WO2018212432A1

WO2018212432A1 - Fiber-reinforced plastic and manufacturing method therefor

Info

Publication number: WO2018212432A1
Application number: PCT/KR2018/002263
Authority: WO
Inventors: 오애리; 박종성; 김희준; 문영이
Original assignee: (주)엘지하우시스
Priority date: 2017-05-19
Filing date: 2018-02-23
Publication date: 2018-11-22
Also published as: KR102253104B1; KR20180127122A

Abstract

Disclosed is a fiber-reinforced plastic having excellent transverse properties, comprising unidirectional continuous fiber composites. The fiber-reinforced plastic according to the present invention comprises: unidirectional continuous fiber composites in which continuous fibers are oriented in a first direction; and a reinforcement layer disposed between the unidirectional continuous fiber composites, wherein the reinforcement layer comprises a long fiber composite in which long fibers are oriented in a second direction crossing the first direction.

Description

Fiber Reinforced Composites and Manufacturing Method Thereof

The present invention relates to a fiber-reinforced composite, and more particularly, to reinforce the widthwise properties of a unidirectional continuous fiber composite unidirectionally oriented, and also to solve the problem of widthwise splitting of a unidirectional continuous fiber composite unidirectionally oriented. The present invention relates to a composite material and a method of manufacturing the same.

Lightweight and high strength fiber-reinforced composite materials are used in many fields, such as sports leisure structures such as golf clubs, structures such as telephone poles, automobile parts, and aircraft.

Fiber Reinforced Plastics (FRP) refers to composites in which fibers are applied as a reinforcing material in a polymer matrix. Fiber composites that are widely used include glass fiber composites, carbon fiber composites, and the like, depending on the type of fiber.

Fibers are classified into short fibers, long fibers, and continuous fibers according to their length and shape. In general, short fiber refers to a fiber having a length of less than 2mm, long fiber refers to a fiber having a length of 2mm or more, the long fiber generally has a length of 50mm or less. Continuous fibers depend on the final size of the sheet and generally refer to fibers which have a longer length than the long fibers but which are present in a continuous form without breaking at least in the orientation direction within the sheet rather than how long.

Continuous fiber composites using continuous fibers are classified into one-way continuous fiber composites, two-way continuous fiber composites, random direction continuous fiber composites, etc. according to the fiber orientation direction.

Of these, the unidirectional continuous fiber composite material oriented in a single direction has the advantage of excellent rigidity, strength properties. However, unidirectional continuous fiber composites often cause cracking problems due to their weakness in the width direction. Therefore, there is a need for a fiber-reinforced composite material that can improve the cracking problem of the unidirectional continuous fiber composite material and has excellent widthwise physical properties and can solve the cracking problem in the widthwise direction.

In order to improve the widthwise physical properties of the unidirectional continuous fiber composites, a method of alternately repeating the continuous fiber composites oriented in the first direction and the continuous fiber composites oriented in the second direction crossing the first direction, alternately in a random direction And a method of disposing the long filament composite between the continuous fiber composites oriented in the first direction. However, these methods have a problem that it is difficult to secure the formability. Furthermore, in the case of long fiber composites oriented in a random direction, it may be difficult to manufacture a thin part in a relatively thick relationship.

Background art related to the present invention is Republic of Korea Patent Publication No. 10-2016-0054661 (2016.05.17.), The document discloses a one-way continuous fiber-reinforced thermoplastic composite manufacturing apparatus and method.

One object of the present invention is to provide a fiber-reinforced composite material which is excellent in the widthwise physical properties and solves the widthwise cracking problem based on the unidirectional continuous fiber composite material.

Another object of the present invention is to provide a method for producing a fiber-reinforced composite manufacturing method excellent in the widthwise physical properties.

Fiber-reinforced composite material according to the present invention for achieving the above object is one direction continuous fiber composites in which the continuous fibers are oriented in the first direction; And a reinforcement layer disposed between the one-way continuous fiber composites, wherein the reinforcement layer comprises a long fiber composite oriented in a second direction in which the long fibers intersect the first direction.

In this case, the reinforcement layer may be formed in a sheet form. As another example, the reinforcement layer may be formed in a plurality of pieces spaced apart from each other.

In addition, the thickness of the reinforcing material layer may be the same as the thickness of the continuous fiber composite or less than the thickness of the continuous fiber composite.

The one-way continuous fiber composites may include 20 to 70 parts by weight of continuous fiber, based on 100 parts by weight of thermoplastic resin.

