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 a back portion of the back mold facing the back surface of the injection product includes a heat dissipation metal.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0031020 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 molten injection material into an injection mold using heat.

[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 part through injection molding, and includes a transfer mold located in front of the injection part to form a pattern on a front surface of the injection part, and a back mold located behind the injection part, and a back portion of the back mold facing the back surface of the injection part may include a heat dissipation metal.

[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, the rear surface of the rear mold facing the rear surface of the injection product is formed of a heat dissipating metal, 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] This is an enlarged image of an example of region B in Figure 1. [Figure 4] This is an enlarged image of region B in Figure 1 in another example. [Diagram 5] 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 6] 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 the same 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 the description of 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.

[0013] Referring to FIG. 1, an injection mold 10 according to an embodiment of the present invention is an injection mold for manufacturing an injection item M through injection molding, and includes a transfer mold 100 for forming a pattern on the front surface 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 surface of the injection item M include heat dissipating metal.

[0014] FIG. 2 is an enlarged cross-sectional view of region A in FIG.

[0015] 1 and 2, the transfer mold 100 is located 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 when referring to FIG.

[0016] 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.

[0017] Meanwhile, the roughness Ra of the embossed pattern formed on the front surface 111 of the transfer mold 100 may be, for example, 50 μm or less. Specifically, the roughness Ra of the embossed pattern formed on the front surface 111 may be, for example, 5.8 to 30 μm. More specifically, the roughness Ra of the embossed pattern formed on the front surface 111 may be, for example, 10 μm.

[0018] 1, 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 in reference to FIG 1. In this case, for example, the rear die 200 may be located below the injection item M.

[0019] Here, the rear portions 211 and 221 of the rear mold 200 facing the rear surface of the injection item M may include a heat dissipating metal. In this case, the heat dissipating metal may be made of a Porcerax material.

[0020] Therefore, in the injection mold 10 according to the embodiment of the present invention configured as above, the rear portions 211 and 221 of the rear mold 200 facing the injection object M include a heat dissipating metal, which has the effect of enabling uniform transfer during injection.

[0021] In particular, in the split-structure rear mold 200, the rear portions 211, 221 are made of porcelain, a heat-dissipating metal, and heat exchange is accelerated during injection, enabling uniform transfer without the generation of a heterogeneous texture in the injected object M corresponding to the split mold portions.

[0022] FIG. 3 is an image showing an example of region B in FIG. 1 in an enlarged manner, and FIG. 4 is an image showing another example of region B in FIG. 1 in an enlarged manner.

[0023] Meanwhile, referring to Fig. 3, the rear portions 211 and 221 of the rear mold 200 may be, for example, electric discharge machined. At this time, the rear portions 211 and 221 made of the electric discharge machined porcelain material may have 20 to 30% air pores formed therein. As a result, the rear portions 211 and 221 of the rear mold 200 may have a gas vent function by utilizing a pore-type ventilation structure.

[0024] Also, referring to FIG. 4, the rear portions 211 and 221 of the rear mold 200 may be subjected to a surface milling process or a grinding process after the electric discharge machining process in another example.

[0025] FIG. 5 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. 6 is a plan view showing another example of a back mold in an injection mold according to an embodiment of the present invention.

[0026] 1 and 5, the rear mold 200 may be provided in a divided form. Here, 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.

[0027] 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.

[0028] Meanwhile, referring to FIG. 6, 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 (see FIG. 5 and FIG. 6). In this case, the end of the first split mold 210 may be the end of the part where the injection part M is formed in the first split mold 210. Referring to FIG. 5, the cross section of the second split mold 220 may be formed in a rectangular shape, for example. In this case, the first split mold 210 may have a connection hole 212 corresponding to the second split mold 220 so that the second split mold 220 can be connected to the first split mold 210.

[0029] 6, the second split mold 220' may be formed to 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.

[0030] <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.

[0031] In addition, an embossed pattern was formed on the front surface of the transfer mold facing the front surface of the injection product, and the transfer mold was chemically etched so that the roughness Ra of the embossed pattern formed on the front surface of the transfer mold was 10 μm.

