JP6347082B2 - Carbon fiber sliver manufacturing method and manufacturing apparatus thereof - Google Patents

Description

  The present invention relates to a method for manufacturing a carbon fiber sliver formed by mixing synthetic fibers and carbon fibers, and a manufacturing apparatus therefor.

Carbon fiber is expected to be a composite material such as fiber reinforced plastic because it has light weight and high strength characteristics.
However, when carbon fiber is used as a composite material, it is preferable to arrange the carbon fiber in one direction and spin it into a thread. However, the carbon fiber does not have crimpability and is slippery. It was difficult to spin the yarns with carbon fiber alone. Further, when the carbon fibers opened in random directions are rearranged in one direction, there is a problem that the carbon fibers break and the strength decreases.

In order to cope with this problem, for example, a step of blending natural fibers and / or synthetic fibers with pitch-based carbon fibers and opening them to obtain mixed cotton, and weighing a predetermined amount and supplying it to a carding machine, A pitch system consisting of a cotton-making process in which the mixed cotton supplied using a cotton-making machine is formed into a fleece and then formed into a sliver, and a spinning process in which the sliver is drawn and twisted using an open-end spinning machine to spin A method for producing a carbon fiber spun yarn is disclosed in Patent Document 1.
As shown in FIG. 9, the carding machine used in the carding process of Patent Document 1 includes a feed lattice 161 that supplies mixed cotton 141, and a feed roller 181 that supplies mixed cotton on the feed lattice 161 to the take-in 201. The take-in 201 which rotates at high speed and scrapes the mixed cotton from the feed roller 181 with saw blades planted on the surface and passes it to the cylinder 221. A cylinder 221 for receiving fibers with the walker roller 241 while receiving with a needle implanted in the carrier, a doffer 261 for receiving the fibers twisted from the cylinder 221 as a fleece shape, and a fleece shape taken out from the doffer 261 Roller that converges the mixed cotton 281 to form a sliver 301 Consisting of 21.

JP-A-8-158170

However, the manufacturing method described in Patent Document 1 has the following problems because the carding machine having the above structure is used.
That is, in the mixed cotton 141 mixed and opened by the hopper feeder 101, the pitch-based carbon fiber and the natural fiber and / or the synthetic fiber are not sufficiently entangled, and the mixed cotton 141 is not taken by the take-in 201 or the doffer 261. When passing through, there is nothing to catch the fiber from below. Therefore, there has been a problem that pitch-based carbon fibers that are not entangled with natural fibers and / or synthetic fibers fall apart and fall in the middle.
Further, when the fiber passes between the cylinder 221 and the walker roller 241, there is a problem that only the pitch-based carbon fiber that is weak against the bending load is broken.

  The present invention has been made to solve the above-mentioned problems, and its object is to easily provide a carbon fiber sliver in which synthetic fibers are entangled and mixed with carbon fibers while preventing breakage of the carbon fibers. It is providing the manufacturing method and manufacturing apparatus of the carbon fiber sliver to manufacture.

In order to solve the above problems, a carbon fiber sliver manufacturing method and a manufacturing apparatus thereof according to the present invention have the following configuration.
(1) A method for producing a carbon fiber sliver formed by mixing carbon fiber and synthetic fiber,
The carbon fibers are cotton fibers cut into short fibers and opened in random directions, and the synthetic fibers are crimpable cotton formed in short fibers and arranged in substantially the same direction. Fiber-like,
The synthetic fibers are substantially aligned with the crimping direction and the feeding direction, and the carbon fibers are distributed substantially evenly above the synthetic fibers laminated to a predetermined thickness to form a layer with the same width as the synthetic fibers. A first step of superimposing on,
The carbon fiber and the synthetic fiber superposed in the first step are sandwiched between a front roller disposed in the front in the feeding direction and a back roller disposed in the rear in the feeding direction, and the front roller is applied while drafting the fibers. And a second step of forming a fleece-shaped web by twisting fibers in the feeding direction in a gil device disposed in an intermediate part between the back roller and the back roller;
The fleece-shaped web fed from the front roller is provided with a calender roller having a guide hole formed in the introduction portion to converge and pass in a bundle at one place, and the fleece-shaped web passes through the calender roller. And a third step of forming a continuous carbon fiber sliver by concentrating the upper carbon fiber from both sides with the lower synthetic fiber through the guide hole and converging into a bundle.

In the present invention, the crimping direction and the feeding direction of the synthetic fiber are substantially matched in the first step. Therefore, when the synthetic fiber is drafted in the feeding direction, the fibers are closely entangled and stretched. However, the connection strength between the fibers increases. In addition, since the carbon fibers are layered on top of the synthetic fibers laminated to a predetermined thickness, when the draft is applied in the feed direction, the connecting strength between the fibers increases and the stretched synthetic fibers are above it. The carbon fibers to be stacked can be transferred while being supported from below.
Further, in the second step, the carbon fiber and the synthetic fiber overlapped in the first step are sandwiched between the front roller arranged in the front in the feeding direction and the back roller arranged in the rear in the feeding direction, and the draft is put into the fibers. Since the fibers are wound in the feeding direction by the gil device arranged in the middle between the front roller and the back roller while hanging, the overlapped carbon fiber and synthetic fiber are drafted in the feeding direction and brought close to each other Now the gil device can beat both fibers. Further, the gil device can align the carbon fibers oriented in a random direction in the feeding direction in a state where the synthetic fibers and the carbon fibers are supported from below by the lower teeth. When the carbon fibers are aligned in the feeding direction, the carbon fibers are supported from below by the synthetic fibers, and therefore do not fall apart.

Here, the synthetic fiber is a crimpable cotton-like fiber that is formed in a short fiber shape and arranged in substantially the same direction, and is arranged with the crimping direction and the feeding direction of the synthetic fiber substantially matched in advance. Therefore, when the needle of the gil device turns the fiber in the feeding direction, the synthetic fiber is easily entangled with the carbon fibers adjacent to each other. In addition, since the synthetic fibers are entangled with the carbon fibers when the carbon fibers are aligned in the feeding direction, the carbon fibers are prevented from being bent excessively, and the carbon fibers are not easily broken. In addition, the carbon fibers are entangled with the synthetic fibers to be held in an aligned state in the feeding direction.
As a result, the carbon fibers aligned in the feeding direction without breaking and the synthetic fibers intertwined around them are mixed to form a fleece web.

