TW201912364A - Divided injection molding method and device thereof capable of preventing appearance defects caused by additional structures such as ribs or bosses on the back surface of a molded article main body - Google Patents

Abstract

The present invention provides a divided injection molding method, which can prevent appearance defects caused by additional structures such as ribs or protrusions on the back surface of the molded article main body when injection molding is carried out by using an injection molding composition containing metal particles, thereby greatly improving the appearance characteristics of the molded article. The divided injection molding method includes: a first injection molding step of closing an molding unit and injecting an injection molding composition into a first forming unit from an injection unit for performing one injection molding; a molding unit rotating step of opening the molding unit and rotating the molding unit to switch the positions of the molds of the first forming unit and a second forming unit; a second injection molding step of closing the rotated molding unit, injecting the injection molding composition into the first forming unit and the second forming unit from the injection unit for sequentially performing one injection molding and a second injection molding, and then performing cooling procedure; and an injection molding subsequent step for opening the molding unit and taking out a second injection molded product produced by the second injection molding.

Description

Segment injection molding method and device

The present invention relates to a segment injection molding method and apparatus which can improve the appearance characteristics of a molded article. [Reciprocal Reference of Related Applications] This application is filed on September 4, 2017 and July 25, 2018, submitted to the Korea Intellectual Property Office, and the Korean Patent Application Nos. 10-2017-0112689 and 10-2018-0086650 Priority is hereby incorporated by reference in its entirety.

When injection molding is performed using a filler such as aluminum, a structure such as a rib or a boss on the back surface of the molded article to be produced is liable to cause an appearance defect. For example, the detergent filling port of a washing machine has been manufactured by a method of applying an acrylonitrile-butadiene-styrene resin (ABS) material after injection molding, but in order to avoid the coating process, it has recently been mainly adopted. A method of injection molding an ABS material to which metal particles are added. However, such an ABS material containing metal particles may have poor appearance characteristics upon injection molding according to a conventional method due to inconsistent orientation of the metal particles. In particular, when the shape of the molded article is complicated and plate-like metal particles are used, depending on the orientation change of the metal particles, the light reflection difference causes a flow mark to appear in appearance. In order to solve this problem, methods such as removing the structure on the molded article and injecting the composition for injection molding at a low speed of about 1 to 50 cc/s have been proposed. However, with the former method, there is a limitation in the removal of the structure, and for the latter method, it is difficult to sufficiently improve the appearance characteristics of the low-speed injection, and there is also a problem that the processability due to the low-speed process is degraded and the process time becomes long. Further, as a method of preventing poor appearance, a double injection molding method has been proposed. However, the method utilizes a double molding apparatus in which two molds are mounted in one injection molding apparatus, and then performs double injection molding, and the two injection molding processes require two cylinders and the like to be complicated, thereby causing a process. Time and cost increase. Further, deformation of the injection molded article is likely to occur during cooling after one injection molding, and as a result, precise injection molding cannot be achieved.

