KR102583993B1 - Short Staple Composite Materials Manufacturing Method Using Multi-Layer Fiber Direction Control and Injection Mold for the Same - Google Patents

Abstract

The method of molding a single fiber composite injection product using a multi-layer fiber direction control method according to the present invention involves forming a plurality of gates connected at different relative angles to a molding space within an injection mold having a shape corresponding to the single fiber composite injection product to be manufactured. In the molding process of molding a single fiber composite injection product by injecting a molding material containing short fibers through a molding process, a plurality of layers are sequentially molded n times within the molding space, and in the process of molding each layer, The molding material is injected through one of the gates selected to exhibit the target single fiber orientation tendency.

Description

Short Staple Composite Materials Manufacturing Method Using Multi-Layer Fiber Direction Control and Injection Mold for the Same}

The present invention relates to a method for forming short fiber composite injection products and a short fiber composite injection mold for the same. In more detail, the present invention relates to a method for molding short fiber composite injection products, and more specifically, to target each area of the short fiber composite injection product to be manufactured using a multi-layer fiber direction control method. It relates to a method for molding a single fiber composite injection product that can be induced to have a short fiber orientation tendency and a single fiber composite injection mold for the same.

Injection molding is a method of molding a product of a target shape by injecting liquid molding material into a pre-processed mold. It is optimized for mass production and has the advantage of being able to mold almost all thermoplastic materials and even some thermoset materials. .

In the case of general injection molding, the product is molded by putting the molding material in an injection device and melting it or adding liquid molding material and then injecting the material into the mold under high temperature or high pressure conditions.

In particular, recently, a method of mixing single fibers with molding materials and molding injection molded products of single fiber composite materials has been applied for various purposes in order to improve strength and express specific properties.

In this way, when the molding material contains single fibers, a specific orientation occurs in the single fibers according to the flow of fluid during the process of injecting the liquid material into the mold.

At this time, the orientation of single fibers is very important because it directly affects the mechanical properties such as Young's modulus and thermal expansion coefficient of the product. In general, it is desirable to arrange them randomly, but it may vary locally depending on the shape of the mold and process variables. Alternatively, the overall fiber orientation tends to occur in a specific direction.

Using this orientation phenomenon has the advantage of being able to implement targeted mechanical properties in a desired area of the product, but there is a limitation that it is difficult to intentionally implement this with current injection technology.

Therefore, a method to solve these problems is required.

Korean Patent Publication No. 10-2017-0040627

The present invention is an invention made to solve the problems of the prior art described above. By inducing the single fibers to have an orientation tendency for a molding material containing single fibers, injection molded products of single fiber composites having various target physical properties are produced. The purpose is to enable molding.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

In order to achieve the above object, the method of forming a single fiber composite injection product using the multi-layer fiber direction control method of the present invention has a relative angle to each other in the molding space within the injection mold having a shape corresponding to the single fiber composite injection product to be manufactured. In the molding process of molding a short fiber composite injection product by injecting a molding material containing short fibers through a plurality of differently connected gates, a plurality of layers are sequentially molded n times within the molding space, and each layer is molded. In the process, the molding material is injected through one gate selected from among the plurality of gates that can exhibit the target single fiber orientation tendency.

At this time, the forming process includes step (a) of forming a layer of a predetermined thickness having a target single fiber orientation tendency by injecting a molding material through a selected gate among the plurality of gates, formed immediately before the gate. In the process of forming the layer located at the bottom, the molding material is injected through another gate formed at a different relative angle from the selected gate to form a layer of a predetermined thickness that has a different single fiber orientation tendency from the layer formed immediately and located at the bottom. It may include step (b) of additional forming and step (c) of repeating step (b) n times (n is an integer of 0 or more).

In addition, the short fiber composite injection product is divided into a plurality of regions, and in this case, steps (a) to (c) can be formed as a set and repeatedly performed for each region of the short fiber composite material.

In addition, the molding space is formed to be rotatable within the injection mold. In this case, after one set of steps (a) to (c), the molding space is rotated in any direction to form the short fiber composite. The set of steps (a) to (c) may be performed for other areas.

Meanwhile, after forming any one layer in steps (a) to (c), the layer can be cured to a preset degree of curing.

In order to achieve the above object, the single fiber composite injection mold using the multi-layer fiber direction control method of the present invention has different relative angles in the molding space so that the molding material containing single fibers can be injected into the molding space. It includes a plurality of gates that are connected to display the target single fiber orientation tendency during the injection process of the molding material.

At this time, the molding space may be formed to be rotatable relative to the plurality of gates.

