JPS6214348B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a partial painting method of a resin molded article, which is performed by applying a masking tape to the parts that are not to be painted.

Conventionally, when applying partial painting to resin molded products,
As shown in FIG. 1, the resin molded product 1 is placed on a mold stand 2, the unpainted parts are covered with a jig 3, and the exposed parts are painted 5 with a spray gun 4, or
Alternatively, as shown in Fig. 2, masking tape 6 and paper 7 were applied to the unpainted parts of the resin molded product 1' and a coating 5 was applied, but in the former case, it was difficult and complicated to seal the parting lines. In the case of a molded product with a large shape, it is not possible to cover it completely, so there are problems such as a large amount of repair work required.In the case of the latter, the number of work required for pasting is large, which is cumbersome, and it is difficult to paste curved parting line parts. Not only does this require skill, but it is also impossible to completely prevent the tape from lifting, so when the tape is peeled off,
There were also problems such as the paint on the area peeling off.

In order to solve the above-mentioned conventional problems, according to a patent application (Japanese Patent Application No. 55-109832) previously filed by the applicant, a resin molded product 1, as shown in FIG.
A strippable paint 12 is applied to the surface of the paint 1, and after drying, the strippable paint 12 on the coated part is cut off with a cutter 13, and a paint 15 is applied to the part with a spray gun 14 or the like, and the paint 15 is This method provides a method for completing the product by peeling off the strippable paint 12 from other parts after drying. Although this method can solve the above conventional problems, it is difficult to apply the strippable paint 12. , it takes time to peel off.

Therefore, the present invention has been made in order to solve the problems without impairing the advantages of the above-mentioned invention, and its purpose is to fix a tape in a mold for molding a resin molded product, By cutting the tape with a press die, marking a parting line, painting after molding, and peeling off the tape, partial painting can be done easily, reliably, and in a short time even if the shape is complex. The goal is to make it possible. Therefore, in the present invention, a mold for molding a resin molded product has a sharp edge in the part located at the parting part in the mold, a tape is fixed in the mold, and a parting line is formed on the tape by a pressing die. After cutting and removing unnecessary parts, the mold is closed, and then a resin material is injected into the mold, molded, and demolded, and after demolding, degreased, paint is applied, and then baked. The intended purpose is achieved by providing a method for partially painting a resin molded article, in which the tape is peeled off after the baking treatment.

The present invention will be described below with reference to illustrative embodiments.

For partial painting of a resin molded product according to the present invention, a fourth coating is applied to the mold on the side that will be the painted surface of the resin molded product.
A mold as shown in the figure, in this example, a lower mold 21
use. That is, a mold having a sharp edge 22 in the part located at the parting part in the lower mold 21 is used. This is because after the tape 23 is fixed to the lower die 21, a parting line is drawn in the tape 23 by the press die 24 and unnecessary portions (protruding portions) are removed. Reference numeral 25 denotes a temperature control pipe buried within the lower mold 21.

Next, the working procedure for partial painting according to the present invention will be described. First, as shown in FIG. 5A, a tape 23 is fixed to a portion of the lower mold 21 corresponding to the portion of the resin molded product a that is not to be painted. Note that the tape 23 may be preliminarily pasted with a film that has one side treated to be easily peeled and the other side coated with an adhesive, or coated with an adhesive. It may also be pasted onto the mold 21.
Furthermore, if necessary, a release agent may be applied before fixing the tape 23, but in this case, the tape 23 may be fixed with static electricity using a charged tape, or the tape 23 may be fixed with a negative charge. Apply pressure to secure. Next, a parting line 26 is placed in the parting part of the tape 23 using a press die 24, and unnecessary parts are cut and removed (see FIG. 5B), and a release agent 28 such as silicone is applied with a spray gun 27 or the like. (See Figure 5 C.) As for the mold release process, if it is performed before fixing the tape 23 as described above, it may be omitted, or the mold release process may be omitted and performed here. Alternatively, mold release treatment may be performed on both.

Thereafter, as shown in FIG. 5D, the upper die 29 of the mold, whose surface has been subjected to the same mold release treatment as described above, is polymerized and clamped, and the resin material 30 is injected to form the resin molded product a. to be molded. Preferably, the resin material 30 is made of reinforced thermosetting resin because it is baked after painting. Next, the mold is opened and removed, and trimming such as removing burrs 31 is performed (see Fig. 5 E), and degreasing equipment 3 is performed (see Fig. 5 F).
Degreasing treatment is performed by step 2. After degreasing (see Figure 5, T), a paint 34 is applied using a spray gun 33, etc. (see Figure 5, H), and is baked and dried using an opener 35. (See FIG. 5, R) Finally, the tape 23 is peeled off, and the resin molded product a is completed (See FIG. 5, N). (See Figure 5).

As described above, according to the present invention, a tape is fixed in a mold in which a sharp edge is formed in the part located at the parting part, a parting line is made on the tape with a press die, and the unnecessary part is cut and removed. Since the resin molded product is molded, removed from the mold with the tape attached, and painted, the parting lines are sharp and no corrections are necessary. Further, according to the present invention, there is no need to attach tape along the parting line as in the conventional method, so not only can the number of man-hours be reduced, but the work can be performed easily without requiring any skill. Furthermore, according to the present invention, since the tape is fixed and unnecessary parts are simply cut with a press die, masking time can be shortened compared to applying strippable paint, and there is no need for knife cutting. This not only improves yield, but also ensures sufficient masking thickness and strength because tape is used.
Therefore, it is easy to remove after painting and baking.
Moreover, it has effects such as being able to provide a smooth molded skin.

[Brief explanation of the drawing]

Figure 1 is a side view showing a conventional partial painting method, Figure 2 is a partial perspective view showing another embodiment of the same as above, and Figure 3 is a side view showing a conventional partial painting method.
Figures I to D are working process diagrams showing an improved example, Figure 4 is an enlarged side view of a mold used in the present invention, and Figures 5 I to I are working process diagrams showing a coating method according to the present invention. a is a resin molded product, 21 is a lower die, 22 is a sharp edge, 23 is a tape, and 24 is a press die.

Claims (1)

[Claims] 1. Use a mold that has a sharp edge in the part located at the parting part in the mold for molding the resin molded product, fix the tape in the mold, put a parting line in the tape with a press die, and remove the unnecessary part. After cutting and removing, the mold is closed, and then a resin material is injected into the mold, molded and demolded, and after demolding, degreased, paint is applied, and a baking process is performed. A method for partially painting a resin molded article, characterized in that after the baking treatment, the tape is peeled off to obtain the product.