KR101931030B1 - Through-the-thickness carbon fiber composites and method of preparing the same - Google Patents

Abstract

A carbon fiber composite material with a reinforced fiber in a Z-axis direction by using a carbon fiber composite and a manufacturing method thereof are disclosed. The carbon fiber composite material includes a unit layer formed of carbon fibers, and an interlayer bonding member binding the unit layer and having a stapler shape including carbon fibers, and is manufactured by binding at least one layer with the interlayer binding member while stacking the unit layers.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon fiber composite material having fibers reinforced in a thickness direction thereof and a method of manufacturing the same. BACKGROUND ART < RTI ID = 0.0 >

The following examples relate to a carbon fiber composite material for manufacturing a high strength preform and a method of manufacturing the same.

Fiber reinforced composite materials using carbon fiber as a reinforcing material are applied to aircrafts, space structures, and high-end sporting goods, and recently their use has been expanded to automobile parts that require mass production.

A characteristic of such a fiber-reinforced composite material is that it is generally high in non-rigidity and non-rigidity. However, these performances are limited to the direction of fiber reinforcement. In the composite material in which the fibers are arranged in one direction or two-dimensionally, since the fibers are not arranged in the thickness direction, they are not reinforced with respect to interlaminar shear strength, and their strength is remarkably lower than that in the fiber direction. 2.5-dimensional and 3-dimensional fabrics have been proposed as strength substrates to overcome these disadvantages.

The three-dimensional fabric is mainly woven with 3D weaving or 3D braiding techniques, wherein the 3D weaving has a structure in which the arrangement direction of the fibers is arranged not only in a plane but also in a thickness direction, Are twisted and integrated in a three-dimensional space. Since the two-dimensional fabric has a sheet form, while the two-dimensional fabric has fibers in the thickness direction, the 3D weaving technique has a block shape, and the 3D braiding technique can produce a cylinder-shaped three-dimensional shape. Therefore, the three-dimensional fabric has a near-net-shape that is close to the shape of the final product. Therefore, in the case of a composite material having a relatively complicated shape, a three-dimensional weaving technique is used to simplify the manufacturing process, There is also an effect of reducing the production cost.

However, the three-dimensional weaving technique is limited in that the thickness that can be manufactured is limited to 25 mm or less in the present technology, the weaving time is long, the orientation of the fibers arranged in the plane is limited mainly to 0 ° and 90 °, There is a disadvantage that the cost for the equipment is rapidly increased.

Therefore, 2.5D weaving technology is attracting attention as an alternative technique which is beyond the limit of the three-dimensional weaving technology and can be realized commercially. Among the 2.5D weaving techniques, stitching and needle punching are typical techniques for manufacturing thick preforms.

Stitching is a technology that binds a whole by laminating a plurality of two-dimensional fabrics and penetrating the needle in the thickness direction, thereby making a very economical three-dimensional structure. However, with stitching, it is difficult to stitch a thickness of 25 mm or more, and the fibers of the laminated fabric may be damaged as the needles penetrate. Further, the material to be stitched is limited to aramid fibers or glass fibers having good toughness.

Needle punching is a method in which fibers arranged in a plane by punching a needle are forcibly arranged in the thickness direction to bind the lower layer and the upper layer. The needle used has a barb shape and a barb is formed in the direction of punching. When punching down, the needle pulls down the fiber, and the fiber does not fall off when the needle moves upward. Needle punching has the advantage that thick preforms can be economically manufactured without limitations in thickness, since lamination can be continued to bond the new layer and its underlying layer. However, due to the continuous punching, the damage of the fiber in the cotton is serious, and the fabric which can be used also needs to use the fabric using the discontinuous fiber such as the felt, and the amount of the fibers in the thickness direction bound to each other is limited. The mechanical properties of the preform are deteriorated.

According to the embodiments, a carbon fiber composite material reinforced with carbon fibers in the Z-axis direction without damaging the fibers in the surface and a method for manufacturing the same are provided to overcome the weakness of the Z-axis bonding force in the carbon fiber composite material to which the needle punching technique is applied .

The tasks to be solved in the embodiments are not limited to the above-mentioned tasks, and other tasks not mentioned can be clearly understood by those skilled in the art from the following description.

According to embodiments of the present invention for achieving the above object, the carbon fiber composite material includes a unit layer formed of carbon fibers and an interlayer bonding member having a stapler shape including the carbon fibers, , And binding the at least one layer with the interlayer binding member while laminating the unit layers.