In order to solve the above problems, the method of forming a single fiber composite injection product using the multi-layer fiber direction control method of the present invention and the single fiber composite injection mold for the same include a plurality of gates connected to each other at different relative angles in the molding space within the injection mold. By injecting the molding material containing single fibers through the molding material containing single fibers, the single fibers are induced to have an orientation tendency, making it possible to mold single fiber composite injection products with various target physical properties. It has advantages.

In particular, according to an embodiment of the present invention, a single fiber composite injection product can be divided into a plurality of regions and each region can be induced to have different physical properties, so that a wider variety of single fiber composite injection products can be molded.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a diagram showing each step of the molding process in the method of molding a single fiber composite injection product using a multi-layer fiber direction control method according to the present invention;
2 to 5 are diagrams showing the process of injection molding a single fiber composite product according to a method for molding a single fiber composite injection product using a multi-layer fiber direction control method according to the first embodiment of the present invention;
Figures 6 to 8 are diagrams showing the process of injection molding a single fiber composite product according to a method for molding a single fiber composite injection product using a multi-layer fiber direction control method according to a second embodiment of the present invention; and
Figure 9 is a diagram showing the process of injecting a single fiber composite injection product according to a method for molding a single fiber composite injection product using a multi-layer fiber direction control method according to the third embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention, in which the object of the present invention can be realized in detail, will be described with reference to the attached drawings. In describing this embodiment, the same names and the same symbols are used for the same components, and additional description accordingly will be omitted.

As described in the technical background of the invention, when the molding material contains single fibers, a specific orientation occurs in the single fibers according to the flow of fluid during the process of injecting the liquid material into the injection mold.

Therefore, the present invention provides a method for molding single fiber composite injection products with various target physical properties by inducing the single fibers to have an orientation tendency for a molding material containing single fibers.

Specifically, in the present invention, a molding space having a shape corresponding to the short fiber composite injection product to be manufactured is formed in an injection mold, and the molding space includes a plurality of gates connected to each other at different relative angles.

In the present invention, a molding material containing single fibers is injected through a plurality of gates, and a single fiber composite injection product is molded through a molding process. Accordingly, the single fibers have an orientation tendency relative to the molding material containing single fibers. It is possible to mold short fiber composite injection products with various target properties.

In particular, the present invention can sequentially mold a plurality of layers n times in a molding space, and in this case, in the process of molding each layer, any one gate selected from the plurality of gates that can exhibit the target single fiber orientation tendency is selected. It goes through a process of injecting molding materials.

The molding material may be a polymer such as a thermoplastic resin or thermosetting resin.

Below, the molding process of the present invention will be described in more detail.

Figure 1 is a diagram showing each step of the molding process in the method of molding a single fiber composite injection product using a multi-layer fiber direction control method according to the present invention.

As shown in Figure 1, the molding process conducted through the method for molding a single fiber composite injection product using the multi-layer fiber direction control method according to the present invention may include steps (a) to (c).

First, step (a) is a process of forming a layer of a predetermined thickness with a target single fiber orientation tendency by injecting a molding material through a selected gate among a plurality of gates.

That is, in this step, the molding material is injected through one gate that can induce the target orientation tendency of the single fibers, thereby forming a primary layer with a predetermined thickness within the molding space.

In particular, when liquid molding material is injected into the molding space through the gate selected in this process, the molding material is filled at the bottom of the molding space by gravity to a certain height, that is, the thickness of the first layer.

In other words, the process of forming a layer using a molding material can be performed based on the floor surface parallel to the ground in the direction of gravity.

Next, step (b) is performed to additionally form a layer of a predetermined thickness having a different single fiber orientation tendency from the layer formed just before and positioned below.

In this step, among the plurality of gates, the molding material is injected through another gate formed immediately before and formed at a different relative angle from the gate selected during the formation of the lower layer.

Accordingly, a layer of a predetermined thickness having a different single fiber orientation tendency from the layer formed just before and positioned below is additionally formed.

And step (c) is the process of repeating step (b) n times (n is an integer greater than 0). That is, step (b) may be performed only once, or step (c) may be performed additionally.

Additionally, in steps (a) to (c), after forming one layer, the layer may be cured to a preset degree of curing before forming the next layer.

This curing process can be achieved through natural curing or temperature control of the injection mold until the molding material is completely cured or cured to the intended degree of curing. This is to prevent the components of adjacent layers from mixing with each other and to prevent the molding material from flowing down during the rotation of the molding space, which will be described later.

Meanwhile, the molding material injected during the molding process of each layer may be injected by mixing volatile solvents to lower the viscosity. This is to lower the viscosity of the molding material through the volatile solvent to achieve a flat top surface within a short period of time when the molding material is injected into the molding space. This is because the volatile solvent evaporates quickly, so the curing process can also proceed quickly.

Below, the present invention will be described in more detail through specific examples.