Technical Problem The present invention has been made in an effort to solve the problem of the prior art injection molding to provide a segment injection molding method which can improve the appearance characteristics of a molded article when injection molded using a composition for injection molding containing metal particles. Furthermore, the present invention is directed to a segmented injection molding apparatus that facilitates the implementation of the segmented injection molding method. Technical Solution According to an embodiment of the present invention, there is provided a segment injection molding method using an injection molding apparatus including a mold clamping unit and an injection unit, the mold clamping unit comprising an implementation for manufacturing one injection molding a first molding unit for one injection molding of the object and a second molding unit for performing double injection molding of the primary injection molding, the mold clamping unit rotating the mold in the first molding unit and the second molding unit by rotation The positions are interchanged according to an injection molding unit that injects an injection molding composition into the first molding unit and the second molding unit of the mold clamping unit, the segment injection molding method comprising: a first injection molding step After the mold clamping unit is closed, the injection molding composition is injected into the first molding unit from the injection unit to perform one injection molding; the mold clamping unit rotation step, after the first injection molding is completed, the mold clamping unit is opened, Rotating the mold clamping unit to mold the first molding unit and the second molding unit The second injection molding step, after the rotating mold clamping unit is closed, the injection molding composition is injected into the first molding unit and the second molding unit from the injection unit, and is successively performed in sequence. Injection molding and secondary injection molding, followed by cooling; and subsequent steps of injection molding, after the second injection molding is completed, the mold clamping unit is opened to take out the overmolded final injection molded article, the segment The injection molding method further includes the steps of: rotating the mold clamping unit before or after the injection molding is taken out to interchange the positions of the mold of the first molding unit and the mold of the second molding unit, the injection molding The composition comprises metal particles and a thermoplastic or thermosetting polymer resin. Further, according to another embodiment of the present invention, there is provided an injection molding apparatus including a mold clamping unit that completes injection molding and an injection unit that injects an injection molding composition into the mold clamping unit, the combination The mold unit includes a first molding unit that performs one injection molding for manufacturing a single injection molding and a second molding unit that performs secondary injection molding for one injection molding, the mold clamping unit makes the first by rotation The positions of the molds in the molding unit and the second molding unit are interchanged according to the injection molding step. EFFECT OF THE INVENTION The segment injection molding method according to the present invention uses a single cylinder, and performs a segment injection molding on a single composition under two or more injection molding conditions, so that the appearance characteristics of the molded article can be easily improved without worrying about the process. Equipment will increase and thus result in increased process time and costs. Further, according to the segment injection molding method of the present invention, when injection molding is carried out using an injection molding composition containing metal particles such as aluminum, an injection molded article can be classified into an appearance surface (outer surface) and a non-appearance surface (or interior). The injection molding is sequentially performed, so that the orientation of the metal particles on the appearance surface can be made uniform in one direction, and as a result, defects such as flow marks can be improved. In particular, the segment injection molding method according to the present invention is more advantageous in preventing appearance defects when manufacturing a molded article having a complicated back structure due to an additional structure such as a rib or a boss, and is also manufactured. When the thickness of the molded product is thick, the process time can be greatly shortened.