According to one aspect of the present invention, the interlayer binding member can be formed using a prepreg impregnated with a carbon fiber and a polymer. For example, the polymer may use either epoxy or urethane.

According to one aspect, the unit layer is formed of a flat plate, and the unit layer comprises: And may be formed of any one of a weave fabric including a mandrel, a short-fiber mat, a long-fiber mat, a braid fabric, a multi-shaft warp, and a non-crimp fabric.

According to one aspect, the unit layer is formed in a conical shape, and the unit layer is formed by orienting axial fibers along a conical axial direction, Winding the fibers, and winding the second knitted fibers in the -45 direction on the first knitted fibers.

According to another aspect of the present invention, there is provided a method of manufacturing a carbon fiber composite material, the method including: forming a unit layer formed of carbon fibers; and stacking the unit layers one by one, And bonding the laminated unit fibers with each other, wherein the interlayer bonding member can be made of carbon fiber and polymer impregnated.

As described above, according to the embodiments, it is possible to reinforce the strength in the Z-axis direction without damaging the in-plane fibers by using an interlayer bonding member having a stapler shape and made of a carbon fiber material. In addition, thick preforms can be produced without limitation in thickness by laminating the unit layers.

The effects of the carbon fiber composite material and the manufacturing method thereof according to one embodiment are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description, serve to further the understanding of the technical idea of the invention, It should not be construed as limited.
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view for explaining a configuration and a manufacturing method of an interlayer binding member according to an embodiment. Fig.
2 is a side view of a planar carbon fiber composite material according to an embodiment.
3 is a plan view of the planar carbon fiber composite material of Fig.
4 to 5 are side views of a conical carbon fiber composite material according to an embodiment.

Hereinafter, embodiments will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments, detailed description of known functions and configurations incorporated herein will be omitted when it may make the best of an understanding clear.

In describing the components of the embodiment, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

Fig. 1 is a view for explaining a configuration and a manufacturing method of the interlayer binding member 1 according to one embodiment.

The interlayer binding member 1 has a form of a stapler. Further, the interlayer bonding member 1 is formed of a prepreg 1 'impregnated with a polymer in a carbon fiber. For example, the prepreg 1 'may be formed in a state in which an epoxy resin is embedded in the carbon fiber (or carbon). In addition, the prepreg 1 'may be made of a polymer such as epoxy or urethane.

1, a semi-hardened prepreg 1 'is injected into a first mold 110, and the first mold 110 and the second mold 120 are closed and pressed together to form a prepreg 1' 1 'are injected into the cavity 111 formed in the first mold 110, and are compressed. Then, the prepreg 1 'is cured by applying heat to the prepreg 1' in a state where the first and second molds 110 and 120 are closed.

The cured prepreg 1 'has a plate shape in which a plurality of interlayer bonding members 1 are arranged in parallel and the cross section is bent in a' C 'shape. When the interlayer bonding member 1 is used, it is used one by one in a plurality of interlayer bonding members 1 formed in a plate shape.

The interlayer binding member 1 has a sharp-pointed end so as to be easily inserted. Here, the end of the interlayer binding member 1 may be ground with sandpaper or the like so as to be more sharpened so as to be easy to use. However, this is merely an example, and the shape of the interlayer binding member 1 and the method of manufacturing the interlayer binding member 1 may be substantially varied.

Next, the carbon fiber composite material according to the embodiments and the manufacturing method thereof will be described with reference to Figs. 2 to 5. Fig.

2 to 3, a description will be given of a flat plate-type preform 10 of a carbon fiber composite material and a manufacturing method thereof.

The unit layer 11 is formed in the form of a flat plate or sheet having a predetermined thickness using carbon fibers. The unit layer 11 is applicable to fabrics of various weave patterns capable of forming a flat or sheet shape. For example, the unit layer 11 can be a weave fabric such as a twill fabric, a twill fabric, a short fiber or a long fiber mat, a braid fabric, a multi-shaft warp, or a non-crimp fabric. Hereinafter, a sheet-like fabric or the like forming the unit layer 11 is referred to as a "fabric ".

The unit layer is formed by stacking several sheets of 2D carbon fiber plain weave fabrics in the form of a sheet having a thickness of about 0.2 mm. For example, about 15 sheets of the fabric may be laminated to form a unit layer 11 of about 3 mm in thickness have. However, this is merely an example, and the thickness of the fabric and the thickness of the unit layer 11 may be substantially varied.

