Injection mould

Abstract

The present invention relates to an injection mold, and the injection mold according to the present invention is an injection mold for manufacturing an injection product through injection molding, and includes a transfer mold located in front of the injection product to form a pattern on the front surface of the injection product, and a back mold located behind the injection product, and an embossed pattern is formed on a back surface of the back mold facing the back surface of the injection product.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0031021 dated March 9, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an injection mold. [Background technology]

[0003] Injection molding is a method of molding an injection product by injecting a heated and melted injection material into an injection mold.

[0004] Many parts for automobiles and electronic products are manufactured by injection molding, and parts with various exterior designs are provided by using patterns engraved on the injection mold. The design required for exterior parts can be a glossy surface (mirror finish), but the adoption of micro-embossed patterns is becoming more and more common to impart aesthetic functions such as texture and surface properties such as scratch and stain resistance. However, depending on the structure of the mold, the transfer of the micro-embossed pattern during injection molding may not be uniform, which often results in uneven gloss and uneven appearance of the molded product. Injection molded products with normal embossed patterns are mostly applied without post-processing such as painting / plating, and it is impossible to hide the unevenness through post-processing, so the aesthetic problem of uneven surfaces is a serious issue that must be resolved as soon as possible. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent No. 10-2189820 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE PRESENT EMBODIMENT An aspect of the present invention is to provide an injection mold capable of achieving uniform transfer onto an injection product. [Means for solving the problem]

[0007] An injection mold according to an embodiment of the present invention is an injection mold for manufacturing an injection product through injection molding, and includes a transfer mold located in front of the injection product to form a pattern on a front surface of the injection product, and a back mold located behind the injection product, and an embossed pattern may be formed on a back portion of the back mold facing the back surface of the injection product.

[0008] Furthermore, the injection product according to the embodiment of the present invention may be manufactured using the injection mold according to the embodiment of the present invention. Effect of the Invention

[0009] According to the present invention, when a pattern is formed on the front surface of the injection product through a transfer mold, an embossed pattern is formed on the rear surface of the rear mold facing the rear surface of the injection product, which enables uniform transfer and prevents defects in the appearance of the injection product. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing an injection mold according to an embodiment of the present invention. [Diagram 2] 2 is an enlarged cross-sectional view of region A in FIG. 1. [Diagram 3] FIG. 2 is a plan view showing an example of a back mold in an injection mold according to an embodiment of the present invention. [Figure 4] 11 is a plan view showing another example of a back mold in an injection mold according to an embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The object, particular advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings. In this specification, when referring to components in each drawing, it should be noted that the same components are numbered as much as possible even if they are shown in different drawings. In addition, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. In addition, in describing the present invention, detailed descriptions of related known technologies that may unnecessarily obscure the gist of the present invention will be omitted. Injection mold according to the embodiment

[0012] FIG. 1 is a cross-sectional view showing an injection mold according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an enlarged view of area A in FIG. 1, FIG. 3 is a plan view showing an example of a back mold in an injection mold according to an embodiment of the present invention, and FIG. 4 is a plan view showing another example of a back mold in an injection mold according to an embodiment of the present invention.

[0013] 1 to 4, an injection mold 10 according to an embodiment of the present invention is an injection mold for manufacturing an injection item through injection molding, and includes a transfer mold 100 for forming a pattern on the front side of the injection item M, and a back mold 200 located behind the injection item M, and back portions 211, 221 of the back mold 200 facing the back side of the injection item M are formed with an emboss pattern.

[0014] More specifically, the transfer mold 100 is positioned in front of the injection object M to form a pattern on the front surface of the injection object M. Here, the front surface of the injection object M means the front surface of the injection object M, and may be the upper surface of the injection object M with reference to FIG.

[0015] Also, a pattern may be formed on a front surface 111 of the transfer mold 100 facing the front surface of the injection item M, so that the pattern may be transferred to the injection item. Here, an embossed pattern may be formed on the front surface 111 of the transfer mold 100. At this time, the front surface 111 of the transfer mold 100 may be subjected to a chemical etching treatment so that surface roughness may be formed.

[0016] The rear die 200 may be located behind the injection item M to support the rear of the injection item M. Here, the rear of the injection item M means the rear surface of the injection item M, and may be the lower surface of the injection item M with reference to FIG. 1. In this case, for example, the rear die 200 may be located below the injection item M.

[0017] At this time, the rear portions 211 and 221 of the rear mold 200 facing the rear surface of the injection item M may be formed with an emboss pattern.

[0018] In addition, the rear mold 200 may be provided in a divided form. Referring to Fig. 3, the rear mold 200 may include, for example, a first divided mold 210 and a second divided mold 220 located at the center of the first divided mold 210 in a plan view.

