KR102267885B1 - Sandwich type composite material and method for preparing the same - Google Patents

Abstract

porous composite sheet; and a continuous fiber-reinforced composite sheet disposed on both sides of the porous composite sheet, wherein the porous composite sheet includes a first fiber; a second fiber; and a binder for binding the first fiber and the second fiber, wherein the first fiber and the second fiber are bound by the binder to form an irregular network structure including pores, the first The fiber includes an inorganic fiber or an organic fiber, the second fiber includes a first thermoplastic resin, the binder includes a second thermoplastic resin, the inorganic or organic fiber, and the melting point of the first thermoplastic resin Each is higher than the melting point of the second thermoplastic resin, the continuous fiber-reinforced composite material sheet provides a sandwich-type composite material comprising a third thermoplastic resin and continuous fibers having a single orientation, and a method for manufacturing the same.

Description

Sandwich type composite material and manufacturing method thereof

It relates to a sandwich-type composite material and a method for manufacturing the same.

In the case of a conventional porous composite material, reinforcing fibers such as glass fibers and carbon fibers and polymer fibers are mixed in a wet papermaking process to form a sheet, and then laminated and heated to foam (lofting) and press molding. The porous composite material prepared as described above exhibits excellent sound absorbing and insulating performance, thermal insulation properties and weight reduction. However, the porous structure has a disadvantage in that absolute strength is lowered compared to the conventional high-density composite material, and it is difficult to impart strength in a desired direction.

On the other hand, in order to impart strength in a desired direction, a composite material in which the orientation of the fibers is adjusted is used. For example, the unidirectional continuous fiber-reinforced composite material is manufactured in the form of a sheet by impregnating a reinforcing fiber such as glass fiber or carbon fiber, which exhibits high rigidity, in a sheet form, laminating and heating according to the purpose, and then press molding.

Such a composite material has high strength and can be laminated according to the purpose to give strength in a desired direction, but it is heavier than a porous composite material and has a problem in that sound absorption and insulation performance and thermal insulation performance are lowered.

One embodiment of the present invention provides a lightweight sandwich-type composite material having high mechanical properties and excellent sound absorbing and insulating performance and thermal insulation properties. The sandwich-type composite material can easily impart strength in a desired direction, and can simultaneously secure not only mechanical properties such as tensile strength and flexural strength, but also sound absorbing and insulating performance, thermal insulation performance, and weight reduction.

Another embodiment of the present invention provides a method for manufacturing the sandwich-type composite material.

In one embodiment of the present invention, a porous composite sheet; and a continuous fiber-reinforced composite sheet disposed on both sides of the porous composite sheet, wherein the porous composite sheet includes a first fiber; a second fiber; and a binder for binding the first fiber and the second fiber, wherein the first fiber and the second fiber are bound by the binder to form an irregular network structure including pores, the first The fiber includes an inorganic fiber or an organic fiber, the second fiber includes a first thermoplastic resin, the binder includes a second thermoplastic resin, the inorganic or organic fiber, and the melting point of the first thermoplastic resin Each is higher than the melting point of the second thermoplastic resin, the continuous fiber-reinforced composite material sheet provides a sandwich-type composite material comprising a third thermoplastic resin and continuous fibers having a single orientation.

In another embodiment of the present invention, (a) providing a porous composite sheet and a continuous fiber-reinforced composite sheet; and (b) laminating the continuous fiber-reinforced composite material sheet on both sides of the porous composite material sheet, and then press-molding to prepare a sandwich-type composite material; including, wherein the manufacturing of the porous composite material sheet comprises: (a1) preparing a slurry solution by dispersing the reinforcing fibers and the bicomponent polymer fibers in an aqueous solution; (a2) forming a web from the slurry solution by a wet papermaking process; and (a3) heat-treating and drying the web to prepare a porous composite material sheet, wherein the reinforcing fiber is a first fiber including an inorganic fiber or an organic fiber, and the bicomponent polymer fiber is It includes a core portion including a first thermoplastic resin and a sheath portion including a second thermoplastic resin, wherein the melting point of the inorganic fiber or organic fiber and the first thermoplastic resin is that of the second thermoplastic resin, respectively. Higher than the melting point, the step of manufacturing the continuous fiber-reinforced composite material sheet comprises the steps of (a4) introducing a continuous fiber pulled out from a plurality of skeins in the form of roving into a mold; and (a5) impregnating a third thermoplastic resin into the continuous fiber put into the mold to prepare a continuous fiber-reinforced composite material sheet, wherein the continuous fiber-reinforced composite material sheet has a third thermoplastic resin and single orientation Provided is a method for manufacturing a sandwich-type composite material including continuous fibers.

The sandwich-type composite material has excellent sound absorption performance and thermal insulation performance, and mechanical strength and weight reduction by a structure in which a porous composite material sheet and a continuous fiber-reinforced composite material sheet are laminated.

