JPH04338265A - Method for coating molding - Google Patents

Abstract

PURPOSE:To provide the easy coating method for a molding having excellent appearance which makes the boundary line of a coated film layer clean along the end edges of a masking material. CONSTITUTION:This coating method for a front grille 1 as the molding having a curved part 8 formed of a flat part 6 and a sloped part 7 sloping downward from this flat part 6 consists in installing an electrocasting mask 10 as the masking material to the sloped part 7 mentioned above and up to the flat part 6 beyond the curved part 8 film the sloped part 7 and spray coating of a coating material in this state.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of painting a molded article such as a front grill attached to the front of an automobile.

0002

2. Description of the Related Art Conventionally, front grills have been painted in the following manner. FIG. 6 is a sectional view showing the horizontal frame 21 forming the grid of the front grill. As shown in the figure, a front flat part 22 on the left side and a rear flat part 23 on the right side in the figure.
A sloped portion 24 is provided between the two, and a curved portion 28 is provided between the sloped portion 24 and the rear flat portion 23. A coating layer 25 of the same color as the vehicle body, for example blue, is provided on both the flat portions 22, 23 and the inclined portion 24, and is formed to have a constant thickness over the entire body.

As shown in FIG. 7, an electroformed mask 2 as a masking material is placed on the front flat part 22 and the inclined part 24.
6 is placed. This electroformed mask 26 is made of metal such as copper by electrodeposition to match the shapes of the front flat part 22 and the inclined part 24. Then, in this state, for example, black paint is spray-painted. Next, after drying the paint to form a coating layer 27, the electroforming mask 26 is removed, thereby obtaining the horizontal frame 21 having two coating colors, blue and black.

0004

As shown in FIG. 7, a curved portion 28 formed by the inclined portion 24 and the rear flat portion 23.
is provided to improve the separation between the coating layers 25 and 27. However, in this curved portion 28, a slight gap s is created between the electroformed mask 26 and the rear flat portion 23, so that the paint sprayed from there is transferred to the inclined portion 2.
4 and adheres to it.

Therefore, as shown in FIG. 8, after painting, the coating layer 27 made of the black paint that was applied later is coated on the slope part 2.
4 will also be formed. As a result, as shown by the two-dot chain line in FIG. 9, when viewed from above, the boundary line Q between the coating layers 25 and 27 formed by the two types of paint becomes wavy on the inclined portion 24, which impairs the appearance. There was a point. The present invention has been made to solve the above problems, and its purpose is to make the boundary line of the coating layer neat along the edge of the masking material, and to easily produce a molded product with a good appearance. The purpose is to provide a painting method.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for painting a molded product having a curved part formed by a flat part and an inclined part inclined downward from the flat part. , the gist of this method is a method for painting a molded article, which is characterized in that a masking material is placed on the sloped part and from the sloped part over the curved part to the flat part, and the paint is spray-painted in this state.

[0007]

[Operation] After placing the masking material on the sloped part of the molded product and from the sloped part to the flat part beyond the curved part, by spray painting the molded product, the sprayed paint is tilted away from the curved part. It is painted on the flat part without entering the side,
The boundary line of the coating layer is along the edge of the masking material.

[0008]

[Embodiments] Examples embodying the present invention will be described below with reference to FIGS. 1 to 5. FIG. 5 is a perspective view showing a part of the front grill 1 at the front of an automobile. As shown in the figure, inside the rectangular cylindrical main body 2 there is a horizontal frame 3 extending in the horizontal direction;
Vertical frames 4 extending in the vertical direction are supported in a grid pattern. These members are made of ABS resin which has excellent rigidity.

FIG. 1 is a sectional view showing the horizontal frame 3. As shown in FIG. As shown in the figure, the upper surface of this horizontal frame 3 has a front flat part 5 on the left side in the figure and a rear flat part 6 on the right side located at a higher position.
and an inclined portion 7 connecting the two. A curved portion 8 is formed by this rear flat portion 6 and an inclined portion 7 that slopes downward from the rear flat portion 6 to the front side. Next, spray painting on the horizontal frame 3 will be explained.

As shown in FIG. 1, first, paint of the same color as the vehicle body, for example, blue, is sprayed over the entire surface of the front flat part 5, the inclined part 7, and the rear flat part 6 using a spray gun. This blue paint is a two-component acrylic-urethane paint. Then, dry at 70°C for 30 minutes. In this way, the blue first coating layer 9 is formed on the entire surface of the front flat part 5, the inclined part 7, and the rear flat part 6. Note that a clear layer may be formed by further applying an acrylic clear paint on top of this.