[0019] Meanwhile, referring to Fig. 4, in another example, the rear mold 200' may include a first split mold 210 and a second split mold 220' located at an end of the first split mold 210 in a plan view. That is, the second split mold 220, 220' may be located at the center or end of the first split mold 210 (Reference Figs. 3 and 4). In this case, the end of the first split mold 210 may be the end of a portion where the injection part M is formed in the first split mold 210.

[0020] As a result, after injection, the second separate mold 220 moves upward relative to the first separate mold 210, making it easy to separate the injected object M from the back mold 200.

[0021] 3, the cross section of the second separate mold 220 may be formed, for example, in a rectangular shape. In this case, the first separate mold 210 may have a coupling hole corresponding to the second separate mold 220 so that the second separate mold 220 can be coupled thereto.

[0022] 4, the second split mold 220' may have a circular cross section in another example. In this case, the rear part 221' of the second split mold 220' may be formed to have a circular cross section in a plan view.

[0023] An emboss pattern may be formed on rear portions 211 and 221 of the first and second separate molds 210 and 220, respectively, facing the rear surface of the injection item M.

[0024] The rear portions 211 and 221 of the rear mold 200 may be subjected to a chemical etching process so that roughness is formed on the surface.

[0025] Meanwhile, in the first example, the roughness of the embossed pattern formed on the rear parts 211, 221 of the rear mold 200 may be formed to be the same as the roughness of the embossed pattern formed on the front part 111 of the transfer mold 100. Here, the roughness Ra of the embossed pattern formed on the rear parts 211, 221 and the front part 111 may be formed to be, for example, 50 μm or less. In this case, specifically, the roughness Ra of the embossed pattern formed on the rear parts 211, 221 and the front part 111 may be formed to be, for example, 5.8 to 30 μm. In this case, the roughness Ra of the embossed pattern is formed to be 5.8 μm or more, which is the lower limit, so that the heterogeneity of the injection product M at the part where the mold is divided is significantly reduced or may not occur. And, more specifically, the roughness Ra of the embossed pattern formed on the rear parts 211, 221 and the front part 111 may be formed to be, for example, 10 μm.

[0026] Also, in the second example, the roughness of the embossed pattern of the rear parts 211 and 221 may be greater than the roughness of the embossed pattern of the front part 111. Meanwhile, for example, the roughness Ra of the embossed pattern of the rear parts 211 and 221 may be greater than the roughness Ra of the embossed pattern of the front part 111 by 5 to 15 μm. In this case, specifically, for example, the roughness Ra of the embossed pattern of the rear parts 211 and 221 may be greater than the roughness Ra of the embossed pattern of the front part 111 by 10 μm.

[0027] Therefore, the injection mold 10 according to the embodiment of the present invention configured as described above has an embossed pattern formed on the rear portions 211, 221 of the rear mold 200 facing the rear surface of the injection item M, thereby enabling a uniform transfer onto the injection item during injection.

[0028] In particular, in the split-structure rear mold 200, an embossed pattern is formed on the rear portions 211, 221, which accelerates heat exchange during injection, enabling uniform transfer without creating a heterogeneous texture in the injected product M corresponding to the split mold portions.

[0029] <Production Example 1> An injection mold was manufactured including a transfer mold located in front of the injection product to form a pattern on the front surface of the injection product, and a back mold located behind the injection product. The back mold was formed in a form divided into a first split mold and a second split mold including a second split mold located in the center of the first split mold in a plan view.

[0030] Here, an emboss pattern having the same roughness was formed on the rear surface of the rear mold facing the rear surface of the injection product and on the front surface of the transfer mold facing the front surface of the injection product. At this time, the first and second split molds in the rear mold were formed with an emboss pattern having the same roughness.

[0031] The rear surface of the rear mold and the front surface of the transfer mold were both subjected to chemical etching treatment so that the roughness Ra of the embossed pattern was 10 μm.

[0032] In addition, the back mold and transfer mold were made of HP4M material, and ASA Resin was used as the injection material.

[0033] <Production Example 2> An injection mold was manufactured in the same manner as in Example 1, except that the embossed pattern on the rear surface of the rear mold was chemically etched to have a roughness Ra of 20 μm, and the embossed pattern on the front surface of the transfer mold was chemically etched to have a roughness Ra of 10 μm.

[0034] <Comparative Example 1> An injection mold was manufactured in the same manner as in Example 1, except that in the rear mold, the rear portion of the second separate mold was lapped to a surface roughness Ra of 0.2 μm, and the rear portion of the first separate mold was ground to a surface roughness Ra of 1.6 μm.