The porous composite sheet is a method using a wet process, and as compared to a dry process, uniform physical properties can be implemented throughout, and fiber dispersibility is improved. The continuous fiber-reinforced composite material sheet is manufactured to have a single orientation of continuous fibers pulled out from skeins of a roving type, thereby exhibiting excellent mechanical strength according to the fiber direction.

The sandwich-type composite material according to the manufacturing method of the present invention exhibits a high level of sound absorption performance, flexural strength and stiffness, for example, package trays, road floors, and luggage of automobiles requiring rigidity and sound absorption performance. It can be applied to interior materials such as trim, insulation boards and partition panels of buildings that require rigidity, sound absorption and insulation performance.

1 is a schematic schematic diagram of a sandwich-type composite material according to an embodiment of the present invention.
2 is a schematic schematic view of a porous composite material sheet in a sandwich-type composite material according to an embodiment of the present invention.
3 is a schematic schematic view of a continuous fiber-reinforced composite sheet in a sandwich-type composite material according to an embodiment of the present invention.
4 is a flowchart illustrating a method of manufacturing a sandwich-type composite material according to an embodiment of the present invention.
5 schematically illustrates a process of manufacturing a porous composite sheet in the method for manufacturing a sandwich-type composite material according to an embodiment of the present invention.
6 schematically illustrates a process in which a continuous fiber-reinforced composite sheet is manufactured in a method for manufacturing a sandwich-type composite material according to an embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

In order to clearly express any layer or region in the drawings, the thickness or size thereof is enlarged. And in the drawings, for convenience of description, some layers or regions are exaggerated. Like reference numerals refer to like elements throughout.

Hereinafter, a sandwich-type composite material and a method for manufacturing the same according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Sandwich type composite material

In one embodiment of the present invention, a porous composite sheet; and a continuous fiber-reinforced composite sheet disposed on both sides of the porous composite sheet, wherein the porous composite sheet includes a first fiber; a second fiber; and a binder for binding the first fiber and the second fiber, wherein the first fiber and the second fiber are bound by the binder to form an irregular network structure including pores, the first The fiber includes an inorganic fiber or an organic fiber, the second fiber includes a first thermoplastic resin, the binder includes a second thermoplastic resin, the inorganic or organic fiber, and the melting point of the first thermoplastic resin Each is higher than the melting point of the second thermoplastic resin, the continuous fiber-reinforced composite material sheet provides a sandwich-type composite material comprising a third thermoplastic resin and continuous fibers having a single orientation.

In the present specification, the first fiber and the second fiber are only described separately as the first and second for convenience in order to indicate that they are separate from each other in consideration of their raw material components, and that they are necessarily fibers of different materials. it doesn't mean

Likewise, in the present specification, the first thermoplastic resin, the second thermoplastic resin, and the third thermoplastic resin are only described separately as first, second, and third for convenience to indicate that they are separate from each other, and must be It does not mean that resins of different materials are used.

1 is a schematic schematic diagram of a sandwich-type composite material 100 according to an embodiment of the present invention. Referring to FIG. 1 , the sandwich type composite material 100 includes a porous composite material sheet 10 and a continuous fiber-reinforced composite material sheet 20 disposed on both sides of the porous composite material sheet.

Porous Composite Sheet (10)

2 is a schematic schematic view of a porous composite material sheet 10 in a sandwich-type composite material according to an embodiment of the present invention. Referring to FIG. 2 , the porous composite material sheet 10 includes a first fiber 11 and a second fiber 12 , and a binder for binding the first fiber 11 and the second fiber 12 . ashes (13).

In this case, the first fiber 11 includes an inorganic fiber or an organic fiber, the second fiber 12 includes a first thermoplastic resin, and the binder 13 includes a second thermoplastic resin. In addition, the inorganic fiber or organic fiber, and the melting point of the first thermoplastic resin is higher than the melting point of the second thermoplastic resin, respectively.

The binder 13 is present in a coated state on a part or the entire surface of each of the first fibers 11 and the second fibers 12 . The coating portions formed on the respective surfaces of the first fiber 11 and the second fiber 12 by the binder 13 are fused to each other, and the first fiber 11 and the second fiber 12 are fused to each other. ) between; between a plurality of the first fibers (11); Alternatively, the plurality of second fibers 12 may be irregularly bound. Accordingly, the porous composite material sheet 10 has an irregular three-dimensional network structure including open pores, and has a porous structure through the irregular three-dimensional network structure.

Since the sound wave entering through the open cell of the porous structure is attenuated by the vibration of the fiber, sound absorbing and insulating performance can be realized.

The porous composite material sheet 10 may have a porosity of about 20% by volume to about 80% by volume, and in this range, light weight and excellent sound absorbing and insulating performance may be achieved.

