KR20190075698A - Composite material reinforced with natural fiber and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a composite material reinforced with natural fibers and a method of manufacturing the same, which comprises heat treating a rope-like natural fiber from which lignin and hemicellulose have been removed, a polymer resin containing at least one thermoplastic polymer, an elastomer and a compatibilizer And then extruding the mixed resin composition with the thermally treated natural fiber to form an extruded material, and cutting the extruded material.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a composite material reinforced with natural fibers,

The present invention relates to a composite material and a method of manufacturing the composite material. More particularly, the present invention relates to a composite material reinforced with natural fibers.

Composite materials are used in various fields because they can improve the physical stiffness of general polymer materials. Since the composite material exhibits the main properties in the longitudinal direction of the fiber used as the reinforcement, the range of physical properties to be exhibited varies depending on the type and composition of the fiber reinforcement. That is, the fiber reinforcing material or the functional additive may be mixed with the matrix resin and the desired properties may be imparted by adjusting the content and arrangement. Among them, natural fibers reinforced with natural fibers, glass fiber reinforced polymers reinforced with glass fibers or carbon fibers, and carbon fiber reinforced polymers are representative examples.

For natural fiber composites, extruders are used to make pellets. However, since the natural fiber has a low apparent density because it is a porous article, when it is cut into a predetermined size for melt kneading and is fed into an extruder, feeding is not smooth and processing is difficult. Further, there is a problem that the natural fiber having a relatively low thermal stability is carbonized due to a high process temperature at the time of extrusion. Nevertheless, the melt-kneading process is fast and can be applied as a variety of products.

In order to overcome the problem of incorporation of conventional natural fibers, a method of modifying a natural fiber with a hydrophobic group and mixing with a polymer resin in a short fiber form has been proposed. However, this may increase the affinity with the polymer resin, but if the content of the staple fiber increases, the incorporation will not be smooth. As a result, there is a problem that the content of the natural fibers in the composite material is limited and the problem of carbonization (pyrolysis) of the natural fiber during the processing of the produced composite material is not solved. Particularly, when it is added to a polymer resin by using a short fiber of natural fibers, there is a disadvantage that the effect of reinforcing the physical properties of the polymer resin is insufficient.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a thermoplastic polymer composition which can be produced by continuously mixing rope-like natural fibers with a polymer resin containing a thermoplastic polymer, Fiber composite material.

It is another object of the present invention to suppress the generation of gas due to carbonization and moisture of natural fibers during the processing of a composite material through processing of natural fibers.

However, these problems are exemplary and do not limit the scope of the present invention.

According to one aspect of the present invention, there is provided a method for producing a thermoplastic resin composition, comprising the steps of: heat treating a rope-like natural fiber from which lignin and hemicellulose have been removed; a resin composition comprising a polymer resin containing at least one thermoplastic polymer, And extruding the heat-treated natural fiber to form an extruded material, and cutting the extruded material.

Also, according to an embodiment of the present invention, the heat treatment may be performed at a temperature ranging from 80 to 120 ° C for 8 to 24 hours to remove water from the natural fibers.

Also, according to an embodiment of the present invention, in the extruding step, the heat-treated natural fiber may be extruded by being mixed with the resin composition without breaking, and may be reinforced on the matrix of the polymer resin.

Also, according to one embodiment of the present invention, the extrusion may be performed at a temperature ranging from 150 to 180 ° C.

According to an embodiment of the present invention, injection molding may be further performed at a temperature ranging from 160 to 190 ° C.

According to an embodiment of the present invention, the thermoplastic polymer may be a polypropylene (PP), a polyethylene (PE), a low-density polyethylene (LDPE), a high-density polyethylene ), Polyvinyl alcohol (PVA), polyamide 11 (PA11), polyamide 12 (PA12), ethylene-propylene diene terpolymer rubber (EPDM rubber) and styrene-ethylene Butylene-styrene (SEBS), or a combination thereof.

According to an embodiment of the present invention, the natural fibers may be selected from the group consisting of jute, sial, coconut fiber, coir, hemp, bamboo, Naphtha, and kenaf, or combinations thereof.

