KR102200964B1 - Fiber reinforced composite material and methode for manufacturing the same - Google Patents

Abstract

A fiber-reinforced composite material comprising a first UD prepreg having a hollow, wherein the hollow is filled with foamed foam is provided.

Description

Fiber reinforced composite and its manufacturing method {FIBER REINFORCED COMPOSITE MATERIAL AND METHODE FOR MANUFACTURING THE SAME}

It relates to a fiber-reinforced composite and a method of manufacturing the same.

In recent years, interest in increasing crude oil prices and energy saving has been greatly increased, and accordingly, it is one of the important factors to improve fuel efficiency and reduce weight in transportation means such as vehicles and aircraft.

Most of the parts constituting the existing vehicles and aircraft are made of metal as the main material to secure high strength and rigidity. When parts are made of metal, it is expensive to process and has a disadvantage in improving fuel economy or reducing weight due to high weight. Therefore, in recent years, various parts have been manufactured using plastic as a main material instead of metal to meet the purpose of promoting weight reduction. Since plastics generally have a specific gravity of about 1/4 to about 1/5 compared to metal, a weight reduction effect can be obtained and fuel economy can be improved.

However, since metals have high resistance to fracture, they delay complete fracture of the material even after reaching the maximum strength through permanent deformation due to external force, store energy, and have a large degree of deformation. On the other hand, plastic materials show the maximum strength of the material at a very small elongation and then abruptly break, and when an external force is applied, there is a disadvantage that permanent deformation does not occur before breaking, and the degree of deformation is small. .

Therefore, it is becoming important to develop a composite material that can withstand external impacts while securing mechanical properties in accordance with the development of lightweight materials.

One embodiment of the present invention provides a lightweight fiber-reinforced composite material that can sufficiently withstand external impacts to realize excellent durability, and to realize improved three-dimensional shape realization and reinforced physical properties in a multiaxial direction.

Another embodiment of the present invention provides a method of manufacturing the fiber-reinforced composite.

In one embodiment of the present invention, it includes a first UD prepreg having a hollow, wherein the hollow provides a fiber-reinforced composite material filled with foamed foam.

In another embodiment of the present invention, forming a first molded article by molding a prepreg in a molding mold; Forming a second molded product by filling the first molded product with a foamable resin composition; And cooling the second molding in a cooling mold to form a third molding. It provides a method for producing a fiber-reinforced composite comprising a.

The fiber-reinforced composite material can sufficiently withstand external impacts to achieve excellent durability, and can realize improved three-dimensional shape realization and reinforced physical properties in multiaxial directions. In addition, the method of manufacturing the fiber-reinforced composite may more easily fill the foamable resin composition, and form a uniform foamed foam to provide excellent physical properties. In addition, it is possible to impart excellent productivity by providing a fiber-reinforced composite material filled with foamed foam in a single process.

Figure 1 (a) is a schematic view of a method of manufacturing a fiber-reinforced composite according to an embodiment of the present invention, and (b) is a schematic view of changes in prepreg in each step.
Figure 2 is a schematic view of a method of manufacturing a fiber-reinforced composite according to another embodiment of the present invention.
3 (a) is a schematic perspective view of a fiber-reinforced composite according to an embodiment of the present invention, (b) is a schematic perspective view of a fiber-reinforced composite according to another embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments to be described later. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, However, these embodiments are provided to complete the disclosure of the present invention, and to fully inform the scope of the invention to those of ordinary skill in the art to which the present invention pertains, and the present invention is defined by the scope of the claims. It just becomes.

In the drawings, the thicknesses are enlarged to clearly express various layers and regions. And in the drawings, for convenience of description, the thickness of some layers and regions is exaggerated. The same reference numerals refer to the same elements throughout the specification.

In addition, in the present specification, when a part such as a layer, film, region, plate, etc. is said to be "on" or "on" another part, it is not only "directly above" another part, but also when another part is in the middle. Also includes. Conversely, when one part is "directly above" another part, it means that there is no other part in the middle. In addition, when a part such as a layer, film, region, or plate is said to be "below" or "under" another part, it is not only "directly below" another part, but also if there is another part in the middle. Include. Conversely, when one part is "right under" another part, it means that there is no other part in the middle.

