomes too large.
Moreover, after giving a sizing agent to the carbon fiber bundle, the ratio T (B / w) of the width B (mm) of the groove bottom flat portion of the conveying roller to the carbon fiber yarn bundle width w is in the range of 1 <T ≦ 4. It is preferable that When the ratio T is less than 1, yarn breakage occurs at the edge of the groove roller at the end of the carbon fiber bundle, and adverse effects such as cracking occur during high-order workability. On the other hand, if the ratio T exceeds 4, the machine width of the machine becomes too large with respect to the carbon fiber yarn bundle width, leading to an increase in equipment cost.
In the method for producing a carbon fiber package of the present invention, the sizing agent is attached to the carbon fiber bundle and dried, the yarn form is flattened to some extent, and then the remaining twist is performed in the conveying process while being wound as a package. It is important to be able to wind up in a state with little. As a guide roller shape when the yarn is conveyed, a grooved roller or a ridged roller is generally used. However, a relatively soft yarn that is easy to meander easily touches the grooves and folds, and as a result, a continuous residual twist is likely to occur even when a roller having a relatively large groove width is used. However, there is no problem if the residual twist is released with a certain amount of tension at the free-length portion between the rollers if the residual twist is instantaneous even if it enters.
As this method, the grooved roller system up to the traverse guide is used, for example, by using a roller with a hook having a shape as shown in FIG. 2 (FIG. 3 is a cross-sectional view taken along the line AA ′ in FIG. 2). Can be conveyed to the final traverse guide so that continuous residual twist does not enter the conveyed yarn. The groove ratio is preferably 5 to 40%, more preferably 10 to 20%. If the groove ratio is less than 5%, the fiber bundles interfere with each other and mix, resulting in yarn breakage and poor productivity. Further, if the groove ratio exceeds 40%, the edge of the groove roller may be contacted for a long time, so that yarn breakage may occur and the yarn width on the package may be narrowed. The groove ratio here will be described with reference to FIG. FIG. 2 is a side view illustrating a guide roller with a hook in a certain time zone showing an embodiment of the present invention, and FIG. 3 is a cross-sectional view along AA ′ through the hook roller shaft 2 of the guide roller in FIG. It is sectional drawing.
As shown in FIG. 2, the groove ratio is a guide roller with ridges that conveys the fiber bundle F, and the convex width L of the ridge roller with respect to the circumference (of the ridge roller radius) of the portion with which the fiber bundle F contacts. It represents the ratio of the total length in the rotation direction of the heel part shown, and is obtained by the following formula.

Groove ratio = power x L / 2π x radius x 100 [%]
In addition, as a method for preventing the residual twist from entering the carbon fiber bundle, a guide roller that has no wrinkles due to the yarn running surface of the conveyance guide being curved concavely can be used. The radius of curvature R of the roller with a hook at the portion where the running yarn contacts the guide roller is dependent on the thickness of the yarn, etc., but if it is a general-purpose carbon fiber bundle having about 12,000 single fibers, 20-40 mm is preferable, More preferably, it is 25-35 mm. When the radius R of the flanged roller is less than 20 mm, a force for converging the fiber bundle may be exerted greatly, or a residual twist may occur depending on circumstances. On the other hand, when the radius R of the flanged roller exceeds 40 mm, it cannot be stably conveyed, and the productivity tends to decrease.
Then, it winds up as a package through a traverse guide so that twist may not be put. The traverse guide at this time will be described with reference to FIG. 4 showing a schematic side view of a traverse guide device portion for illustrating one embodiment of the carbon fiber package manufacturing method of the present invention. As shown in FIG. 4, it is preferable to further install one guide roller 5b having a rotation axis substantially parallel to the rotation axis of the winding bobbin 10 directly above the final guide roller 5a. It is preferable to have two or more guide rollers including the final guide roller 5a, the guide rollers having the rotation shaft arranged substantially parallel to the rotation shaft of the winding bobbin 10. The total contact length is preferably 25 mm or more. According to this embodiment, it is possible to further stabilize the yarn path. However, in consideration of the increase in the size of the apparatus as described above, the rotation axis is substantially parallel to the rotation axis of the winding bobbin 9. The number of guide rollers arranged is preferably 3 or less, and the total contact length is 75 mm or less.