The terminology used in the description is for the purpose of describing the exemplary embodiments, and is not intended to limit the invention. The singular forms used herein are also intended to include the plural, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising," "having," "having," Features, steps, components, or a combination thereof. In addition, when the various layers or elements are described as being "on" or "above" the various elements or elements, it is meant that the various layers or elements are formed directly on the various layers or elements, or the other layers or elements may be further formed. Between the layers, on the object body, above the substrate. The present invention is capable of various modifications and may be in various forms. It should be understood, however, that the invention is not intended to be limited A segmental injection molding method according to a specific embodiment of the present invention is described in more detail below. A segmental injection molding method according to an embodiment of the present invention utilizes an injection molding apparatus including a mold clamping unit and an injection unit, the mold clamping unit including one injection molding having an implementation for manufacturing a single injection molding (or primary injection molding) a first molding unit of the molded mold and a second molding unit having a mold for performing overmolding of the primary injection molding, the mold clamping unit being rotated by the first molding unit and the second molding unit The position of the mold is interchanged according to an injection molding step in which the injection molding composition is injected into the first molding unit and the second molding unit of the mold clamping unit, the segment injection molding method comprising: the first injection molding After the mold clamping unit is closed, the injection molding composition containing the metal particles and the thermoplastic or thermosetting polymer resin is injected into the first molding unit from the injection unit to perform one injection molding (step 1); Step, after the first injection molding is completed, the mold clamping unit is opened, and the mold clamping unit is Rotating causes the positions of the mold of the first molding unit and the mold of the second molding unit to be interchanged (step 2); the second injection molding step, after the rotating mold clamping unit is closed, the injection molding combination is used from the injection unit Injecting into the first molding unit and the second molding unit respectively, performing injection molding and secondary injection molding in sequence, followed by cooling (step 3); and subsequent steps of injection molding, after the second injection molding is completed, Opening the mold clamping unit to take out the overmolded finally produced by the overmolding (step 4), the step injection molding method further comprises the steps of: before or after the second injection molding is taken out, The rotation of the mold clamping unit interchanges the positions of the mold of the first molding unit and the mold of the second molding unit. At this time, in the injection molding apparatus, the molds of the first molding unit and the second molding unit may each independently include a first portion defining a main body shape of the injection molded article and performing the one-shot molding of the step 1 and Defining an additional structural shape on the body and performing the second portion of the overmolding of step 3, and may include one or more gate valves, more specifically two or more of the gate valves, The gate valve is located at a position corresponding to the injection molded article that moves according to the displacement of the mold, and operates according to the injection molding conditions. For example, when the detergent dispensing opening of the washing machine is injection molded, the molds in the first molding unit and the second molding unit may be a first portion defining a shape of the body of the detergent dispensing opening and a second portion forming an appearance surface of the main body composition. Further, in the injection molding apparatus, the injection unit includes an injection cylinder that continuously injects an injection molding composition into each of the first molding unit and the second molding unit during an injection molding process The injection can be carried out by changing the injection conditions of the composition for injection molding according to the injection molding conditions according to the injection molding step. Thus, according to the section injection molding method of one embodiment of the present invention, an injection molding process for manufacturing a molded article is carried out in stages, and an injection molding composition is continuously injected by an injection cylinder and will be injection-molded according to The injection molding composition injected under the injection molding conditions set in steps is sequentially injection molded. Therefore, when manufacturing an injection molded article, it can be divided into an appearance surface and an inner side by injection molding. As a result, in the case of manufacturing a molded article having a complicated back structure, the appearance characteristics of the molded article can be greatly improved by the multi-step segmental injection molding process, and the loop time can be reduced when manufacturing a thick molded article. In addition, since a single-component injection molding composition is injected through one injection cylinder, the injection molding process and apparatus can be simplified, and the mold is rotated in the gap of the injection molding step, thereby completing the injection molding in a single mold, so that the injection molding does not It deforms when cooled, enabling precision injection molding. The segment injection molding method according to an embodiment of the present invention will be described in more detail below in accordance with the respective steps, and the step 1 is a step of manufacturing an injection molding by one injection molding process. The first injection molding process in the step 1 can be carried out in accordance with a conventional injection molding method. Specifically, the injection molding composition may be injected into the mold of the first molding unit through one or more gate valves of the injection cylinder of the above-described segment injection molding apparatus, and one injection molding may be performed according to the set injection molding conditions. The injection molding conditions of the first molding unit can