In the porous composite material sheet 10, the higher the porosity, the higher the content of the second fibers 12, and the longer the length through which the sound wave passes, the better the energy attenuation effect. The length through which the sound wave passes, for example, becomes longer when the thickness of the material itself is large or the connectivity of pores is excellent even when the material has the same porosity.

The first fiber 11 uses an inorganic fiber such as glass fiber or carbon fiber or an organic fiber made of a thermoplastic resin material, and the second fiber 12 uses a fiber made of a thermoplastic resin material.

Based on 100 parts by weight of the first fiber 11, the total content of the second fiber 12 and the binder 13 may be about 20 parts by weight to about 60 parts by weight. If it is out of this range, it may be difficult to exhibit excellent strength according to the first fiber 11 and the second fiber 12 , and it may be insufficient to form a porous structure by the binder 13 .

In addition, the amount of the binder 13 may be about 30 parts by weight to about 200 parts by weight based on 100 parts by weight of the second fiber 12 .

The second fiber 12 and the binder 13 originate from a bicomponent polymer fiber, and the second fiber 12 corresponds to a core portion of the bicomponent polymer fiber, and the binder 13 ) corresponds to the sheath of the bicomponent polymer fiber, and the first fiber 11 originates from the reinforcing fiber. In the manufacturing method to be described later, the porous composite sheet 10 capable of exhibiting excellent mechanical strength and weight reduction by controlling the content ratio of each component constituting the bicomponent polymer fiber and the content ratio of the reinforcing fiber and the bicomponent polymer fiber is obtained. can

The specific gravity of the inorganic or organic fiber and the first thermoplastic resin is preferably greater than about 1, and more preferably about 1 to about 2. The porous composite sheet 10 is manufactured by a wet papermaking process, and reinforcing fibers and the bicomponent polymer fibers are blended and dispersed in an aqueous solution. At this time, considering that the specific gravity of water is about 1, when the specific gravity of the first fiber 11 and the second fiber 12 is greater than about 1, the first fiber 11 and the second fiber 12 are It can exhibit excellent dispersibility without floating on the surface of the aqueous solution, and can exist in the form of fibers even after thermoforming. Accordingly, the mechanical strength of the porous composite material sheet 10 may be improved.

The first fiber 11 may have a cross-sectional diameter of about 5 μm to about 30 μm. In this range, the first fibers 11 are strong against external impacts, and at the same time provide adequate strength, and at the same time ensure excellent dispersibility in aqueous solution, thereby facilitating sheet formation.

The first fiber 11 may have a length of about 1 mm to about 20 mm. In this range, the first fibers 11 exhibit excellent strength of the porous composite material sheet 10 by imparting appropriate strength and binding force between the fibers at the same time. In addition, when the length of the first fiber 11 exceeds 20 mm, it may be unsuitable to form a sheet having a uniform thickness.

The first thermoplastic resin forming the second fiber 12 may be, for example, polyester, polypropylene (PP), polyethylene (PE), acrylbutadiene styrene (ABS), polycarbonate (PC), or nylon (Nylon). , polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polymethyl methacrylate (PMMA), polylactic acid (PLA), at least one selected from the group consisting of Teflon (polytetrafluoroethylene) and combinations thereof may include.

The second fiber 12 may have a cross-sectional diameter of about 5 μm to about 30 μm. In this range, the second fibers 12 are strong against external impacts, and at the same time provide adequate strength, and at the same time ensure excellent dispersibility in aqueous solution, thereby facilitating sheet formation.

The second fiber 12 may have a length of about 1 mm to about 18 mm. In this range, the second fibers 12 can secure excellent dispersibility in an aqueous solution, and exhibit excellent strength of the porous composite material sheet 10 by imparting a bonding force between the fibers. In addition, when the length of the second fiber 12 exceeds 18 mm, the fibers are agglomerated and agglomerated, resulting in reduced dispersibility and may be unsuitable to form a sheet having a uniform thickness.

The second thermoplastic resin forming the binder 13 is, for example, polyester, polypropylene (PP), polyethylene (PE), acrylbutadiene styrene (ABS), polycarbonate (PC), nylon (Nylon), At least one selected from the group consisting of polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polymethyl methacrylate (PMMA), polylactic acid (PLA), Teflon (polytetrafluoroethylene), and combinations thereof may include

The binder 13 corresponds to the sheath portion of the bicomponent polymer fiber, and the sheath portion is melted under a predetermined temperature condition and a part thereof is transferred to the surface of the first fiber 11, and as the binder 13, It serves to bind the first fiber 11 and the second fiber 12 .

Accordingly, the second thermoplastic resin constituting the binder 13 has a lower melting point than the inorganic or organic fibers constituting the first fiber 11 and the first thermoplastic resin.

More specifically, each of the inorganic or organic fibers and the first thermoplastic resin may have a melting point of about 200°C to about 280°C. If it is out of this range, it may be difficult to maintain the fiber shape because the binder may also be melted as the binder is melted. When their melting point is less than 200° C., the thermoforming temperature must be lowered to maintain the fiber shape, and the thermal stability of the porous composite sheet 10 may be lowered, which may result in dimensional deformation.

