JPS60122078A - Partial painting method of resinous mold - Google Patents

Abstract

PURPOSE:To carry out easily and rapidly a masking operation with less man- hours by molding simultaneously in one-piece a resinous mold and a masking cover for covering the region not to be painted of the resinous mold which is releasable. CONSTITUTION:A masking cover 2 for covering the part B not to be painted of a bumper body 1 is releasably adhered to the resinous bumper body 1 used as an end product. The resinous mold is obtained by molding the bumper body 1 and the masking cover 2 in one-piece by an injecting molding or an extrusion in two colors. In this case, the sticking or adhesive strength between both materials is regulated so that the cover 2 may not be stripped off by the vibration or a light collision before painting and may be easily released after painting. The resinous mold released from a mold is painted wholly or partly in desired colors at a painting stage, and the masking cover 2 is released from the bumper body 1 after a paint film 3 is cured.

Description

Detailed Description of the Invention 10 Industrial Application Fields of the Invention This invention relates to a method for applying partial coating by coating areas and non-coating areas, in particular, by masking the unpainted areas of the object to be coated. This invention relates to an improvement in a partial painting method.

PRIOR ART Recently, automobile bumpers are mainly made of resin, which has more elasticity than metal bumpers and absorbs shock, in order to improve the protection function of the vehicle body in the event of a light collision and to increase the degree of freedom in molding. There is a tendency for this resin bumper to be colored for decoration. As for the method of imparting this color, the method of painting is preferred because it can achieve a higher level of aesthetic appearance than the method of directly mixing pigments into the cable material III of the bumper.
Particularly, as shown in FIG. 1, when a synthetic resin bumper is cured in its longitudinal direction and color coded, it is best to use the partial coating method. In the case of this partial painting, it is necessary to mask the parts not to be painted or the parts to be painted with another color.

As a masking jig, it deforms along the resin panbar that is the object to be coated in order to prevent paint from getting caught up and to eliminate misalignment of the parting line (boundary line between painted and non-painted surfaces) when the paint film dries. In addition, it is preferable that the bumper be in close contact with the bumper and expand and contract together with the bumper.

'For this reason, masking tape has traditionally been used.

For masking using this masking tape, as shown in FIG.
Since the masking paper 103 is further attached from above with tape 104 to cover the non-painted surface B, it is constantly in close contact with the resin bumper 101 and a beautiful parting line can be obtained. However, the above-mentioned masking method using masking tape requires a large amount of man-hours, and if the parting tape 102 and masking paper 103 are not carefully pasted by hand by an operator, they tend to bend easily and a beautiful older parting line cannot be obtained. Therefore, the masking work requires considerable effort. In order to reduce the number of man-hours, a method of painting using a fixed molding jig made of synthetic resin or metal may be considered.

However, with the current bumper structure, it is not possible to prevent thermal deformation of the bumper white body, so a standard masking jig cannot bring the bumper into close contact with the bumper surface with the accuracy of the cutting line. Additionally, if the masking tape is removed when curing the paint film in the drying oven, the flow of paint will easily disturb the cut lines, so it is common to proceed with the work from the primer coat to the top coat with the masking on. be. Furthermore, when the tape is removed and used again, it is difficult to obtain a straight parting line.

Unfortunately, the masking tape is disposable.

However, in a mass production line, it is undesirable to dispose of masking tape and auxiliary materials such as masking paper used at the same time after one unit because it increases costs.

■0 Purpose of the Invention This invention was made by focusing on the above-mentioned conventional problems, and allows for easy, reliable, and quick low-cost masking, and allows unskilled people to perform masking with less man-hours. The purpose is to provide a practical partial painting method.

■8 Structure of the Invention Characteristic Structure of the Invention In order to achieve the above object, the method for partially painting a resin molded product of the present invention includes a resin molded product and a masking cover that covers the non-painted area of the resin molded product. The resin molded product and the masking cover are removed from the mold in the attached state and the surface including the masking cover is painted, and after painting, the masking cover is peeled off and removed. By exposing the non-painted surface covered by the masking cover, the resin molded product is partially painted with a painted area and a non-painted area.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below based on an embodiment of a resin molded product shown in the drawings. Note that this example shows the case where it is applied to a resin bumper.

The resin molded product shown in the cross-sectional view in FIG.
A masking cover 2 covering the surface is removably attached. In this resin molded product, a bumper wood body 1 and a masking cover 2 are integrally molded by injection or extrusion, which is a so-called two-color molding method.

