KR102184463B1 - Method for manufacturing thermoplastic composite and thermoplastic composite prepared by the same - Google Patents

Abstract

Manufacturing a first molded article by laminating a composite sheet including inorganic fibers and a thermoplastic resin and a nonwoven sheet including organic fibers; Forming a second molded product by press-forming the first molded product; And inserting the second molded product into a mold for injection molding, wherein the injection molding comprises: heating the mold at a first temperature for 30 seconds to 50 seconds; And cooling the mold at a second temperature of 30° C. to 40° C. for 1 to 3 minutes, wherein the first temperature is higher than the glass transition temperature of the thermoplastic resin and the glass transition temperature of the organic fiber. It provides a method of manufacturing a phosphorus thermoplastic composite.

Description

Manufacturing method of thermoplastic composite material and thermoplastic composite material manufactured thereby {METHOD FOR MANUFACTURING THERMOPLASTIC COMPOSITE AND THERMOPLASTIC COMPOSITE PREPARED BY THE SAME}

It relates to a method of manufacturing a thermoplastic composite and a thermoplastic composite manufactured thereby.

In the case of industrial fields that are exposed to external environments such as automobiles and construction materials, a lot of composite materials with a high level of toughness are required. This is especially true of automotive exterior parts such as back beams, seat backs, and undercovers that are exposed to a lot of external shocks.

Therefore, strength and elongation are the two most important factors that affect the toughness of composites, as the degree of resistance and resistance against the force when impact is applied is the most important factor of composites and an essential standard factor that can be used for parts. The two variables are contradictory concepts, and the elongation is low because the strength is high and it is easy to break when it is hard, and the relatively soft composite material has high elongation, but the strength is not high. Therefore, various studies are being conducted to make a composite material excellent in both strength and elongation.

One embodiment of the present invention provides a method of manufacturing a thermoplastic composite material having excellent surface quality.

Another embodiment of the present invention provides a thermoplastic composite material having excellent roughness manufactured by the above manufacturing method.

In one embodiment of the present invention, manufacturing a first molded article by laminating a composite sheet including inorganic fibers and a thermoplastic resin and a nonwoven sheet including organic fibers; Forming a second molded product by press-forming the first molded product; And inserting the second molded product into a mold for injection molding, wherein the injection molding comprises: heating the mold at a first temperature for 30 seconds to 50 seconds; And cooling the mold at a second temperature of 30° C. to 40° C. for 1 to 3 minutes, wherein the first temperature is higher than the glass transition temperature of the thermoplastic resin and the glass transition temperature of the organic fiber. It provides a method of manufacturing a phosphorus thermoplastic composite.

In another embodiment of the present invention, a thermoplastic composite material manufactured according to the method for manufacturing the thermoplastic composite material is provided.

The method of manufacturing the thermoplastic composite material may prevent inorganic fibers from being exposed on the surface of the thermoplastic composite material, spoiling the appearance, and improve roughness. Accordingly, the thermoplastic composite material manufactured by the method of manufacturing the thermoplastic composite material may realize excellent surface quality.

1 schematically shows a composite sheet according to an 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, a method of manufacturing a thermoplastic composite is provided. The method of manufacturing the thermoplastic composite includes the steps of preparing a first molded product by laminating a composite sheet including inorganic fibers and a thermoplastic resin and a nonwoven sheet including organic fibers; Forming a second molded product by press-forming the first molded product; And inserting the second molded product into a mold for injection molding.

In this case, the step of injection molding may include heating the mold at a first temperature for 30 to 50 seconds; And cooling the mold at a second temperature of 30° C. to 40° C. for 1 to 3 minutes, wherein the first temperature is higher than the glass transition temperature of the thermoplastic resin and the glass transition temperature of the organic fiber. to be.

The thermoplastic composite material produced by the method of manufacturing the thermoplastic composite material is not exposed to the surface of the thermoplastic composite material, so that the inorganic fiber may have an excellent tactile and visual appearance design. Therefore, the thermoplastic composite material manufactured by the method for manufacturing the thermoplastic composite material can be used as an interior and exterior material for automobiles having a large area. In addition, since the thermoplastic composite material manufactured by the method of manufacturing the thermoplastic composite material has an improved roughness, excellent surface quality may be realized.

Hereinafter, a method of manufacturing the thermoplastic composite will be described in more detail.