In one embodiment of the present invention, it includes a first UD prepreg having a hollow, wherein the hollow provides a fiber-reinforced composite material filled with foamed foam.

3 (a) is a schematic perspective view of a fiber-reinforced composite according to an embodiment of the present invention. Referring to this, the fiber-reinforced composite includes a first UD prepreg 2 having a hollow, and the hollow is filled with a foamed foam 3.

Fiber-reinforced composites having hollows are being manufactured to reduce the weight of parts such as vehicles, and fiber-reinforced composites are generally manufactured by a pultrusion process. The pultrusion molding process of a fiber-reinforced composite material refers to continuously producing a molded product by impregnating a continuous fiber reinforcement with a thermosetting or thermoplastic resin and then curing or solidifying it in a mold. In the case of a fiber-reinforced composite manufactured by a general pultrusion molding process, the fiber reinforcement is oriented in one direction (uni-direction), so mechanical properties in that direction are excellent, but the properties in the transverse direction perpendicular to the one direction and Flexural properties have a weak problem.

The fiber-reinforced composite may include a first UD prepreg having a hollow and fill the hollow with foamed foam to improve physical properties and flexural properties in a transverse direction.

Specifically, the first UD prepreg may include a first fiber reinforcement material and a first resin matrix material, and the fiber reinforcement material may have orientation. In this case, having'orientation' means that single strands of fibers of the fiber reinforcement are arranged side by side in any one direction. UD prepreg (unidirection prepreg) means a fiber reinforced sheet containing such fiber reinforcement

The first UD prepreg may secure a certain level of strength and rigidity in an oriented direction including a first fiber reinforcement material and a first resin matrix material having orientation.

Specifically, the first fiber reinforcement may include one selected from the group consisting of glass fibers, carbon fibers, aramid fibers, and combinations thereof. Specifically, the first fiber reinforcement may be a continuous fiber reinforcement. Unlike the case where the first UD prepreg includes short fibers or long fibers including a continuous fiber reinforcement, it is easy to control orientation in a desired single direction, and flexibility and impact resistance can be greatly improved. More specifically, the first fiber reinforcement may be glass fiber, it is easy to construct equipment, and has advantageous advantages in terms of securing price competitiveness compared to mechanical properties.

The single strand of the first fiber reinforcement has a cross-sectional diameter, for example, about 1 μm to about 200 μm, about 1 μm to about 50 μm, about 1 μm to about 30 μm, or about 1 μm to 20 μm Can be The first fiber reinforcement may have excellent unidirectional orientation by having a cross-sectional diameter within the above range, and improve impregnation into the resin matrix during the manufacturing process.

The first resin matrix may include a thermoplastic resin, specifically, polytetrafluoroethylene (PTFE), polyethylene, polypropylene, polystyrene, polyphenylene oxide (polyphenylene). oxidel; PPO), polyvinyl chloride (PVC), polyethylene terephthalate (PET), nylon 6.6, polymethyl methacrylate (PMMA), and combinations thereof It may contain a selected one.

For example, the first resin matrix may include polyethylene terephthalate (PET) as a thermoplastic resin. When the first resin matrix includes polyethylene terephthalate, it has price competitiveness and can impart excellent thermal and mechanical properties.

The foamed foam filled in the hollow is a polyurethane, polyurea, polyvinyl chloride, polypropylene, polyethylene, polystyrene, polyvinyl acetate, melamine resin, phenol resin, and combinations thereof, as filled by the manufacturing method described below. It may be one material selected from the group consisting of. The fiber-reinforced composite material includes a first UD prepreg having a hollow filled with the foamed foam, and improves physical properties and flexural properties in a transverse direction perpendicular to one direction of the oriented first fiber reinforcement. I can. That is, the fiber-reinforced composite material has an excellent bending load and can sufficiently withstand external impacts, thereby implementing excellent durability. For example, a polyurethane foam may be included in the hollow interior, and excellent elasticity may be imparted to increase compressive strength, and excellent heat resistance may be imparted with low thermal conductivity of the polyurethane foam foam. .