(Note that in the present invention, the colors do not necessarily have to be different, and it is not two-color molding in the strict sense.) For example, in the case of two-color injection molding using a rotary mold, one of the two injection cylinders The bumper body (primary molded product) 1 is molded using the resin injected into the primary side, and the bumper body 1 is attached to the core ( ) 7j and moved to the secondary side. A space is created between the V bitty and the masking cover 2 (secondary molded product) by injecting new resin into the space from the other injection cylinder.This allows the bumper body 1 and its non-painted parts to be formed. A finished product is obtained in which the masking cover 2 covering B is integrally molded, and the molding and masking of the resin product are completed at the same time.At this time, the time for moving the mold from the next side to the secondary side is adjusted. The temperature of the primary molded product is lowered to reduce the strength of the fusion bond between the secondary molded product and the primary molded product. The resin molded product is integrally molded.In addition, if the masking cover 2, which is a secondary molded product, is molded into a thin film by high-speed injection, the fusion between 21! The strength is reduced, and the peelability is further improved.Also, when forming grooves on the Banba wooden body 1 from a decorative point of view, these grooves are used to improve the physical relationship between the Banba wooden body 1 and the masking cover 2. (JW
Sometimes we try to

Furthermore, unlike the bumper body 1 which is the final product, the masking cover 2, which is discarded after painting is completed, can be fused to the bumper body 1 as the material for the masking 7J bar 2, since the resin used can be freely selected. Sometimes difficult resins are used to provide peelability. Here, Bamba body 1
The adhesion or adhesion strength between the masking cover 2 and the masking cover 2 is so light that it will not fall off due to vibration or light collision when being sent to the subsequent painting process, and that it can be easily peeled off and removed after painting is completed. It is hoped that it will be a thing.

In addition, it is difficult to move the primary molded product from the -next side to the secondary side11.
In the case of long resin molded products, an in-mold movable two-color molding machine is recommended, which moves a part of the mold rotating cavity and injects new resin into the moving protrusion for secondary molding. is convenient.

In addition, in the case of resin products with a constant cross-sectional shape such as rod-shaped products, a two-color extrusion molding machine is used to make the resin forming amount main body and the masking 7
It is preferable to simultaneously extrude the bar and integrate it into the peel angle 018.

The finished resin product, in which the Banba body 1 and the masking cover 2 covering the non-painted area B are removably attached, is removed from the mold and then sent as is to the painting process to achieve the desired color. Fully or partially painted. Painting is uniform thickness coating II! 3, the coating is applied not only to the entire painted surface A of the bumper body 1 but also to the upper part of the masking cover 2. Therefore, the coating film 3 is uniformly formed from the coating area A of the bumper body 1 to the surface of the masking cover 2. Therefore, the bumper body 1 and the masking cover 2 are carried into a baking process while being integrally attached, so that the coating film 3 is solidified.

ml! After solidification of J3, an impact is applied to the masking cover 2 portion to separate the masking cover 2 from the bumper body 1. As a result, the base of the bumper body 1 that has been covered with the masking cover 2 is exposed, so that painting of the desired pattern portion depending on the paint color and base type is completed.

In addition, when peeling off the masking cover 2, use a sharp cutter or the like to remove the bumper corresponding to the -C-older cut line, since the strength of the coating film will be affected and the fractured surface of the coating film 3 will be disturbed. It is preferable to cut the part between the main body 1 and the mass 4 and the ring cover 2 in advance so that A)

IV. EFFECTS OF THE INVENTION As is clear from the above explanation, the method for partially painting a resin molded product of the present invention makes it possible to separate the bumper body and the mustang cover that covers the non-painted area of the bumper body.
The bumper is molded in one piece ■ The culm is molded to the same size as 11.1, and after painting, the resin cover is peeled off and the partial painting is completed, which eliminates the complicated masking work required by the operator and ensures consistent quality. Partial painting can be done extremely easily, quickly, and with less man-hours even by unskilled people, and auxiliary materials such as expensive masking paper and masking tape are not required, and even unskilled people can perform the masking work. Significant cost reductions can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of a conventional partial coating method for a resin bumper, Fig. 2 is an enlarged sectional view taken along the line II-[( A cross-sectional view showing an example of a resin molded product, No. 4
The figure is a cross-sectional view of the resin molded product after the masking cover has been peeled off and partially painted. 1... Bamba body, 2... Masking cover, 3
... Paint film, 4... Brother cut line. Patent applicant: Nissan Motor Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] In a method of applying partial coating to the surface of a resin molded product using a painted area and a non-painted area, the resin molded product and a masking cover that covers the non-painted area of the resin molded product are molded by being removably attached, The resin molded product and the masking cover are removed from the mold while still attached, the surface including the masking cover is painted, and after painting, the masking cover is peeled off and the unpainted material covered on the masking cover is removed. A method for partially painting a resin molded product, characterized by applying partial coating to a painted area and a non-painted area while avoiding exposing the surface.