First, the method of manufacturing the thermoplastic composite material includes the step of manufacturing a first molded article by laminating a composite sheet including inorganic fibers and a thermoplastic resin and a nonwoven sheet including organic fibers.

In the case of manufacturing a thermoplastic composite material using only a composite sheet containing inorganic fibers and a thermoplastic resin without a nonwoven sheet, the inorganic fibers included in the composite sheet may be exposed on the surface of the thermoplastic composite material, thereby impairing the appearance design. For example, an arrangement shape of inorganic fibers may be seen on the surface of the composite material, and some of the inorganic fibers may be exposed on the surface to reduce the surface quality of the composite material.

The first molding is a laminated sheet of a nonwoven fabric containing organic fibers on a composite sheet containing inorganic fibers and a thermoplastic resin, and the shape of the inorganic fibers included in the composite sheet can be prevented from being exposed to the surface of the thermoplastic composite. have.

Specifically, the nonwoven sheet may be laminated on one side of the composite sheet so that the nonwoven sheet is positioned toward the surface of the thermoplastic composite manufactured by the thermoplastic composite manufacturing method. Since the first molded article has the above structure, inorganic fibers are not exposed on the surface of the thermoplastic composite material, so that it can have an excellent tactile and visual appearance design. Therefore, the thermoplastic composite material manufactured by the method for manufacturing the thermoplastic composite material can be used as an interior and exterior material for automobiles having a large area.

The first molded article includes a composite sheet comprising inorganic fibers and a thermoplastic resin. The composite sheet may be manufactured by a conventional method in the field to which this invention belongs. For example, the composite sheet may be prepared by impregnating an inorganic fiber with a thermoplastic resin, or may be prepared by laminating a thermoplastic resin sheet on the inorganic fiber sheet and pressing at a high temperature.

The thermoplastic resin included in the composite sheet is an aromatic vinyl resin, a rubber-modified aromatic vinyl resin, a polyphenylene ether resin, a polycarbonate resin, a polyester resin, a (meth)acrylate resin, and a polyarylene sulfide. It may include one selected from the group consisting of resins, polyamide resins, polyvinyl chloride resins, polyolefin resins, and combinations thereof.

For example, the thermoplastic resin may include a polyolefin resin, and specifically may include a polypropylene resin. When the thermoplastic resin includes a polypropylene resin, it may be advantageous in terms of price competitiveness, and may be advantageous in improving the impact strength and tensile properties of the fiber-reinforced composite material. More specifically, the polypropylene resin may include a propylene-ethylene copolymer resin or a polypropylene homopolymer resin.

The composite sheet may include inorganic fibers together with the thermoplastic resin to simultaneously secure a light weight effect and an effect of improving strength. The inorganic fibers may include one selected from the group consisting of glass fibers, basalt fibers, carbon fibers, and combinations thereof.

The average diameter of the cross section of the inorganic fiber may be about 15 μm to about 20 μm. When the inorganic fiber has an average diameter in the above range, it is contained in a high content in the composite material to ensure excellent strength and stiffness compared to the thickness, it is advantageous to secure lightweight properties, and it may be advantageous in terms of processability in the manufacturing process. .

The inorganic fibers may be included in the form of continuous fibers.

In this case, the continuous fiber means that it exists in a continuous form without being broken inside, depending on the final size of the composite sheet. For example, like the continuous fibers in a UD sheet (unidirection sheet), the continuous fibers can be produced in a continuous process, and by continuously supplying the continuous fibers to this continuous process, a composite sheet including continuous fibers can be manufactured. I can. Accordingly, the thermoplastic composite may be manufactured into a product having a specific shape, such as a sheet, and in such a product, the continuous fibers have a length of a specific range depending on the shape of the product. However, since the length of this specific range can be arbitrarily adjusted in the manufacturing process in which the continuous fiber is continuously supplied, the continuous fiber should be considered to have'continuity', and most of the continuous fibers such as UD sheet or continuous fiber In case, it does not break inside the product and has continuity.

In one embodiment, the composite sheet may include continuous fibers such that the continuous fibers have a single orientation, such as a UD sheet.

1 is a schematic plan view of a composite sheet 100 according to an embodiment of the present invention. Referring to FIG. 1, the composite sheet 100 includes continuous fibers 10, and in this case, the continuous fibers may have a single orientation within the composite sheet. Since the continuous fiber has a single orientation in the composite sheet, it may be advantageous in securing excellent strength and rigidity.