The fiber-reinforced composite may have a density of about 0.94g/cm3 to about 0.96g/cm3, and the foamed foam is uniformly foamed in the hollow, so that excellent weight reduction and excellent mechanical properties and shock absorption may be exhibited.

3B is a schematic perspective view of a fiber-reinforced composite according to another embodiment of the present invention. Referring to this, the fiber-reinforced composite material includes a second UD prepreg wound around the outer circumferential surface of the first UD prepreg, and the second UD prepreg is a second fiber reinforcement material and a second resin base. A material may be included, and orientation directions of the first fiber reinforcement material of the first UD prepreg and the second fiber reinforcement material of the second UD prepreg may be different from each other.

Specifically, the fiber reinforced composite material is the first UD prepreg filled with a hollow foam; And a second UD prepreg bonded in a wound state on an outer peripheral surface of the first UD prepreg. In the second UD prepreg, as in the manufacturing method to be described later, there may be a boundary between the second UD prepregs wound on the first UD prepreg in a form wound on the first UD prepreg, or , The boundary between the second UD prepregs wound on the first UD prepreg may be absent by the heating and pressing process.

The second UD prepreg includes a second fiber reinforcement and a second resin matrix.

The second fiber reinforcement may include one selected from the group consisting of glass fibers, carbon fibers, aramid fibers, and combinations thereof. The second fiber reinforcement may have the same material and properties as the first fiber reinforcement included in the first UD prepreg.

The second resin matrix may include a thermoplastic resin, specifically, polytetrafluoroethylene (PTFE), polyethylene, polypropylene, polystyrene, polyphenylene oxide (polyphenylene). oxidel; PPO), polyvinyl chloride (PVC), polyethylene terephthalate (PET), nylon 6.6, polymethyl methacrylate (PMMA), and combinations thereof It may contain a selected one. The second resin matrix may have the same material and properties as the first resin matrix included in the first UD prepreg.

The first UD prepreg includes a first fiber reinforcement oriented in one direction. Orientation directions of the first fiber reinforcement of the first UD prepreg and the second fiber reinforcement of the second UD prepreg may be different from each other.

For example, the first orientation direction of the first fiber reinforcement may be a long axis direction of the first UD prepreg, and the second orientation direction of the second fiber reinforcement material is alternately with the first orientation direction of the first fiber reinforcement. , The included angle between the first fiber reinforcement and the second fiber reinforcement may be greater than about 0° and less than about 180°. By the included angle between the first fiber reinforcement material and the second fiber reinforcement is greater than about 0° and less than about 180°, the method of manufacturing a fiber-reinforced composite material can provide a fiber-reinforced composite material reinforced in a multiaxial direction. have.

The second UD prepreg is a string-shaped sheet and can be wound on the surface of the first UD prepreg using a filament winding method. For example, the second UD prepreg is on the first UD prepreg. Can be spirally wound on.

The shape of the fiber-reinforced composite material is not particularly limited, but may be, for example, a column shape having a long axis and a short axis, and more specifically, may be a polygonal column shape or a cylindrical shape. The shape of the fiber-reinforced composite may be determined by the shape of the first UD prepreg.

For example, when the first UD prepreg is designed in a tubular shape having a hollow, the fiber-reinforced composite material may include the first UD prepreg and the second UD prepreg wound around the tubular shape. . As described above, the orientation direction of the first fiber reinforcement and the orientation direction of the second fiber reinforcement are different from each other. The fiber-reinforced composite may be manufactured in a column shape rather than a sheet shape or a panel shape, and thus, unlike a fiber-reinforced composite material in a sheet shape or a panel shape, it can be manufactured in a three-dimensional shape according to a molding mold.

Another embodiment of the present invention provides a method of manufacturing a fiber-reinforced composite. Figure 1 (a) is a schematic view of a method of manufacturing a fiber-reinforced composite according to an embodiment of the present invention, and (b) is a schematic view of changes in prepreg in each step. Referring to this, the method of manufacturing the fiber-reinforced composite includes forming a first molded article by molding a prepreg in a molding mold; Forming a second molded product by filling the first molded product with a foamable resin composition; And cooling the second molding in a cooling mold to form a third molding. Includes.

