KR102311811B1 - Manufacturing Methode for Natural fiber composite material for injection molding using Reduced nozzle heating jig - Google Patents

Abstract

The present invention relates to a method for manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig, wherein one or more natural fiber yarns are located in the center, and the synthetic fiber yarns surround the outer periphery to produce a ply-twisted yarn. ply-twisted yarn manufacturing step (S1); And, the ply-twisted yarn is heat-compressed while passing through the reduction nozzle heating jig 100, and the synthetic fiber yarn is melted and compressed so that the voids C are reduced or disappeared, and partially absorbed by the natural fiber so as to be fusion-bonded. A fusion-bonded ply-twisted yarn manufacturing step (S2) of manufacturing a ply-twisted yarn; And, a pelletizing step (S3) of pelletizing the fusion-bonded ply-twisted yarn; It relates to a method of manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig, characterized in that it comprises a.

Description

Manufacturing method for natural fiber composite material for injection molding using Reduced nozzle heating jig

The present invention relates to a method for manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig, wherein one or more natural fiber yarns are located in the center, and the synthetic fiber yarns surround the outer periphery to produce a ply-twisted yarn. ply-twisted yarn manufacturing step (S1); And, the ply-twisted yarn is heat-compressed while passing through the reduction nozzle heating jig 100, and the synthetic fiber yarn is melted and compressed so that the voids C are reduced or disappeared, and partially absorbed by the natural fiber so as to be fusion-bonded. A fusion-bonded ply-twisted yarn manufacturing step (S2) of manufacturing a ply-twisted yarn; And, a pelletizing step (S3) of pelletizing the fusion-bonded ply-twisted yarn; It relates to a method of manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig, characterized in that it comprises a.

Natural fiber composite materials can be easily obtained from waste resources (such as woody raw materials such as wood waste, small hardwood and thinning wood, rice hull or husk powder derived from agricultural by-products, MDF processing by-product powder generated during MDF processing, tannin powder, etc.) Not only can it be obtained, but it is also relatively easy to compound and recycle. have meaning

In addition, unlike the existing inorganic raw materials, it is inexpensive to manufacture a composite using a material derived from nature as a reinforcing filler, and it is non-toxic and minimizes the impact on environmental pollution due to recycling of waste resources and unique biodegradability. Natural products used in natural fiber composites have several advantages in solving environmental problems that will become a big problem in the future, and are currently being used in the automobile and construction industries in Europe and the United States.

Most of the natural fiber composite materials currently used or researched are used as deck materials for construction by adding natural fibers to polyolefin (PP, PE, PS) polymers, which are currently most used in the polymer industry, and are also used as structural materials and packaging materials. It is practically used or is being developed as a solvent or as an interior material for automobiles.

The manufacturing of natural fiber composite materials is largely divided into Nonwoven Web Process and Melt Blending Process, and among them, research on natural fiber-plastic composite materials manufactured by melt-kneading is the most active. The possibility of replacing existing calcium carbonate (CaCO3), talc (Talc), clay, etc. has been explored while applying the processing technology used in the existing plastic industry as it is, and these natural fibers reinforce the synthetic resin. Its use as a filler shows considerable potential from an environmental point of view.

In addition, the advantages obtained by using natural fibers as reinforcing fillers are that the density of the final product can be lowered, the abrasiveness of the processing machine can be reduced, and the price is low. On the other hand, disadvantages include incompatibility between polar lignocellulosic raw materials and non-polar thermoplastic polymers and biodegradable polymers, and poor resistance to moisture and weather resistance.

In relation to such a natural fiber composite material, in the prior art, "Method for manufacturing natural fiber-reinforced plastic for automobile interior material and natural fiber-reinforced plastic for automobile interior material manufactured by the method of Patent Document 1 (Korea Patent Publication No. 10-2016-) 0023967)", 5 to 35% by weight of natural fibers having an average length of 5 mm or more and 1 to 10% by weight of a coupling agent are first mixed, and then 55 to 80% by weight of a plastic resin is added to the main inlet of the twin-screw extruder, and the A technique for performing extrusion by introducing a mixture of natural fibers and a coupling agent into a side inlet of a twin-screw extruder is disclosed.