Specifically, the fact that the continuous fiber has a single orientation means that when one specific fiber strand is determined among the continuous fibers in the thermoplastic resin, the angle formed by the specific continuous fiber with any other continuous fiber is about 10° or less, specifically about It should be understood that this includes cases of less than 5°, and not only completely parallel to each other, but also non-parallel cases with an error range of a degree that is difficult to discern when observed with the naked eye.

The composite sheet may include continuous fibers other than long fibers or short fibers, and thus there is no problem of dispersibility of fibers, and may include fibers of a high content. Accordingly, the thermoplastic composite material prepared from the composite sheet may have improved mechanical properties such as excellent surface quality, evenly realizing physical properties, and high strength properties. Typically, short fibers may mean fibers of about 1 mm or less, and long fibers may mean fibers of about 50 mm or less. When using such short fibers or long fibers, there is a problem of dispersibility in the composition, and the fibers cannot be included in a high content. In addition, there is a problem that the surface quality of the composite material is deteriorated and physical properties such as mechanical strength are deteriorated.

As such, the composite sheet may provide excellent strength and rigidity by including inorganic fibers in the form of continuous fibers.

The composite sheet may include 30 parts by weight to 60 parts by weight of the inorganic fiber based on 100 parts by weight of the thermoplastic resin. When the inorganic fiber is included in less than the above range, the required strength and rigidity of the thermoplastic composite material including the composite sheet cannot be secured, and light weight properties may be deteriorated. In addition, when the inorganic fiber is included in an amount exceeding the above range, it is difficult to uniformly impregnate the inorganic fiber in the composite sheet during the manufacturing process, and there is a concern that the surface properties of the composite sheet may be deteriorated.

The first molded product is manufactured by laminating a nonwoven fabric sheet on the composite sheet, and the nonwoven fabric sheet includes organic fibers. The first molded product may include a nonwoven fabric sheet including organic fibers in the composite sheet, so that the inorganic fibers included in the composite sheet may be prevented from being exposed on the surface of the thermoplastic composite material and spoiling the exterior design. For example, it is possible to prevent an arrangement of inorganic fibers from being seen on the surface of the composite material, or from exposing some of the inorganic fibers to the surface to deteriorate the apparent surface quality of the composite material.

The organic fiber may include one selected from the group consisting of polyethylene terephthalate, polypropylene, polyurethane, and combinations thereof. For example, the nonwoven fabric sheet may be a polyethylene terephthalate nonwoven fabric and/or a polypropylene nonwoven fabric, and the nonwoven fabric sheets may each be prepared using a spun bonding method or a chemical bonding method. have.

For example, the first molded product may include a polyethylene terephthalate nonwoven fabric manufactured using a chemical bonding method, and in this case, in particular, sound absorption performance and scratch resistance may be easily improved.

The ratio of the thickness of the composite sheet to the thickness of the nonwoven sheet may be about 3:1 to about 5:1. The first molded product may maintain excellent mechanical properties and have excellent surface properties by including the composite sheet and the nonwoven sheet in a thickness ratio within the above range.

The method of manufacturing the thermoplastic composite material includes the step of forming a second molded product by pressing the first molded product. The first molded product may be press-molded at a temperature of about 80° C. to about 90° C. for about 3 minutes to about 4 minutes, thereby achieving a high level of stiffness and impact strength in the second molded product manufactured therefrom.

The method of manufacturing the thermoplastic composite material includes the step of inserting the second molded product into a mold and performing injection molding. In this case, the step of injection molding may include heating the mold at a first temperature for 30 to 50 seconds; And cooling the mold at a second temperature of 30° C. to 40° C. for 1 minute to 3 minutes. The first temperature is a temperature higher than the glass transition temperature of the thermoplastic resin and the glass transition temperature of the organic fiber. Specifically, the first temperature may be about 30° C. to about 50° C. higher than the glass transition temperature of the thermoplastic resin and the glass transition temperature of the organic fiber.

The thermoplastic composite material is heated and cooled as described above, so that inorganic fibers are not exposed on the surface of the thermoplastic composite material, so that it can have an excellent tactile and visual appearance design. In addition, since the thermoplastic composite material manufactured by the method of manufacturing the thermoplastic composite material has an improved roughness, excellent surface quality may be realized.