Further, in the third step, with a calender roller guide hole for passing the fleece-like web being fed from the front roller and focused in a bundle in one place it is formed in the introduction, the fleece-like web, calendar When passing through the roller, the upper carbon fiber is wrapped from both sides by the lower synthetic fiber through the guide hole and converged into a bundle to form a continuous carbon fiber sliver, so it is aligned in the feed direction without breaking A continuous carbon fiber sliver having a predetermined thickness can be formed from a web formed by kneading the formed carbon fibers and the synthetic fibers entangled around them. In addition, since the carbon fiber sliver is formed by bundling fleece webs in a bundle, the synthetic fibers stacked below can wrap the upper carbon fibers from the outer peripheral side. Therefore, by wrapping the carbon fiber that has not been entangled with the synthetic fiber in the second step from the outer peripheral side in the third step, it is possible to reduce the risk of the carbon fiber falling or detaching from the carbon fiber sliver.
Therefore, according to the present invention, it is possible to provide a method for manufacturing a carbon fiber sliver that easily manufactures a carbon fiber sliver in which synthetic fibers are entangled with and mixed with carbon fibers while preventing breakage of the carbon fibers. .

(2) In the method for producing a carbon fiber sliver described in (1),
The synthetic fiber laminated in a predetermined thickness in the first step is a carbon fiber sliver formed in the third step.

  In the present invention, since the synthetic fiber laminated to a predetermined thickness in the first step is a carbon fiber sliver formed in the third step, in the first step, the carbon fibers aligned in the feed direction and Synthetic fibers entangled around them are mixed and a new carbon fiber is laminated on a carbon fiber sliver having a predetermined thickness and having a predetermined thickness. Therefore, a carbon fiber sliver with a further increased carbon fiber mixing rate can be formed via the second step and the third step. Also in this case, the synthetic fiber is entangled around the new carbon fiber, and the carbon fiber can be prevented from being broken while the carbon fiber is kept aligned in the feeding direction. Therefore, an even higher strength carbon fiber sliver can be formed. Moreover, the alignment degree of the carbon fiber in the carbon fiber sliver can be further increased.

(3) In the method for producing a carbon fiber sliver described in (1) or (2),
The weight per unit area of the carbon fibers to be overlapped in the first step is approximately the same as the weight per unit area of the synthetic fibers laminated to a predetermined thickness.

  In the present invention, the weight per unit area of the carbon fibers to be overlapped in the first step is approximately the same as the weight per unit area of the synthetic fibers laminated to a predetermined thickness. When sandwiching the carbon fiber and the synthetic fiber, the carbon fiber and the synthetic fiber can be crushed at a substantially equal ratio and drafted. Therefore, when the needle | hook of a gil apparatus beats a fiber, it can wind smoothly, disperse | distributing carbon fiber and a synthetic fiber substantially equally. As a result, a carbon fiber sliver in which carbon fibers and synthetic fibers are more evenly dispersed can be formed.

(4) In the method for producing a carbon fiber sliver described in any one of (1) to (3),
The free length of the synthetic fiber is shorter than the free length of the carbon fiber.

In the present invention, since the free length of the synthetic fiber is shorter than the free length of the carbon fiber, the carbon fiber and the synthetic fiber are sandwiched between the front roller and the back roller, and the needle of the gil device holds the fiber while drafting. The synthetic fibers that are short and move easily tend to enter the gaps between the carbon fibers. Therefore, the synthetic fibers that have entered the gaps between the carbon fibers can be entangled more strongly with the carbon fibers. As a result, an even higher strength carbon fiber sliver can be formed.
The free length of the synthetic fiber is preferably about 1/4 to 1/2 times the free length of the carbon fiber. For example, the free length of the carbon fiber is preferably about 15 to 25 cm, and the free length of the synthetic fiber is preferably about 5 to 10 cm.

(5) A manufacturing apparatus used in the method for manufacturing a carbon fiber sliver described in any one of (1) to (4),
A transport conveyor for placing and transporting the carbon fiber and the synthetic fiber, a back roller disposed on a front end side of the transport conveyor, a front roller disposed in a forward direction of the back roller, and the back A gil device disposed in an intermediate portion between the roller and the front roller, and a calender roller disposed in front of the front roller in the feed direction,
The rotation speed of the front roller is faster than the rotation speed of the back roller, and the outer diameter of the upper roller in the front roller is larger than the outer diameter of the lower roller in the front roller.

In the present invention, a transport conveyor for placing and transporting carbon fibers and synthetic fibers, a back roller disposed on the front end side of the transport conveyor, a front roller disposed in the forward direction of the back roller, It includes a gil device disposed in the middle of the roller and the front roller, and a calendar roller disposed in front of the front roller in the feed direction. The rotation speed of the front roller is faster than the rotation speed of the back roller. In a state where the flattened carbon fiber and the synthetic fiber are stretched in the feed direction (draft) and brought closer to each other, the gil device beats the fiber so that the carbon fiber is entangled with the synthetic fiber. It can be made easier. Further, since the outer diameter of the upper roller in the front roller is larger than the outer diameter of the lower roller in the front roller, extreme bending of the carbon fiber is prevented and the carbon fiber is not easily broken.
As a result, carbon fibers aligned in the feed direction without breaking and synthetic fibers entangled around them are mixed to form a fleece-like web, preventing the carbon fibers from breaking, and the synthetic fibers The carbon fiber sliver entangled with the carbon fiber can be easily manufactured.

(6) A method for producing a carbon fiber sliver formed by mixing carbon fiber and synthetic fiber,
The carbon fibers are cotton fibers cut into short fibers and opened in random directions, and the synthetic fibers are crimpable cotton formed in short fibers and arranged in substantially the same direction. Fiber-like,
A first step in which the crimping direction of the synthetic fiber and the feeding direction are substantially matched, and the carbon fiber is layered on the synthetic fiber laminated to a predetermined thickness;
A second step of winding the carbon fiber and the synthetic fiber overlapped in the first step as a first web around the cylinder outer periphery of the unfolding machine arranged in the feed direction;
A third step of removing the first web wound in the second step from the cylinder of the unfolding machine and cutting it into strip members in the feed direction;
The strip member cut in the third step is sandwiched between a front roller and a back roller disposed rearward in the feed direction, and a gil device disposed at an intermediate portion between the front roller and the back roller while being drafted. A fourth step of forming a fleece-shaped second web by winding fibers in the feeding direction;
The second web fed from the front roller includes a fifth step of forming a continuous carbon fiber sliver converged at one place.