be determined by comprehensively considering the use, shape, physical properties, and composition for injection molding of the molded article to be produced. Further, the first injection molding process in the step 1 may be performed on the first portion of the mold defining the shape of the body of the injection molded article. Further, the segment injection molding method according to one embodiment of the present invention can greatly improve the appearance characteristics of the injection molded article, and therefore it is possible to make the composition for injection molding containing a metal particle filler such as aluminum and which is liable to cause a poor appearance. In this case, the injection molding composition contains metal particles and a thermoplastic or thermosetting polymer resin for injection molding. At this time, the kind and content of the metal particles and the polymer resin can be determined according to the use of the finally produced molded article and improved physical properties. Specifically, as the metal particles, for example, a metal such as aluminum, copper or manganese or an alloy thereof, or the like, any one or a mixture of two or more of them may be used. Further, the shape and size of the metal particles are not particularly limited and may be appropriately selected depending on the use and shape of the molded article. Specifically, the metal particles may have a shape such as a sphere, a polygon, an ellipse, a fiber or a plate. In particular, when it has a shape in which a plate shape or the like exhibits orientation, it can exhibit significantly improved appearance characteristics as compared with the case of application to an existing injection molding method. In the present invention, the plate-like shape means a structure having two faces which are corresponding to each other or opposite to each other and whose dimension in the horizontal direction is larger than the dimension in the vertical direction, specifically, two faces which are parallel or parallel to each other and which are parallel and include plates. The ratio of the diameter in the cross section of the center of the shaped particle to the average length between the two flat faces, i.e., the thickness (= diameter/thickness), is greater than one. At this time, the diameter refers to the longest length of the line length connecting the two points in the closed curve composed of the circumference of the flat surface in a manner of passing through the center of the plate-shaped particle. The plate shape includes not only a complete plate shape but also a flake-like shape, a scale shape, and the like. The metal particles may contain 0.01 to 20 parts by weight, more specifically 0.1 to 10 parts by weight, or 0.1 to 5 parts by weight, or 1 to 3 parts by weight, relative to 100 parts by weight of the polymer resin. When the metal particles are contained in the above-mentioned content range, a further increase in the appearance suppressing effect can be exhibited. Further, specific examples of the polymer resin are acrylonitrile-butadiene-styrene resin (ABS resin), acetal resin, acrylic resin, polyethylene, polypropylene, polyamine, polyethylene terephthalate An alcohol ester, a polycarbonate (PC), a polyphenylene sulfide, a polyphenylene ether, a phenol resin, a urea resin or an epoxy resin, and the like, and any one or a mixture of two or more of them may be used. As the polymer resin, acrylonitrile-butadiene-styrene resin, polycarbonate or polyamine can be used because they have characteristics which can realize the appearance like metal, and are suitable for the segment injection molding method of the present invention. It is possible to exhibit a further improved appearance characteristic improvement effect. Further, aluminum which is more effective in improving the effect when used in combination with this can be used. In the conventional injection molding method using an injection molding composition containing a filler such as metal particles, the injection molding composition is once injected into a single molding unit defining the structure of the injection molded article, and then injection molding is performed, so the injection speed is faster. The more complicated the structure of the injection molded article, the more serious the appearance of the injection molded article caused by the inconsistent orientation of the metal particles. Therefore, in the conventional method, in order to prevent the appearance defect in the injection molded article, it is necessary to inject the composition for injection molding at a low speed of 50 cc/s or less to perform low-speed injection molding. However, in the segment molding method according to the present invention, the molding process can be carried out in stages according to the structure of the injection-molded article, and thus, as an example, the molding unit is divided into an appearance surface forming portion and a non-appearing surface forming portion, and an injection molding composition The injection molding process is carried out after batch injection, so that the structure in each molding unit can be simplified, and the injection speed of the composition can be increased. Further, for the molding unit forming the appearance surface, the portion for forming the additional structure is not included, and thus the composition for injection molding can be injected in one direction. As a result, even if the injection speed is increased, the orientation of the metal particles contained in the composition is kept constant, thereby improving the orientation uniformity of the metal particles in the injection molded article, and the appearance characteristics can be greatly improved. Further, at the time of the injection molding, the injection molding composition is injected at a high speed without fear of occurrence of appearance defects. Specifically, in the segment injection molding method according to the present invention, the injection speed of the injection molding composition injected into the first molding unit for one injection molding or forming a non-appearing surface can be increased up to 200 cc / s, specifically, may be greater than 50 cc/s and less than or equal to 200 cc/s, and more specifically may be from 70 cc/s to 200 cc/s. When injected at the described injection speed, process time and processability can be shortened. Next, step 2 is a step of rotating the mold clamping unit to interchange the positions of the molds in the first molding unit and the second molding unit. In the segment injection molding device, one injection molding is performed in the first molding unit and the secondary injection molding is