According to another aspect of the present invention, there is provided a resin composition comprising a polymer resin containing at least one thermoplastic polymer, an elastomer, and a compatibilizer, and a rope-like A natural fiber composite material comprising natural fibers is provided.

According to an embodiment of the present invention, the natural fibers may be heat-treated at a temperature ranging from 80 to 120 캜 for 8 to 24 hours to remove moisture.

Further, according to one embodiment of the present invention, the natural fibers can be continuously mixed with the resin composition without breaking, extruded, and reinforced on the matrix of the polymer resin.

According to an embodiment of the present invention, the thermoplastic polymer may be a polypropylene (PP), a polyethylene (PE), a low-density polyethylene (LDPE), a high-density polyethylene ), Polyvinyl alcohol (PVA), polyamide 11 (PA11), polyamide 12 (PA12), ethylene-propylene diene terpolymer rubber (EPDM rubber) and styrene-ethylene Butylene-styrene (SEBS), or a combination thereof.

According to an embodiment of the present invention, the natural fibers may be selected from the group consisting of jute, sial, coconut fiber, coir, hemp, bamboo, Naphtha, and kenaf, or combinations thereof.

According to one embodiment of the present invention as described above, a rope-like natural fiber is continuously mixed with a polymer resin containing a thermoplastic polymer to produce a natural fiber composite material in which natural fibers are uniformly reinforced on a matrix of a polymer .

In addition, the present invention has an effect of suppressing the generation of gas due to carbonization and moisture of natural fibers during the processing of the composite material through the processing of natural fibers.

Of course, the scope of the present invention is not limited by these effects.

1 is a flowchart showing a method of manufacturing a natural fiber composite material according to an embodiment of the present invention.
2 is a schematic view showing an extrusion process of a natural fiber and a resin composition according to an embodiment of the present invention.
3 is a photograph showing the extrusion process of the natural fiber and the resin composition according to one embodiment of the present invention.
4 is a schematic view showing the shape of a natural fiber composite material according to an embodiment of the present invention.
5 is a photograph showing a pellet type natural fiber composite material according to an embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views, and length and area, thickness, and the like may be exaggerated for convenience.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

First, with reference to Figs. 1 to 3, a method of manufacturing the natural fiber composite material 1 will be described. FIG. 1 is a flow chart showing a manufacturing process of a natural fiber composite material 1 according to an embodiment of the present invention. FIG. 2 is a view showing a process of extruding a natural fiber 10 and a resin composition 20 according to an embodiment of the present invention 3 is a photograph showing the extrusion process of the natural fiber 10 and the resin composition 20 according to an embodiment of the present invention.

1, a step 10 of heat-treating a rope-like natural fiber 10 from which lignin and hemicellulose have been removed (S10), a resin composition 20 comprising a polymer resin containing at least one thermoplastic polymer, an elastomer and a compatibilizer, (S20) of cutting the extruded material (30) and cutting (S30) the extruded material (30) by mixing the heat-treated natural fibers (10)

First, the rope-like natural fiber 10 from which lignin and hemicellulose are removed through a chemical refining process is heat-treated (S10). The moisture contained in the natural fiber 10 is removed through the heat treatment to prevent generation of gas due to moisture during processing and an increase in processing temperature. The heat treatment may be performed by heat treatment for 8 to 24 hours at a temperature in the range of 80 to 120 占 폚 using a vacuum oven or a hot air oven to remove moisture.

Next, the resin composition 20 including the polymer resin, the elastomer and the compatibilizer containing the thermally treated natural fiber 10 and at least one thermoplastic polymer is extruded (S20). As shown in FIGS. 2 and 3, the material to be fed into the extruder 100 can be simultaneously fed into the feeder 110. The resin composition 20 is fed into the feeder 110 of the extruder 100 and the natural fiber 10 is fed directly into the screw 130 of the extruder 100. Meanwhile, the feeder 110 of the extruder 100 may be divided into a main feeder and a side feeder. The polymer resin of the resin composition 20 is a main feeder, the elastic material and the compatibilizer are fed into a main feeder or a side feeder, It is possible.