Specifically, in the injection molding, the mold is heated for 30 seconds to 50 seconds at a first temperature that is higher than the glass transition temperature of the thermoplastic resin and the glass transition temperature of the organic fiber. The heating temperature is a temperature higher than the glass transition temperature of the thermoplastic resin and the glass transition temperature of the organic fiber, and by heating for the above range time, heat can be uniformly and widely spread to the surface of the second molded product. The design may be more uniformly implemented on the surface of the thermoplastic composite material, and the entire second molded product may be prevented from being cracked or cracked by the high temperature. Accordingly, it is possible to improve the surface quality without deteriorating the mechanical properties of the thermoplastic composite material including the second molding. Specifically, when the heating temperature and the heating time are less than the above ranges, there may be a problem in that the design is not expressed delicately, and the pattern or design is not completely transferred. In addition, when the heating temperature and heating time exceed the above ranges, there may be a problem in that the physical properties of the thermoplastic composite material are deteriorated, and the second molded product is distorted or overheated and partially carbonized.

In addition, the injection molding includes cooling the mold at a second temperature of 30°C to 40°C for 1 to 3 minutes after the heating step. The surface structure can be microscopically adjusted by cooling during the temperature range and the above time, and thus, remarkably improved roughness can be realized. Specifically, when the second temperature is less than the above range and the time is shorter than the above time, there may be a problem that the design is not clearly expressed and stains are generated on the surface. In addition, when the second temperature exceeds the above range and the cooling time exceeds the above time, there may be a problem in that the physical properties of the thermoplastic composite material are deteriorated.

Another embodiment of the present invention provides a thermoplastic composite manufactured according to the method of manufacturing the thermoplastic composite. The method of manufacturing the thermoplastic composite material is as described above, and the thermoplastic composite material produced accordingly does not reveal inorganic fibers on the surface of the thermoplastic composite material, and thus may have an excellent tactile and visual appearance design. Therefore, the thermoplastic composite material manufactured by the method for manufacturing the thermoplastic composite material can be used as an interior and exterior material for automobiles having a large area. In addition, since the thermoplastic composite material manufactured by the method of manufacturing the thermoplastic composite material has an improved roughness, excellent surface quality may be realized.

The thermoplastic composite material manufactured according to the method of manufacturing the thermoplastic composite material may have a total thickness of about 1.0 mm to about 2.0 mm. The thermoplastic composite material maintains excellent mechanical properties even in the above-described thickness range, while simultaneously implementing various designs evenly on the surface and implementing excellent roughness.

The thermoplastic composite may have an average surface roughness (Rz) of about 20 μm to about 50 μm. In the present invention, the average surface roughness (Rz) is a surface roughness parameter representing the surface roughness based on the standard KS B 0601, and RZ is also referred to as a ten point average roughness (ten point height). A random straight line (reference line) parallel to the average line of the cross-sectional curve is drawn and expressed as the difference between the average value of the distance from the reference line of the five highest peaks and the average value of the distance from the reference line of the lowest five valleys.

The thermoplastic composite material can be used for interior and exterior materials for automobiles having a large area by having an average surface roughness within the above range. In addition, the thermoplastic composite material can be exposed to the surface of the interior and exterior materials for automobiles as it is, without additional work to cover the surface, so that the production speed can be improved and it is economical.

The thermoplastic composite material may be used as an interior and exterior material for automobiles. The thermoplastic composite material may exhibit excellent mechanical properties including inorganic fibers and thermoplastic resins. In addition, as described above, the thermoplastic composite material manufactured by using the method of manufacturing the thermoplastic composite material does not reveal the inorganic fibers on the surface of the thermoplastic composite material, and thus has an excellent tactile and visual appearance design, and has improved roughness, Excellent surface quality can be realized.

Therefore, the thermoplastic composite material can be used as an interior and exterior material for automobiles having a large area. Specifically, it is possible to implement excellent durability when used as a vehicle exterior material that is exposed to the outside.

For example, the thermoplastic composite material is automobile exterior materials such as bumpers, spoilers, side visors, cowl vent grills, radiator grills, side moldings, and end panel garnishes, and automotive interior materials such as instrument panels, ceilings, doors, seats, and trunk compartment It can be used for the purpose of.

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.