completed in the second molding unit. Therefore, after the first injection molding in the step 1 is completed, it is not necessary to complete the injection molding. The mold containing the primary injection molding is moved to the second molding unit by double injection molding. Therefore, after the first injection molding is completed, the mold clamping unit is opened, and the mold clamping unit is rotated to interchange the positions of the mold of the first molding unit and the mold of the second molding unit. At this time, the rotation of the mold clamping unit, such as the rotation of the mold plate, can be accomplished by a moving mold attached to the mold, or by a rotating device inside the mold. Next, step 3 is a second injection molding step of performing double injection molding on the primary injection molding of the second molding unit by the rotation of the mold clamping unit in the step 2. Specifically, after the mold clamping unit in which the empty mold is located in the first molding unit and the primary injection molding is located in the second molding unit is closed, the injection molding composition is injected into the first molding from the injection unit. In the mold of the unit and the second molding unit, and performing injection molding in the first molding unit and performing secondary injection molding in the second molding unit according to the set molding conditions. At this time, the injection molding and injection molding process for the injection molding composition of the first molding unit and the second molding unit may be sequentially performed after the injection molding composition injection molding and the one injection molding process of the first molding unit are completed. In the injection molding composition injection molding and the secondary injection molding process of the second molding unit, the process in the second molding unit may be performed first, or the processes in the first molding unit and the second molding unit may be simultaneously performed. Further, when the injection molding composition is injected into the first molding unit and the second molding unit, it is not injected from the injection cylinder other than the injection cylinder in the step 1, but from the injection cylinder in the step 1 Continuous injection is performed according to set injection conditions by one or more gate valves located in each mold. Further, in the segment molding method according to the present invention, the injection speed of the injection molding composition and the injection into the first molding unit are injected into the molding unit for forming the appearance surface into the second molding unit. The injection molding composition may be injected at a rate up to 200 cc/s, specifically greater than 50 cc/s and less than or equal to 200 cc/s, and more specifically from 70 cc/s to 200 cc/s. As described above, the injection speed of the composition for injection molding of the second molding unit is also increased as compared with the prior art, in which the first molding unit and the second molding unit are respectively controlled at the injection speed. The injection molding composition is injected in batches so that appearance defects do not occur, and process time and processability can be shortened. Further, when the injection molding process of the first molding unit and the second molding unit is carried out, the injection molding conditions can be determined by comprehensively considering the use, shape, physical properties, and composition for injection molding of the molded article to be manufactured. Specifically, the one-shot molding process of the first molding unit may be performed in a first portion of a mold defining a shape of a body of the injection molded article, and the double injection molding process in the second molding unit may be on a defined body The second part of the additional structural shape of the mold is implemented. Therefore, the primary injection molding of the main body shape is manufactured by one injection molding in the first molding unit, and the overmolded product of the final molded product shape is produced by the secondary molding of the second molding unit. As an example, the additional structure on the body of the injection molded article may be a structure such as a rib or a projection. After the overmolding process is completed, a cooling step for curing the overmolded article in the second molding unit is performed. In the conventional segmentation molding process, the cooling process needs to be performed in accordance with each of the segment injection molding steps, but in the present invention, it can be cooled together after the primary and secondary continuous injection molding, so that the time and steps of the segmentation molding process can be shortened. The cooling can be carried out in accordance with a conventional method. Next, step 4 is the second step of the second injection molding of the step 3, and the mold clamping unit is opened to take out the overmolded finally produced by the double injection molding to obtain the finished molded article. At this time, the step of rotating the mold clamping unit to interchange the positions of the mold of the first molding unit and the mold of the second molding unit before or after the secondary injection molding is taken out is also performed. As described in the step 2, the rotation of the mold clamping unit can be accomplished by a method such as die rotation. Further, when the rotation of the mold clamping unit is completed before the secondary injection molding is taken out, the removal of the secondary molding is performed in the first molding unit, and when the rotation is completed after the secondary injection molding is taken out, The removal of the secondary injection molding is completed in the second molding unit. Thus, by the rotation of the mold clamping unit, the empty mold for taking out the secondary molding moves to the first molding unit for one injection molding, and the mold containing the primary molding moves to the second for the secondary injection molding. The molding unit can continuously perform one injection molding and two injection molding processes. 