However, the prior art has a problem in that the natural fiber and the plastic resin must be mixed together with the coupling agent in the equipment for performing the extrusion, so the process is relatively complicated, and efficient and uniform mixing is not guaranteed. There is a problem that the added coupling agent may have a harmful effect such as generation of volatile organic compounds (VOCs) during the process.

In order to solve this problem, a method of pre-mixing a natural fiber composite material in the form of pellets and manufacturing it, and then allowing it to be used directly in a conventional extrusion or injection process has been continuously studied. As an existing invention related to the pelletization of such a natural fiber composite material, in the "Method for Manufacturing Kenyaf Composite Material for Automotive Interior Material (Republic of Korea Patent Publication No. 10-2018-0068731)" of Patent Document 2, Kenyaf fiber and Preparing a polypropylene fiber (S1); braiding the Kenyaf fibers and polypropylene fibers (S2); coating the surface of the braided ply-twisted yarn (S3); and pelletizing the coated ply-twisted yarn using an injection machine (S4).

However, in the case of the prior art, there was a problem that the raw material used as a coating agent may have a harmful effect such as VOC generation during the process. In addition, since the coating agent merely coats the surface of the braided ply-dyed yarn, the voids between the braided natural fibers and the polypropylene fibers were often left in a bubble state even when the coating agent was impregnated. Therefore, in the subsequent injection or extrusion process, there is a problem in that it is easy to generate defects or decrease in process efficiency due to the remaining air bubbles.

1. Republic of Korea Patent Publication No. 10-2016-0023967 2. Republic of Korea Patent Publication No. 10-2018-0068731

The present invention solves the problems of the existing inventions described above, and heat-compresses the braided ply-twisted yarn while passing through a reduction nozzle heating jig without adding a separate binder, so that the synthetic fiber is melted and compressed while being partially absorbed by the natural fiber. Reduction nozzle heating jig capable of removing or minimizing the presence of voids or air bubbles inside through fusion by compression as well as fundamentally eliminating the generation of harmful substances due to the addition of a binder by making it possible to fuse. An object of the present invention is to provide a method for manufacturing a natural fiber composite material for injection molding using

In addition, the natural fiber yarn is placed on the inside and the synthetic fiber yarn is braided so that the outer periphery is surrounded by the natural fiber yarn, so that the natural fiber yarn does not come into direct contact with the heat source applied to melt the chemical fiber yarn. To provide a method for manufacturing a natural fiber composite material for injection molding using a reducing nozzle heating jig, which can prevent the natural fiber yarn from being thermally deformed, resulting in a decrease in its strength, or from breaking due to carbonization in the natural fiber yarn make that task

In addition, heating and compression are performed simultaneously, so that fusion by compression is performed within a short time at a relatively low temperature, thereby preventing the problem of carbonization of natural fibers exhibiting relatively low thermal stability.

In order to solve the above problems, the present invention provides a method for manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig, while one or more natural fiber yarns are located in the center, and the synthetic fiber yarns surround the outer periphery, A ply-twisted yarn manufacturing step (S1) of manufacturing a ply-twisted yarn; And, the ply-twisted yarn is heat-compressed while passing through the reduction nozzle heating jig 100, and the synthetic fiber yarn is melted and compressed so that the voids C are reduced or disappeared, and partially absorbed by the natural fiber so as to be fusion-bonded. A fusion-bonded ply-twisted yarn manufacturing step (S2) of manufacturing a ply-twisted yarn; And, a pelletizing step (S3) of pelletizing the fusion-bonded ply-twisted yarn; It is characterized in that it comprises a.