The manufacturing method of the fiber-reinforced composite material can more easily fill the foamable resin composition between the molding mold and the cooling mold, and can provide excellent physical properties by forming a uniform foamed foam. In addition, it is possible to impart excellent productivity by providing a fiber-reinforced composite material filled with foamed foam in a single process.

The fiber-reinforced composite material manufactured by the method for manufacturing the fiber-reinforced composite material includes, as described above, a first UD prepreg having a hollow, and is filled with a foamed foam to fill the hollow to physical properties in the transverse direction. And it is possible to improve the flexural properties. In addition, the fiber-reinforced composite has a low density, and the foamed foam is uniformly foamed in the hollow, so that excellent weight reduction and excellent mechanical properties and shock absorption can be exhibited.

Specifically, the method of manufacturing the fiber-reinforced composite material includes forming a first molded article by molding a prepreg in a molding mold. The molding mold may have a temperature of about 180° C. to about 250° C., and a first molded product may be formed in the temperature range. The first molding is a hollow structure in which the UD prepreg is rolled like a horseshoe shape, and the cross section perpendicular to the longitudinal direction of the fiber reinforcement included in the UD prepreg is partially opened, as shown in Fig. 1(b). It can have a shape.

In addition, the method of manufacturing the fiber-reinforced composite material includes the step of forming a second molded product by filling the first molded product with a foamable resin composition. The manufacturing method of the fiber-reinforced composite material can provide excellent physical properties by filling a foamable resin composition between the molding mold and the cooling mold to more easily form a uniform foamed foam. In addition, it is possible to impart excellent productivity by providing a fiber-reinforced composite material filled with foamed foam in a single process.

Specifically, the second molded product may have a structure in which a foamable resin composition is filled in a hollow having a partially opened structure, as shown in (b) of FIG. 1. The circumference length of the cross-section perpendicular to the longitudinal direction of the fiber reinforcement material included in the second molding, that is, the average circumference length of the inner circumference length and the outer circumference length is smaller than the length of the open part of the circumference length of the first molding I can.

As shown in (a) of FIG. 1, the foamable resin composition may be filled at about 2.5/4 to about 3.5/4 between the molding mold and the cooling mold. In addition, the foamable resin composition may be filled when the surface temperature of the first molded product is about 70°C to about 80°C. The foamable resin composition may be filled at the time point and foamed at the same time as the filling.

The foamable resin composition is filled in a second molded product having a partially open structure and foamed at the same time, so that gas generated during foaming can be easily removed, and excellent physical properties can be provided by forming a uniform foamed foam. .

Therefore, the method of manufacturing the fiber-reinforced composite may not include a separate heating step for foaming the foamable resin composition. That is, it is possible to impart excellent productivity by providing a fiber-reinforced composite material filled with foamed foam in the hollow without an additional step in one in-line process.

The foamable resin composition may include a polyol compound and an isocyanate compound, which are aliphatic compounds having two or more hydroxy groups.

Specifically, the polyol compound may include one polyol selected from the group consisting of a polyester-based polyol, a polyether-based polyol, and a combination thereof. The polyol may have an isocyanate index of about 105 to about 115. For example, the polyol may be Ethylene glycol adipates-Butane diol adipates, Hexane diol adipates, and the like.

In addition, the manufacturing method of the fiber-reinforced composite includes the step of cooling the second molded product in a cooling mold to form a third molded product.

Specifically, the cooling mold may have a temperature of about 45° C. to about 65° C., and a third molded article may be formed in the temperature range. The third molded article may be a first UD prepreg having a hollow filled with foamed foam, as shown in (b) of FIG. 1. As described above, the first UD prepreg may include the first fiber reinforcement and the first resin matrix.

The method for manufacturing the fiber-reinforced composite may further include drawing and cutting the third molded product.

In addition, Figure 2 is a schematic view of a method of manufacturing a fiber-reinforced composite according to another embodiment of the present invention. Referring to this, the method of manufacturing the fiber-reinforced composite material may further include a winding step of winding a second UD prepreg on the first UD prepreg. When the second UD prepreg is wound on the first UD prepreg, a heating and pressurizing step of applying heat and pressure to an interface between the first UD prepreg and the second UD prepreg; including, and the second, the second UD prepreg. The UD prepreg may include a second fiber reinforcement material and a second resin matrix material, and orientation directions of the first fiber reinforcement material of the first UD prepreg and the second fiber reinforcement material of the second UD prepreg may be different from each other. .