1 is a process flow diagram schematically showing a segment injection molding method in accordance with an embodiment of the present invention. Fig. 1 is an illustration for explaining an example of the present invention, and the present invention is not limited thereto. Next, a manufacturing process of an injection molded article based on the segment injection molding method according to an embodiment of the present invention will be described with reference to FIG. First, as step 1 of the first injection molding, in the segment injection molding apparatus, the first molding unit 10a for performing one-shot injection molding for manufacturing one injection molding and the secondary injection molding for one injection molding are carried out. The mold clamping unit 10 of the second molding unit 10b is closed (S11), and the injection molding composition is injected into the first molding unit 10a through the gate valve 30a of the mold from the injection cylinder of the injection unit 20 to perform one-time injection molding (S12). Next, as step 2, after the first injection molding in the step 1, the mold clamping unit is opened (S21), and the mold clamping unit is rotated to include the first injection molding finished by the first injection molding. The positions of the mold of the first molding unit and the mold of the second molding unit are interchanged (S22). Next, as a step 3 of the second injection molding, after the rotating mold clamping unit is closed (S31), the injection molding composition is injected from the injection cylinder through the gate valve 30a in the mold of the first molding unit. One injection molding is carried out (S32), and then the same injection molding composition is injected from the injection cylinders through the gate valves 30b and 30c in the mold of the second molding unit to perform secondary injection molding (S33). After the secondary injection molding process is completed, the mold for performing the secondary injection molding is subjected to a cooling process. FIG. 1 shows that the secondary injection molding in the second molding unit is performed after one injection molding of the first molding unit, but may also be carried out in the first molding unit after the secondary injection molding of the second molding unit is completed. The injection molding process of the first molding unit and the second molding unit can be performed simultaneously in one injection molding. As a result of the step 3 described above, the mold memory of the first molding unit is in the primary injection molding 40' and the mold memory of the second molding unit is in the overmolded article 50. Next, as a second step of the second injection molding, in step 4, the mold clamping unit (S41) containing the primary molding and the secondary molding respectively is opened in the mold, and the mold clamping unit is rotated to make the mold of the first molding unit and After the positions of the molds of the second molding unit are interchanged (S42), the secondary injection molded product is taken out from the second molding unit in the mold clamping unit to obtain a molded article. As described above, the segment molding method according to the present invention injects the composition for injection molding through a single injection cylinder during the one injection molding process and the secondary injection molding process, so that the injection molding process and the apparatus are simple in structure. Further, not only injection molding is performed in a single mold, but also a subsequent injection molding process is performed before the injection molding of the previous step is cooled and deformed, so that precise injection molding can be achieved. As an embodiment, the washing machine detergent dispensing opening is injection molded using the segmentation molding method according to the present invention. Specifically, 3 parts by weight of plate-shaped aluminum is mixed as metal particles with respect to 100 parts by weight of the ABS resin to prepare a composition for segment injection molding, and the segment injection molding composition is loaded into the segment according to the present invention. After the injection cylinder in the injection molding apparatus, the segment injection molding was carried out in accordance with the process flow chart shown in FIG. At this time, the segment injection molding apparatus includes a first molding unit and a second molding unit for a single injection molding process and a secondary injection molding process, the molding units including a body shape defining an injection molded product and used to form a non- A first portion of the exterior portion and a second portion that forms an apparent surface relative to the body as an additional structure. Further, for the purpose of comparison, the composition for injection molding described above was injected into a molding unit in a single injection according to a conventional injection molding method, and injection molding was carried out to manufacture a washing machine detergent inlet. Fig. 3a is a photograph of the appearance of one injection molded article when the washing machine detergent inlet is manufactured by the segment injection molding method according to the present invention, and Fig. 3b is a photograph of the appearance of the overmolded article. Moreover, FIG. 4 is a photograph which looked at the external appearance of the washing|cleaning-washing opening of the washing machine manufactured by the conventional injection molding method. As shown in Fig. 3b, the detergent injection port manufactured by the segment injection molding method according to the present invention exhibits metal-like appearance characteristics because the orientation of the metal particles after the secondary injection molding is uniform, and no flow marks are generated. In contrast, as shown in FIG. 4, the laundry detergent mouth of the comparative example manufactured by the existing injection molding method clearly showed that the flow marks showed poor appearance. Furthermore, Figure 5a schematically shows the orientation of the metal particles in the composition during segmental injection molding according to the present invention, and Figure 5b schematically shows the metal particles in the composition during injection molding according to the prior art injection molding method. orientation. The difference in appearance characteristics in the above experiment is explained with reference to Figs. 5a and 5b, and the detergent dispensing opening manufactured by the segment injection molding method according to the present invention is divided into portions for forming the main body of the detergent dispensing opening (first The molding unit 10a and the portion (second molding unit) 10b for forming the appearance surface are subjected to injection molding, and the injection molding composition is injected from the injection cylinder 21 in only one direction in the portion where the appearance surface is formed, so the metal in the composition The orientation of the particles 22 can be kept constant. In contrast, for a comparative