KR20210029077A - Method for manufacturing curved cover of mobile terminal having fine pattern - Google Patents

Abstract

Disclosed is a method for manufacturing a curved cover for a mobile terminal having a fine pattern to increase productivity. According to the present invention, the method comprises: a first step of preparing a molding material in which polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), and polyethylene terephthalate (PET) are sequentially stacked; a second step of preparing a first mold having a first molding surface on which a predetermined pattern is formed, and a second mold having a second molding surface which has a shape corresponding to the first molding surface; a third step of heating the first and second molds to reach a predetermined surface temperature (T1); a fourth step of disposing the molding material heated at a predetermined molding temperature (T2) on the second molding surface; and a fifth step of molding the molding material by matching the first and second molding surfaces to apply a predetermined molding pressure (P) to the molding material.

Description

Method for manufacturing curved cover of mobile terminal having fine pattern}

The present invention (Disclosure) relates to a method for manufacturing a curved surface cover for a mobile terminal in which a fine pattern is formed, and specifically, to a method for manufacturing a curved surface cover for a mobile terminal in which a fine pattern is formed that can improve productivity by performing a fine pattern and a curved surface simultaneously About.

Here, background technology related to the present invention is provided, and these do not necessarily mean known technology (This section provides background information related to the present disclosure which is not necessarily prior art).

In general, the injection mold includes a first mold and a second mold that are combined with each other to form a cavity having a shape to be manufactured and an injection product to be manufactured therebetween.

The first mold and the second mold are arranged vertically and side by side so that the first mold is disposed above the second mold, and a cavity is formed by the first mold and the second mold. A gate may be formed in the second mold so that molten resin can be injected into the cavity.

In the injection mold manufacturing method using such an injection mold, when a film is placed between the first mold and the second mold, and then the molten resin is injected through the gate provided in the second mold, the temperature of the molten resin and the pressure acting on the molten resin are applied. As the film is deformed into a shape corresponding to the first mold, it is in close contact with the first mold, and the molten resin is solidified in this state, thereby completing the production of an injection product coated with a film on one side.

The in-mold molding method is a technology for applying not only to cell phone covers, control panels, automobile interior and exterior materials, control panels and parts of various electronic products, but also to synthetic resin products whose surfaces are decorated. Conventionally, printing is used to decorate the surface after injection molding of synthetic resin. It is a technology that can manufacture synthetic resin products decorated with complex printing or graphics and patterns with only one injection molding process compared to the method that has been carried out over several stages, such as the stage and post-processing stage.

Specifically, the in-mold molding method is to form various printed layers on the lower surface of a base film such as polyethylene terephthalate (PET), polycarbonate (PC), etc., and then put them into the mold together with the synthetic resin injection product. It is a technology that manufactures a synthetic resin product that attaches and installs a film on which a printed layer is formed by injection molding.

As a method of manufacturing a synthetic resin product using the in-mold molding method, first, print the shape or figure desired by the user on the upper surface of the film layer forming the surface of the final synthetic resin product by using a method such as silk screen printing. After forming the layer, there is a method of manufacturing a synthetic resin product by inserting a film on which the printed layer is formed into a mold and injection molding by injecting a synthetic resin injection product into the upper surface of the printed layer.

Alternatively, a release layer is formed on the lower surface of the film layer, a printed layer is formed on the lower surface of the release layer, and then inserted into a mold, and a synthetic resin injection product is injected into the upper surface of the printing layer and injection molded. . When injection molding is completed, the film layer is removed, and there is a method of forming a UV hard coating layer to impart abrasion resistance thereto.

As another method, after forming a UV hard coating layer on the upper surface of the film layer and a printing layer on the lower surface of the film layer, inserting it into the mold and injection molding by inserting a synthetic resin injection product into the lower surface of the printing layer. There is a way.

The manufacturing methods of synthetic resin products using this in-mold molding method can not only implement various designs and colors, but also implement a three-dimensional surface by using various printing methods on the upper or lower surface of the film layer. Since it is manufactured in a type, it has the advantage of being able to manufacture a synthetic resin product without a bonding line.