Specifically, it may further include a winding step of winding the second UD prepreg on the first UD prepreg and a heating and pressing step.

The second UD prepreg includes a second fiber reinforcement material and a second resin matrix material, as described above.

The winding step is a process of winding the second UD prepreg on the first UD prepreg. As described above, the orientation directions of the first fiber reinforcement material of the first UD prepreg and the second fiber reinforcement material of the second UD prepreg may be different from each other.

The second UD prepreg is a string-shaped sheet and may be wound around the surface of the first UD prepreg using a filament winding method. Specifically, the second UD prepreg may be spirally wound on the first UD prepreg.

The heating and pressing step is a process of applying heat and pressure to an interface between the first UD prepreg and the second UD prepreg when the second UD prepreg is wound on the first UD prepreg.

Where the first UD prepreg and the second UD prepreg contain a thermoplastic resin as a resin matrix, adhesion between the first UD prepreg and the second UD prepreg is consolidation without a boundary surface. The heating device 5 and the pressurizing device 1 are required to achieve this.

The manufacturing method of the fiber-reinforced composite includes a heating step of heating the interface between the first UD prepreg and the second UD prepreg with a heating device 5, and the first UD prepreg and the second UD prepreg. It includes a pressing step of pressing the boundary surface of the pressing device 1.

It is preferable that the heating process and the pressing process are performed substantially simultaneously, and when there is a time difference between the heating process and the pressing process, the heating process is preferably performed before the pressing process.

The first UD prepreg may be rotated in a clockwise or counterclockwise direction. The second UD prepreg is guided toward the UD prepreg via the guide bar 4 while maintaining a constant tension, and may be wound on the surface of the UD prepreg rotating clockwise or counterclockwise. For example, the second UD prepreg may be spirally wound on the first UD prepreg.

In addition, in the manufacturing method of the fiber-reinforced composite material, in a winding process, the second UD prepreg may be sequentially wound along a long axis of the first UD prepreg while maintaining a pre-designed tension. In this case, the boundary surface between the first UD prepreg and the second UD prepreg is moved along a long axis of the first UD prepreg. In this case, in the heating and pressing process, heat and pressure are applied to the interface between the first UD prepreg and the second UD prepreg moving along the long axis of the first UD prepreg.

On the top of the first UD prepreg, a pressing device 1, for example, a pressing roll 1 as shown in FIG. 2 may be disposed. Specifically, the second UD prepreg 6 may be disposed between the first UD prepreg and the pressure roll 1.

The second UD prepreg 6 is inserted between the first UD prepreg and the pressure roll 1 via a guide bar 4 while maintaining a constant tension, and the first UD prepreg (2) can be placed on top. When the second UD prepreg 6 is inserted between the first UD prepreg 2 and the pressure roll 1 and contacts the surface of the first UD prepreg 2, the first The UD prepreg 2 and the second UD prepreg 6 may be heat treated by a heating device 5 to a temperature equal to or higher than the melting point.

By doing so, the second UD prepreg 6 wound on the surface of the first UD prepreg 2 can be bonded to the first UD prepreg 2, and the pressure roll 1, In order to remove voids at the contact point of the first UD prepreg 2 and the second UD prepreg 6 and to smoothly bond, the first UD prepreg 2 is located above the second UD prepreg 6. ) Can be rotated in the opposite direction to the direction of rotation.

The guide bar 4 may move along a long axis direction or a length direction of the first UD prepreg 2. The heating device 5 can move along the long axis direction or the length direction of the first UD prepreg 2 in association with the guide bar 4.

The heating device 5 may be designed to track the bonding surface of the first UD prepreg 2 and the second UD prepreg 6. The heating device (5) tracks the bonding surface of the first UD prepreg (2) and the second UD prepreg (6), and the first UD prepreg (2) and the second UD prepreg (6) can be heated locally at the same time.