The melting point of the second thermoplastic resin may be less than about 200 °C, specifically, from about 100 °C to less than about 200 °C.

Melting points of the inorganic fiber or organic fiber, the first thermoplastic resin, and the second thermoplastic resin may be measured using a thermogravimetric analysis (TGA) device.

The porous composite sheet 10 may be made from about 50 g / m ² to have a basis weight of about 400g / m ^2, for ease of later-described heat treatment.

Continuous Fiber Reinforced Composite Sheet (20)

3 is a schematic schematic view of a continuous fiber-reinforced composite sheet in a sandwich-type composite material according to an embodiment of the present invention. Referring to FIG. 3 , the continuous fiber-reinforced composite material sheet 20 includes a third thermoplastic resin and continuous fibers 21 having a single orientation.

The continuous fiber 21 means a fiber existing in a continuous form without being broken depending on the final size of the composite material sheet to be manufactured, and the continuous fiber 21 may be manufactured in a continuous process, , By continuously supplying the continuous fibers to this continuous process, it is possible to manufacture a continuous fiber-reinforced composite material containing continuous fibers. The continuous fiber-reinforced composite material may be manufactured into a product having a specific shape such as a sheet, and in the product such as a sheet, the continuous fiber has a length in a specific range according to the shape of the product. However, the length of this specific range should be regarded as having continuity in that the continuous fiber 21 can be arbitrarily adjusted in the manufacturing process in which the continuous fiber 21 is continuously supplied.

That the continuous fibers 21 have a single orientation may mean that the continuous fibers 21 are impregnated in the third thermoplastic resin and arranged in one direction. In this case, the acute angle formed by the two predetermined continuous fibers in the continuous fiber-reinforced composite material sheet 20 may be about 10° C. or less, specifically, about 5° C. or less.

Since the continuous fiber 21 has a single orientation, it can exhibit superior strength than a general thermoplastic resin sheet, and can increase the strength in the fiber direction due to less bending of the fiber, and can exhibit structurally excellent strength and rigidity.

A sheet in which the continuous fibers 21 have a single orientation may be referred to as a unidirectional sheet (UD).

The continuous fiber 21 having the single orientation may have a cross-sectional diameter of about 5 μm to about 30 μm. By maintaining the average diameter of the continuous fibers 21 in this range, excellent strength can be realized, and the continuous fiber-reinforced composite material sheet 20 manufactured therefrom can exhibit appropriate thickness and physical properties.

The continuous fiber 21 may be, for example, glass fiber, carbon fiber, or the like.

The third thermoplastic resin is, for example, polyester, polypropylene (PP), polyethylene (PE), acrylbutadiene styrene (ABS), polycarbonate (PC), nylon (Nylon), polyvinyl chloride (PVC), polystyrene (PS), polyurethane (PU), polymethyl methacrylate (PMMA), polylactic acid (PLA), Teflon (polytetrafluoroethylene), and may include at least one selected from the group consisting of combinations thereof.

Like the second thermoplastic resin, the third thermoplastic resin may have a melting point of less than about 200°C, specifically, about 100°C to less than 200°C.

Based on 100 parts by weight of the continuous fiber having the single orientation, the amount of the third thermoplastic resin may be about 100 parts by weight to about 300 parts by weight. If the content of the resin is less than 100 parts by weight, it may be insufficient to impregnate the resin in the continuous fiber 21, and if it exceeds 300 parts by weight, waste of the resin occurs as the content of the resin increases and the resin is of a uniform thickness. It is difficult to manufacture the continuous fiber-reinforced composite material sheet 20 .

Considering the thickness and basis weight of the continuous fiber-reinforced composite material sheet 20, at least one sheet may be laminated, for example, 2 sheets each on both sides of the porous composite material sheet 10, a total of 4 sheets By laminating, the sandwich type composite material 100 can be manufactured. The stacking orientation of the continuous fiber-reinforced composite material sheet 20 may be from about 0° to about 90°, which means that the orientation directions of the continuous fibers 21 included in the adjacent continuous fiber-reinforced composite material sheet 20 are horizontal to each other. direction or perpendicular to each other. Depending on the lamination orientation of the continuous fiber-reinforced composite material sheet 20, the mechanical strength of the sandwich type composite material 100 varies, and when the lamination orientation is 0˚, horizontal direction, or one direction, it can be applied to a bumper back beam for automobiles. And, when the stacking orientation is 90˚, vertical, it can be applied to a seatback for an automobile.

As described above, the sandwich type composite material 100 according to an embodiment of the present invention is a continuous fiber-reinforced composite material sheet 20 including a porous composite material sheet 10 and continuous fibers having a single orientation. Due to the structure, the mechanical properties are high, and the effect of excellent sound absorption and insulation performance and thermal insulation performance is provided.