Figures 2 to 5 are diagrams showing the process of injecting a single fiber composite injection product according to a method for molding a single fiber composite injection product using a multi-layer fiber direction control method according to the first embodiment of the present invention.

In the case of the first embodiment of the present invention shown in FIGS. 2 to 5, the short fiber composite injection product to be manufactured is set to have a rectangular parallelepiped shape, and accordingly, the molding space 10 also has a rectangular parallelepiped shape. Additionally, in this embodiment, a total of three layers were formed within the entire molding space 10.

Therefore, the injection mold of this embodiment is connected to the molding space at different relative angles so that the molding material containing single fibers can be injected into the molding space, so that the target single fiber orientation tendency can be displayed during the injection process of the molding material. It has a form including three gates (11, 12, 13).

In this embodiment, as shown in FIG. 3, the molding material is first filled through the first gate 11 connected to the lower left part of the molding space 10 to form a first layer (L1) in the molding space 10. form

Accordingly, the first layer (L1) has a single fiber orientation tendency from left to right as shown on the right side of FIG. 3, and then a curing process is performed up to a certain degree of curing.

Next, as shown in FIG. 4, the molding material is filled through the second gate 12 connected to the rear middle portion of the molding space 10, and the molding material is filled on the first layer L1 formed in the molding space 10. A second layer (L2) is formed.

Accordingly, the second layer (L2) has a single fiber orientation tendency from rear to front as shown on the right side of FIG. 4, and then a curing process is performed to a certain degree of curing.

Next, as shown in FIG. 5, the molding material is filled through the third gate 13 connected to the upper right portion of the molding space 10 to form a molding material on the second layer L2 formed in the molding space 10. A third layer (L3) is formed.

Accordingly, the third layer (L3) has a single fiber orientation tendency from right to left as shown on the right side of FIG. 5, and then a curing process is performed up to a certain degree of curing.

Through the above process, a single fiber composite injection product containing a plurality of layers with different single fiber orientation tendencies is molded. The shape of the short fiber composite injection product and molding space shown in this example is presented as an example only, and is not limited to this example.

Figures 6 to 8 are diagrams showing the process of injecting a single fiber composite injection product according to a method for molding a single fiber composite injection product using a multi-layer fiber direction control method according to a second embodiment of the present invention.

In the case of the second embodiment of the present invention shown in FIGS. 6 to 8, the short fiber composite injection product to be manufactured was set to have a square pipe shape, and accordingly, the molding space 10 has an overall rectangular parallelepiped shape, and the molding space ( A core 20 in the form of a rectangular parallelepiped is provided in the central part of 10).

Additionally, in this example, two layers were formed on each side of the short fiber composite injection product in the form of a square pipe to be manufactured.

Therefore, the injection mold of this embodiment is connected to the molding space at different relative angles so that the molding material containing single fibers can be injected into the molding space, so that the target single fiber orientation tendency can be displayed during the injection process of the molding material. It has a form including two gates (11, 12).

In particular, in the case of this embodiment, since two layers must be formed on all four sides of the single fiber composite injection product, it is divided into a plurality of regions, with one region on each side.

In addition, the molding process applied in this embodiment can be performed repeatedly for each region of the short fiber composite by forming a set of steps (a) to (c) described above.

For this purpose, in this embodiment, the molding space 10 is formed to be rotatable within the injection mold, and after one set of steps (a) to (c), the molding space 10 can be rotated in any direction. By rotating, the set of steps (a) to (c) can be performed on different areas of the short fiber composite.

At this time, the injection mold may have a plurality of communication holes formed so as to communicate with the first gate 11 and the second gate 12, respectively, even when the molding space 10 is rotated at any angle.

In this embodiment, as shown in FIG. 6, the molding material is first filled through the first gate 11 connected to the lower left part of the molding space 10, so that the molding material is filled from each side of the short fiber composite injection product in the form of a square pipe. The first layer (L1) is formed in the area corresponding to the lower surface, and then a curing process is performed up to a certain degree of curing.

Next, as shown in FIG. 7, the molding material is filled through the second gate 12 connected to the rear middle portion of the molding space 10, so that the lower part of each side of the square pipe-shaped short fiber composite injection product is filled. A second layer (L2) is formed on the first layer (L1) formed in an area corresponding to the surface located in .

Accordingly, the first layer (L1) and the second layer (L2) formed in the area corresponding to the lower surface have different single fiber orientation tendencies, and then a curing process is performed for the second layer (L2) to a certain degree of curing. This comes true.

Next, as shown in FIG. 8, the entire molding space 10 is rotated so that the other side of the square pipe-shaped short fiber composite injection product moves to the lower side. At the same time, the first layer (L1) and the second layer (L2) formed in FIGS. 6 and 7 move to the side with the rotation of the molding space 10.