In addition, since injection molding is performed with only one process at the same time as the decoration of the surface, the process is shortened, saving time and reducing production cost.

However, since the process of forming the film layer on which the pattern is formed and the molding and molding process are performed separately, a process time is required, which is an obstacle to productivity improvement.

1. Korean Patent Application Publication No. 10-2009-0030932

An object of the present invention is to provide a method of manufacturing a curved surface cover for a mobile terminal in which a fine pattern and a curved surface are formed at the same time to improve productivity.

Here, a summary of the present invention is provided, and this section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features).

In order to solve the above problems, a method of manufacturing a curved surface cover for a mobile terminal having a fine pattern according to any one of the various aspects describing the present invention includes polyethylene terephthalate (PET), polycarbonate (PC), and PMMA. A first step of preparing a molding material in which (Poly methylmethacrylate) and PET (Polyethylene terephthalate) are sequentially laminated; A second step of preparing a first mold having a first molding surface on which a set pattern is formed and a second mold having a second molding surface having a shape corresponding to the first molding surface; A third step of heating the first and second molds to have a set surface temperature (T1); A fourth step of disposing the molding material heated to a molding temperature (T2) set on the second molding surface; And a fifth step of forming the molding material by matching the first and second molding surfaces to apply a set molding pressure (P) to the molding material.

In the method for manufacturing a curved surface cover for a mobile terminal having a fine pattern according to an aspect of the present invention, in the fourth step, the set surface temperature (T1) of the first and second molds is 120°C, and the molding material The set molding temperature (T2) of is 130°C, and the molding pressure (P) applied to the molding material is 100kgf/cm ² .

In the method of manufacturing a curved surface cover for a mobile terminal in which a fine pattern is formed according to an aspect of the present invention, the first and second forming surfaces have a three-dimensional curved surface.

In the method of manufacturing a curved surface cover for a mobile terminal having a fine pattern according to an aspect of the present invention, the third step is provided independently of the first and second molds, and adjacent to the first and second molds. The first and second molds are heated by a mold heating unit disposed and having a reflective heat source for heating the first and second molds.

In a method for manufacturing a curved surface cover for a mobile terminal having a fine pattern according to an aspect of the present invention, the mold heating unit includes: a heating light source emitting infrared rays of a set temperature; And a reflecting unit configured to reflect infrared rays radiated from the heating light source toward the first and second molds.

In a method of manufacturing a curved surface cover for a mobile terminal having a fine pattern according to an aspect of the present invention, the reflective unit includes: a reflective layer disposed toward the first and second molds and having an irregular surface shape; And a heat insulating layer disposed on the rear surface of the reflective layer.

According to the present invention, by employing a molding material made of a composite layer of PET/PC/PMMA/PET, three-dimensional curved surface molding and surface fine pattern molding can be performed at the same time.

According to the present invention, the quality of fine pattern formation can be improved by uniformly maintaining the temperature (T1) of the mold by the mold heating unit, controlling the temperature (T2) of the molding material, and controlling the molding pressure (P). There will be.

1 is a process flow diagram showing an embodiment of a method for manufacturing a curved surface cover for a mobile terminal in which a fine pattern is formed according to the present invention.
Figure 2 is a view showing the molding material in Figure 1;
3 is a view showing a mold and a mold heating unit in FIG. 1.
4 is a photograph showing the quality of fine pattern formation according to the molding material and mold temperature.

Hereinafter, an embodiment implementing the method for manufacturing a curved surface cover for a mobile terminal having a fine pattern according to the present invention will be described in detail with reference to the drawings.

However, the intrinsic technical idea of the present invention cannot be said to be limited by the embodiments described below, and the intrinsic technical idea of the present invention is given below by a person of ordinary skill in the art. It is revealed that the embodiment described in the above is encompassed by a range that can be easily proposed by a method of substitution or modification.