2 and 3, in the extrusion step S20, the heat-treated natural fiber 10 is mixed with the resin composition 20 without being broken and is mixed and extruded to be reinforced on the matrix of the polymer resin .

The natural fiber 10 can be continuously mixed with the resin composition 20 and the extruder 100 and extruded to form the extruded material 30 in order to solve the mixing problem due to the low density of the natural fiber 10. 2, when the resin composition 20 is fed into the feeder 110 of the extruder 100, the rope-like natural fibers 10 are continuously mixed with the screw 130 positioned directly on the feeder 110 . At this time, the natural fiber 10 is put into the extruder 100 without breaking. The natural fiber 10 is continuously introduced into the resin composition 20 along with the screw 130 of the extruder 100 and is extruded. Particularly, since the natural fiber 10 is not broken, it can be continuously incorporated into the resin composition 20 while maintaining the shape of the long fiber. This means that it is possible to increase the effect of reinforcing the physical properties while preventing the separation due to the density difference caused by mixing the natural fibers 10 of short fibers.

Further, according to one embodiment of the present invention, extrusion can be performed at a temperature in the range of 150 to 180 占 폚. Since the natural fiber 10 accelerates carbonization at 190 DEG C or higher, it is necessary to carry out the process at a temperature of 190 DEG C or lower. Further, since the polymer resin contains the thermoplastic polymer, it can be melted at an extrusion temperature of 150 to 180 DEG C and mixed well with the natural fiber 10, the elastomer and the compatibilizer. Preferably, the extrusion process can be carried out at 160 캜 to 170 캜.

The extruded material 30 is cut (S30), and the natural fiber composite material 1 is produced. The natural fiber composite material 1 may have a long shape or a cut shape. The extruded material 30 produced by extrusion is produced in a relatively large-diameter and long-length shape. At this time, it can be cut into a pellet using a pelletizer. The extruded material 30 is produced through the extruder 100 at a high temperature. At this time, it is preferable that the extruded material 30 is dried and cut in an air-cooling manner so that moisture is not absorbed. The pellet type natural fiber composite material 1 is easy to store and can be molded into a desired shape. The natural fiber composite material (1) can be produced as pellets having a size of 10 mm to 15 mm. However, the embodiment of the present invention is not limited thereto.

According to an embodiment of the present invention, injection molding may be performed at a temperature ranging from 160 to 190 ° C. The produced natural fiber composite material 1 can be molded into a specific shape through an injection process. At this time, injection molding can be performed at a temperature of 190 캜 or less so as to prevent the natural fiber 10 from being carbonized while having the shape of a molded product. Preferably injection molding can be carried out at a temperature in the range of 160 [deg.] C to 175 [deg.] C. The injection-molded natural fiber composite material 1 may be dried to remove volatile organic compounds such as inherent odor, carbon odor, and aldehyde. The drying may be performed at a temperature ranging from 80 ° C to 120 ° C for 8 hours to 24 hours using a vacuum oven or a hot air oven.

Next, the natural fiber composite material 1 will be described with reference to Fig. 4 is a schematic view showing a natural fiber composite material 1 reinforced on a matrix of a polymer resin of the resin composition 20 according to an embodiment of the present invention.

According to Fig. 4, the natural fiber composite material 1 comprises a resin composition 20 containing a polymer resin containing at least one thermoplastic polymer, an elastomer and a compatibilizing agent, lignin and hemicellulose removed, And may include reinforced rope-like natural fibers 10.

The natural fiber composite material (1) can be reinforced with a natural fiber (10) on a matrix of the polymer resin of the resin composition (20). The natural fiber 10 is a porous article having a low apparent density and thus is difficult to melt and knead. However, the natural fiber 10 can be reinforced on the matrix of the polymer resin by continuously injecting it into the resin composition 20 and the extruder.

According to one embodiment of the present invention, the natural fibers 10 may be continuously mixed with the resin composition 20 without breaking, and extruded to be reinforced on the matrix of the polymer resin.