In other words, the heating device 5 is sequentially wound along the long axis of the first UD prepreg 2 while the second UD prepreg 6 maintains a constant tension. 1 track the bonding surface of the first UD prepreg (2) and the second UD prepreg (6) moving along the long axis of the UD prepreg (2), and the first UD prepreg (2) and the first 2 Heat is applied to the interface of the UD prepreg 6 to locally sequentially heat the first UD prepreg 2.

In the opposite case, for example, if heat is applied to the entire length of the first UD prepreg, it is continuously heated at a point other than the boundary where consolidation is to be made and the shape of the material is deformed or seriously the material is damaged. It can be oxidized. Accordingly, an example of the heating device 5 is a laser capable of locally applying heat to the bonding surface of the first UD prepreg 2 and the second UD prepreg 6 while maintaining a constant temperature. At least one of an irradiation device, a hot gas injection device, an ultraviolet irradiation device, and a direct fire device may be mentioned.

On the other hand, the pressing device 1, for example, the pressing roll 1, may move along the long axis direction or the length direction of the first UD prepreg 2 in conjunction with the guide bar 4 Alternatively, the first UD prepreg 2 may have a long axis longer than the length of the long axis, and may be fixedly disposed on the first UD prepreg 2. For consolidation of the bonding surface of the first UD prepreg 2 and the second UD prepreg 6, the pressurizing device 1 applies the second UD prepreg 6 using pneumatic pressure. It must be able to pressurize with a constant pressure. On the other hand, for consolidation of the bonding surface of the first UD prepreg 2 and the second UD prepreg 6, a certain tension is applied even when the bobbin on which the second UD prepreg 6 is wound is unwound. Should be maintained.

The first UD prepreg 2 and the second UD prepreg 6 are preferably prepared in a process separate from the process of the manufacturing method of the fiber-reinforced composite material.

For example, when the second UD prepreg 6 is manufactured during the process in the manufacturing method of the fiber-reinforced composite material, in the process of guiding the reinforcing fiber mat to the outer circumferential surface of the first UD prepreg 2 while maintaining a certain tension. , By allowing the reinforcing fiber mat to pass through a resin bath containing the resin matrix, a method of impregnating the fiber reinforcing material into the resin matrix may be considered. However, with the above-described method, there is a problem that the fiber reinforcement material is not completely impregnated with the resin matrix material. In addition, when the fiber reinforcement is impregnated with the resin matrix, since the resin impregnation process is performed in the atmosphere, fine voids may be included in the resin matrix impregnated with the fiber reinforcement by air in the atmosphere.

In addition, the first UD prepreg 2 and the second UD prepreg 6 include a thermoplastic resin as a resin matrix, and the first UD prepreg 2 and the second UD prepreg 6 Excellent bonding strength can be imparted just by applying heat to the bonding surface of

In the case of manufacturing a thermosetting resin-based fiber reinforcement using the filament winding method, a metal mandrel or liner is used instead of the first UD prepreg (2), and the reinforcing fiber mat is maintained at a constant tension. In the process of guiding to the mandrel or liner, the reinforcing fiber mat is passed through a bath containing the thermosetting resin to obtain a thermosetting resin impregnated with the reinforcing fiber, and then wound around the mandrel or liner, followed by thermosetting. Although a method of curing the resin may be considered, this method has a problem in that productivity is lowered due to a subsequent curing process of the thermosetting resin, and the toughness in the longitudinal direction of the mandrel or liner is weak.

The manufacturing method of the fiber-reinforced composite material is, for example, on the first UD prepreg 2 in which the first fiber reinforcement is oriented in one direction in the long axis direction of the first UD prepreg 2, the second fiber reinforcement By winding the second UD prepreg 6 so that the orientation direction of the first fiber reinforcement crosses the orientation direction of the first fiber reinforcement material, it is possible to provide a fiber-reinforced composite material with reinforced toughness by reinforcing in the multiaxial directions in the major axis direction and the minor axis direction. have.

In addition, in the manufacturing method of the fiber-reinforced composite material, in manufacturing a multiaxially reinforced fiber-reinforced composite material using a filament winding method, the resin of the first UD prepreg 2 and the second UD prepreg 6 By including a thermoplastic resin as a matrix, a subsequent curing process is not required unlike the case where the thermosetting resin is used, and thus productivity can be improved compared to the case where the thermosetting resin is used.

