Method for preparing natural fiber composite material for injection molding by using convergent nozzle heating jig

Abstract

The present invention relates to a manufacturing method of a natural fiber composite material for injection molding using a reduced nozzle heating jig, and particularly, to a manufacturing method of a natural fiber composite material for injection molding using a reduced nozzle heating jig, which is configured to include: combining natural fibers and synthetic fibers (S1); heat-pressing the combined ply yarn while passing through a reduced nozzle heating jig 100 and melting and pressing the synthetic fibers and fusing the synthetic fibers to the natural fibers (S2); and palletizing the mixed ply yarn (S3).

Claims

1. A method for manufacturing a natural fiber composite material for injection molding using a convergent nozzle heating jig, comprising: combining natural fibers and synthetic fibers to form a combined ply yarn; heat-pressing the combined ply yarn while passing through a convergent nozzle heating jig, and melting and pressing the synthetic fibers and fusing the synthetic fibers to the natural fibers to form a mixed ply yarn; palletizing the mixed ply yarn wherein the convergent nozzle heating jig includes a jig body, one or more convergent nozzles formed in the jig body, and one or more heating heater installed in the jig body, and the convergent nozzle further includes a derivation introduction unit, a convergent heating pressing unit formed subsequently to the derivation introduction unit and a heating pressing unit formed subsequently to the convergent heat pressing unit.

2. The manufacturing method of claim 1, wherein an inner diameter d1 of the heat-pressing unit is smaller than an outer diameter d0 of the combined ply yarn.

3. The manufacturing method of claim 1, wherein the natural fiber includes any one of flax, linen, hemp, jute, kenaf, abaca, bamboo, coir, pineapple, ramie, sisal, and henequen, and the synthetic fiber includes any one of polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), ethylene-vinyl acetate (EVA), Nylon, and polyethylene terephthalate (PET).

4. The manufacturing method of claim 2, wherein the natural fiber includes any one of flax, linen, hemp, jute, kenaf, abaca, bamboo, coir, pineapple, ramie, sisal, and henequen, and the synthetic fiber includes any one of polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), ethylene-vinyl acetate (EVA), Nylon, and polyethylene terephthalate (PET).

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a diagram illustrating a method for manufacturing a natural fiber composite material for injection molding using a convergent nozzle heating jig according to an embodiment of the present invention.

(2) FIG. 2 is a diagram illustrating a structure of the convergent nozzle heating jig according to an embodiment of the present invention

(3) FIGS. 3(A), 3(B), and 3(C) are diagrams illustrating a processing process of a ply yarn when passing through each part (a-a*, b-b*, or c-c*) of a convergent nozzle heating jig in a method for manufacturing a natural fiber composite material for injection molding using a convergent nozzle heating jig according to an embodiment of the present invention.

DESCRIPTION OF OF REFERENCE NUMERALS USED IN DRAWINGS

(4) N: Natural fiber S: Synthetic fiber C: Crevice 100: Convergent nozzle heating jig 110: Jig body 120: Convergent nozzle 121: Derivation introduction unit 122: Convergent heating pressing unit 123: Heating pressing unit 130: Heating heater

MODE FOR INVENTION

(5) Hereinafter, a method for manufacturing a natural fiber composite material for injection molding using a convergent nozzle heating jig according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. First, in the drawings, it should be noted that the same constituent elements or components are represented by the same reference numerals. In describing the present invention, a detailed description of known functions and configurations incorporated will be omitted so as to avoid obscuring the gist of the present invention.

(6) As illustrated in FIG. 1, the method for manufacturing a natural fiber composite material for injection molding using a convergent nozzle heating jig is configured to include: combining natural fibers and synthetic fibers (S1); heat-pressing the combined ply yarn while passing through a convergent nozzle heating jig 100 and melting and pressing the synthetic fibers and fusing the synthetic fibers to the natural fibers (S2); and palletizing a mixed ply yarn (S3).

(7) In this case, the natural fibers are preferably configured to include any one of flax, linen, hemp, jute, kenaf, abaca, bamboo, coir, pineapple, ramie, sisal, and henequen. As a most preferred embodiment, the natural fiber is preferably configured to include kenaf. Meanwhile, the synthetic fiber is preferably configured to include any one of poly-propylene (PP), polypthylene (PE), polyvinyl chloride (PVC), pthylene vinyl acetate (EVA), nylon, and poly ethylene terephthalate (PET).