The natural fiber 10 can be reinforced to the polymer resin by extrusion using an extruder 100. At this time, the resin composition 20 may be fed into the feeder of the extruder 100, and the natural fiber 10 may be fed into the main feeder or the side feeder of the feeder. The natural fiber 10 can be mixed with the resin composition 20 while being introduced into the form of long fibers without breaking through the screw 130 located in the feeder 110 of the extruder 100. Since the extrusion is performed simultaneously with the mixing, the phenomenon that the natural fibers 10 and the resin composition 20 are separated from each other due to the difference in density is reduced. It is possible to reinforce the natural fiber 10 on the matrix of the polymer resin with a large amount of content, so that the improvement of the physical properties of the natural fiber composite material 1 can be maximized.

At this time, the natural fibers 10 may be rope-shaped long fibers. When the natural fiber 10 is fed into the extruder 100, the long fiber rope-like natural fibers 10 are mixed with the resin composition 20 without breaking through the feeder 110 of the extruder 100. The short fiber natural fiber 10 has a relatively insufficient reinforcing effect compared to the long fiber. Since the natural fiber 10 of long fiber is difficult to mix as compared with the short fiber form, but the resin composition 20 and the natural fiber 10 are uniformly mixed with each other without being broken by continuous input, 10), it is possible to reinforce the physical properties effectively.

The natural fiber 10 contains lignin and hemicellulose, which causes the natural fiber to be carbonized (pyrolyzed) during the processing of the natural fiber composite material 1. When the natural fiber 10 is carbonized in the process of forming the composition of the natural fiber composite material 1 into a desired shape, the effect of reinforcing the physical property may be reduced. Therefore, it is necessary to chemically refine the natural fiber 10 to remove lignin and hemicellulose.

Also, according to an embodiment of the present invention, the natural fiber 10 may be subjected to heat treatment for 8 to 24 hours at a temperature ranging from 80 to 120 ° C to remove moisture. The natural fiber 10 contains moisture in addition to lignin and hemicellulose. The moisture contained in the natural fiber 10 may cause gas to be generated during the high-temperature processing. Further, since the processing temperature is increased, the carbonization rate of the natural fiber 10 is increased, which affects the physical properties of the natural fiber composite material 1. Therefore, it is necessary to heat-treat the natural fiber 10 before putting it into the extruder to remove water. Preferably, the natural fibers 10 may be heat treated using a vacuum oven or hot air oven at a temperature ranging from 80 to 120 DEG C for 8 to 24 hours to remove moisture.

According to an embodiment of the present invention, the thermoplastic polymer may be at least one selected from the group consisting of polypropylene (PP), polyethylene (PE), low-density polyethylene (LDPE), high-density polyethylene Polyethylene, HDPE, Polyvinylalcohol, PVA, Polyamide 11, PA11, Polyamide 12, PA12, Ethylene-propylene diene terpolymer rubber, EPDM rubber, And may be at least one selected from the group consisting of styrene-ethylene-butylene-styrene (SEBS), or a combination thereof. The thermoplastic polymer included in the polymer resin may be a commonly usable polymer. In order to minimize the carbonization of the natural fiber 10 during the processing of the natural fiber composite material 1, the processing temperature is adjusted to 190 ° C. or less. In this case, the thermoplastic polymer having a melting point of 190 ° C. or less . ≪ / RTI > The thermoplastic polymer may be one kind or two or more kinds of blend materials. Preferably, the thermoplastic polymer may be polypropylene.

In addition, according to one embodiment of the present invention, the natural fibers 10 may be selected from the group consisting of jute, sial, coconut fiber, coir, hemp, bamboo, And kenaf, or a combination thereof. The natural fiber 10 may be a material used to reinforce the polymer resin as an eco-friendly material. Lignin and hemicellulose may be chemically treated and removed and heat treated to remove moisture. The diameter of the natural fibers 10 may be between 1 mm and 15 mm, preferably 3 mm.