< Example And Comparative example >

Example One:

A first molded article was manufactured by laminating a nonwoven sheet made of polyethylene terephthalate on the top of the composite sheet including glass fibers and polypropylene resin. At this time, the composite sheet contains 60 parts by weight of the glass fiber based on 100 parts by weight of the polypropylene resin, and the glass fiber is a continuous fiber.

The first molded product was press-molded at 80-90°C to form a second molded product. Then, the second molding was inserted into a mold and injection-molded to prepare a thermoplastic composite. At this time, in the injection molding, the mold was heated at a first temperature of about 220° C. for 45 seconds, and then the mold was cooled at a second temperature of 40° C. for 3 minutes.

Comparative example One:

A thermoplastic composite was manufactured in the same manner as in Example 1, except that the injection molding was heated at a first temperature of 250° C. for 45 seconds.

Comparative example 2:

A thermoplastic composite was manufactured in the same manner as in Example 1, except that the injection molding was cooled at a second temperature of 60°C-70°C for 3 minutes.

Comparative example 3:

A thermoplastic composite was manufactured in the same manner as in Example 1, except that the injection molding was heated at a first temperature of 250° C. for 45 seconds, and then cooled at a second temperature of 60° C.-70° C. for 3 minutes.

<Evaluation>

Experimental example 1: Average surface roughness ( Rz )

For the thermoplastic composites prepared in Example 1 and Comparative Examples 1-3, the average value (Rz) of the surface irregularities was measured using a surface roughness meter (roughness meter SJ-301, Mitutoyo Corporation), and is shown in Table 1 below. The smaller the average value of the irregularities, the more even the surface is.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Rz(㎛) 32 84 55 116

As shown in the table above, the composite material of the example was manufactured through heating and cooling processes, and unlike the composite material of the comparative example, it can be confirmed that it has excellent roughness.

100: composite sheet
10: continuous fiber

Claims (13)

Manufacturing a first molded article by laminating a composite sheet including inorganic fibers and a thermoplastic resin and a nonwoven sheet including organic fibers;
Forming a second molded product by press-forming the first molded product; And
Including; inserting the second molded product into a mold for injection molding;
The injection molding may include heating the mold at a first temperature for 30 to 50 seconds; And cooling the mold at a second temperature of 30° C. to 40° C. for 1 to 3 minutes, wherein the first temperature is higher than the glass transition temperature of the thermoplastic resin and the glass transition temperature of the organic fiber. sign
Method for producing a thermoplastic composite.
The method of claim 1,
The thermoplastic resin is an aromatic vinyl resin, rubber-modified aromatic vinyl resin, polyphenylene ether resin, polycarbonate resin, polyester resin, (meth)acrylate resin, polyarylene sulfide resin, polyamide Containing one selected from the group consisting of resins, polyvinyl chloride resins, polyolefin resins, and combinations thereof
Method for producing a thermoplastic composite.
The method of claim 1,
The inorganic fibers include one selected from the group consisting of glass fibers, basalt fibers, carbon fibers, and combinations thereof.
Method for producing a thermoplastic composite.
The method of claim 1,
The average diameter of the cross section of the inorganic fiber is 15㎛ to 20㎛
Method for producing a thermoplastic composite.
The method of claim 1,
The inorganic fiber is a continuous fiber
Method for producing a thermoplastic composite.
The method of claim 5,
The continuous fiber has a single orientation in the composite sheet
Method for producing a thermoplastic composite.
The method of claim 1,
The composite sheet comprises 30 parts by weight to 60 parts by weight of the inorganic fiber based on 100 parts by weight of the thermoplastic resin
Method for producing a thermoplastic composite.
The method of claim 1,
The organic fiber comprises one selected from the group consisting of polyethylene terephthalate, polypropylene, polyurethane, and combinations thereof
Method for producing a thermoplastic composite.
The method of claim 1,
The ratio of the thickness of the composite sheet to the thickness of the nonwoven sheet is 3:1 to 5:1
Method for producing a thermoplastic composite.
A thermoplastic composite material manufactured according to the method for manufacturing a thermoplastic composite material according to any one of claims 1 to 9.
The method of claim 10,
With a total thickness of 1.0 mm to 2.0 mm
Thermoplastic composite.
The method of claim 10,
With an average surface roughness (Rz) of 20 μm to 50 μm
Thermoplastic composite.
The method of claim 10,
Used as interior and exterior materials for automobiles
Thermoplastic composite.

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