In addition, the long fiber composite material may include 20 to 70 parts by weight of long fibers having a length of 2 mm or more with respect to 100 parts by weight of a thermoplastic resin.

In addition, each of the continuous fibers and long fibers may include one or more of glass fibers, carbon fibers, aramid fibers and natural fibers.

Fiber-reinforced composite manufacturing method according to the present invention for achieving the above another object is a sheet in which a long fiber is oriented in a second direction intersecting the first direction, on a one-way continuous fiber composite material is a continuous fiber is oriented in a first direction Placing the fiber composite; Disposing a continuous fiber composite material on which the continuous fibers are oriented in the first direction; And performing lamination.

In the fiber reinforced composite material according to the present invention, as a result of inserting the long fiber composite oriented in the second direction, that is, the width direction, between the continuous fiber composites oriented in the first direction, while maintaining the formability in the width direction, It is possible to solve the cracking problem and to improve the physical properties in the width direction.

In addition, in the case of the long fiber composites oriented in one direction (second direction) as compared to the long fiber composites oriented in the random direction, it is possible to manufacture less than or equal to the thickness of the unidirectional continuous fiber composites. Therefore, a thin part can be manufactured in addition to the excellent width direction properties.

Figure 1 schematically shows a one-way continuous fiber composite material used in the present invention.

2 schematically illustrates a long fiber composite oriented in a random direction.

3 schematically shows a long fiber composite oriented in one direction.

4 shows an example of laminating continuous fiber composites oriented in a first direction.

5 shows an example in which the continuous fiber composite oriented in the second direction is interposed between the continuous fiber composites oriented in the first direction.

6 illustrates an example in which a long fiber composite oriented in a random direction is interposed between continuous fiber composites oriented in a first direction.

7 illustrates an example in which a long fiber composite oriented in a second direction is interposed between continuous fiber composites oriented in a first direction according to the present invention.

[Description of the code]

100: one-way continuous fiber composite

110: resin

120: fiber

130: random direction long fiber

140: unidirectional long fiber

200: random long fiber composite

300: unidirectional long fiber composite

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, with reference to the accompanying drawings, a fiber reinforced composite according to a preferred embodiment of the present invention and a manufacturing method thereof will be described in detail.

The fiber reinforced composite according to the present invention comprises a unidirectional continuous fiber composite and a reinforcement layer.

One-way continuous fiber composites are composites in which the continuous fibers are oriented in a first direction.

At this time, the one direction, including the case where the predetermined two continuous fibers are 10 degrees or less, specifically 5 degrees or less, and not only completely parallel to each other, but also difficult to identify with the naked eye. Error ranges should be understood to include.

Referring to FIG. 1, the unidirectional continuous fiber composite material 100 has a structure in which a continuous fiber 120 oriented in one direction is impregnated into a base material 110 including a thermoplastic resin.

Continuous fiber composite material 100 may be formed to a thickness of approximately 0.1 ~ 10mm, but is not limited thereto.

In the present invention, the reinforcement layer is disposed between the unidirectional continuous fiber composites.

2 schematically illustrates a random directional long fiber composite comprising long fibers 130 oriented in a random direction. 3 schematically shows a long fiber composite oriented in one direction.

In the case of the long fiber included in the long fiber composite material shown in Figure 2, it is mainly obtained by the extrusion process, the fiber length is about 2 ~ 50mm. On the other hand, in the case of the long fiber included in the long fiber composite material shown in Figure 3, it can be obtained as a long fiber in one direction by cutting the continuous fiber, the fiber length may be about 2 to 50mm, but is not limited thereto and as needed It may have a length of 50mm or more. In addition, the long fiber content in the long fiber composite shown in FIG. 2 is limited to about 40% by weight, but the long fiber content in the long fiber composite shown in FIG. 3 may be up to about 70%. That is, the long fibers included in the long fiber composite shown in FIG. 2 and the long fibers included in the long fiber composite shown in FIG. 3 correspond to different types of fibers depending on the manufacturing process, length, and content range.

The long fiber composite is classified into a unidirectional long fiber composite and a random direction long fiber composite according to the orientation direction of the long fiber. The random long fiber composite as in the example shown in FIG. 2 is a case where the long fibers do not have a specific orientation. However, such a random direction long fiber composite is difficult to manufacture in a thin thickness. One-way long fiber composites such as the example shown in Figure 3 is a composite material in which the long fibers are oriented in a specific direction, there is an advantage in excellent formability and processability.