Matters related to the first fiber reinforcement material and the second fiber reinforcement material, and the first resin matrix material and the second resin matrix material are as described above.

Meanwhile, in addition to the above, two or more layers of the second UD prepreg 6 having different second orientation directions of the second fiber reinforcement may be wound on the first UD prepreg 2. In other words, the second UD prepreg 6 may be wound on the first UD prepreg 2 in a multi-layered structure. In this case, the multi-layered structure of the second UD prepreg 6 is, The second fiber reinforcement may include layers having different second orientation directions. In the multi-layered structure of the second UD prepreg 6, the included angle between the second fiber reinforcements of different layers may be, for example, greater than about 0° and less than about 180°.

The multi-layered structure of the second UD prepreg 6 is the toughness of a portion vulnerable to external force when the second UD prepreg 6 is wound in a single layer on the outer circumferential surface of the first UD prepreg 2 In order to further reinforce the first orientation direction of the first fiber reinforcement of the first UD prepreg (2) and a second between the second fiber reinforcement of each layer of the multilayer structure of the second UD prepreg (6). It is preferable that the orientation directions are different from each other.

Therefore, when the second UD prepreg 6 is wound in a multilayer structure on the outer circumferential surface of the first UD prepreg 2, the fiber-reinforced composite material is the first fiber of the first UD prepreg 2 The first orientation direction of the reinforcement material and the second orientation direction of the second fiber reinforcement material of each layer of the multilayer structure of the second UD prepreg 6 may each include at least one region different from each other.

The fiber-reinforced composite material includes the first UD prepreg having a hollow filled with the foamed foam manufactured by the above method, and a second UD prepreg wound around the outer circumferential surface of the first UD prepreg. Including, it is possible to provide a fiber-reinforced composite material having excellent weight reduction and excellent mechanical properties and shock absorption at the same time, excellent 3D shape realization and productivity, and further reinforced in a multiaxial direction.

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are merely for illustrating or explaining the present invention in detail, and the present invention is not limited thereto.

<Examples and Comparative Examples>

Example 1

A prepreg prepared by impregnating a first resin base material with polyethylene terephthalate resin into a continuous glass fiber as a first fiber reinforcement material was molded in a molding mold at about 220° C. to prepare a first molded article having a partially open structure. . A second molded product was formed by filling the first molded product manufactured by the molding mold with a foamable resin composition. At this time, the foamable resin composition contains polyol, ethylene glycol adipates-butane diol adipates, and methylene diphenyl diisocyanate (MDI) in a mass ratio of 2: 1, , The foamable resin composition was filled in the first molding at a point 3/4 between the molding mold and the cooling mold. In addition, the second molded product was cooled in a cooling mold at about 50° C. to about 60° C. to prepare a third molded product, which is a first UD prepreg having a hollow filled with polyurethane foam. The third molding was drawn and cut to prepare a fiber-reinforced composite.

Example 2

The second UD prepreg sheet was disposed on the top of the first UD prepreg having a hollow filled with polyurethane-based foam foam that rotates in a counterclockwise direction, and rotates in a clockwise direction. Supplied. At this time, the second UD prepreg sheet was prepared by impregnating continuous glass fibers, which is a second fiber reinforcing material, with polyethylene terephthalate resin, which is a second resin matrix.

In addition, the second UD prepreg sheet is in a state in which a constant tension is maintained by a supply roll rotating in a counterclockwise direction, the first UD prepreg rotating in a counterclockwise direction, and a pressure roll rotating in a clockwise direction. Via a bar, the first UD prepreg was inserted between the first UD prepreg and the pressing roll along the long axis direction of the first UD prepreg.

The outer circumferential surface of the first UD prepreg and the interface of the second UD prepreg in contact with each other were heated by using a heating device at a temperature equal to or higher than the melting point of the first UD prepreg and the second UD prepreg sheet.

A fiber-reinforced composite material including the second UD prepreg sheet joined in a wound state on the outer peripheral surface of the first UD prepreg by means of a heating device and a pressure roll was obtained.