In the present invention, the crimping direction and the feeding direction of the synthetic fiber are substantially matched in the first step. Therefore, when the synthetic fiber is drafted in the feeding direction, the fibers are closely entangled and stretched. However, the connection strength between the fibers is increased. In addition, since the carbon fibers are layered on top of the synthetic fibers laminated to a predetermined thickness, the synthetic fibers stretched by increasing the connection strength between the fibers when drafted in the feed direction are above it. The carbon fibers to be stacked can be transferred while being supported from below.
Moreover, since the carbon fiber and synthetic fiber which were piled up at the 1st process are equipped with the 2nd process which winds up as a 1st web in the cylinder outer periphery of the unfolding machine arrange | positioned ahead of a feed direction, it comprises a carbon fiber and synthetic | combination. The 1st web which consists of mixed cotton which laminated | stacked the fiber in multiple layers can be formed.
In addition, since the first web wound in the second step is removed from the cylinder of the unfolding machine and cut into strip members in the feeding direction, carbon fibers and synthetic fibers are laminated in a plurality of layers. The mixed cotton webs can be aligned to the required width size in the feed direction.
In addition, the strip member cut in the third step is sandwiched between the front roller and the back roller arranged at the back in the feed direction, and applied to the gil device arranged at the intermediate portion between the front roller and the back roller while being drafted. And a fourth step of forming a fleece-shaped second web by winding the fibers in the feeding direction, so that a strip member composed of carbon fibers and synthetic fibers laminated in a plurality of layers is drafted in the feeding direction to each other. The gill device can beat both fibers in close proximity. Further, the gil device can align the carbon fibers oriented in a random direction in the feeding direction in a state where the synthetic fibers and the carbon fibers are supported from below by the lower teeth. When the carbon fibers are aligned in the feeding direction, they are supported from below by the synthetic fibers laminated in a plurality of layers, so that they do not fall apart even if the fiber length is short. Therefore, the carbon fiber to be reused can be effectively utilized.

Here, the synthetic fiber is a crimpable cotton-like fiber that is formed in a short fiber shape and arranged in substantially the same direction, and is arranged with the crimping direction and the feeding direction of the synthetic fiber substantially matched in advance. Therefore, when the needle of the gil device turns the fiber in the feeding direction, the synthetic fiber is easily entangled with the carbon fibers adjacent to each other. In addition, since the synthetic fibers are entangled with the carbon fibers when the carbon fibers are aligned in the feeding direction, the carbon fibers are prevented from being bent excessively, and the carbon fibers are not easily broken. In addition, the carbon fibers are entangled with the synthetic fibers to be held in an aligned state in the feeding direction.
As a result, the carbon fibers aligned in the feeding direction without breaking and the synthetic fibers intertwined around them are mixed to form a fleece second web.

In addition, since the second web fed out from the front roller includes a fifth step formed in a continuous carbon fiber sliver converged at one place, the carbon fibers aligned in the feeding direction without breaking and the rotation A continuous carbon fiber sliver having a predetermined thickness can be formed from the second web formed by mixing the synthetic fibers entangled with each other.
Therefore, according to the present invention, it is possible to provide a method for manufacturing a carbon fiber sliver that easily manufactures a carbon fiber sliver in which synthetic fibers are entangled with and mixed with carbon fibers while preventing breakage of the carbon fibers. .

  According to the present invention, there is provided a carbon fiber sliver manufacturing method and a manufacturing apparatus thereof for easily manufacturing a carbon fiber sliver in which synthetic fibers are entangled with and mixed with carbon fibers while preventing breakage of the carbon fibers. Can do.

It is typical sectional drawing showing the manufacturing apparatus used for the manufacturing method of the carbon fiber sliver which concerns on this embodiment. It is a typical perspective view in the manufacturing apparatus shown in FIG. In the manufacturing method of the carbon fiber sliver which concerns on this embodiment, it is explanatory drawing explaining the mechanism which makes a carbon fiber entangle a synthetic fiber. It is an external appearance photograph of the carbon fiber used for this embodiment. It is an external appearance photograph of the synthetic fiber used for this embodiment. It is an external appearance photograph of the fleece-like web formed at the 2nd process of this embodiment. It is an external appearance photograph of the carbon fiber sliver formed at the 3rd process of this embodiment. It is typical sectional drawing in the modification which adds an opening machine to this embodiment. It is a schematic side view of the apparatus used for the manufacturing method of the pitch-type carbon fiber spun yarn shown in patent document 1.

  Next, a carbon fiber sliver manufacturing method according to an embodiment of the present invention will be described in detail with reference to the drawings. Here, after first explaining a carbon fiber sliver manufacturing apparatus and manufacturing process, a mechanism for entanglement of synthetic fibers with carbon fibers in the carbon fiber mat manufacturing method according to the present embodiment will be described. Finally, a modified example in which the opening machine is added to the present embodiment will be described.

<Carbon fiber sliver manufacturing apparatus and manufacturing process>
First, a carbon fiber sliver manufacturing apparatus and manufacturing process will be described with reference to FIGS. 1 and 2. In addition, about a manufacturing process, there exist 1st Embodiment and 2nd Embodiment. In FIG. 1, the typical sectional drawing showing the manufacturing apparatus used for the manufacturing method of the carbon fiber sliver which concerns on this embodiment is shown. FIG. 2 shows a schematic perspective view of the manufacturing apparatus shown in FIG.

(manufacturing device)
As shown in FIGS. 1 and 2, the carbon fiber sliver manufacturing apparatus 100 includes a storage container 21, a conveyor 22, back rollers 31 and 32, front rollers 33 and 34, and gil devices 41 and 42. A calendar roller 51 is provided.
The storage container 21 is a container that stores the sliver of the synthetic fiber 12 in a continuous state. By providing the plurality of storage containers 21, a plurality of slivers of the synthetic fiber 12 can be simultaneously supplied to the conveyor 22. The carbon fiber 11 is a cotton-like fiber that is cut into a short fiber shape and opened in a random direction, and is thus stored in another storage container (not shown).
The conveyor 22 is a belt-type conveyor having a predetermined belt width and belt length. The belt of the conveyer 22 is arranged substantially horizontally, and the carbon fiber 11 and the synthetic fiber 12 are placed thereon and moved in the feeding direction (the direction of the arrow f1). Back rollers 31 and 32 are disposed adjacent to the front end side of the conveyor 22.