Next, the interlayer bonding member 1 is inserted while the unit layers 11 are laminated to form the flat plate-like preform 10. For example, the flat plate-like preforms 10 may be formed by stacking several unit layers 11 to have a thickness of about 25 mm or more, preferably 30 mm or more.

2, the planar preforms 10 are formed by laminating the unit layers 11 one by one while inserting the interlayer bonding member 1, and the interlayer bonding member 1 is composed of two unit layers 11, As shown in Fig. However, this is merely an example, and the interlayer bonding member 1 can bond two or more unit layers 11.

Hereinafter, a method of manufacturing the flat plate-type preform 10 will be briefly described.

First, two unit layers (11a and 11b in the drawing) are laminated, and an interlayer bonding member (hereinafter referred to as 1a) is inserted so as to bond the laminated unit layers 11a and 11b.

Next, an interlayer bonding member (hereinafter referred to as 1b) is laminated so as to bond the unit layers 11b and 11c thus stacked after the interlayer bonding member 1a is bonded and the next unit layer . Here, the interlayer bonding member 1b in the upper layer is arranged so as to be vertically displaced from the interlayer bonding member 1a in the lower layer, thereby preventing the interlayer bonding members 1a and 1b from colliding with each other.

Next, an interlayer bonding member 1c (hereinafter, referred to as " 1c ") is formed so as to bond the unit layers 11c and 11d thus stacked after the interlayer bonding member 1b is bonded, . Here, the interlayer binding member 1c is disposed at a position shifted upward and downward from the interlayer binding member 1b inserted in the previous layer. The interlayer binding member 1c may be formed at the same position as the interlayer binding member 1a inserted in the one-layer separated layer.

However, this is merely an example, and the upper and lower positions of the interlayer binding members 1a to 1c may be arranged substantially variously.

Thus, by repeating the operation of stacking the unit layers 11 and inserting the interlayer bonding member 1 so as to bond the two unit layers 11, the plate-like preform 10 of a predetermined thickness can be formed have. In addition, the positions of the upper and lower interlayer bonding members 1 are shifted each time the unit layers 11 are laminated so that the interlayer binding members 1 are positioned on the same line in the unit layer 11 spaced apart from each other It is possible to improve the interlayer bonding force in the vertical direction within the flat plate-type preform 10 while preventing interferences and collisions between the interlayer bonding members 1a to 1c.

On the other hand, the interlayer binding members 1 can be arranged in a predetermined distribution on the plane of one unit layer 11 as well. For example, as shown in Fig. 3, the interlayer binding members 1 are arranged in a plurality of rows along the x-axis, and the adjacent rows can be arranged so as to be shifted in position on the y-axis. This is for the purpose of enabling the interlayer binding member 1 to be uniformly arranged in the unit layer 11. However, this is merely an example, and the arrangement form of the interlayer binding member 1 can be changed substantially variously. For example, the interlayer bonding member 1 can be uniformly arranged in the x-axis and y-axis directions on the plane of the unit layer 11. [ The interlayer binding member 1 is inserted so as to cross at a predetermined angle (for example, 45 占 with respect to the fiber direction of the unit layer 11).

Next, the cone-shaped preform 20 of the carbon fiber composite material and the manufacturing method thereof will be described with reference to Figs. 4 to 5. Fig.

The conical preform 20 has a structure in which axial fibers 21a are oriented in an axial direction on a conical mold and braiding yarns are formed on the axial fibers 21a at an angle with respect to the axial fibers 21a. A single layer of fabric is formed by winding the plurality of layers 21b and 21c, and the unit layer 21 is formed by repeating formation of such a plurality of layers. Here, the axial fibers 21a are arranged in the 90 占 direction, the knitted fibers 21b and 21c wind the first knitted fiber 21b in the + 45 占 direction, and then, in the -45 占 direction, (21c) is wound to form the unit layer (21). By forming the unit layer 21 repeatedly by lamination, the conical preform 20 having a predetermined thickness can be formed.

When the unit layer 21 is laminated, the interlayer bonding member 1 is inserted every time the unit layer 21 is laminated one layer at a time, and the interlayer bonding member 1 is interposed between the two Can be inserted so as to bind the unit layers 21 of the two units.