In addition, the reduction nozzle heating jig 100, the jig body 110; And, at least one reduction nozzle 120 formed in the jig body 110; And, one or more heating heaters 130 installed in the jig body (110); Consists of including,

The reduction nozzle 120 includes an induction introduction part 121; And, is formed in succession to the induction introduction portion 121, the inner diameter of the shrinking heat compression portion 122 that is gradually reduced; And, the heat compression portion 123 formed successively to the heat compression compression portion 122; It characterized in that it is configured to further include, and the inner diameter (d1) of the heat-compressed part 123 is, the cross-sectional area of the heat-compressed part 123 is the sum of the cross-sectional area of the natural fibers and the cross-sectional area of the synthetic fibers and It is characterized in that it is determined to be equal to or smaller than.

On the other hand, the natural fibers are flax, linen, hemp, jute, kenaf, abaca, bamboo, coir, pineapple, ramie. ), sisal (sisal), is composed of any one of henequen (henequen), the synthetic fiber is PP (PolyPropylene), PE (PolyEthylene), PVC (polyvinyl chloride), EVA (Ethylene-Vinyl Acetate), It is characterized in that it is composed of any one of nylon, and PET (poly ethylen terephthalate).

According to the present invention, the plied ply-twisted yarn is heat-compressed while passing through a reduction nozzle heating jig without the addition of a separate binder, so that the synthetic fiber is compressed while melting and fused to the natural fiber. There is an advantage that it is possible to fundamentally remove the generation of harmful substances by the addition of

In addition, by removing or minimizing the presence of voids or air bubbles inside through fusion by compression, defects that may occur in the injection process or reduction in process efficiency are minimized, as well as the relatively high mechanical strength of the manufactured pellets. However, there is an advantage that damage during transportation can be reduced.

In addition, the natural fiber yarn is placed on the inside and the synthetic fiber yarn is braided so that the outer periphery is surrounded by the natural fiber yarn, so that the natural fiber yarn does not come into direct contact with the heat source applied to melt the chemical fiber yarn. There is an advantage in that it is possible to prevent the natural fiber yarn from being thermally denatured, thereby reducing its strength, or preventing the natural fiber yarn from being broken due to carbonization.

In addition, since heating and compression are performed at the same time, so that fusion by compression is performed within a short time at a relatively low temperature, there is an advantage in that the problem of carbonization of natural fibers exhibiting relatively low thermal stability can be prevented.

On the other hand, since the outer diameter and shape are manufactured to maintain a constant standard after passing through the reduction nozzle heating jig, there is an advantage in that it is possible to manufacture pellets of uniform quality.

1 is a view showing a method of manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig according to an embodiment of the present invention.
Figure 2: A view showing the structure of the reduction nozzle heating jig according to an embodiment of the present invention.
Figure 3: In the method of manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig according to an embodiment of the present invention, each part (a-a', b-b', c-) of the reduction nozzle heating jig A drawing showing the processing process of ply-twisted yarn when c') is passed.

Hereinafter, a method of manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that in the drawings, the same components or parts are denoted by the same reference numerals as much as possible. In describing the present invention, detailed descriptions of related known functions or configurations are omitted so as not to obscure the gist of the present invention.

The method for manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig of the present invention is a ply-twisted yarn manufacturing step (S1) of plying natural fibers and synthetic fibers as shown in FIG. 1; A fusion ply-twisted yarn manufacturing step (S2) in which the twisted yarn is heat-compressed while passing through the reduction nozzle heating jig 100, and the synthetic fiber is melted and compressed to be fused to the natural fiber (S2); and the mixed ply-twisted yarn is pelletized a pelletizing step (S3); It is characterized in that it comprises a.

First, the ply-twisted yarn manufacturing step (S1) will be described. The ply-twisted yarn manufacturing step (S1) is characterized in that one or more natural fiber yarns are located in the center and are braided so that the outer periphery is surrounded by synthetic fiber yarns. That is, as shown in (A) in FIG. 3 , synthetic fiber yarns are located on the outer surface of the ply-twisted yarn, and the natural fiber yarn is located inside the ply-twisted yarn and braided so as not to be exposed to the outer surface. Therefore, the natural fiber yarn is not directly contacted as much as possible with the heat source applied to melt the chemical fiber yarn, so that thermal deformation occurs in the natural fiber yarn due to heat, so that the strength is lowered, or the natural fiber yarn is carbonized. This will prevent it from getting up and breaking.