detergent inlet manufactured by an existing injection molding method, the composition is injected at a time from the injection cylinder 21' to a single clamping unit 10' having a structure corresponding to the detergent dispensing opening. Since the injection direction of the composition changes depending on the structure, the orientation uniformity of the metal particles 22' is lowered, and as a result, the appearance characteristics are lowered. Further, the final molded article is manufactured by the overmolding process as described above, but the segment injection molding method according to an embodiment of the present invention may also undergo three or more injection molding processes. In this case, the mold clamping unit may include three or more molding units, and the molds located in each molding unit may respectively include three or more portions that perform an injection molding process. As an example, when the segment injection molding method is subjected to four injection molding, the mold clamping unit in the segment injection molding apparatus may include a first molding unit for performing one injection molding, and the first molding unit a second molding unit positioned at a position of 90 degrees and used for performing double injection molding on a single injection molded article, which is positioned at a position of 90 degrees with respect to the second molding unit and used for performing three injection molding on the overmolded article a formed third molding unit, and a fourth molding unit positioned at a position of 90 degrees with the third molding unit and used for performing four injection moldings on the three injection moldings, and the mold clamping unit is rotated according to each injection molding step 90 degrees to make the mold move to complete the injection molding. Further, the mold in each molding unit may include a first portion defining a shape of the body and a second portion, a third portion, and a fourth portion respectively defining shapes of the additional structures 1 to 4 on the body, once in the first molding unit Molding is carried out in a first part of the mould, secondary forming in the second forming unit is carried out in a second part of the mould, three mouldings in the third moulding unit are carried out in a third part of the mould, and in a fourth moulding unit The four-time forming is carried out in the fourth part of the mold, and the finally produced injection molded article is taken out from the mold of the fourth molding unit. Therefore, the segment injection molding method may include: after the mold clamping unit is closed, injecting the injection molding composition from the injection unit into the first molding unit to perform a first injection molding step of one injection molding; After the injection molding is completed, the mold clamping unit is opened, the mold clamping unit is rotated by 90 degrees to make the mold of the first molding unit be located in the second molding unit; after the rotating clamping unit is closed, the injection unit is The injection molding composition is injected into the first molding unit and the second molding unit, respectively, and the injection molding and the secondary injection molding are sequentially performed in sequence, and then the second injection molding step of cooling is performed; after the second injection molding is completed, Opening the mold clamping unit, rotating the mold clamping unit by 90 degrees to place the mold of the second molding unit in the third molding unit; after closing the rotating mold clamping unit, respectively, molding the injection molding composition from the injection unit Injecting into the first to third molding units, performing one injection molding, two injection molding, and three injection molding in sequence, and then a third injection molding step of performing cooling; after the third injection molding is completed, the mold clamping unit is opened, and the mold clamping unit is rotated by 90 degrees so that the mold of the third molding unit is located in the fourth molding unit; After the mold clamping unit is closed, the injection molding composition is injected into the first to fourth molding units from the injection unit, and one injection molding, two injection molding, three injection molding, and four injection molding are continuously performed in sequence. And then performing a fourth injection molding step of cooling; after the fourth injection molding is completed, the mold clamping unit is opened to take out a subsequent step of injection molding of the injection molding, and the injection molding may be included before the four injection moldings are taken out or After taking out, the mold clamping unit is rotated by 90 degrees to place the mold of the fourth molding unit in the first molding unit. According to another embodiment of the present invention, a segment injection molding apparatus that is advantageous for use in the segment injection molding method is provided. Fig. 6 is a photograph for observing a segment injection molding apparatus according to the present invention, and Fig. 7 is a schematic view schematically showing a section of the segment injection molding apparatus. Referring to FIG. 7 , the segment injection molding apparatus 100 specifically includes a mold clamping unit 110 that performs injection molding and an injection unit 120 that injects an injection molding composition into the mold clamping unit, the mold clamping unit 110 includes Implementing a first molding unit 110a for manufacturing one injection molding of a primary injection molding and a second molding unit 110b for performing secondary injection molding of a primary injection molding, the clamping unit 110 further including the rotation by the The positions of the molds in the first molding unit and the second molding unit are interchanged according to the injection molding step. In addition, the injection unit 120 includes an injection cylinder 121 that is respectively connected to the molds in the first molding unit and the second molding unit 110a, 110b, and is injection molded by opening and closing of the gate valves 130a, 130b according to the molding step. The composition is injected into the first molding unit 110a or the second molding unit 110b. The various components in the segmented injection molding apparatus and their operation are as previously described. The invention has been described above by way of limited embodiments and the accompanying drawings, but the invention is not limited thereto. Various modifications and recombinations can be made by those skilled in the art to which the invention pertains.