Sandwich type composite material 100 according to an embodiment of the present invention by adjusting the diameter, length, content ratio of fibers such as the first fiber 11 , the second fiber 12 , and the continuous fiber 21 . and it may have a basis weight of about 2mm to about 10mm and a thickness of approximately 1000g / m ² to about 5000g / m ^2.

As such, the sandwich-type composite material 100 may be made of a thin plate or sheet, and may exhibit excellent mechanical strength and weight reduction.

Sandwich Composite Manufacturing Method

In another embodiment of the present invention, there is provided a method for manufacturing the sandwich composite material.

4 is a flowchart illustrating a method of manufacturing a sandwich-type composite material according to an embodiment of the present invention. Referring to FIG. 4, the method for manufacturing a sandwich-type composite material includes the steps of preparing a porous composite sheet and a continuous fiber-reinforced composite sheet (S110) and the continuous fiber-reinforced composite sheet on both sides of the porous composite sheet. After lamination, press molding to prepare a sandwich-type composite material (S120).

5 schematically illustrates a process of manufacturing a porous composite sheet in the method for manufacturing a sandwich-type composite material according to an embodiment of the present invention.

First, preparing the porous composite sheet 10 includes (a1) preparing a slurry solution by dispersing reinforcing fibers and bicomponent polymer fibers in an aqueous solution, (a2) web by wet papermaking from the slurry solution Forming a (web), and (a3) heat-treating and drying the web (web) to prepare a porous composite sheet.

In this case, the reinforcing fiber is a first fiber including an inorganic fiber or an organic fiber, and the bicomponent polymer fiber includes a core portion including a first thermoplastic resin and a sheath portion including a second thermoplastic resin. include

Melting points of the inorganic or organic fibers and the first thermoplastic resin are higher than the melting points of the second thermoplastic resin, respectively. The inorganic or organic fiber, the first thermoplastic resin, and the second thermoplastic resin are the same as described above.

The slurry solution is prepared by dispersing the reinforcing fibers and the bicomponent polymer fibers in an aqueous solution. In this case, the reinforcing fiber and the bicomponent polymer fiber may further improve dispersibility in an aqueous solution by using a surface-treated surface of each of the fibers.

For example, in the surface treatment, functional groups such as a fluorine group, a hydroxyl group, a carboxyl group, an alkyl group, and a silane group may be introduced on the outermost surfaces of the reinforcing fiber and the bicomponent polymer fiber, or may be coated with a coating agent. Specifically, by silane-treating the surface of the reinforcing fiber and the bicomponent polymer fiber with a surface treatment agent or a coating agent, the bonding force between fibers is improved, or heat resistance is improved by carbonization, or hydrolysis (Hydrolysis). ) to improve hydrophilicity, or by oxidation (Oxidation) to improve water-based dispersibility.

In addition, when the surface of the reinforcing fiber and the bicomponent polymer fiber are surface treated, hydrophilicity/hydrophobicity, water repellency, flame retardancy, nonflammability, heat resistance, acid resistance, alkali resistance, durability, stain resistance, etc. may be provided depending on the coating agent can For example, the coating agent for the surface treatment may include a fluorine-based wax, a hydrocarbon-based wax, a silicone-based polymer, and the like, and the fluorine-based wax or the hydrocarbon-based wax may serve as a water repellent.

In the step of preparing the slurry solution, the total content of the reinforcing fibers and the bicomponent polymer fibers per 1 L of the aqueous solution may be about 0.1 g to about 10 g, and excellent dispersibility can be ensured in this range, and uniformity A web of one thickness can be produced.

In addition, the pH of the aqueous solution may be about 1 to about 4. By adjusting the pH of the aqueous solution to the above range, electric charges are generated on the surfaces of the reinforcing fiber and the bicomponent polymer fiber, thereby further improving dispersibility.

The slurry solution may include about 20 parts by weight to about 60 parts by weight of the bicomponent polymer fiber based on 100 parts by weight of the reinforcing fiber.

In addition, the bicomponent polymer fiber may include about 30 parts by weight to about 200 parts by weight of the sheath, for example, about 50 parts by weight to about 100 parts by weight based on 100 parts by weight of the core part. have.

The web 60 is manufactured by using the slurry solution in a wet papermaking process.

The slurry solution 40 is prepared by uniformly mixing and stirring the reinforcing fibers and the bicomponent polymer fibers in an aqueous solution using a stirrer 30 . The slurry solution is made into a wet web while following a mesh moving along the conveyor belt 50 . The wet web 60 may be manufactured while the slurry solution is dehydrated by passing through the vacuum intake system 70 .

The conveyor belt may have an inclination at a predetermined angle with respect to the ground, if necessary. Accordingly, at least a portion of the reinforcing fibers and the bicomponent polymer fibers may have orientation in the moving direction of the conveyor belt, and in this case, high strength may be realized in the orientation direction.