  In addition, it is preferable to further install one guide roller 4b having a rotation shaft arranged at a position twisted substantially at right angles to the rotation shaft of the winding bobbin 10 immediately below the first guide roller 4a. It is preferable to have two or more guide rollers including the first guide roller 4a in which the rotation shaft is arranged at a position twisted substantially at right angles to the rotation shaft of the winding bobbin 10. The total contact length between the thread F and the yarn F is preferably 25 mm or more. According to this embodiment, it is possible to further stabilize the yarn path. However, in consideration of the increase in the size of the device as described above, the position twisted substantially perpendicular to the rotation axis of the winding bobbin 10. It is preferable that the number of guide rollers provided with a rotating shaft is 3 or less, and the total contact length is 75 mm or less.

  As described above, the total contact length of all the guide rollers and the yarn F that the traverse guide device 1 of the present invention has is preferably as long as possible from the viewpoint of stabilizing the yarn path. Considering that the apparatus will be enlarged again, it is preferably 50 mm or more and 150 mm or less. Similarly, the total number of guide rollers is preferably 7 or less.

  Next, the shorter one of the distance from the separation point of the yarn in the final guide roller 5a to the contact point of the yarn F in either the winding bobbin 10 or the winding machine pressure roller 7 is 25 mm or less. It is preferable. For example, in FIG. 4, it is preferable that the distance H from the yarn separation point in the final guide roller 5a to the yarn contact point in the winder pressure roller 7 is 25 mm or less. The distance H is preferably as short as possible from the viewpoint of stabilizing the yarn path, but is preferably 5 mm or more from the viewpoint of roller arrangement and threading workability. Further, when the winding bobbin 10 is wound and then contacted by the winder pressure roller, the distance from the yarn separation point on the final guide roller 5a to the yarn contact point on the winding bobbin is 25 mm. The following is preferable. In addition, the positional relationship between the guide roller and the traveling yarn when passing through the traverse guide is such that the rotation axis is arranged in a straight line or substantially parallel to the rotation axis of the winding bobbin so as not to twist. It is preferable to use a guide roller.

  Hereinafter, the present invention will be described more specifically with reference to examples.

[Example 1]
An acrylonitrile fiber bundle having 12,000 single fibers and a single fiber fineness of 1.1 [dtex] is heated in an oxidizing atmosphere at a temperature of 240 ° C. for 120 minutes to obtain a flameproof fiber bundle, and then inert. Pre-carbonized by heating at a maximum firing temperature of 700 ° C. in an atmosphere to obtain a pre-carbonized fiber bundle. Subsequently, the preliminary carbonized fiber bundle was carbonized in an inert atmosphere having a maximum firing temperature of 2000 ° C. and stretched 0.95 times to obtain a carbonized fiber bundle. Next, the surface of the obtained carbonized fiber bundle is subjected to electrolytic treatment in an aqueous solution, and a sizing agent (manufactured by Takemoto Yushi Co., Ltd., product name: T1800 is added so as to be 0.5% by weight, followed by preliminary drying Hot roller drying at a temperature of 130 ° C. for 6 seconds and drying at a temperature of 200 ° C. in air gave a carbon fiber bundle having a drape value of 8 cm.
Subsequently, the obtained carbon fiber bundle was run using a groove roller and a guide roller having a ratio of the width of the groove bottom flat portion of the transport roller to the running carbon fiber yarn bundle width of 2 and a groove rate of 20%. Thereafter, the traverse guide device (traverse guide roller) 3 was installed as shown in FIG. 4, and the guide roller contact length was adjusted to 20 mm. At this time, the first guide roller 4a and the guide roller 4b in FIG. 4 are attached with the shaft of the guide roller so as to be parallel to the plane perpendicular to the rotation axis of the winding bobbin 10, and the final guide roller 5a The guide roller 5 b was attached so as to be parallel to the rotation axis of the winding bobbin 10. Further, with respect to the auxiliary guide roller 6, both the yarn path between the guide roller 4b and the auxiliary guide roller 6 and the yarn path between the auxiliary guide roller 6 and the guide roller 5b are surfaces perpendicular to the rotation axis of the auxiliary guide roller 6. The auxiliary guide roller 6 was disposed so as to be inside. That is, all of the five guide rollers of the traverse guide were arranged so that the guide roller rotation shafts were twisted vertically with respect to the respective yarn paths before and after the traverse guide. Subsequently, the distance H to the contact point of the yarn in the pressure roller 7 of the winder was adjusted to 20 mm, and wound up as a square end type carbon fiber package. The characteristics when the carbon fiber package was pulled out in the transverse direction under a tension condition of 4.2 [N] were as follows. The results are shown in Table 1.