When the natural fiber 10 is mixed with the resin composition 20 and the natural fiber 10 to increase the content of the natural fiber 10 to improve the physical properties of the natural fiber 10, The impact strength of the natural fiber composite material 1 can be reduced. To compensate for this, the resin composition 20 may include an elastic body. The elastic body may be a conventional elastic body having a pellet shape and capable of blending with an affinity with a polymer resin during processing. Further, when the elastic body is non-polar, it may be an elastic body into which the polar group is introduced to increase the interfacial bonding force with the natural fiber 10 having polarity.

On the other hand, the resin composition (20) may contain a compatibilizing agent. A compatibilizer may be added to improve the interfacial bonding strength between the natural fiber 10 and the polymer resin. Preferably, the compatibilizing agent may be flupropylene incorporating maleic anhydride. Further, the natural fiber composite material 1 may further include a functional additive depending on the use thereof. It is possible to improve the functionality of the natural fiber composite material 1 including a lubricant, an inorganic filler, an odor removing agent and other additives. In particular, the odor of the natural fiber composite material 1 including the deodorant can be reduced, and a reinforcing agent can be added to improve rigidity, dimensional stability, and impart functionality such as surface roughness and friction coefficient.

5 is a photograph showing a pellet type natural fiber composite material 1 according to an embodiment of the present invention. Referring to FIG. 5, it can be seen that the pellet type natural fiber composite material 1 has a form in which the natural fiber 10 is reinforced on the matrix of the polymer resin contained in the resin composition 20. The natural fiber composite material 1 may be of the pellet type, but the embodiment of the present invention is not limited thereto. Conventional composite materials were able to separate natural fibers from polymeric resins due to differences in density, or to contain only a small amount of natural fibers. Since the natural fiber composite material 1 of the present invention is extruded by mixing the resin composition 20 and the long fiber natural fiber 10 without breaking the extruder 100, the natural fiber 10 is formed on the matrix of the polymer resin It can be reinforced effectively. In the natural fiber composite material 1, a large amount of the natural fibers 10 can be reinforced with the polymer resin.

Hereinafter, experimental examples for facilitating understanding of the present invention will be described. It should be understood, however, that the following examples are for the purpose of promoting understanding of the present invention and that the present invention is not limited to the following examples.

Experimental Example

First, the polymer resin, the natural fiber, the elastomer and the compatibilizer used in the present experimental example will be described.

Polypropylene (PP) is prepared as a thermoplastic polymer contained in the polymer resin. A polymer resin having at least a certain level of melt flow index (MI) mixed with at least two polypropylene is prepared in consideration of the moldability which varies depending on the content of the natural fiber. A polypropylene having a melt flow index (MI) of 30, 100 is prepared and referred to as MI 30 and MI 100, respectively.

The natural fibers are chemically refined to prepare rope-like refined kenafs containing lignin and hemicellulose without chemically refining with rope-like refining kenafs from which lignin and hemicellulose have been removed. Prepared long fibers of natural fibers for continuous introduction into an extruder, and prepared short fibers of comparative examples. The natural fiber is a rope-like fiber having a diameter of 3 mm.

The elastomer is TPV (Thermoplastic vulcanizates) which is exonmobil Santoprene 121-80 and the compatibilizer is polypropylene-graft-maleic anhydride with maleic anhydride.

Next, a method for producing a natural fiber composite material according to an experimental example of the present invention will be described.

First, a heat treatment process is performed to adjust the water content of natural fibers. The natural fibers are dried by heating at 80 DEG C for 24 hours using a vacuum oven or a hot air oven.

Then, the polymer resin containing polypropylene and the heat-treated natural fiber are continuously mixed in an extruder and extruded to form an extruded material. The polymer resin is fed into the main feeder of the extruder, and the elastomer, compatibilizer and other additives are selectively fed into the main feeder or the side feeder. The rope-like natural fibers are fed directly into the screw located in the feeder. The feed rate of the natural fiber can be controlled by the rotational speed of the main screw. At this time, the extrusion processing is performed at 160 캜 to 170 캜.