The back rollers 31 and 32 are made up of a pair of cylindrical roller bodies arranged facing each other in the vertical direction, and feed the carbon fibers 11 and the synthetic fibers 12 supplied from the conveyor 22 while being pressed in the vertical direction. It is a device that moves in the direction. An uneven groove is formed in the axial direction on the outer peripheral surface of each cylindrical roller body. The rotational speed u1 of the back rollers 31 and 32 can be synchronized with the feed speed of the conveyor 22. Front rollers 33 and 34 are disposed in front of the back rollers 31 and 32 in the feeding direction.
The front rollers 33 and 34 are composed of a pair of cylindrical roller bodies disposed facing each other in the vertical direction, and hold the carbon fiber 11 and the synthetic fiber 12 fed from the back rollers 31 and 32 in the vertical direction. It is a device that moves in the feed direction. An uneven groove is formed in the axial direction on the outer peripheral surface of each cylindrical roller body. The rotational speed u2 of the front rollers 33 and 34 is set larger than the rotational speed u1 of the back rollers 31 and 32. The front rollers 33 and 34 are formed such that the outer diameter of the upper roller body is larger than the outer diameter of the lower roller body. A fiber entrainment prevention belt 35 is wound around the lower roller body. Gill devices 41 and 42 are disposed at intermediate portions between the front rollers 33 and 34 and the back rollers 31 and 32.

The gil devices 41 and 42 are configured such that a plurality of upper teeth and lower teeth in which a plurality of needles are arranged in a comb-like shape are arranged orthogonal to the feed direction, and the needles move in the feed direction while the carbon fibers 11 and A scissor device that scoops the synthetic fiber 12. A plurality of upper teeth and lower teeth are alternately arranged in the feed direction, and each moves in the direction of the arrow p and circulates. In front of the gil devices 41 and 42, guide rods 61 and 62 for guiding the carbon fiber 11 and the synthetic fiber 12 into the gil devices 41 and 42 are provided upright.
Calendar roller 51 is arranged in the feed direction in front of the front rollers 33 and 34, a guide hole fleece-like web 13 fed from the front roller 33 Ru passed by focusing the bundle in one place is formed It is an apparatus that includes an introduction part and forms a continuous carbon fiber sliver 14 with a predetermined thickness. The fleece-shaped web 13 passes through the calendar roller 51 while the upper synthetic fiber 12 wraps the upper carbon fiber 11 from both sides through the guide hole . Therefore, there is little possibility that the carbon fiber 11 will fall or detach from the carbon fiber sliver 14.

(Manufacturing process of the first embodiment)
The manufacturing method of the carbon fiber sliver according to the first embodiment includes first to third steps.
In the first step, a conveyor 22 is disposed. In the first step, the synthetic fiber 12 is laminated on the belt of the conveyor 22 with a predetermined width and a predetermined thickness so that the crimping direction of the fibers and the feeding direction of the conveyor are substantially matched. When the belt of the conveyor 22 moves in the feeding direction (the direction of the arrow f1), the synthetic fiber 12 is automatically pulled out from the storage container 21. The synthetic fibers 12 are stacked on a belt having a plurality of slivers adjacent to each other in the width direction and having a width substantially the same as the belt width. Here, the synthetic fiber 12 is a sliver of crimpable cotton fibers in which each fiber has a substantially wavy crimped shape, is formed in a short fiber shape, and is arranged in substantially the same direction. . The synthetic fiber 12 corresponds to, for example, polyester, polyamide, polypropylene, polyethylene, and the like, and may be a mixed fiber thereof. The free length of each synthetic fiber is preferably about 5 to 10 cm.

  Further, in the first step, the carbon fibers 11 are dispersed substantially uniformly above the synthetic fibers 12 and are layered. The weight per unit area of the carbon fiber 11 is approximately the same as the weight per unit area of the synthetic fiber 12, but the weight per unit area of the carbon fiber 11 is smaller than the weight per unit area of the synthetic fiber 12. (For example, about 40 to 60%) may be used. By making the carbon fiber 11 into a small amount, it is possible to reduce breakage in a gil device which will be described later. The method of superimposing the carbon fibers 11 may be manual or automatic using a dedicated machine. Here, the carbon fiber 11 is a cotton-like fiber that is cut into short fibers from a filament-like carbon fiber material and opened in random directions. The carbon fibers 11 correspond to, for example, bread-based carbon fibers and pitch-based carbon fibers, but may be recycled materials thereof. The free length of each carbon fiber is preferably about 15 to 25 cm.

  Next, in the second step, the back rollers 31, 32, the gil devices 41, 42, and the front rollers 33, 34 are arranged in order with respect to the feeding direction. In the second step, the carbon fiber 11 and the synthetic fiber 12 superposed in the first step are made by the front rollers 33 and 34 disposed in the front in the feed direction and the back rollers 31 and 32 disposed in the rear in the feed direction. Clamp and crush from the top and bottom. The carbon fiber 11 and the synthetic fiber 12 crushed in the vertical direction are flattened and close to each other. Since the rotational speed u2 of the front rollers 33 and 34 is faster than the rotational speed u1 of the back rollers 31 and 32, the carbon fiber 11 and the synthetic fiber 12 that have been crushed and flattened are stretched in the feed direction (draft). The gill devices 41 and 42 are rolled in a state where they are hung and brought closer to each other. The gil devices 41 and 42 form the fleece web 13 from the carbon fibers 11 and the synthetic fibers 12 by turning in the feeding direction.

Here, when the needles of the gil devices 41 and 42 roll the fibers in the feeding direction, the carbon fibers 11 opened in a random direction are supported by the synthetic fibers 12 laminated below, and the feeding direction. Aligned. On the other hand, the synthetic fiber 12 is a crimpable cotton-like fiber that is formed into a short fiber shape and arranged in substantially the same direction, and is arranged with the crimping direction and the feeding direction of the synthetic fiber 12 approximately matched in advance. As a result, the carbon fibers 11 aligned in the feed direction from a random direction can approach and be entangled easily.
The carbon fibers 11 are entangled with the synthetic fibers 12 to be held in an aligned state in the feeding direction. In addition, since the synthetic fibers 12 are entangled with the carbon fibers 11 when the carbon fibers 11 are aligned in the feeding direction, extreme bending of the carbon fibers 11 is prevented and the carbon fibers 11 are not easily broken.
As a result, the carbon fibers 11 aligned in the feeding direction without breaking and the synthetic fibers 12 intertwined around the carbon fibers 11 are mixed to form a fleece web 13.