[Example 2]
A carbon fiber package was obtained in the same manner as in Example 1 except that the conveyance guide was curved, that is, a guide roller having no wrinkles was used, and the carbon fiber package was pulled out in a lateral direction under a tension condition of 4.2 [N]. The characteristics were as follows. The results are shown in Table 1.

[Example 3]
After obtaining a relatively hard carbon fiber having a sizing agent (Sz) adhesion amount of 1.0% and a drape value of 16 cm, the same carbon fiber package as in Example 1 was obtained. The characteristics when pulled in the direction under a tension condition of 4.2 [N] were as follows. The results are shown in Table 1.

[Comparative Example 1]
A carbon fiber package was obtained in the same manner as in Example 1 except that a groove roller and a guide roller having a groove ratio of 100% were used, and the carbon fiber package had a tension of 4.2 [N] in the transverse direction. The characteristics when drawn out under the conditions were as follows. The results are shown in Table 1.

[Comparative Example 2]
A carbon fiber package was obtained in the same manner as in Example 3 except that a groove roller and a guide roller having a groove ratio of 100% were used, and the carbon fiber package had a tension of 4.2 [N] in the transverse direction. The characteristics when drawn out under the conditions were as follows. The results are shown in Table 1.

  The carbon fiber packages of Examples 1 to 3 are good high-order processed with fewer defects such as cracks when used as reinforcing fibers for higher-order processability than the carbon fiber packages of Comparative Examples 1 and 2. Goods were obtained.

  In the carbon fiber package of the present invention, the winding width of the carbon fiber bundle per fineness is widened, and the soft shape retention is small. Small variation in yarn bundle shape and variation in yarn width immediately before entering For this reason, by using the carbon fiber package of the present invention, it is possible to produce an inexpensive high-order processed product with excellent widening stability at the time of high-order workability such as a prepreg or a woven fabric, and a good quality.

FIG. 1 is a schematic side view showing a drape value measuring method used in the present invention. FIG. 2 is a side view illustrating a hooked guide roller of a certain time zone showing an embodiment of the present invention. FIG. 3 is a cross-sectional view taken along line A-A ′ of the guide roller in FIG. 2. FIG. 4 is a schematic side view of a traverse guide device portion for illustrating an embodiment of the carbon fiber package manufacturing method of the present invention.

Explanation of symbols

1: Drape value 2: Roller shaft with hook 3: Traverse guide device 4a: First guide roller 4b: Guide roller 5a: Final guide roller 5b: Guide roller 6: Auxiliary guide roller 7: Pressure roller 8: Guide guide Part 9: Yarn package 10: Winding bobbin (paper tube)
F: Fiber bundle R: Roller radius with ridge L: Convex width of roller with ridge

Claims (6)

The relationship between the average yarn width W1 [mm] on the winding package of the carbon fiber bundle and the average yarn width W2 [mm] of the unwinding yarn after transverse unwinding is W2 / W1 ≧ 0.95, and A carbon fiber package, wherein the relationship between the average yarn width W2 [mm] of the unwinding yarn and the total fineness D [tex] is W2 ≧ 0.225 × D1 ^{/ 2} .   The carbon fiber package according to claim 1, wherein the CV value of the average yarn width W2 of the unwinding yarn is 10% or less. The carbon fiber package according to claim 1 or 2, wherein the unwinding tension is 0.3 x (D / 2) ^1/2 [N] or less.   The carbon fiber package according to any one of claims 1 to 3, wherein the carbon fiber bundle is a carbon fiber bundle having a drape value of 9 cm or less at a temperature of 23 ° C of substantially no twist.   When producing a carbon fiber package by winding a carbon fiber bundle, a guide roller having a groove ratio of 5 to 40% for conveying the carbon fiber bundle to a traverse guide roller is used. A method for producing a carbon fiber package, wherein the contact length of the carbon fiber bundle is 15 mm or more.   When producing a carbon fiber package by winding a carbon fiber bundle, a guide roller having a curved radius R of a guide roller in which the yarn running surface is curved concavely and has no wrinkles is in a range of 20 to 40 mm is used. A method for manufacturing a carbon fiber package.

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