Next, an electroformed mask 10 as a masking material is placed over the front flat part 5, the inclined part 7, and the curved part 8. The distance D from the curved portion 8 to the rear flat portion 6 is preferably about 0.3 to 0.5 mm. If this distance D is too short, paint droplets will easily enter the inclined portion 7, and if it is too long, the paint droplets will easily enter the first paint layer 9 and the second paint layer 1, which will be described later.
1 and the curved portion 8 are too far apart, and the appearance tends to be poor. Further, as shown in FIG. 2, the portion of the electroforming mask 10 beyond the curved portion 8 is located at a position floating from the surface of the blue first coating layer 9 with a slight gap d. .

By attaching this electroformed mask 10, the front flat part 5 and the inclined part 7 are covered with the same electroformed mask 10, and are protected from adhesion of the second paint described below. In addition, this electroformed mask 10 can be installed by simply placing a pre-formed mask in a predetermined shape over a predetermined position, so it can be installed in a shorter time than in the case of sequentially pasting masking tape. Good sex.

Next, in this state, black paint is sprayed using the spray gun 12. This black paint is of the same type as the blue paint, but has a different colored pigment. When spraying this paint, droplets of paint are sprayed onto the rear flat portion 6 and the electroformed mask 10. Electroformed mask 1
Since the gap d between 0 and the rear flat part 6 is very narrow,
An effect similar to the so-called labyrinth effect works, and paint droplets do not enter this gap d.

[0014] Next, it is dried at 70°C for 30 minutes. After drying, by removing the electroforming mask 10, a black second coating layer 11 is formed on the rear flat portion 6, as shown in FIG. When viewed from above, as shown in FIG. 4, a boundary line P between the black second coating layer 11 and the first coating layer 9
extends substantially in a straight line along the edge 10a of the electroformed mask 10. Therefore, the appearance is good.

As described above, according to the method of painting the front grill 1 of this embodiment, the shape of the end of the electroformed mask 10 is changed, and the end edge 10a is attached to the inclined part 7 of the front grill 1.
Since the paint is positioned from the top to the rear flat part 6 beyond the curved part 8, when spraying the second paint (black paint), the paint droplets enter the slope part 7 and reach the lower part of the slope part 7. It doesn't drip down. Therefore, the boundary line P between the blue first coating layer 9 and the black second coating layer 11 is the masking material 10.
The curved portion 8 of the front grille 1 has an excellent appearance.

[0016] Furthermore, before forming the second coating layer 11,
Since the electroforming mask 10 previously formed into a predetermined shape is attached and the coating is performed, the coating layer 11 as described above can be easily and reliably obtained. The present invention is not limited to the above embodiments, and may be configured as follows, for example, without departing from the spirit of the invention. (1) The type, color, etc. of the paint to be applied can be appropriately set depending on the type of molded product, etc., and for example, urethane paint, epoxy paint, etc. may be used. (2) The angle of inclination of the inclined portion 7 and the position of the curved portion 8 can be arbitrarily set depending on the molded product. (3) Molded products include automobile parts such as back panels, headlamps, air spoilers, mudguards,
Examples include console boxes.

[0017]

[Effects of the Invention] According to the method for coating molded products of the present invention, the boundary line of the coating layer can be neatly formed along the edge of the masking material, giving an excellent appearance and making it possible to easily and reliably apply such a coating layer. It has the effect that it can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram representing an embodiment of the present invention, and is a sectional view showing a state in which masking material is placed on the horizontal frame of a front grill.

FIG. 2 is an enlarged cross-sectional view of the main part of FIG. 1;

FIG. 3 is a cross-sectional view showing a state in which the masking material is removed after the second paint is applied.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a perspective view of main parts showing the front grill.

FIG. 6 is a cross-sectional view showing a conventional example in which a first coating layer is provided on the front grille surface.

7 is a sectional view showing a state in which the front flat part and the inclined part are covered with a masking material from the state shown in FIG. 6;

8 is a sectional view showing a state in which the masking material is removed after the second paint is applied in the state shown in FIG. 7; FIG.

FIG. 9 is a plan view of FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Front grill as a molded article, 6... Rear side flat part as a flat part, 7... Inclined part, 8... Curved part, 10... Electroformed mask as a masking material.

Claims (1)

[Claims] [Claim 1] A curved portion (8) formed by a flat portion (6) and an inclined portion (7) that slopes downward from the flat portion (6).
A method of painting a molded article (1) having a masking material (10) is arranged in the inclined part (7) and from the inclined part (7) over the curved part (8) to the flat part (6). , a method for painting molded products characterized by spray painting paint in that state.