Therefore, later, as the molding space 10 rotates, the third layer (L3) is formed in the area corresponding to the other surface located at the bottom, and then hardening to a certain degree of hardness can be achieved.

Afterwards, by repeating the above process, two layers can be formed on each side of the square pipe-shaped single fiber composite injection product, and the two layers that make up each area all have different single fiber orientation tendencies. do.

Through the above process, it can be confirmed that the present invention is applicable to injection molded products of short fiber composites divided into a plurality of regions.

The shape of the short fiber composite injection product and molding space shown in this example is also presented as an example, and is of course not limited to this example.

Figure 9 is a diagram showing the process of injecting a single fiber composite injection product according to a method for molding a single fiber composite injection product using a multi-layer fiber direction control method according to the third embodiment of the present invention.

In the third embodiment of the present invention shown in Figure 9, like the above-described second embodiment, the short fiber composite injection product to be manufactured is set to have a square pipe shape. Accordingly, the molding space 10 has an overall rectangular parallelepiped shape, A core 20 in the form of a rectangular parallelepiped is provided in the center of the molding space 10.

In addition, in this example, two layers were formed on each side of the short fiber composite injection product in the form of a square pipe to be manufactured.

However, in this embodiment, the molding material is filled through the first gate 11 connected to the lower left part of the molding space 10, so that the molding material is filled with the molding material corresponding to the lower side of each side of the short fiber composite injection product in the form of a square pipe. Unlike the second embodiment in which an additional layer is formed on top of the first layer (L1) after forming the first layer (L1) in the area, the molding space (10) is rotated after forming the first layer (L1). The other side of the square pipe-shaped short fiber composite injection product was placed at the bottom, and then an additional second layer (L2) was formed in that area.

In this way, the present invention can also be applied to a single fiber composite injection product divided into a plurality of regions by repeatedly forming layers alternately for each region.

As described above, the preferred embodiments according to the present invention have been examined, and the fact that the present invention can be embodied in other specific forms in addition to the embodiments described above without departing from the spirit or scope thereof is recognized by those skilled in the art. It is self-evident to them. Therefore, the above-described embodiments are to be regarded as illustrative and not restrictive, and thus the present invention is not limited to the above description but may be modified within the scope of the appended claims and their equivalents.

10: Molding space
11: 1st gate
12: Second gate
13: Third gate
20: core

Claims (7)

In the molding process of molding a single fiber composite injection product by injecting a molding material containing single fibers through a plurality of gates into a molding space within an injection mold having a shape corresponding to the short fiber composite injection product to be manufactured,
The injection mold includes an outer mold formed as a rectangular parallelepiped with an internal space, and a core in the form of a rectangular parallelepiped at the center of the internal space,
In the four sides continuously connected to the external mold of the rectangular parallelepiped shape,
Each of the four sides is provided with a first inlet perpendicular to one side and adjacent to a corner formed by the four sides, wherein the first inlet is disposed adjacent to a different corner,
In addition, in one vertical plane perpendicular to the four sides,
The vertical surface is provided with a second injection port formed in a direction perpendicular to the first injection port provided on the vertical surface and the side,
Meanwhile, the second injection port is formed in communication with the space formed by the core and the external mold, and is disposed closer to the core compared to the first injection port, and is located on each of the four sides of the external mold. One is provided at each position facing the core,
In addition, the injection mold is rotatable,
Meanwhile, the forming process is,
Step (a) of injecting the molding material through any one of the first injection ports whose injection direction is perpendicular to the direction of gravity to form a layer of a predetermined thickness parallel to the ground with a target single fiber orientation tendency;
Step (b) of rotating the injection mold by 90 degrees and then forming a layer having a single fiber orientation tendency and having a predetermined thickness parallel to the ground through a first injection port that is different from the first injection port through which the molding material was injected immediately before;
Step (c) of repeating step (b) twice;
Step (d) of injecting a molding material through any one of the second injection ports to form a layer of a predetermined thickness on top of a previously formed layer parallel to the ground with a target single fiber orientation tendency;
After rotating the injection mold 90 degrees, a layer of a predetermined thickness is formed on the upper part of the previously formed layer parallel to the ground with a single fiber orientation tendency through a second injection port different from the second injection port through which the molding material was injected immediately before (e). )step; and
Step (f) of repeating step (e) twice;
Including,
Molding method of single fiber composite injection product using multi-layer fiber direction control method.
According to paragraph 1,
After forming any layer in steps (a) to (c), curing is performed to a preset degree of curing for the layer,
Molding method of single fiber composite injection product using multi-layer fiber direction control method.
According to claim 1 or 2,
After forming any layer in steps (d) to (f), curing is performed to a preset degree of curing for the layer,
Molding method of single fiber composite injection product using multi-layer fiber direction control method.
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