In the present invention, the reinforcing material layer using a long fiber composite or a material containing the same, wherein the long fiber composite is a unidirectional long fiber composite. That is, in the present invention, the long fiber composite material 100 has a structure in which the long fiber 140 oriented in one direction is impregnated in the base material 110 including the thermoplastic resin, as shown in FIG. Is oriented in a second direction crossing the first direction.

The reinforcement layer may be formed in the form of a sheet, as shown in FIG. 3. As another example, the reinforcement layer may be formed in a plurality of pieces spaced apart from each other, which is a continuous fiber composite oriented in the first direction is cut in the second direction, so that the length of the fiber is about 50mm or less Can be. As described above, in the example shown in FIG. 3, the fiber length of the long fibers may be 50 mm or more.

The thickness of the reinforcement layer may be the same as the thickness of one layer of continuous fiber composite or less than the thickness of one layer of continuous fiber composite. Accordingly, the fiber-reinforced composite according to the present invention can be produced up to three times the thickness of one layer of continuous fiber composite. When the reinforcement layer is made of a random directional long fiber composite material, there are many thickness constraints. However, when the reinforcement layer is made of a unidirectional long fiber composite material, the thickness constraint is relatively small, so that a thin thickness can be realized. For example, when the continuous fiber composite thickness is 0.25mm, the unidirectional long fiber composite may be manufactured to 0.25 mm or less, but the random directional long fiber composite may be manufactured to a relatively thick thickness of about 1.0 mm. As a result, the fiber-reinforced composites according to the invention can be produced in thin thicknesses, and as a result can provide a custom thickness to the desired part thickness.

Composites comprising continuous fibers or long fibers can be produced by melt impregnation methods such as in-mold impregnation, roll impregnation, belt impregnation, and the like.

In the case of a long fiber composite, it can be manufactured by the following method, for example. In the case of the long fiber composite material shown in FIG. 2, the composite including the continuous fiber or the long fiber may be manufactured in the form of a sheet by melt extruding the extruded long fiber and the thermoplastic resin, pressing, and cutting. In the case of the long fiber composite material illustrated in FIG. 3, the long fiber may be manufactured by arranging and pressing long fibers in one direction on a thermoplastic resin sheet. In the case of the long fiber composite shown in Figures 2 and 3, in addition to the above-described method it can be produced by a variety of known methods.

In the case of a continuous fiber composite, for example, it can be produced by the following method. The thermoplastic resin is introduced into an extruder and melted at a temperature of 200 ° C. or more, and the continuous fiber is taken out of the thread of the fiber wound in the roving form and put into a mold. The thermoplastic resin melted through the extruder is introduced into the mold to be impregnated into the continuous fiber. Next, by pressing it and cutting it to an appropriate size, it is possible to produce a continuous fiber composite in the form of a sheet. Specifically, by pressing using a calendar (calendar) process, it is possible to manufacture a continuous fiber composite having excellent surface properties by controlling the single orientation of the continuous fiber.

The thermoplastic resin serves as a matrix in the continuous fiber composite or the long fiber composite, and may be a polypropylene resin, an aromatic vinyl resin, a rubber modified aromatic vinyl resin, a polyphenylene ether resin, a polycarbonate resin, a polyester resin, It may include one or more of methacrylate resin, polyarylene sulfide resin, polyamide resin and polyvinyl chloride resin.

For example, the thermoplastic resin may include a polypropylene resin, and the polypropylene resin may be a propylene-ethylene copolymer resin, a propylene-butene copolymer resin, and an ethylene-propylene-butene copolymer resin as the polypropylene copolymer resin. It may include.

The continuous fiber or long fiber may include, for example, one or more of glass fiber, carbon fiber, aramid fiber and natural fiber.

On the other hand, in a continuous fiber composite material or a long fiber composite material, it is preferable that 20-70 weight part is preferable with respect to 100 weight part of thermoplastic resin, and, as for continuous fiber or long fiber composite, it is more preferable that 20-60 weight part is included. If the content of the continuous fiber or long fiber is less than 20 parts by weight, it is difficult to expect the mechanical strength, and if the content of the continuous fiber or long fiber exceeds 70 parts by weight, the content of the continuous fiber or long fiber is too high to reduce the light weight and formability of the composite material .

As described above, long fiber refers to a fiber having a length of 2 mm or more, and continuous fiber refers to a fiber that is present in a continuous form without breaking in the alignment direction inside the sheet. In the present invention, the distinction between the long fibers and the continuous fibers is not dependent on the length, but on whether the fibers are broken in the alignment direction or continuous. That is, in the present invention, the fiber form cut in the orientation direction inside the sheet is a long fiber, and the fiber form present in a continuous form without breaking in the orientation direction is a continuous fiber. In the case of long fibers, it is advantageous in formability, and in the case of continuous fibers, the bending of the fibers is small, so that the strength in the fiber orientation direction can be increased, and the structurally excellent strength and rigidity can be exhibited.