Then, the wet web may be heat-treated and dried through a dryer to manufacture the porous composite material sheet 10 . The drying is performed at a temperature lower than the melting point of the second thermoplastic resin so that the sheath portion of the bicomponent polymer fiber does not melt, and the drying temperature of the dryer may be about 100°C to about 180°C.

6 schematically illustrates a process in which a continuous fiber-reinforced composite sheet is manufactured in a method for manufacturing a sandwich-type composite material according to an embodiment of the present invention.

The manufacturing of the continuous fiber-reinforced composite material sheet 20 includes (a4) introducing continuous fibers drawn from a plurality of skeins of a roving type into a mold, and (a5) adding to the continuous fibers injected into the mold. and impregnating a third thermoplastic resin to prepare a continuous fiber-reinforced composite material sheet.

The continuous fibers 21 are continuously drawn out from the continuous fibers in the roving form and are continuously introduced into the mold. At this time, the continuous fibers 21 may be input to have a single orientation within the continuous fiber-reinforced composite material sheet. . Accordingly, with respect to 100 parts by weight of the continuous fiber having a single orientation, the third thermoplastic resin may be included in an amount of about 100 parts by weight to about 300 parts by weight. In addition, since the continuous fibers 21 have a single orientation, it is possible to easily secure the strength and rigidity of the continuous fiber-reinforced composite material sheet 20 .

The sheet in which the continuous fiber 21 is impregnated with the third thermoplastic resin is press-molded using the calendar process, so that the single orientation of the continuous fiber 21 can be easily secured and continuous fiber reinforcement with excellent surface properties A composite material sheet 20 can be obtained.

Then, the continuous fiber-reinforced composite material sheet 20 is laminated on both sides of the prepared porous composite material sheet 10 and press-molded to prepare a sandwich-type composite material 100 .

The press molding is performed by pressing at a predetermined temperature, and more specifically, the press molding may be performed at a temperature higher than the melting point of the second thermoplastic resin and the third thermoplastic resin to a temperature lower than the melting point of the first thermoplastic resin. have.

Through the press molding, the sheath portion of the bicomponent polymer fiber may be melted to serve as a binder, and a pore structure may be formed by physically weaving the reinforcing fiber and the core portion of the bicomponent fiber. In addition, as the third thermoplastic resin is melted, the bonding force between the sheet and the sheet is increased, so that the sandwich type composite material 100 may be manufactured in the form of a single sheet or plate.

The press molding may be performed under a pressure of about 1 bar to about 20 bar. When the pressing pressure is less than 1 bar, adhesion between the interfaces of the sheets may be reduced, and if it exceeds 20 bar, it is difficult to form a pore structure of the porous composite sheet.

The press forming may be performed at about 100° C. to about 180° C., and when out of this range, the sandwich-type composite material 100 is manufactured in the form of one sheet or plate while the adhesion between the interfaces of the sheets is reduced. It is difficult.

The sandwich-type composite material according to the manufacturing method of the present invention exhibits a high level of sound absorption performance, flexural strength and stiffness, and can be applied to parts requiring rigidity, sound absorption performance and thermal insulation performance.

For example, it can be applied to interior materials such as package trays, road floors, and luggage trims of automobiles that require rigidity and sound absorption performance, and insulation boards and partition panels of buildings that require rigidity, sound absorption performance and thermal insulation performance.

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

<Examples and Comparative Examples>

Example 1

First, the polyester core part having a melting point of 260°C and the polyester sheath part having a melting point of 160°C have a weight ratio of 50:50, the length is 5 mm, and the diameter of the cross section perpendicular to the longitudinal direction is 4 denier (about 20 μm) of bicomponent polymer fibers were prepared.

Then, a glass fiber having a length of 13 mm, a diameter of a cross section perpendicular to the longitudinal direction of 13 μm and a melting point of 250° C. was prepared as a reinforcing fiber.

Based on 100 parts by weight of the reinforcing fiber, 40 parts by weight of the bicomponent polymer fiber was blended, and the mixture was stirred in an aqueous hydrochloric acid (HCl) solution adjusted to a pH of 2 to 2.5 for 1 hour to prepare a slurry solution. At this time, the amount of the reinforcing fibers and the bicomponent polymer fibers per 1 L of the aqueous solution was 2 g in total.

Then, the slurry solution was passed through a vacuum suction system while moving through a mesh moving on a conveyor belt to prepare a wet web. The wet web was completely dried by passing through an oven dryer at 140° C. to prepare a porous composite sheet. The dried porous composite sheet had a basis weight of 200 g/m 2 and a thickness of 2 mm.