[0035] <Comparative Example 2> An injection mold was manufactured in the same manner as in Example 1, except that in the rear mold, the rear portion of the second separate mold and the rear portion of the first separate mold were ground to a surface roughness Ra of 1.6 μm.

[0036] <Comparative Example 3> An injection mold was manufactured in the same manner as in Example 1, except that in the rear mold, the rear portion of the second split mold was chemically etched to have a surface roughness Ra of 10 μm, and the rear portion of the first split mold was ground to have a surface roughness Ra of 1.6 μm.

[0037] <Comparative Example 4> An injection mold was manufactured in the same manner as in Example 1, except that in the rear mold, the rear portion of the second split mold was chemically etched to have a surface roughness Ra of 20 μm, and the rear portion of the first split mold was ground to have a surface roughness Ra of 1.6 μm.

[0038] <Comparative Example 5> An injection mold was manufactured in the same manner as in Example 1, except that in the rear mold, the rear portion of the second split mold was ground to a surface roughness Ra of 1.6 μm, and the rear portion of the first split mold was lapped to a surface roughness Ra of 0.2 μm.

[0039] <Comparative Example 6> An injection mold was manufactured in the same manner as in Example 1, except that in the rear mold, the rear portion of the second split mold was ground to a surface roughness Ra of 1.6 μm, and the rear portion of the first split mold was chemically etched to a surface roughness Ra of 10 μm.

[0040] <Comparative Example 7> An injection mold was manufactured in the same manner as in Example 1, except that in the rear mold, the rear portion of the second separate mold was ground to a surface roughness Ra of 1.6 μm, and the rear portion of the first separate mold was chemically etched to a surface roughness Ra of 20 μm.

[0041] <Experimental Example 1> Appearance evaluation samples of Production Examples 1 and 2 and Comparative Examples 1 to 7 were produced under the same molding conditions using an LsMtron LGE-ΙΙ220N electric molding machine.

[0042] All experimental results were measured on the appearance of the upper surface where the micro-embossing pattern was applied. To quantify the appearance change characteristics of the molded product, the transfer rate was evaluated using a Gloss-Meter and is shown in Table 1 below.

[0043] [Table 1]

[0044] As shown in Table 1, when compared with the visual appearance evaluation results, it was found that the difference in the embossed pattern was visually observed as a different texture of the glossy part when the Gloss Gap was 0.3 or more. That is, it can be seen that no different texture of the glossy part occurred in Production Examples 1 and 2, whereas a different texture of the glossy part occurred in Comparative Examples 1 to 7. Therefore, it can be seen that a uniform transfer was performed when an embossed pattern was formed on the rear part of the rear mold facing the injection product through a chemical etching treatment so that the surface roughness Ra was 10 and 20 μm.

[0045] Although the present invention has been described in detail above through specific examples, these are merely for the purpose of specifically explaining the present invention, and the present invention is not limited thereto. It can be said that various implementations are possible within the technical concept of the present invention by those having ordinary skill in the art.

[0046] The specific scope of protection of the invention will be defined by the appended claims. [Explanation of symbols]

[0047] 10: Injection mold 100: Transfer mold 111: Front part 200: Back mold 210: First split mold 220: Second split mold 211, 221: Back part M: Injection product

Claims

1. An injection mold for manufacturing an injection part through injection molding, a transfer mold positioned in front of the injection object to form a pattern on the front surface of the injection object; and A back mold is provided behind the injection part, The rear part of the rear mold facing the rear of the injection product has an embossed pattern formed thereon, The back mold is provided in a divided form, An embossed pattern is formed on a front surface of the transfer mold facing the front surface of the injection product, and the roughness of the embossed pattern formed on the rear surface of the rear mold is formed to be the same as the roughness of the embossed pattern formed on the front surface of the transfer mold, and in this case, the roughness (Ra) of the embossed pattern formed on the rear surface of the rear mold and the front surface of the transfer mold is formed to be 5.8 to 30 μm, or An injection mold, wherein the roughness of the embossed pattern on the rear part of the rear mold is formed to be greater than the roughness of the embossed pattern on the front part of the transfer mold, and in this case, the roughness (Ra) of the embossed pattern on the rear part of the rear mold is formed to be 5 to 15 μm greater than the roughness (Ra) of the embossed pattern on the front part of the transfer mold.

2. The back mold is 2. The injection mold of claim 1, comprising a first part mold and a second part mold located in a center or end of the first part mold in plan view.

3. The injection mold according to claim 2 , wherein the embossed pattern is formed on a rear surface of the first and second split molds facing the injection object.

4. The injection mould according to any one of claims 1 to 3, wherein the back part of the back mould is chemically etched to create surface roughness.

5. A method for producing an injection part, comprising using the injection mold according to any one of claims 1 to 4.

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