In addition, since the terms used below are selected for convenience of description, in grasping the intrinsic technical idea of the present invention, it is not limited to the dictionary meaning and is appropriately interpreted as a meaning consistent with the technical idea of the present invention. It should be.

1 is a process flow diagram showing an embodiment of a method for manufacturing a curved surface cover for a mobile terminal having a fine pattern according to the present invention, FIG. 2 is a view showing a molding material in FIG. 1, and FIG. 3 is a mold and a mold heating unit in FIG. 4 is a photograph showing the quality of fine pattern formation according to a molding material and a mold temperature.

1 to 4, a method for manufacturing a curved surface cover for a mobile terminal having a fine pattern according to the present embodiment (S100) includes a molding material preparation step (S110), a mold preparation step (S120), and a mold heating step (S130). ), a molding material arrangement step (S140), and a molding step (S150).

The molding material preparation step (S110) is a step of preparing a molding material in which polyethylene terephthalate (PET), polycarbonate (PC), poly methylmethacrylate (PMMA), and polyethylene terephthalate (PET) are sequentially stacked.

-Forming material (composite material) lamination method, lamination thickness, pattern formation only on PET

Polyethylene terephthalate (PET) is a material with high transparency and good thermal insulation properties.

Polycarbonate (PC) is a material that is resistant to external pressure or impact, which is used as a bullet-proof glass material. It is about 250 times stronger than ordinary glass and has excellent heat resistance and durability, so it is a material that has a wide range of uses such as industry, architecture, and medical care.

Poly methylmethacrylate (PMMA) is a _{polymer obtained by polymerizing methyl methacrylate CH 2} =C(CH ₃ )COOCH ₃ and is a typical methacrylic resin.

Among plastic materials, it has outstanding transparency and light resistance, and has a good balance between mechanical strength and moldability.

The mold preparation step (S120) includes a first mold 10 having a first molding surface 11 on which a set pattern is formed and a second molding surface 21 having a shape corresponding to the first molding surface 11. It is prepared with a second mold 20.

In order to form a fine pattern on the surface of the molding material (M) and to form a curved surface at the same time, the first molding surface (11) of the first mold (10) is provided concavely, and that of the second mold (20). It is located at the top, and the second molding surface 21 of the second mold 20 is provided to be convexly engaged with the first molding surface 11.

In addition, the first and second shaping surfaces 11 and 21 have a three-dimensional curved surface.

Here, the three-dimensional curved surface includes a case where both side ends of a rectangle, which is a screen shape of the mobile terminal, are formed as curved surfaces, and a case where a curved surface is formed at all side ends and corners of the rectangle.

In this embodiment, for forming a fine pattern, the first molding surface 11 has a cavity space 12, and a thin plate-shaped stamper 30 is provided in the cavity space 12. .

The stamper 30 has a metal micropatterned mold formed on its surface.

The mold heating step (S130) is a step of heating the first and second molds 10 and 20 to have a set surface temperature T1. This is for the molding of the molding material (M).

Here, a mold heating unit 40 for heating the first and second molds 10 and 20 is provided.

The mold heating unit 40 is physically separated from the first and second molds 10 and 20 and provided independently, and is disposed adjacent to the first and second molds 10 and 20.

The mold heating unit 40 has a reflective heat light source that heats the first and second molds 10 and 20.

According to this, since the mold heating unit 40 is not provided in the first and second molds 10 and 20, or combined with the first and second molds, the volume of the first and second molds 10 and 20 is minimized. can do. Accordingly, it is possible to shorten the heating time of the first and second molds 10 and 20 and easily achieve temperature uniformity.

In this embodiment, the mold heating unit 40 is provided with a heating light source 41 and a reflecting portion 42.

The heating light source 41 emits light having thermal energy by inputting electrical energy, and may be a halogen lamp or an arc lamp.

The reflector 42 is configured to reflect light (eg, infrared rays) radiated from the heating light source 41 to the first and second molds 10 and 20.