4 shows an example of laminating continuous fiber composites oriented in a first direction. The fiber-reinforced composite shown in FIG. 4 has excellent strength because the one-way continuous fiber composites have a fiber shape oriented only in the first direction, but the formability is not good, and the widthwise division problem is difficult to solve.

5 shows an example in which the continuous fiber composite oriented in the second direction is interposed between the continuous fiber composites oriented in the first direction. The fiber reinforced composite shown in FIG. 5 is composed of only one-way continuous fiber composites as in the fiber reinforced composite shown in FIG. 4. However, in the case of the fiber-reinforced composite shown in Fig. 5, the continuous fiber composites on both sides in the thickness direction have a fiber shape oriented in the first direction, while the continuous fiber composites inserted in the middle are oriented in the second direction. In this case, the problem of widthwise cracking can be solved, but it has a disadvantage in that moldability is poor because it is composed of only continuous fiber composites.

6 illustrates an example in which a long fiber composite oriented in a random direction is interposed between continuous fiber composites oriented in a first direction. In the fiber-reinforced composite material shown in FIG. 6, continuous fiber composite materials oriented in the first direction are disposed on both sides in the thickness direction, and long fiber composite materials oriented in a random direction are disposed in the center. In this case, both the widthwise cracking and the moldability can exhibit excellent characteristics. However, in the case of random oriented long fiber composites, the thickness of the unidirectional long fiber composites is higher than that of the unidirectional long fiber composites, which makes it difficult to manufacture thin-walled components. It is somewhat lower than the problem.

7 illustrates an example in which a long fiber composite oriented in a second direction is interposed between continuous fiber composites oriented in a first direction according to the present invention. In the fiber-reinforced composite shown in FIG. 7, continuous fiber composites oriented in the first direction are disposed on both sides in the thickness direction, and long fiber composites oriented in the second direction are disposed in the center. According to this, the long-fiber composite material oriented in the second direction can not only solve the problem of the splitting in the width direction, but also improve the formability and the second direction physical properties, and by applying the long-fiber excellent fluidity compared to the continuous fiber Can improve design freedom.

The fiber reinforced composite manufacturing method according to the present invention includes a lower first direction continuous fiber composite disposition step, a second direction long fiber composite disposition step, an upper first direction continuous fiber composite disposition step and a laminating step.

In the step of arranging the lower first direction continuous fiber composite, the lower first direction continuous fiber composite in which the continuous fibers are oriented in the first direction is disposed.

In the second direction long fiber composite disposing step, the second direction long fiber composite oriented in the second direction in which the long fibers cross the first direction is disposed on the lower first direction continuous fiber composite.

In the step of arranging the upper first direction continuous fiber composite, the upper first direction continuous fiber composite in which the continuous fibers are oriented in the first direction is disposed on the second direction long fiber composite.

In the above, the example of the three-layer fiber reinforced composite having the second direction long fiber composite disposed between the two first direction continuous fiber composites has been described, but the present invention is not limited thereto, and the three first direction continuous fiber composites are provided. And two second direction long fiber composites may be a five-layer structure alternately stacked, and may be a seven-layer structure and the like. Furthermore, it may be a four-layer structure in which two first direction continuous fiber composites and two second direction long fiber composites are alternately stacked, and may be a six-layer or an eight-layer structure.

In the laminating step, the lower first direction continuous fiber composite, the second direction long fiber composite and the upper first direction continuous fiber composite are laminated. Laminating can use the thermal laminating method.

실시예Example

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, this is presented as a preferred example of the present invention and in no sense can be construed as limiting the present invention.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

1. 연속섬유 복합재 및 장섬유 복합재의 제조1. Preparation of continuous fiber composites and long fiber composites

A unidirectional long fiber composite material having a thickness of 0.25 mm, including 35 parts by weight of glass fiber (average length 10 mm), was prepared based on 100 parts by weight of polypropylene resin. Moreover, the 1.00-mm-thick random direction long fiber composite material containing 35 weight part of glass fibers (average length 10 mm) was prepared with respect to 100 weight part of polypropylene resins.

To 100 parts by weight of polypropylene resin, a 0.25 mm thick one-way continuous fiber composite including 35 parts by weight of glass fibers (average length 50 mm) was prepared.