In this case, the natural fiber yarn (N) is flax, linen, hemp, jute, kenaf, abaca, bamboo (bamboo), coir (coir), Pineapple, ramie (ramie), sisal (sisal), it is preferably configured to include any one of heteken (henequen). In a most preferred embodiment, the natural fiber is preferably composed of sheep hemp (kenaf).

On the other hand, the synthetic fiber yarn (S) is composed of any one of PP (PolyPropylene), PE (PolyEthylene), PVC (polyvinyl chloride), EVA (Ethylene-Vinyl Acetate), Nylon, and PET (poly ethylen terephthalate) It is preferable to be, and as a most preferred embodiment, it is good to include PP (PolyPropylene). In this case, the fiber-containing yarn may be generally used in the form of a yarn, and may be implemented in the form of a sliver in order to more efficiently prevent exposure of the inner yarn and wrap it.

The ply-twisted yarn is preferably such that the weight ratio of the natural fiber yarn to the total weight is in the range of 1 wt% to 99 wt%.

The ply-twisted yarn may be braided such that the natural fiber yarns (N) are first braided to form one core, and then the synthetic fiber yarns (S) surround the outer circumferential surface. On the other hand, the ply-twisted yarn may be braided such that the synthetic fiber yarns (S) surround the outer circumferential surface of the natural fiber yarns (N) in a state in which they are aligned with each other without being separately braided. In addition, the ply-twisted yarn may be plied in such a way that the natural fiber yarns (N) are not separately braided, but arranged so that the synthetic fiber yarns (S) surround the outer circumferential surface thereof in a state in which they are aligned with each other.

Next, the fusion-bonded ply-twisted yarn manufacturing step (S2) will be described. In the manufacturing step (S2) of the fusion-bonded ply-twisted yarn, the ply-twisted yarn is heat-compressed while passing through the reduction nozzle heating jig 100 having the configuration as shown in FIG. 2 . In this process, as shown step by step in FIG. 3 , the synthetic fiber yarn (S) is melted and compressed while being fused to the natural fiber yarn (N). In this case, it is preferable that a portion of the molten synthetic fiber yarn (S) is partially absorbed by the natural fiber yarn (N) to serve as a stronger binder.

In this way, without the need to add a separate binder, the synthetic fiber itself is melted and compressed by heat compression and fused to the natural fiber or further partially absorbed and fused. Since it is possible to carry out, there is an advantage that it is possible to fundamentally remove the generation of harmful substances due to the addition of the binder.

In addition, in this process, as shown step by step in FIG. 3 , the voids C existing between or between the natural fiber yarns or each of the synthetic fiber yarns are reduced or disappeared. Therefore, when the pellets are melted again for the subsequent manufacturing process of other articles, the generation of microbubbles that may remain in the pellets can be suppressed or removed, and the quality of the products can be improved.

On the other hand, since it is possible to perform more efficient fusion bonding by compression within a short time at a relatively low temperature due to the characteristics of heating and pressing at the same time as described above, natural fibers exhibiting relatively low thermal stability are delivered and carbonized. It has the advantage of being able to prevent further

In this case, the reduction nozzle heating jig 100 is, as shown in FIG. 2 , a jig body 110 , one or more reduction nozzles 120 formed on the jig body 110 , and the jig body 110 . It is preferable to include one or more heating heaters 130 installed in the . On the other hand, as shown in FIG. 2 , the reduction nozzle 120 includes an induction introduction part 121 and a reduction thermocompression compression part 122 which is formed in succession to the induction introduction part 121 and whose inner diameter is gradually reduced, and the It is preferable to further include a heat-compression-compression-compression part 123 that is formed in succession to the shrink-compression-compression part 122 .

On the other hand, in order to reduce or remove the void (C) existing between the efficiently braided natural fiber and the synthetic fiber, the inner diameter (d1) of the thermocompression part 123 is the Preferably, the cross-sectional area is determined to be equal to or smaller than the sum of the cross-sectional area of the natural fibers and the cross-sectional area of the synthetic fibers.