The reflector 42 reflects the light radiated from the heating light source 41 so that it can evenly spread to the surfaces of the first and second molds 10 and 20. The reflector 42 may be provided in a flat plate type or a parabolic type.

On the other hand, in this embodiment, the reflective portion 42 is disposed toward the first and second molds, and has a reflective layer 42a having an irregular surface shape and a heat insulating layer 42b disposed on the back surface of the reflective layer 42a. It can be provided.

Accordingly, it is possible to evenly irradiate the surface of the first and second molds 10 and 20 by diffusely reflecting the light emitted from the heating light source 41 due to the irregular surface shape, and the heating light source 41 by the heat insulating layer 42b. ), it is possible to prevent heat from being radiated to the outside through the reflector 42.

The molding material disposing step (S140) is a step of disposing the molding material heated to the molding temperature T2 set on the second molding surface 21.

Here, the set surface temperature (T1) of the first and second molds (10, 20) is 120°C, the set molding temperature (T2) of the molding material (M) is 130°C, and the molding applied to the molding material (M) It is preferable that the pressure (P) is 100kgf/cm ^2.

4 is a picture showing the quality of fine pattern formation according to the molding material and mold temperature. Referring to this, when the molding pressure is ^{kept constant at 100kgf/cm 2} , the best T1 is 120°C and T2 is 130°C. It can be seen that the fine pattern formation quality is shown.

The molding step (S150) is a step of forming the molding material (M) by matching the first and second molding surfaces (11, 21) so that the set molding pressure (P) is applied to the molding material (M).

According to the embodiment of the present invention as described above, by employing a molding material (M) made of a composite layer of PET/PC/PMMA/PET, three-dimensional curved surface molding and surface fine pattern molding can be performed at the same time.

In addition, by maintaining the temperature (T1) of the mold uniformly by the mold heating unit (40), controlling the temperature (T2) of the molding material (M), and controlling the molding pressure (P), the quality of fine pattern formation is improved. You will be able to improve.

Claims (6)

A first step of preparing a molding material in which polyethylene terephthalate (PET), polycarbonate (PC), poly methylmethacrylate (PMMA), and polyethylene terephthalate (PET) are sequentially stacked;
A second step of preparing a first mold having a first molding surface on which a set pattern is formed and a second mold having a second molding surface having a shape corresponding to the first molding surface;
A third step of heating the first and second molds to have a set surface temperature (T1);
A fourth step of disposing the molding material heated to a molding temperature (T2) set on the second molding surface; And
A method for manufacturing a curved surface cover for a mobile terminal comprising a; a fifth step of forming the molding material by matching the first and second molding surfaces to apply a set molding pressure (P) to the molding material. The method according to claim 1,
The fourth step,
The set surface temperature (T1) of the first and second molds is 120°C,
The set molding temperature (T2) of the molding material is 130°C,
The molding pressure (P) applied to the molding material is a method of manufacturing a curved surface cover for a mobile terminal having a fine pattern ^{of 100kgf/cm 2.} The method according to claim 1,
A method of manufacturing a curved surface cover for a mobile terminal in which a fine pattern having a three-dimensional curved surface is formed on the first and second molding surfaces. The method according to claim 1,
The third step,
The first and second molds are provided independently of the first and second molds, are disposed adjacent to the first and second molds, and have a reflective heat source for heating the first and second molds. The method of manufacturing a curved surface cover for a mobile terminal in which the heated fine pattern is formed. The method of claim 4,
The mold heating unit,
A heating light source emitting infrared rays of a set temperature; And
A method of manufacturing a curved surface cover for a mobile terminal having a fine pattern having a; reflecting unit for reflecting the infrared rays radiated from the heating light source toward the first and second molds. The method of claim 5,
The reflective part,
A reflective layer disposed toward the first and second molds and having an irregular surface shape; And
A method of manufacturing a curved surface cover for a mobile terminal having a fine pattern having a heat insulating layer disposed on the rear surface of the reflective layer.

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