(8) First, the step (S1) of combining the natural and synthetic fibers will be described. In the combining step (S1), due to characteristics of the present invention in which a fusion process is performed by pressing in addition to heating, it is characterized in that the combining of the natural fibers and the synthetic fibers may be formed by comparatively various embodiments. In other words, in addition to a case where the natural fibers and the synthetic fibers are uniformly or regularly arranged in the ply yarn even in a case where the natural fibers and the synthetic fibers are arranged irregularly to some extent or a distribution of the natural fibers and the synthetic fibers is biased to either side, fused synthetic fibers are not simply attached to the natural fibers, but the synthetic fibers fused to the natural fibers are also fused by pressing, and as a result, the synthetic fibers fused to the natural fibers may be fused and mixed uniformly to some extent.

(9) Next, the step (S2) of heat-pressing the combined ply yarn while passing through the reduced nozzle heating jig 100 and melting and pressing the synthetic fibers and fusing the synthetic fibers to the natural fibers will be described. In this step, the combined ply yarn is heat-pressed while passing through the convergent nozzle heating jig 100 having the configuration illustrated in FIG. 2. In this process, the synthetic fibers are melted and pressed to be fused to the natural fibers as illustrated stepwise in FIG. 3. There is an advantage in that more efficient fusion may be performed by pressing is performed at a comparatively low temperature within a short time by the characteristics in that both heating and pressing are performed to prevent a problem in that natural fibers exhibiting relatively low thermal stability are carbonized.

(10) Meanwhile, by the characteristic that the synthetic fibers are melted and pressed to be fused to the natural fibers by heat-pressing without the need to add the separate binder, the melted and fused synthetic fibers themselves serve as a kind of binder, so that there is an advantage in that it is possible to fundamentally remove the generation of the harmful materials by the addition of the binder.

(11) In this case, as illustrated in FIG. 2, the convergent nozzle heating jig 100 is preferably configured to include a jig body 110, one or more convergent nozzles 120 formed in the jig body 110, and one or more heating heaters 130 installed in the jig body 110. Meanwhile, as illustrated in FIG. 2, the convergent nozzle 120 is preferably configured to include a derivation introduction unit 121, a convergent heating pressing unit 122 formed subsequently to the derivation introduction unit 121 and having an inner diameter which is gradually convergent, and a heat-pressing unit 123 formed subsequently to the convergent heat-pressing unit 122.

(12) Meanwhile, in order to efficiently remove a crevice C which exists between the natural fibers and synthetic fibers, an inner diameter d1 of the heat-pressing unit 123 is preferably formed to be smaller than an outer diameter d0 of the combined ply yarn. More specifically, in respect to the inner diameter d1 of the heat pressing unit 123, a cross-sectional area of the heat-pressing unit 123 is preferably close to the sum of the cross-sectional area of the natural fibers and the cross-sectional area of the synthetic fibers.

(13) In the process in which the synthetic fiber is melted and pressed to be fused to the natural fiber, the crevice C which has existed between the combined natural fiber and synthetic fiber as illustrated in FIG. 3(A) is gradually reduced while the synthetic fiber is pressed, which is melted while passing through the convergent reduced heat-pressing unit 122 as illustrated in FIG. 3(B) and then finally disappears as illustrated in FIG. 3(C) while passing through the heat-pressing unit 123. Accordingly, there is an advantage in that existence of a crevice or bubbles is minimized to minimize defects or deterioration in process efficiency which may occur in an injection process and a mechanical strength of a manufactured pellet is relatively high to reduce damage during storage or transportation. Further, since the natural fiber composite material is manufactured so that an outer diameter and a shape maintain constant standards after passing through a reduced nozzle heating jig, there is an advantage in that it is possible to manufacture pellets having a uniform quality.

(14) Hereinabove, optimal embodiments are disclosed in the drawings and the specification. Although specific terms have been used herein, the terms are only used for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the claims. Therefore, it will be appreciated by those skilled in the art that various modifications and other embodiments equivalent thereto can be made therefrom. Accordingly, the true technical scope of the present invention should be defined by the technical spirit of the appended claims.