Then, the extruded material is dried and then cut into pellets using a pelletizer. Polypropylene Dry in air-cooled rather than water-cooled so that moisture is not absorbed during drying. The extruded polypropylene is cut into a pellet of 10 mm to 15 mm to produce a natural fiber composite material.

In order to compare the physical properties of the natural fiber composite material, the above-prepared pellet type natural fiber composite material is injection-molded. Injection molding is carried out at a temperature ranging from 160 ° C to 175 ° C with a variation of the metering rate of 2 seconds to 3 seconds. In order to minimize the carbonization of the natural fiber, and to improve the plasticization and dispersibility, a screw including a mixing portion and an expansion portion is used. The injection-molded natural fiber composite material is dried at 80 DEG C for 24 hours using a vacuum oven to remove odors and volatile organic compounds to produce injection molded articles of natural fiber composites.

[Table 1] below is a table showing comparative examples and experimental examples of the present invention. The physical properties of each of the extruded natural fiber composites were measured using different types and contents of polymer resin, natural fiber, elastomer, compatibilizer, and other additives.

[Table 1]

Referring to Table 1, the physical properties of the natural fiber composite material can be determined according to the comparative examples and experimental examples of the present invention, depending on the content of natural fibers, the shape and chemical refinement of the fibers, and the inclusion of elastomers and other additives have. The natural fiber composites were prepared by using MI 30 and MI 100 as the thermoplastic polymers in the polymer resin and by varying the content and refinement of the kenaf, which is a natural fiber. Particularly, in the case of Comparative Example 3, the natural fibers were used in the form of short fibers cut from 10 mm to 15 mm. At this time, the mixing with the polymer resin was not smooth and the maximum content of the natural fibers was limited to 30 parts by weight.

Hereinafter, the comparison of the physical properties of injection molded articles of the natural fiber composite material will be described with reference to the experimental examples and comparative examples given in Table 1 above.

1. Comparison of physical properties according to the content of natural fiber

Comparing Experimental Examples 1 to 3, the natural fiber composite materials of Experimental Example 1 exhibited excellent tensile strength and flexural strength, and the IZOD impact strength was the largest at 59J / m. In Experimental Examples 2 and 3, as the content of natural fibers increased, MI 30 having a different melt flow index of polypropylene as the polymer resin was used. Nevertheless, tensile strength and flexural strength were high, and IZOD impact strengths remained at 49 J / m and 46 J / m, respectively. In addition, although additives such as lubricants and deodorizers were added, there was no significant change in the physical properties of the natural fiber resin composite material. This means that the natural fiber composite material of the present invention can increase the content of the natural fiber and is not affected by physical properties even if it contains an additive for imparting function.

2. Comparison of physical properties according to elasticity

Comparing Example 1 with Comparative Example 1, the tensile strength, flexural strength and flexural modulus of Comparative Example 1 were similar to or higher than those of Experimental Example 1, but decreased to 38 J / m at IZOD impact strength . It can be seen that the IZOD impact strength, which is an important property in the use of the composite material, is insufficient when the natural fiber composite material is manufactured by excluding the elastic body. That is, it means that the elastomer is necessary to increase the content of natural fibers because it plays a role of complementing the decreasing impact strength as the content of natural fibers increases.

3. Comparison of physical properties according to kinds of natural fibers

First, referring to Experimental Example 1 and Comparative Example 2, it can be seen that when the untreated kenaf without removing lignin and hemicellulose is used as the natural fiber, the IZOD impact strength is reduced from 59 J / m to 17 J / m . This is because the natural fiber is carbonized by lignin and hemicellulose during injection molding, so that the IZOD impact strength is reduced. That is, in order to improve the impact strength of the natural fiber composite material, it is necessary to chemically refine the natural fiber to remove lignin and hemicellulose.

Further, when comparing the first and third comparative examples, it can be seen that the IZOD impact strength was reduced to 30 J / m when short fibers were used. Because natural fibers in short fibers are difficult to incorporate into polymer resins, the natural fiber content is limited and is not effectively reinforced on the matrix of polymeric resins. That is, when the natural fiber and the polymer resin are mixed, it means that the natural fiber of the long fiber is continuously introduced into the extruder and mixed therein, thereby effectively reinforcing the natural fiber on the matrix of the polymer resin.