The first UD prepreg was used in which the first fiber reinforcement was oriented in one direction along a long axis direction. The second UD prepreg sheet was used in which the second fiber reinforcement was oriented in one direction along the longitudinal direction (input direction of the first UD prepreg). At this time, the angle between the first fiber reinforcement and the second fiber reinforcement in the orientation direction was set to 80°.

Comparative Example 1

A fiber-reinforced composite was manufactured in the same manner as in Example 1, except that the foamable resin composition was not filled in the first molded product manufactured by the molding mold.

<Evaluation>

Experimental Example 1: Flexural load (N)

The fiber-reinforced composite material prepared in Examples was subjected to a three-point bending test according to ASTM D790 standard to measure the flexural load, and the results are shown in Table 1.

Experimental Example 2: Density (g/cm 3)

In order to check the weight reduction effect of the fiber-reinforced composite prepared in Examples, the density was measured according to ASTM D792 standard, and the results are shown in Table 1.

Example 1 Example 2 Comparative Example 1 Flexural load (N) 2030 2120 1850 Density (g/cm ³ ) 0.96 1.84 1.83

As shown in Table 1, it can be seen that the fiber-reinforced composite material of the embodiment has an excellent flexural load. In addition, it can be seen that the fiber-reinforced composite material of the embodiment is uniformly filled with foamed foam, so that the non-bending load, which is a value obtained by dividing the bending load by the density, is remarkably excellent. That is, the fiber-reinforced composite material of the embodiment can more effectively achieve weight reduction.

1: pressurization device
2: 1st UD prepreg
3: foaming foam
4: guide bar
5: heating device
6: 2nd UD prepreg

Claims (16)

delete delete delete delete Forming a first molded article by molding a prepreg in a molding mold;
Forming a second molded product by filling the first molded product with a foamable resin composition; And
Cooling the second molding in a cooling mold to form a third molding; It is one in-line process including,
The first molding has a hollow structure in which a part is opened, such as a horseshoe shape,
The foamable resin composition is filled at a point of 2.5/4 to 3.5/4 between the molding mold and the cooling mold.
Method for producing fiber-reinforced composites.
The method of claim 5,
The prepreg comprises a thermoplastic resin as a resin matrix
Method for producing fiber-reinforced composites.
The method of claim 5,
The third molding is a first UD prepreg having a hollow,
The hollow is filled with foam foam
Method for producing fiber-reinforced composites.
The method of claim 7,
The first UD prepreg includes a first fiber reinforcement and a first resin matrix
Method for producing fiber-reinforced composites.
The method of claim 5,
The foamable resin composition is foamed at the same time as it is filled in the first molding
Method for producing fiber-reinforced composites.
The method of claim 5,
Does not include a separate heating step for foaming the foamable resin composition
Method for producing fiber-reinforced composites.
The method of claim 8,
A winding step of winding a second UD prepreg on the first UD prepreg; further comprising,
When the second UD prepreg is wound on the first UD prepreg, a heating and pressurizing step of applying heat and pressure to the interface between the first UD prepreg and the second UD prepreg; and
The second UD prepreg includes a second fiber reinforcement and a second resin matrix,
The orientation directions of the first fiber reinforcement of the first UD prepreg and the second fiber reinforcement of the second UD prepreg are different from each other
Manufacturing method of fiber-reinforced composite.
The method of claim 11,
The second UD prepreg is spirally wound on the first UD prepreg
Manufacturing method of fiber-reinforced composite.
The method of claim 11,
In the winding step, the second UD prepreg is sequentially wound along the long axis of the first UD prepreg while maintaining a pre-designed tension,
The interface between the first UD prepreg and the second UD prepreg is moved along the long axis of the first UD prepreg,
The heating and pressing step is to apply heat and pressure to an interface between the first UD prepreg and the second UD prepreg moving along the long axis of the first UD prepreg.
Manufacturing method of fiber-reinforced composite. The method of claim 5,
The temperature of the molding mold is 180 ℃ to 250 ℃
Manufacturing method of fiber-reinforced composite.
The method of claim 5,
The temperature of the cooling mold is 45 ℃ to 65 ℃
Manufacturing method of fiber-reinforced composite.
The method of claim 5,
The foamable resin composition is filled when the surface temperature of the first molded product is 70 ℃ to 80 ℃
Manufacturing method of fiber-reinforced composite.

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