Next, in the third step, a calender roller 51 having an introduction portion in which a guide hole is formed is disposed. In the third step, the fleece web 13 fed from the front rollers 33 and 34 passes through the calender roller 51 while winding the upper carbon fiber 11 with the lower synthetic fiber 12 through the guide hole . A fleece-shaped web 13 is converged at one place and formed into a bundle-like continuous carbon fiber sliver 14. As a result, the carbon fibers 11 aligned in the feeding direction without breaking and the synthetic fibers 12 entangled therearound can be mixed to form a carbon fiber sliver 14 having a predetermined thickness. .
In the carbon fiber sliver 14 formed by the manufacturing method of the present embodiment, the carbon fibers 11 and the synthetic fibers 12 are aligned in substantially the same direction, and the synthetic fibers 12 are entangled with the carbon fibers 11. Further, it can be processed into a spun yarn of an arbitrary thickness by applying a draft.

(Manufacturing process of the second embodiment)
The carbon fiber sliver manufacturing method according to the second embodiment is also provided from the first step to the third step. Since the second step and the third step are the same as those in the first embodiment, the description thereof is omitted.
In the first step, the transfer conveyor 22 is disposed as in the first embodiment. In the first step, the carbon fiber sliver 14 formed in the first embodiment is substantially matched with the crimp direction of the synthetic fiber and the feeding direction of the conveyor, and on the belt of the conveyor 22 with a predetermined width, Laminate to a predetermined thickness. When the belt of the conveyor 22 moves in the feeding direction (the direction of the arrow f1), the carbon fiber sliver 14 is automatically pulled out from the storage container 21. The carbon fiber sliver 14 is formed by laminating a plurality of slivers adjacent to each other on the belt and having a width substantially the same as the belt width.

  Further, in the first step, the carbon fibers 11 are substantially uniformly dispersed and superposed on the carbon fiber sliver 14. The weight per unit area of the carbon fiber 11 is approximately the same as the weight per unit area of the carbon fiber sliver 14, but the weight per unit area of the carbon fiber 11 is the weight per unit area of the carbon fiber sliver 14. A smaller amount (for example, about 40 to 60%) may be used. By making the carbon fiber 11 into a small amount, it is possible to reduce breakage in a gil device which will be described later. The method of superimposing the carbon fibers 11 may be manual or automatic using a dedicated machine. Here, the carbon fiber 11 is a cotton-like fiber that is cut into short fibers from a filament-like carbon fiber material and opened in random directions. The carbon fibers 11 correspond to, for example, bread-based carbon fibers and pitch-based carbon fibers, but may be recycled materials thereof. The free length of each carbon fiber is preferably about 15 to 25 cm.

  In the first step of the second embodiment, the carbon fiber mixing ratio of the carbon fiber sliver 14 formed in the third step is freely set by superimposing new carbon fibers 11 on the carbon fiber sliver 14. be able to. For example, the carbon fiber sliver 14 in which the mixing ratio of the carbon fibers 11 is 50% is formed by the manufacturing method of the first embodiment, and the carbon fiber in which the mixing ratio of the carbon fibers 11 is 75% in the manufacturing method of the second embodiment. A sliver 14 can also be formed. Further, by gradually increasing the carbon fibers 11, the synthetic fibers 12 can be smoothly entangled with the carbon fibers 11, and the carbon fibers 11 can be uniformly mixed while further preventing breakage. it can. Furthermore, it is also possible to form a carbon fiber sliver 14 with a high mixing ratio of the carbon fibers 11 and freely reduce the diameter of the spun yarn while adding the synthetic fiber 12 in the spinning process.

<Mechanism to entangle carbon fiber with synthetic fiber>
Next, in the method for manufacturing a carbon fiber sliver according to the present embodiment, a mechanism for confounding the synthetic fiber with the carbon fiber will be described with reference to FIGS. FIG. 3 is an explanatory view for explaining a mechanism for confounding a synthetic fiber with a carbon fiber in the method for producing a carbon fiber sliver according to the present embodiment. In FIG. 4, the external appearance photograph of the carbon fiber used for this embodiment is shown. In FIG. 5, the external appearance photograph of the synthetic fiber used for this embodiment is shown. In FIG. 6, the external appearance photograph of the fleece-shaped web formed at the 2nd process of this embodiment is shown. In FIG. 7, the external appearance photograph of the carbon fiber sliver formed at the 3rd process of this embodiment is shown.

FIG. 3A is a schematic cross-sectional view showing a state in which the carbon fibers 11 are layered above the synthetic fibers 12 laminated to a predetermined thickness. Here, as shown in FIG. 4, the carbon fiber 11 is a cotton-like fiber that is cut into a short fiber shape from a filament-like carbon fiber material and opened in a random direction, and expands with an interval between the fibers. It is in a lump state. Further, as shown in FIG. 5, the synthetic fiber 12 is a crimpable cotton-like fiber that is formed into a short fiber shape and arranged in substantially the same direction, and is in a lump state in which the fiber interval is expanded and expanded. ing.
Therefore, as shown in FIG. 3 (a), even if the carbon fiber 11 and the synthetic fiber 12 are laminated in layers, the carbon fiber 11 and the synthetic fiber 12 are separated from each other with an interval between the fibers. Even if it is beaten by the gil devices 41 and 42, the possibility that the synthetic fiber 12 is entangled with the carbon fiber 11 is low.

In FIG. 3B, the front rollers 33 and 34 and the back rollers 31 and 32 push the carbon fiber 11 and the synthetic fiber 12 flatly by sandwiching the carbon fiber 11 and the synthetic fiber 12 in the up and down direction (direction of the arrow t). It is typical sectional drawing which shows the state which crushed and also applied the draft to the feed direction (direction of arrow d).
As shown in FIG.3 (b), when the carbon fiber 11 and the synthetic fiber 12 are crushed flatly, a fiber space | interval becomes narrow and it adjoins mutually and becomes easy to entangle. Since the synthetic fiber 12 substantially matches the crimping direction and the feeding direction, when a draft is applied in the feeding direction (the direction of the arrow d), the synthetic fibers are closely entangled and connected between the fibers in the feeding direction. Stretch while increasing in strength. Therefore, the synthetic fiber stretched by increasing the connection strength between the fibers in the feeding direction can be transported while supporting the carbon fiber superimposed on the upper side from below.