For example, after two unit layers 21 are laminated, the two unit layers 21 are bonded by inserting the interlayer bonding member 1, and then the following unit layers 21 are laminated to form an interlayer bonding member 1) is inserted to bond the newly stacked unit layer 21 to the immediately preceding unit layer 21. [ Further, a plurality of interlayer binding members 1 are arranged at regular intervals on one layer of the unit layer 21, for example, can be arranged in a zigzag form or uniformly along the same row. Further, the interlayer binding member 1 is inserted along the direction of the conical shaft or axial fibers 21a.

By repeating this operation, the conical preform 20 having a predetermined thickness can be formed.

The interlayer binding member 1 may be arranged such that the positions of the layers are shifted vertically from one layer to the next, and the positions of the layers in the next layer are the same as in the above embodiment.

The interlayer binding member 1 is inserted along the direction of the conical shaft or axial fibers 21a and can be arranged at a predetermined angle (for example, at an angle of 45 degrees) with respect to the knitted fibers 21b and 21c. In addition, the interlayer binding member 1 can be inserted while a predetermined apparatus moves along the axial direction of the conical preform 20. [ However, this is merely one example, and the arrangement and insertion method of the interlayer binding member 1 can be arranged substantially in various ways.

Although not illustrated, cylindrical preforms can also be manufactured by bonding unit layers with an interlayer binder while laminating unit layers, as in the case of the above-described method of manufacturing the conical preform 20. [ That is, the cylindrical preforms orient the fibers in the axial direction and form a fabric layer by winding the knitted fibers at a predetermined angle (for example, + 45 ° and -45 °) with respect to the axial fibers, A plurality of layers can be stacked to form a unit layer having a predetermined thickness. A cylindrical preform having a predetermined thickness can be formed by laminating a plurality of unit layers while inserting an interlayer binder in each unit layer in the axial direction.

In addition, in the production of various types of preforms, a preform having a predetermined thickness and a predetermined shape can be formed by applying the same method of inserting a plurality of interlayer bonding members into each unit layer while stacking unit layers of predetermined thickness.

In summary, the carbon fiber composite material according to one embodiment forms a unit layer and inserts interlaminar bond members 1 made of carbon fiber material in the form of stapler core for each layer while stacking unit layers, have. By simply repeating such lamination and insertion of the interlayer bonding member 1, the fibers in the thickness direction are reinforced by a simple method, the interlayer bonding force is improved, and a thick preform can be produced. Further, a carbon fiber composite material in which carbon fibers are reinforced in the Z-axis direction without damaging the in-plane fibers can be produced.

The embodiments can provide a high-density preform that can be applied to polymer composite materials, metal composite materials, carbon / carbon composite materials, and ceramic composite materials by impregnating or impregnating a preform with a polymer, metal, carbon, or ceramic material.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments and equivalents to the claims are within the scope of the following claims.

1: interlayer bonding member
1 ': prepreg
10: Plate type preform
11: unit layer
20: Conical preform
21: unit layer
21a: axial fiber
21b, 21c: knitted fibers
110: first mold
111: cavity
120: second mold

Claims (7)

A unit layer formed of carbon fibers; And
An interlayer bonding member which binds the unit layer and has a stapler shape including carbon fibers;
Lt; / RTI >
And bonding the at least one layer with the interlayer bonding member while laminating the unit layers.
The method according to claim 1,
Wherein the interlayer bonding member is formed by using a prepreg impregnated with a carbon fiber and a polymer.
3. The method of claim 2,
Wherein the polymer is one of epoxy and urethane.
The method according to claim 1,
Wherein the unit layer is formed of any one of a weave fabric including a main thread, a short fiber mat, a long fiber mat, a braid fabric, a multi-axis warp, and a non-crimp fabric, Carbon fiber composite material.
The method according to claim 1,
Wherein the unit layer is formed by orienting axial fibers along a conical or cylindrical axial direction and winding first knitted fibers in the + 45 ° direction on the axial fibers, And the second knitted fiber is wound in a direction of 45 DEG to form a conical or cylindrical carbon fiber composite material.
6. The method of claim 5,
Wherein the interlayer bonding member is formed along the axial direction of the conical or cylindrical shape.
Forming a unit layer formed of carbon fibers; And
Binding the unit layers stacked with the stapler-shaped interlayer binding member while stacking the unit layers one by one;
Lt; / RTI >
Wherein the interlayer bonding member is impregnated with a carbon fiber and a polymer.

Images