As described above, it was found that the natural fiber composites of Experimental Examples 1 to 3 were excellent in tensile strength, flexural strength, and IZOD impact strength as compared with Experimental Examples 1 to 3 and Comparative Examples 1 to 3. This is because the natural fiber composites according to Experimental Examples 1 to 3 contain natural fibers, polymer resins, elastomers and compatibilizers from which lignin and hemicellulose have been removed, and they are well mixed on the polymer resin matrix by continuous introduction of natural fibers, Can be increased.

Accordingly, the natural fiber composite according to one embodiment of the present invention can uniformly reinforce the natural fibers on the polymer matrix by continuously mixing the rope-like natural fibers into the polymer resin containing the thermoplastic polymer. In addition, there is an effect of suppressing the generation of gas due to carbonization and moisture of the natural fiber during the processing of the composite material through processing of the natural fiber.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken in conjunction with the present invention. Variations and changes are possible. Such variations and modifications are to be considered as falling within the scope of the invention and the appended claims.

1: Natural fiber composites
10: Natural fibers
20: Resin composition
30: extruded material
100: extruder
110: feeder
130: screw

Claims (12)

Heat treating the rope-like natural fiber from which lignin and hemicellulose have been removed;
Forming an extruded material by mixing and extruding the thermally treated natural fiber with a resin composition comprising a polymer resin including at least one thermoplastic polymer, an elastomer, and a compatibilizer; And
Cutting the extruded material;
Wherein the fiber-reinforced composite material is a fiber-reinforced composite material. The method according to claim 1,
Wherein the heat treatment is performed at a temperature ranging from 80 to 120 DEG C for 8 to 24 hours to remove moisture of the natural fiber. The method according to claim 1,
Wherein the thermally treated natural fiber is extruded and reinforced on a matrix of the polymer resin without being cut off by being mixed with the resin composition and extruded. The method according to claim 1,
Wherein the extrusion is carried out at a temperature in the range of from 150 to 180 占 폚. The method according to claim 1,
Lt; RTI ID = 0.0 > 160-190 C. < / RTI > The method according to claim 1,
The thermoplastic polymer may be selected from the group consisting of polypropylene (PP), polyethylene (PE), low density polyethylene (LDPE), high density polyethylene (HDPE), polyvinyl alcohol Polyamide 11, PA11, Polyamide 12, PA12, Ethylene-propylene diene terpolymer rubber, and Styrene-ethylene-butylene-styrene -styrene, SEBS), or a combination thereof. The method according to claim 1,
The natural fiber may be at least one selected from the group consisting of jute, sial, coconut fiber, coir, hemp, bamboo, and kenaf. One or a combination thereof. A resin composition comprising a polymer resin comprising at least one thermoplastic polymer, an elastomer and a compatibilizing agent; And
Rope-like natural fibers reinforced on a matrix of the polymer resin from which lignin and hemicellulose are removed;
/ RTI > 9. The method of claim 8,
Wherein the natural fibers are heat treated at a temperature in the range of 80 to 120 占 폚 for 8 to 24 hours to remove moisture. 9. The method of claim 8,
Wherein the natural fibers are continuously united and continuously mixed with the resin composition and extruded to be reinforced on the matrix of the polymer resin. 9. The method of claim 8,
The thermoplastic polymer may be selected from the group consisting of polypropylene (PP), polyethylene (PE), low density polyethylene (LDPE), high density polyethylene (HDPE), polyvinyl alcohol Polyamide 11, PA11, Polyamide 12, PA12, Ethylene-propylene diene terpolymer rubber, and Styrene-ethylene-butylene-styrene -styrene, SEBS), or a combination thereof. 9. The method of claim 8,
The natural fiber may be at least one selected from the group consisting of jute, sial, coconut fiber, coir, hemp, bamboo, and kenaf. One or a combination thereof.

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