FIG. 3 (c) shows the needles of the gill devices 41 and 42 from above and below the carbon fibers 11 and the synthetic fibers 12 that have been crushed flatly and narrowed in proximity to each other and easily entangled. It is typical sectional drawing which shows the state which pierces and turns into the feed direction (direction of arrow p).
As shown in FIG. 3 (c), when the carbon fibers 11 are aligned from the random direction to the feeding direction by the needles of the gil devices 41 and 42, the synthetic fibers 12 are supported from below and easily entangled closely. However, it can penetrate into the gaps between the carbon fibers 11 and become entangled. Since the synthetic fiber 12 has increased connection strength between the fibers in the feeding direction, the synthetic fiber 12 can maintain the connected state and support the carbon fiber 11 from below when it is beaten by the needles of the gil devices 41 and 42. it can. Therefore, the carbon fibers 11 are less likely to fall downward when aligned.

Further, when the needles of the gil devices 41 and 42 beat the fiber, the synthetic fiber 12 having a short free length and easily moving freely tends to enter the gap between the carbon fibers 11 having a long free length. Therefore, the synthetic fibers 12 that have entered the gaps between the carbon fibers 11 can be entangled more strongly with the carbon fibers 11. The carbon fibers 11 are entangled with the synthetic fibers 12 to be held in an aligned state in the feeding direction. In addition, since the synthetic fibers 12 are entangled with the carbon fibers 11 when the carbon fibers 11 are aligned in the feeding direction, extreme bending of the carbon fibers 11 is prevented and the carbon fibers 11 are not easily broken.
As a result, the carbon fibers 11 aligned in the feeding direction without breakage and the synthetic fibers 12 entangled around the carbon fibers 11 are mixed to form a fleece-shaped web 13 (see FIG. 6). Further, the fleece-shaped web 13 passes through a calender roller 51 (see FIGS. 1 and 2) having an introduction portion in which guide holes are formed, so that the carbon fiber 11 is wrapped and converged at one place. A continuous carbon fiber sliver 14 (see FIG. 7) is formed.

<Effect>
As described above in detail, according to the manufacturing method of the first embodiment, the crimping direction and the feeding direction of the synthetic fiber 12 are substantially matched in the first step. When a draft is applied in the direction, the fibers are closely entangled and stretched while increasing the connection strength between the fibers. Further, since the carbon fiber 11 is superposed on the synthetic fiber 12 laminated to a predetermined thickness, when the draft is applied in the feeding direction, the connecting strength between the fibers is increased and the drawn synthetic fiber 12 is It is possible to transfer the carbon fiber 11 to be superimposed on the carbon fiber 11 while supporting it from below.
Further, in the second step, the carbon fiber 11 and the synthetic fiber 12 that are overlapped in the first step, the front rollers 33 and 34 disposed in the front in the feed direction and the back rollers 31 and 32 disposed in the rear in the feed direction. Between the front rollers 33 and 34 and the back rollers 31 and 32, and the gil devices 41 and 42 disposed in the middle of the front rollers 33 and 32 feed in the feeding direction. The gil devices 41 and 42 can pick up the fibers in a state where they are drafted in the direction and close to each other. When the carbon fibers 11 are aligned in the feeding direction, the carbon fibers 11 are supported from below by the synthetic fibers 12 and therefore do not fall apart.

Here, the synthetic fiber 12 is a crimpable cotton-like fiber that is formed into a short fiber shape and arranged in substantially the same direction, and the crimping direction and the feeding direction of the synthetic fiber 12 are substantially matched in advance. Therefore, when the needles of the gil devices 41 and 42 roll the fibers in the feeding direction, the synthetic fibers 12 are easily entangled with the carbon fibers 11 aligned in the feeding direction from a random direction. The carbon fibers 11 are entangled with the synthetic fibers 12 to be held in an aligned state in the feeding direction. In addition, since the synthetic fibers 12 are entangled with the carbon fibers 11 when the carbon fibers 11 are aligned in the feeding direction, extreme bending of the carbon fibers 11 is prevented and the carbon fibers 11 are not easily broken.
As a result, the carbon fibers 11 aligned in the feeding direction without breaking and the synthetic fibers 12 intertwined around the carbon fibers 11 are mixed to form a fleece web 13.

Further, in the third step, the fleece-shaped web 13 fed from the front rollers 33 and 34 is formed on the continuous carbon fiber sliver 14 while being wrapped in one place while wrapping the carbon fiber, so that it does not break. A carbon fiber sliver 14 having a predetermined thickness can be formed by mixing carbon fibers 11 aligned in the feeding direction with synthetic fibers 12 entangled around them. The carbon fiber sliver 14 is formed by concentrating the fleece-shaped web 13 in one place while wrapping the carbon fiber 11, so that the synthetic fiber 12 laminated below wraps the upper carbon fiber 11 from both sides. be able to. Therefore, there is a risk that the carbon fiber 11 that has not been entangled with the synthetic fiber 12 in the second step is wrapped from the outer periphery side in the third step, so that the carbon fiber 11 falls from the carbon fiber sliver 14 or is detached. Can be reduced.
Therefore, according to the present embodiment, in order to obtain a spun yarn of carbon fiber 11 having excellent strength, a carbon fiber sliver that easily manufactures carbon fiber sliver 14 in which synthetic fiber 12 is entangled with and mixed with carbon fiber 11. The manufacturing method of can be provided.

  According to the manufacturing method of the first embodiment, the weight per unit area of the carbon fibers 11 to be overlapped in the first step is substantially the same as the weight per unit area of the synthetic fiber 12 laminated to a predetermined thickness. Therefore, when the carbon fibers 11 and the synthetic fibers 12 are sandwiched between the front rollers 33 and 34 and the back rollers 31 and 32, the carbon fibers 11 and the synthetic fibers 12 can be crushed at a substantially equal ratio and drafted. . Therefore, when the needles of the gil devices 41 and 42 beat the fibers, the carbon fibers 11 and the synthetic fibers 12 can be wound smoothly while being dispersed substantially evenly. As a result, the carbon fiber sliver 14 in which the carbon fibers 11 and the synthetic fibers 12 are more evenly dispersed can be formed.

  According to the manufacturing method of the first embodiment, since the free length of the synthetic fiber 12 is shorter than the free length of the carbon fiber 11, the carbon fiber 11 and the synthetic fiber 12 are formed by the front rollers 33 and 34 and the back rollers 31 and 32. When the needles of the gill devices 41 and 42 beat the fibers while the draft is applied, the synthetic fibers 12 that are short and easy to move easily enter the gaps between the carbon fibers 11. Therefore, the synthetic fibers 12 that have entered the gaps between the carbon fibers 11 can be entangled more strongly with the carbon fibers 11. As a result, the carbon fiber sliver 14 with higher strength can be formed.

