JPS58118228A - Molding method for multicolor molded work having curved surface - Google Patents

Abstract

PURPOSE:To simplify the number of processes and to recue the number of necessary molds, by a method wherein a multicolor printing female mold formed in one surface of a film sheet is set to an inner surface of a mold positioned opposite a sprue to inject a molten molding material through a sprue. CONSTITUTION:After a required pattern is multicolor-printed on one surface of a film sheet 21, the sheet is set in a given mold to perform a vacuum molding as it is heated to form a female mold 26. The female mold 26 is then set in a mold 27. The mold 27 has a concavities and convexities formed on the inner surface so as to match the concavities and convexities on the female mold 26, which is stably set ot the inner surface of the mold 27. After the mold 26 is set to the mold 27, a molten molding material is injected in the direction of the female mold 26 through a sprue 29 formed in a mold 28 therethrough, and after it is cooled, it is cured to produce a molded work 30 which is designed in a required color.

Description

[Detailed description of the invention] The present invention relates to a method for molding a multicolored molded article having a curved surface.

2. Description of the Related Art Conventionally, FIGS. 1 and 2 show a case in which a molded article having a curved surface and a multicolored surface is molded using thermoplastic plastic. FIG. 1 shows the order of molding the finished product, and FIG. 2 shows the steps in the mold for molding, and the same reference numerals are given to correspond to the order. The final finished product is shown in Figure 1).
The eyes 2 and caudal fin muscles 3 are recessed from the surface of the substrate 1 on a fish-shaped base material 1 and colored with a negative hue (for example, black), and the gill muscles 4 are colored with a different hue (for example, blue) and the body The portion 5 is further colored with another hue (for example, red), and the base material 11 is also colored! It is raised above the surface, has an uneven curve as a whole, and is painted in multiple colors.

When molding this, conventionally, as shown in Fig. 2 (a), the melted molding material was first placed in the cavity 7 of the mold 6 of the injection molding machine, whose inner surface was molded into a fish shape, from the sprue 9 of gold W8 on the opposite side. is injected, cooled and hardened to form the corresponding figure 1 (
A fish-shaped base material 1 with concave eyes and caudal fin muscles shown in a) is molded.

Next, in order to mold the eyes 2 and the caudal fin muscles 3, as shown in FIG. A colored molten molding material (for example, black) is injected from the Sugeru, and the molded material is cooled and hardened to form the eye 2 and caudal fin muscles 3 as shown in FIG. 1(b). The second is necessary for the formation of gill muscles 4.
As shown in Figure 1 (C), replace *Ii in the same manner as in 5 and inject another colored molten molding material (for example, blue) from the sprue of the mold 11 [obtain the shape shown in Figure 1 (C), and To form the body cylinder 5, the same operation as shown in FIG. 2) was carried out to obtain the finished product shown in FIG. 1).

Therefore, the conventional method for this type of painting requires replacing the Venus the same number of times as the number of colors, which not only requires a large number of steps and is not suitable for mass production, but also requires the same number of molds as the number of colors. This was economically unfavorable. Furthermore, it may be difficult for the colored melt-molded molding material to integrate with the base material, and in such cases, the finished product has the disadvantage that the colored portion separates from the base material and falls off.

The present invention was made in view of the shortcomings of the conventional molding method for multi-colored molded products having five curved surfaces. It is an object of the present invention to provide a method for molding a multicolored molded product having a curved surface without separation of colored parts.

The present invention takes advantage of the fact that a thermoplastic film sheet is integrated with the molten molding material injected in a mold, and prints a desired figure in multiple colors on the film sheet, which is then recessed by vacuum forming or the like. The above object is achieved by molding a female mold and injecting a molten molding material into the female mold to mold a multicolored molded product having a curved surface.

Hereinafter, the present invention will be explained with reference to FIGS. 3 and 4.

The desired figure is first drawn on a film sheet 21 as shown in Fig. 3.
0 Printed on one side. In this printing, the parts to be colored are printed in multiple colors in the desired colors. For example, the eyes 22 and caudal fin muscles 23 are printed in black, the gill muscles 24 are printed in blue, and the body tube 25 is printed in red.

Further, as the film sheet, a transparent sheet made of a thermoplastic plastic material or the like stretched flat is used. In this way, multi-color printing is performed on the film sheet 21, and as shown in FIG.

Next, this film sheet 21 is set in a predetermined mold and vacuum-formed while being heated to form a female mold 26 with the printed surface recessed as shown in FIG. 4(b). When molding this female mold 26, irregularities are formed as appropriate to correspond to the curves of the surface of the finished product. Further, since the colored portion is vacuum formed, it does not move or diffuse to other parts and remains in a predetermined position.

After forming the female mold 26 by molding the film sheet 21 printed in multiple colors in this way, as shown in FIG. set. The mold 27 has unevenness formed on its inner surface to correspond to the unevenness of the female mold 26, and the female blind 26 is stably set on the inner surface of the mold 27. After setting in the mold 27, the molten molding material is injected from the sprue 29 provided through the mold 28 on the opposite side toward the knife 1126, and is allowed to cool and harden. In this case, the melt molding material used is thermoplastic, such as vinyl chloride resin, polyethylene,
Conventionally known materials such as acetylcellulose and Ny4in can be used. In addition, since the thermoplastic plastic to be injected comes into contact with the female mold 26 in a high temperature state, the female mold 2
6 is softened or melted by this heat and integrated with the injected puff snack, and at this time, the printing ink in the colored portion colors the molten molding material at each location. Accordingly, a molded article 30 with desired parts painted in desired colors is completed as shown in FIG. 4 after cooling and curing. In this way, according to the present invention, compared to conventional injection molding that required the same number of colors as the number of colors, injection molding only needs to be done once, and the process is not limited to the number of colors to be colored. Mass production is possible because it only takes three steps: molding and injection molding. In addition, only one set of molds is needed for injection molding, which is extremely economical compared to the number of molds needed for the number of colors, and the finished product is also a single injection molding, with the colored part and the base material part being integrated. Therefore, not only the colored part does not come off at all, but also the surface of the figure of the molded product is covered with the softened or melted film sheet, so it can produce excellent effects such as a beautiful surface.

[Brief explanation of the drawing]

Figure 1 (a) to 1) are diagrams showing the process order of the conventional method, Figure 2 (a) to 2) are cross-sectional views of the inside of the mold in that process, and Figure 3 is a diagram showing the process order of the conventional method. front view of the seat,
Figures 4(a) to 4(a) are diagrams showing the order of steps in the method of the present invention. 21... fist film sheet, 22... eyes, 23...
Caudal fin muscle, 24... gill muscle, 25... body tube, 26.
...Female Rei, 27.28...Gold 11.29...Sprue. Figure 2 (a) (b) Figure 2 (c) (d) Figure 3

Claims (1)

[Claims] A predetermined figure is printed in multiple colors on one side of a film sheet, the printed surface is indented to form a female mold, and then this female mold is set on the inner surface of the mold opposite to the sprue, and the molten molding material is poured from the sprue. A method for molding a multicolored molded product having a curved surface, which comprises integrally molding a film sheet and a molten molding material by injection.