2. 시편의 제조2. Preparation of Specimen

Example 1

The lower one-way continuous fiber composite material is disposed so that the fiber direction is the first direction, and the one-way long fiber composite material is disposed on the lower one-way continuous fiber composite material so that the fiber direction is the second direction, and the fiber direction is first formed on the one-way long fiber composite material. The upper one-way continuous fiber composite was placed so as to be in one direction. It was then laminated through a thermal laminating process.

Comparative Example 1

The lower one-way continuous fiber composite, the middle one-way continuous fiber composite and the upper one-way continuous fiber composite were sequentially arranged so that the fiber directions were the first direction, and then laminated through a thermal laminating process.

Comparative Example 2

The lower one-way continuous fiber composite material is disposed so that the fiber direction is the first direction, and the one-way continuous fiber composite material is disposed on the lower one-way continuous fiber composite material so that the fiber direction is the second direction, and the fiber direction is made on the one-way continuous fiber composite material. The upper one-way continuous fiber composite was placed so as to be in one direction. It was then laminated through a thermal laminating process.

Comparative Example 3

The lower one direction continuous fiber composite material is disposed so that the fiber direction is the first direction, the random direction long fiber composite material is disposed on the lower one direction continuous fiber composite material, and the upper one direction the fiber direction is the first direction on the random direction long fiber composite material. Continuous fiber composites were placed. It was then laminated through a thermal laminating process.

3. 물성 평가3. Property evaluation

The widthwise cracking and formability tests were performed on the specimens according to Example 1 and Comparative Examples 1 to 3, and the results are shown in Table 1.

In the widthwise splitting test, when the force was applied in the widthwise direction with the same force, visually confirmed whether cracking occurred, and it was shown as a case where cracking occurred (O) or a case where cracking did not occur (X).

Formability is good (O) if the specimen is bent to a depth of at least half the depth of the U-shaped groove by applying a force to the specimen with the same force with a U-shaped bending tester having a U-shaped groove; It was made.

Flexural properties were measured for flexural strength (MPa) by ASTM D790.

TABLE 1

Referring to Table 1, in Example 1 using the second direction long-fiber composite as a reinforcing material layer, the crack in the width direction did not occur, and the formability was superior to the specimens according to Comparative Examples 1 and 2.

Furthermore, in the case of Example 1, it showed slightly better flexural properties than that of Comparative Example 3. At this time, while the thickness of the reinforcement layer of Example 1 is only 0.25mm, the thickness of the reinforcement layer of Comparative Example 3 is 1.00mm, not only more suitable for Example 1 to implement a thin thickness, but also to implement the flexural properties It was found to be good.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments and can be manufactured in various forms, and having ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims

One-way continuous fiber composites in which the continuous fiber is oriented in a first direction; And

And a reinforcement layer disposed between the one-way continuous fiber composites.

And the reinforcement layer comprises a long fiber composite oriented in a second direction in which the long fibers intersect the first direction.
The method of claim 1,

The reinforcement layer is characterized in that formed in the form of a sheet, fiber reinforced composite material.
The method of claim 1,

The reinforcement layer is characterized in that formed in a plurality of pieces spaced apart from each other, fiber-reinforced composite material.
The method of claim 1,

The thickness of the reinforcing material layer is fiber reinforced composite, characterized in that less than or equal to the thickness of one layer of continuous fiber composite.
The method of claim 1,

The fiber reinforced composite is characterized in that less than three times the thickness of one layer of continuous fiber composite, fiber reinforced composite.
The method of claim 1,

The one-way continuous fiber composites are fiber reinforced composites, characterized in that it comprises 20 to 70 parts by weight of continuous fibers, based on 100 parts by weight of thermoplastic resin.
The method of claim 1,

The long fiber composite material is a fiber-reinforced composite material, characterized in that it comprises 20 to 70 parts by weight of long fibers having a length of 2mm or more with respect to 100 parts by weight of a thermoplastic resin.
The method of claim 1,

The continuous fiber and the long fiber, each fiber-reinforced composite, characterized in that it comprises at least one of glass fiber, carbon fiber, aramid fiber and natural fiber.
Disposing a long fiber composite oriented in a second direction in which the long fibers cross the first direction, on the one direction continuous fiber composite in which the continuous fibers are oriented in the first direction;

Disposing a continuous fiber composite material on which the continuous fibers are oriented in the first direction; And

Performing lamination; Fiber-reinforced composite manufacturing method comprising a.