  Moreover, according to the manufacturing method of 2nd Embodiment, since the synthetic fiber 12 laminated | stacked by predetermined thickness at the 1st process is the carbon fiber sliver 14 formed at the 3rd process, in the 1st process The carbon fibers 11 aligned in the feeding direction and the synthetic fibers 12 entangled around the carbon fibers 11 are mixed, and a carbon fiber sliver 14 having a predetermined thickness is laminated to a predetermined thickness, Carbon fiber is laminated. Therefore, the carbon fiber sliver 14 in which the mixing ratio of the carbon fibers 11 is further increased can be formed through the second step and the third step. Also in this case, the synthetic fiber 12 is entangled around the new carbon fiber 11, and the breakage of the carbon fiber 11 can be prevented while keeping the carbon fiber 11 aligned in the feeding direction. Therefore, the carbon fiber sliver 14 with higher strength can be formed.

Moreover, according to the manufacturing apparatus used for the manufacturing method of the carbon fiber sliver which concerns on embodiment mentioned above, the conveyance conveyor 22 which mounts and conveys carbon fiber and a synthetic fiber, and the back | bag arrange | positioned at the front-end side of a conveyance conveyor Rollers 31, 32, front rollers 33, 34 disposed in front of the back roller in the feed direction, gil devices 41, 42 disposed in the intermediate portion between the back roller and the front roller, and in front of the front roller in the feed direction. Since the rotational speed u2 of the front rollers 33 and 34 is faster than the rotational speed u1 of the back rollers 31 and 32, the carbon fibers 11 and the synthetic fibers 12 that are crushed and flattened are provided. Is stretched in the feed direction (draft) and brought closer to the gil devices 41 and 42, so that the carbon fiber 1 It can be the easily entangled synthetic fibers 12. Further, since the outer diameter of the upper roller body 33 in the front rollers 33, 34 is larger than the outer diameter of the lower roller body 34 in the front rollers 33, 34, extreme bending of the carbon fiber 11 is prevented, and carbon The fiber 11 becomes difficult to break.
As a result, the carbon fibers 11 aligned in the feeding direction without breaking and the synthetic fibers 12 entangled around the carbon fibers 11 are mixed to form a fleece-shaped web 13, and the carbon fibers 11 having excellent strength. In order to obtain a spun yarn, the carbon fiber 11 can be prevented from being broken, and the carbon fiber sliver 14 in which the synthetic fiber 12 is entangled with and mixed with the carbon fiber 11 can be easily manufactured.

<Modification>
Next, a modified example in which the opening machine is added to the present embodiment will be described with reference to FIG. As shown in FIGS. 8A to 8C, the first web 15 is formed by laminating the carbon fibers 11 and the synthetic fibers 12 in a plurality of layers using the unfolding machine 7, and the first web 15 is fed in the feeding direction. After cutting to form a plurality of strip members 16, they can be put into the back rollers 31, 32 shown in FIGS. Here, in front of the conveying conveyor 23 in the feeding direction, the opening machine 7 and feed rollers 73 and 74 arranged in front and rear thereof are provided. The conveyor 23 is the same device as the conveyor 22 in FIG. The unfolding machine 7 includes a cylindrical cylinder 71 having a predetermined outer diameter and length, and a plurality of needles 72 implanted on the outer peripheral surface of the cylinder 71, and rotates in the direction of the arrow. Can do. The feed rollers 73 and 74 can rotate while pushing the carbon fiber 11 and the synthetic fiber 12 into the outer peripheral side of the cylinder 71 of the opening machine 7.

In this modification, the carbon fiber sliver manufacturing method includes the following steps.
That is, the crimping direction and the feeding direction of the synthetic fiber 12 are substantially matched, and the carbon fiber 11 is layered on the synthetic fiber 12 laminated to a predetermined thickness, and the carbon fiber 11 is overlapped in the first step. The second step of winding the combined carbon fiber 11 and synthetic fiber 12 as the first web 15 a plurality of times around the outer periphery of the cylinder 71 of the unfolding machine 7 arranged forward in the feed direction and the second step One web 15 is removed from the cylinder 71 of the opening machine 7 and cut into strip members 16 in the feed direction, and the strip members 16 cut in the third step are fed to the front rollers 33 and 34 and rearward in the feed direction. Fibers are fed in the feed direction by the gil devices 41 and 42 disposed between the front rollers 33 and 34 and the back rollers 31 and 32 while being drafted. The fourth step of forming the fleece-shaped second web 13 and the fifth step of forming the second web 13 fed from the front rollers 33 and 34 into a continuous carbon fiber sliver 14 converged at one place. It is characterized by providing. The carbon fibers 11 are cotton-like fibers cut into short fibers and opened in random directions, and the synthetic fibers 12 are crimpable that are formed into short fibers and arranged in substantially the same direction. It is the same as that of embodiment mentioned above that it is a fluffy fiber.

  In the present modification, the crimping direction and the feeding direction of the synthetic fiber 12 are substantially matched in the first step. Therefore, when the synthetic fiber 12 is drafted in the feeding direction, the fibers are close to each other and entangled. And the connection strength between the fibers is increased while stretching. In addition, since the carbon fibers 11 are layered on the synthetic fiber 12 laminated to a predetermined thickness, the synthetic fiber 12 stretched by increasing the connection strength between the fibers when drafted in the feed direction is It is possible to transport the carbon fiber 11 that is superimposed on the upper side while supporting it from below.

Moreover, since the carbon fiber 11 and the synthetic fiber 12 which were piled up by the 1st process are provided in the 2nd process which winds up as a 1st web 15 several times around the cylinder 71 outer periphery of the opening machine 7 arrange | positioned ahead of a feed direction. The 1st web 15 which consists of a mixed basket which laminated | stacked the carbon fiber 11 and the synthetic fiber 12 in multiple layers can be formed.
Moreover, since the 1st web 15 wound up by the 2nd process is removed from the cylinder 71 of the unfolding machine 7, and the 3rd process cut | disconnected to the strip member 16 by a feed direction is provided, a 1st web is required by a feed direction Can be aligned to various width sizes.