Subsequently, glass fibers drawn from a plurality of skeins in the form of roving are put into a mold, and the glass fibers are impregnated with a polypropylene resin having a melting point of 160° C. to have a basis weight of 400 g/m 2 and a thickness of 0.7 mm. A material sheet was prepared. The glass fiber is coated to have a thickness of 16 μm, and the glass fiber and the polypropylene resin have a weight ratio of 50:50.

Then, 8 sheets are laminated so that the basis weight of the porous composite sheet is 1600 g/m2, and then two sheets of the continuous fiber-reinforced composite material are laminated on both sides, but the orientation directions of the continuous fibers included in adjacent sheets are perpendicular to each other A total of 4 sheets were laminated so as to be in the same direction.

The laminated sheets were pressed at 200° C. under a pressure of 5 bar to prepare a sandwich-type composite material having a final thickness of 5 mm.

Example 2

A sandwich-type composite material was prepared in the same manner as in Example 1, except that the reinforcing fibers included in the porous composite sheet were PET fibers having a cross-sectional diameter of 1.4 denier (about 7 μm) and a length of 13 mm.

Example 3

After stacking 8 sheets so that the basis weight of the porous composite material sheet prepared in Example 1 is 1600 g/m2, laminate 2 sheets of the continuous fiber-reinforced composite material sheet prepared in Example 1 on both sides each, but included in adjacent sheets A sandwich-type composite material was prepared in the same manner as in Example 1, except that a total of four sheets were stacked so that the orientation directions of the continuous fibers were in the horizontal direction to each other.

Comparative Example 1

Only 16 sheets of the porous composite material prepared in Example 1 were laminated, and then pressurized at 200° C. under a pressure of 5 bar to prepare a composite material having a final thickness of 5 mm and a basis weight of 3200 g/m 2 .

Comparative Example 2

Only the continuous fiber-reinforced composite material sheets prepared in Example 1 were laminated, but 8 sheets were laminated so that the orientation directions of the continuous fibers included in adjacent sheets were perpendicular to each other, and then pressurized at 200° C. under a pressure of 5 bar to obtain the final thickness A composite material of 5 mm and a basis weight of 3200 g/m 2 was prepared.

Comparative Example 3

Only the continuous fiber-reinforced composite material sheets prepared in Example 1 were laminated, but 8 sheets were laminated so that the orientation directions of the continuous fibers included in adjacent sheets were in the horizontal direction to each other, and then pressurized at 200 ° C. A composite material of 5 mm and a basis weight of 3200 g/m 2 was prepared.

2. Methods for evaluating physical properties and their results

The composite materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were each left at room temperature for 24 hours, and then measured as follows.

1) Flexural strength and flexural modulus were measured according to ISO 178 standards. In the following flexural strength and flexural modulus, "horizontal" is measured in the transverse direction of the composite material sheet, and "vertical" is measured in the longitudinal direction of the composite material sheet.

2) The average sound absorption coefficient is the average of the values measured at frequencies in the high frequency range (500 Hz to 6300 Hz) based on KS2816-2.

3) Thermal conductivity is measured according to ASTM C 518.

[Table 1]

Referring to the results of Table 1, it can be seen that the composite materials of Examples 1 to 3 have better flexural strength, flexural modulus, and sound absorption performance than the composite materials of Comparative Examples 1 to 3.

Examples 1 to 3 are panels of a sandwich structure, Comparative Example 1 is a porous composite panel, and Comparative Examples 2 and 3 are non-porous panels. The sound absorption performance is due to the presence of a porous structure, and in the case of Examples 1 to 3, it can be confirmed that the porous structure is present, so that it is possible to implement the sound absorption performance. In the case of Comparative Example 1, since the entire material has a porous structure, it can be seen that, while the sound absorption performance is excellent compared to Examples 1 to 3, the flexural strength is significantly lowered.

The sandwich-type composite material of the present invention exhibits a high level of sound absorption performance, flexural strength and stiffness, and can be applied to parts requiring rigidity, sound absorption performance and thermal insulation performance.

The sandwich-type composite material of the present invention can be applied to interior materials such as package trays, road floors, and luggage trims of automobiles that require rigidity and sound absorption performance. In addition, it can be applied to insulation boards, partition panels, etc. of buildings that require rigidity, sound absorption performance and thermal insulation performance.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, but may be manufactured in various different forms, and those of 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 illustrative in all respects and not restrictive.