[0032] Meanwhile, the back part of the back mold, which faces the back of the injection product, was made of Porcerax, a heat dissipating metal, and the back part of the back mold was surface ground after electrical discharge machining.

[0033] The injection material used was ASA Resin.

[0034] <Production Example 2> An injection mold was manufactured in the same manner as in Example 1, except that the surface of the rear part of the rear mold was untreated after the electric discharge machining.

[0035] <Comparative Example 1> An injection mold was manufactured in the same manner as in Example 1, except that the rear part of the rear mold was not divided and general steel section (HP4M) was used.

[0036] <Comparative Example 2> An injection mold was manufactured in the same manner as in Example 1, except that the rear part of the rear mold was made of general steel (HP4M).

[0037] <Comparative Example 3> An injection mold was manufactured in the same manner as in Example 1, except that the rear part of the rear mold was made of a Be-Cu metal material.

[0038] <Comparative Example 4> An injection mold was manufactured in the same manner as in Example 1, except that the rear part of the rear mold was made of PTFE (Teflon (registered trademark)) material.

[0039] <Experimental Example 1> Appearance evaluation samples of the injection molded products manufactured in Examples 1 and 2 and Comparative Examples 1 to 4 under the same molding conditions were prepared using an LsMtron LGE-ΙΙ220N electric molding machine.

[0040] All experimental results refer to the appearance surface of the upper side of the injected product which was micro-embossed patterned. The degree of embossing transfer on the upper side corresponding to the rear split position makes it possible to observe the change in appearance with the naked eye. The degree of transfer was evaluated to quantify the appearance change characteristics of the injected product, and a confocal microscope was used to measure the Ra (roughness) change at the appearance change position and the thickness of the line where the Ra change continues, and the results are shown in Table 1 below. (Confocal microscope, Keynence VK-X1100)

[0041] [Table 1]

[0042] In the case of the difference in the embossing pattern at the dividing position of the back surface, when the change in Ra roughness was ±0.5 μm (5%) or more, and when the thickness of the boundary line was 2 mm or more, a different texture was observed with the naked eye, indicating that the degree of embossing transfer was different. As shown in Table 1, no different texture was observed in Production Example 1 and Production Example 2, whereas a different texture was observed in Comparative Examples 1 to 4. Therefore, it can be seen that a uniform transfer was achieved when the back surface of the back mold facing the back surface of the injection product was made of Porcelainx material, which is a heat dissipating metal.

[0043] 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.

[0044] The specific scope of protection of the invention will be defined by the appended claims. [Explanation of symbols]

[0045] 10: Injection mold 100: Transfer mold 111: Front part 200: Back mold 211, 221: Back part 212: Bonding hole 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 is made of a metal material having a breathable structure with 20 to 30% air pores, An embossed pattern is formed on a front surface of the transfer mold facing the front surface of the injection product, forming the embossed pattern on the front surface of the injection product; The rear mold is provided in a split form, and includes a first split mold and a second split mold located in the center or at an end of the first split mold in a plan view, and the second split mold can be moved upward relative to the first split mold.

2. The injection mold of claim 1 , wherein the back mold portion is electro-discharge machined.

3. 3. The injection mold according to claim 1, wherein the rear part of the rear mold is subjected to a surface milling treatment or a surface grinding treatment after the electric discharge machining.

4. The injection mold according to any one of claims 1 to 3, wherein the first split mold has a connecting hole formed in a shape corresponding to the second split mold so that the second split mold can be connected to the first split mold.

5. 5. The injection mold according to claim 1, wherein rear portions of the first split mold and the second split mold facing a rear surface of the injection item are made of the metal material having a breathable structure in which 20 to 30% of the pores are formed.

6. The injection mold according to any one of claims 1 to 5, wherein the embossed pattern formed on the front surface of the transfer mold has a roughness (Ra) of 5.8 to 30 µm.

7. A method for producing an injection product, comprising: placing an injection material into the injection mold according to any one of claims 1 to 6 to mold the injection product.

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