  Further, the strip member 16 cut in the third step is sandwiched between the front rollers 33 and 34 and the back rollers 31 and 32 disposed rearward in the feed direction, and the front rollers 33 and 34 and the back rollers 31 and 32 are applied while drafting. And the fourth step of forming the fleece-shaped second web 13 by winding the fibers in the feed direction by the gil devices 41 and 42 arranged in the middle of the carbon fiber 11 and the carbon fiber 11 laminated in a plurality of layers. The gil devices 41 and 42 can squeeze both fibers in a state where the strip members 16 made of the fibers 12 are drafted in the feeding direction and brought close to each other. Further, the gil devices 41 and 42 can align the carbon fibers 11 oriented in a random direction in the feeding direction in a state where the synthetic fibers 12 and the carbon fibers 11 are supported from below by the lower teeth 42. Since the carbon fibers 11 are supported from below by the synthetic fibers 12 laminated in a plurality of layers when aligned in the feed direction, even if the fiber length of the carbon fibers 11 is shorter than in the case of the present embodiment, the carbon fibers 11 are separated. It will not fall. Therefore, the carbon fiber 11 to be reused can be used more effectively.

Here, the synthetic fiber 12 is a crimpable cotton-like fiber that is formed into a short fiber shape and arranged in substantially the same direction, and the crimping direction and the feeding direction of the synthetic fiber 12 are substantially matched in advance. Therefore, the synthetic fibers 12 are easily entangled with the carbon fibers 11 that are close to each other when the needles of the gil devices 41 and 42 roll the fibers in the feeding direction. Further, since the synthetic fiber 12 is entangled with the carbon fiber 11 when the carbon fiber 11 is aligned in the feeding direction, the carbon fiber 11 is prevented from being bent extremely, and the carbon fiber 11 is not easily broken. Further, the carbon fibers 11 are entangled with the synthetic fibers 12 to be held in a state aligned in the feeding direction.
As a result, the carbon fibers 11 aligned in the feeding direction without breaking and the synthetic fibers 12 intertwined around the carbon fibers 11 are mixed to form a fleece second web 13.

  Further, since the second web 13 fed out from the front rollers 33 and 34 is provided with a fifth step formed in the continuous carbon fiber sliver 14 converged at one place, the carbon aligned in the feeding direction without breaking. A continuous carbon fiber sliver 14 having a predetermined thickness can be formed from the second web 13 formed by kneading the fibers 11 and the synthetic fibers 12 entangled around them.

  The present invention can be used as a method for producing a carbon fiber sliver formed by mixing synthetic fibers and carbon fibers, for example, for use in composite materials such as fiber reinforced plastics.

DESCRIPTION OF SYMBOLS 11 Carbon fiber 12 Synthetic fiber 13 Web, 2nd web 14 Carbon fiber sliver 15 1st web 16 Strip member 21 Storage container 22 Conveyor 23 Transport conveyor 31, 32 Back roller 33, 34 Front roller, Roller body 41, 42 Gil apparatus 42 Lower teeth 51 Calendar roller 7 Opening machine 71 Cylinder 72 Needle 73, 74 Feed roller 100 Carbon fiber sliver manufacturing equipment

Claims (6)

A method for producing a carbon fiber sliver formed by mixing carbon fiber and synthetic fiber,
The carbon fibers are cotton fibers cut into short fibers and opened in random directions, and the synthetic fibers are crimpable cotton formed in short fibers and arranged in substantially the same direction. Fiber-like,
The synthetic fibers are substantially aligned with the crimping direction and the feeding direction, and the carbon fibers are distributed substantially evenly above the synthetic fibers laminated to a predetermined thickness to form a layer with the same width as the synthetic fibers. A first step of superimposing on,
The carbon fiber and the synthetic fiber superposed in the first step are sandwiched between a front roller disposed in the front in the feeding direction and a back roller disposed in the rear in the feeding direction, and the front roller is applied while drafting the fibers. And a second step of forming a fleece-shaped web by twisting fibers in the feeding direction in a gil device disposed in an intermediate part between the back roller and the back roller;
The fleece-shaped web fed from the front roller is provided with a calender roller having a guide hole formed in the introduction portion to converge and pass in a bundle at one place, and the fleece-shaped web passes through the calender roller. And a third step of forming a continuous carbon fiber sliver by concentrating the upper carbon fiber from both sides through the guide hole while being wrapped from both sides by a synthetic fiber and forming a continuous carbon fiber sliver. Sliver manufacturing method. In the manufacturing method of the carbon fiber sliver described in Claim 1,
The synthetic fiber laminated in a predetermined thickness in the first step is a carbon fiber sliver formed in the third step. In the manufacturing method of the carbon fiber sliver according to claim 1 or claim 2,
The carbon fiber sliver manufacturing method, wherein a weight per unit area of the carbon fibers to be overlapped in the first step is substantially the same as a weight per unit area of the synthetic fibers laminated to a predetermined thickness. Method. In the manufacturing method of the carbon fiber sliver according to any one of claims 1 to 3,
The method for producing a carbon fiber sliver, wherein a free length of the synthetic fiber is shorter than a free length of the carbon fiber. It is a manufacturing apparatus used for the manufacturing method of the carbon fiber sliver described in any one of Claims 1 thru / or 4,
A transport conveyor for placing and transporting the carbon fiber and the synthetic fiber, a back roller disposed on a front end side of the transport conveyor, a front roller disposed in a forward direction of the back roller, and the back A gil device disposed in an intermediate portion between the roller and the front roller, and a calender roller disposed in front of the front roller in the feed direction,
A carbon fiber sliver manufacturing method, characterized in that the rotational speed of the front roller is faster than the rotational speed of the back roller, and the outer diameter of the upper roller in the front roller is larger than the outer diameter of the lower roller in the front roller. apparatus. In the method for producing a carbon fiber sliver formed by mixing carbon fiber and synthetic fiber,
The carbon fibers are cotton fibers cut into short fibers and opened in random directions, and the synthetic fibers are crimpable cotton formed in short fibers and arranged in substantially the same direction. Fiber-like,
A first step in which the crimping direction of the synthetic fiber and the feeding direction are substantially matched, and the carbon fiber is layered on the synthetic fiber laminated to a predetermined thickness;
A second step of winding the carbon fiber and the synthetic fiber overlapped in the first step as a first web around the cylinder outer periphery of the unfolding machine arranged in the feed direction;
A third step of removing the first web wound in the second step from the cylinder of the unfolding machine and cutting it into strip members in the feed direction;
The strip member cut in the third step is sandwiched between a front roller and a back roller disposed rearward in the feed direction, and a gil device disposed at an intermediate portion between the front roller and the back roller while being drafted. A fourth step of forming a fleece-shaped second web by winding fibers in the feeding direction;
A method for producing a carbon fiber sliver comprising: a fifth step in which the second web fed from the front roller is formed on a continuous carbon fiber sliver converged at one place.