10: porous composite material sheet
20: continuous fiber reinforced composite material sheet
21: continuous fiber
11: first fiber
12: second fiber
13: binder
100: sandwich type composite material
30: agitator
40: slurry solution
50: conveyor belt
60: web
70: vacuum intake system

Claims (19)

The sandwich-type composite material includes a porous composite material sheet; and a continuous fiber-reinforced composite sheet disposed on both sides of the porous composite sheet.
The porous composite material sheet
a first fiber; a second fiber; and a binder for binding the first fiber and the second fiber, wherein the first fiber and the second fiber are bound by the binder to form an irregular network structure including pores,
The first fiber includes an inorganic fiber or an organic fiber,
The second fiber comprises a first thermoplastic resin,
The binder includes a second thermoplastic resin,
The inorganic fiber or organic fiber, and the melting point of the first thermoplastic resin is higher than the melting point of the second thermoplastic resin, respectively,
The continuous fiber-reinforced composite material sheet is
A third thermoplastic resin and a continuous fiber having a single orientation,
The sandwich-type composite material has an average sound absorption coefficient of 0.08 to 0.09 in the range of 500 to 6300 Hz.
Sandwich type composite material.
According to claim 1,
The first fiber and the second fiber form a coating part formed by coating a part or the whole by the binder on the surface, and the coating part is fused to each other and bound to each other.
Sandwich type composite material.
According to claim 1,
Based on 100 parts by weight of the first fiber, the total content of the second fiber and the binder is 20 parts by weight to 60 parts by weight
Sandwich type composite material.
According to claim 1,
Based on 100 parts by weight of the second fiber, the binder is 30 parts by weight to 200 parts by weight.
Sandwich type composite material.
According to claim 1,
The first fiber has a cross-sectional diameter of 5 μm to 30 μm, and a length of 1 mm to 20 mm
Sandwich type composite material.
According to claim 1,
The second fiber has a cross-sectional diameter of 5 μm to 30 μm, and a length of 1 mm to 18 mm.
Sandwich type composite material.
According to claim 1,
The inorganic fiber or organic fiber, and the melting point of each of the first thermoplastic resin is 200 ℃ to 280 ℃,
The melting point of the second thermoplastic resin is less than 200 ℃
Sandwich type composite material.
According to claim 1,
The cross-sectional diameter of the continuous fiber having the single orientation is 5㎛ to 30㎛
Sandwich type composite material.
According to claim 1,
The melting point of the third thermoplastic resin is less than 200 ℃
Sandwich type composite material.
According to claim 1,
With respect to 100 parts by weight of the continuous fiber having the single orientation, the third thermoplastic resin is 100 parts by weight to 300 parts by weight.
Sandwich type composite material.
According to claim 1,
The sandwich composite material may have a basis weight of 1000g / m ² to 5000g / m ²
Sandwich type composite material.
According to claim 1,
The sandwich-type composite material has a thickness of 2 mm to 10 mm.
Sandwich type composite material.
(a) providing a porous composite sheet and a continuous fiber-reinforced composite sheet; and
(b) laminating the continuous fiber-reinforced composite material sheet on both sides of the porous composite material sheet, and then press molding to prepare a sandwich-type composite material;
The step of preparing the porous composite material sheet
(a1) preparing a slurry solution by dispersing the reinforcing fibers and the bicomponent polymer fibers in an aqueous solution; (a2) forming a web from the slurry solution by a wet papermaking process; and (a3) heat-treating and drying the web to prepare a porous composite sheet;
The reinforcing fiber is a first fiber including an inorganic fiber or an organic fiber,
The bicomponent polymer fiber includes a core portion including a first thermoplastic resin and a sheath portion including a second thermoplastic resin,
The inorganic fiber or organic fiber, and the melting point of the first thermoplastic resin is higher than the melting point of the second thermoplastic resin, respectively,
The step of manufacturing the continuous fiber-reinforced composite material sheet is
(a4) inputting continuous fibers drawn out from a plurality of skeins in the form of roving into a mold; and
(a5) impregnating the continuous fiber put into the mold with a third thermoplastic resin to prepare a continuous fiber-reinforced composite material sheet;
The continuous fiber-reinforced composite material sheet is
A third thermoplastic resin and a continuous fiber having a single orientation,
The sandwich-type composite material has an average sound absorption coefficient of 0.08 to 0.09 in the range of 500 to 6300 Hz.
A method for manufacturing a sandwich-type composite material.
14. The method of claim 13,
The inorganic fiber or organic fiber, and the melting point of each of the first thermoplastic resin is 200 ℃ to 280 ℃,
The melting point of the second thermoplastic resin is less than 200 ℃
A method for manufacturing a sandwich-type composite material.
14. The method of claim 13,
The melting point of the third thermoplastic resin is less than 200 ℃
A method for manufacturing a sandwich-type composite material.
14. The method of claim 13,
The press molding is
It is performed by applying a pressure of 1 bar to 20 bar at 100 ° C to 180 ° C.
A method for manufacturing a sandwich-type composite material.
14. The method of claim 13,
Mixing so that the total content of the reinforcing fiber and the bicomponent polymer fiber per 1 L of the aqueous solution is 0.1 g to 10 g
A method for manufacturing a sandwich-type composite material.
14. The method of claim 13,
The pH of the aqueous solution is 1 to 4
A method for manufacturing a sandwich-type composite material.
14. The method of claim 13,
The heat treatment and drying of the web is performed at 100°C to 180°C.
A method for manufacturing a sandwich-type composite material.

Images