In the process of being compressed while melting and fused to the natural fiber as described above, as shown in (A) in FIG. 3, the void (C) existing between the braided natural fiber and the synthetic fiber is shown in FIG. As shown in (B), the synthetic fiber melted while passing through the heat-compression compression unit 122 is gradually reduced as it is compressed, and finally passes through the heat-compression unit 123 in FIG. 3 (C). It disappears as shown.

In particular, when the inner diameter d1 of the thermocompression compression part 123 is determined such that the cross-sectional area of the thermocompression unit 123 is smaller than the sum of the cross-sectional areas of the natural fibers and the cross-sectional areas of the synthetic fibers, the thermocompression compression The synthetic fiber yarn melted while passing through the part 123 fills the void C1 between the natural fiber yarns by pressure to effectively reduce or remove the void, as well as being partially absorbed into the natural fiber yarn. It is possible to perform the function of a more efficient binder.

Therefore, it minimizes or removes the presence of voids or bubbles inside, thereby minimizing defects or process efficiency degradation that may occur in the injection process, etc., as well as reducing damage during storage or transportation due to the relatively high mechanical strength of the manufactured pellets It has the advantage of being able to do it. In addition, since the outer diameter and shape are manufactured to maintain a constant standard after passing through the reduction nozzle heating jig, there is an advantage in that it is possible to manufacture pellets of uniform quality.

In the above, the best embodiments have been disclosed in the drawings and the specification. Although specific terms are used herein, they are used only for the purpose of describing the present invention, and are not used to limit the meaning or the scope of the present invention described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

N: natural fiber
S: synthetic fiber
C: voids
100: reduction nozzle heating jig
110: jig body
120: reduction nozzle
121: induction introduction
122: shrink heat compression unit
123: heat compression unit
130: heating heater

Claims (3)

A ply-twisted yarn manufacturing step (S1) of producing a ply-twisted yarn by braiding one or more natural fiber yarns (N) in the center, and plying the outer periphery of the synthetic fiber yarns (S) to surround the ply-twisted yarn;
The ply-twisted yarn is heat-compressed while passing through the reduction nozzle heating jig 100, and the synthetic fiber yarn (S) is compressed while melting, so that the voids (C) are reduced or disappeared, and some of the natural fiber yarns (N). A fusion-bonded ply-twisted yarn manufacturing step (S2) of manufacturing a fusion-bonded ply-twisted yarn by fusion while being absorbed;
a pelletizing step (S3) of pelletizing the fusion-bonded ply-twisted yarn;
It is characterized in that it comprises a
The reduction nozzle heating jig 100,
Jig body 110;
One or more reduction nozzles 120 formed in the jig body 110;
One or more heating heaters 130 installed in the jig body 110; consists of,
The reduction nozzle 120 is
induction introduction part 121;
It is formed in succession to the induction introduction part 121, the inner diameter of the shrinking thermocompression compression portion 122 is gradually reduced;
a heating compression part 123 formed in succession to the shrinkage heating compression part 122; It is characterized in that it further comprises a
The inner diameter d1 of the heat-compressed portion 123 is determined so that the cross-sectional area of the heat-compressed portion 123 is equal to or smaller than the sum of the cross-sectional areas of the natural fibers and the synthetic fibers. A method for manufacturing a natural fiber composite material for injection molding using a reduction nozzle heating jig.
delete 2. The method of claim 1,
The natural fibers are flax, linen, hemp, jute, kenaf, abaca, bamboo, coir, pineapple, ramie, Consists of any one of sisal (sisal), heteken (henequen),
The synthetic fiber is reduced, characterized in that it comprises any one of PP (PolyPropylene), PE (PolyEthylene), PVC (polyvinyl chloride), EVA (Ethylene-Vinyl Acetate), Nylon, and PET (poly ethylen terephthalate) A method for manufacturing a natural fiber composite material for injection molding using a nozzle heating jig.

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