10, 10', 110‧‧ ‧ clamping unit

10a, 110a‧‧‧ first molding unit

10b, 110b‧‧‧ second molding unit

20, 120‧‧‧ injection unit

21, 21', 121‧‧ ‧ injection cylinder

22, 22'‧‧‧ metal particles

30a, 30b, 30c, 130a and 130b‧‧‧ gate valves

40, 40'‧‧‧Injection molding

50‧‧‧Secondary injection molding

160‧‧‧Rotating device

100‧‧‧Segment injection unit

1 is a process flow diagram schematically showing an injection molding process using a segment injection molding method according to an embodiment of the present invention. 2 is a process flow diagram schematically showing a process for manufacturing a detergent washing port of a washing machine by the segment injection molding method according to the present invention. Fig. 3a is a photograph of the appearance of one injection molded article when the washing machine detergent inlet is manufactured by the segment injection molding method according to the present invention, and Fig. 3b is a photograph of the appearance of the overmolded article. Fig. 4 is a photograph of the appearance of a washing machine mouth of a washing machine manufactured according to the conventional injection molding method. Fig. 5a schematically shows the orientation of metal particles in the composition during segmental injection molding according to the invention, and Fig. 5b schematically shows the orientation of metal particles in the composition during injection molding according to the prior art injection molding method. Figure 6 is a photograph of a segmental injection molding apparatus in accordance with the present invention. Fig. 7 is a structural view schematically showing a section of a segment injection molding apparatus according to the present invention.

Claims (11)

A segmental injection molding method using an injection molding apparatus including a mold clamping unit and an injection unit, the mold clamping unit comprising a first molding unit for performing one injection molding for manufacturing a single injection molding and performing one injection molding a second molding unit of overmolding of the molded product, the mold clamping unit is interchanged by rotating the positions of the molds in the first molding unit and the second molding unit according to an injection molding step, and the injection unit is injection molded Injecting the composition into the first molding unit and the second molding unit of the mold clamping unit, the segment injection molding method comprises: a first injection molding step, after the mold clamping unit is closed, injection molding is performed from the injection unit The molding composition is injected into the first molding unit to perform one injection molding; the clamping unit rotating step, after the first injection molding is completed, the mold clamping unit is opened, and the mold clamping unit is rotated to make the mold of the first molding unit and The positions of the molds of the second molding unit are interchanged; the second injection molding step is to rotate the mold clamping sheets After the closure, the injection molding composition is injected into the first molding unit and the second molding unit from the injection unit, and the injection molding and the secondary injection molding are successively performed in sequence, followed by cooling; and the subsequent steps of the injection molding, After the second injection molding is completed, the mold clamping unit is opened to take out the secondary injection molding finished by the second injection molding, and the segment injection molding method further comprises the following steps: before the secondary injection molding is taken out or After taking out, the mold clamping unit is rotated to interchange the positions of the mold of the first molding unit and the mold of the second molding unit, and the composition for injection molding contains metal particles and a thermoplastic or thermosetting polymer resin. The segment injection molding method according to claim 1, wherein the injection unit comprises an injection cylinder, and the injection molding composition is injected in the first injection molding step and the second injection molding step. Injection is performed from the injection cylinder into the first molding unit and the second molding unit. The segment injection molding method according to claim 1, wherein the injection into the injection molding composition in the first molding unit and the second molding unit is each independently greater than or equal to 50 cc/s. Implemented at a speed of 200 cc/s. The segment injection molding method of claim 1, wherein the molds in the first molding unit and the second molding unit each independently include a first portion defining a shape of a body of the injection molded article and defining the A second portion of the additional structural shape on the body, the primary injection molding being performed in the first portion, the secondary injection molding being performed in the second portion. The segment injection molding method according to claim 1, wherein the metal particles comprise one or more selected from the group consisting of aluminum, copper, manganese, and alloys thereof. The segment injection molding method according to claim 1, wherein the metal particles comprise aluminum. The segment injection molding method according to claim 1, wherein the metal particles have a plate shape. The segment injection molding method according to the first aspect of the invention, wherein the metal particles comprise 0.01 to 20 parts by weight with respect to 100 parts by weight of the polymer resin. The segment injection molding method according to the first aspect of the invention, wherein the polymer resin comprises an acrylonitrile-butadiene-styrene resin, an acetal resin, an acrylic resin, a polyethylene, a polypropylene, One or more of polyamine, polyethylene terephthalate, polycarbonate, polyphenylene sulfide, polyphenylene ether, phenol resin, urea resin, and epoxy resin. The segment injection molding method according to claim 1, wherein the polymer resin comprises an acrylonitrile-butadiene-styrene resin. The segment injection molding method according to claim 1, wherein the second injection molding step and the subsequent step of injection molding are repeatedly performed two or more times in order.