JPS586614B2 - Opal size is fine. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming an opalescent pattern on a synthetic resin hollow molded article by a whitening phenomenon.

For example, when a molded article made of a special synthetic resin such as ABS resin is pressed strongly enough not to be destroyed and the pressure is released, a white pattern is formed due to a whitening phenomenon.

This is because when a molded product is strongly pressed, many tiny cracks occur in the pressed areas, which appear as white patterns, and these patterns remain as they are at room temperature.

The pattern resulting from the above-mentioned whitening phenomenon has a white and gorgeous appearance, and exhibits an opal-like pattern.

However, until now, no method has been found to actively apply the whitening phenomenon to synthetic resin moldings to form opalescent patterns.

The present invention was made to improve the above-mentioned situation, and its purpose is to positively utilize the whitening phenomenon on synthetic resin hollow molded products to reliably form gorgeous opal-like patterns. The object of the present invention is to provide a method for forming an opalescent pattern on a synthetic resin hollow molded article, which can be easily and efficiently operated.

The present invention will be explained below with reference to an embodiment shown in FIG.

In the figure, 1 is made of hard material such as metal, and 2
It is a divided mold, and a gap 3 is formed in these molds 1 into which a bottle-shaped hollow molded product 2 shown in FIG. 3 fits, and a lid 4 is provided above this mold 1. A hole 5 is formed in the center of the lid 4 for introducing high pressure fluid into the gap 3.

Further, recesses 7 corresponding to a predetermined pattern are formed in the inner wall 6 of the gap of the mold 1, and the recesses 7 are formed by disposing a large number of linear recesses 7 at regular intervals along the circumferential direction of the body. It is formed in a pattern.

Further, the hollow molded article 2 is made of a special synthetic resin having a whitening phenomenon, such as ABS resin.

In addition, the shape (inner diameter) of the inner wall 6 excluding the recess 7 of the mold 1 above
is at least the outer peripheral surface shape (outer diameter) of the hollow molded product 2
As a result, when the hollow molded product 2 is fitted into the gap 3, the outer peripheral surface of the hollow molded product 2 comes into contact with the inner wall 6 of the mold 1.

Then, the hollow molded product 2 is placed in the gap 3 of the mold 10, and the mold 1
After closing the mold 2 and fitting the molded product 2 into the gap 3, and sealing the upper opening of the mold 1 with the lid 4, high-pressure gas or high-pressure liquid is introduced through the hole 5 of the lid 4. The high-pressure fluid enters the hollow molded product 2, and the hollow molded product 2 is pushed outward by the high-pressure fluid.

Then, when the hollow molded product 2 is pressed within a non-destructive range with a high-pressure fluid, the portions of the molded product 2 corresponding to each of the recesses 7 elastically bulge outward and bulge. As the molded product 2 slightly enters the molded product 2, many minute cracks occur in the bulged part, which becomes a white pattern 8.
appears on the outer surface 9 of.

Then, after pressing within the above range, when the high-pressure fluid inside the hollow molded product 2 is discharged, the elastically bulged portion returns to its original state, but the white pattern 8 remains as it is.

In this way, a white pattern 8 remains on the outer surface 9 of the molded product 2 corresponding to the recess 7 due to the whitening phenomenon, and therefore, the outer surface 9 of the hollow molded product 2 has the inner wall of the gap as shown in FIG. 6
A vertically striped white pattern 8 corresponding to each concave portion 7 is formed, and this white pattern 8 exhibits an opal-like pattern that is white and gorgeous, and has a beautiful appearance.

Further, another embodiment of the present invention will be explained with reference to FIG.
Hollow molded product 1 formed into a cylindrical shape with a bottom made of ABS resin
Forming a gap 11 in the mold 12 into which 0 fits,
Three ring-shaped recesses 14a, 14b,
14c are formed at regular intervals along the axial direction, and the intermediate recess 14b is deeper than the other recesses 14a and 14c.

After the hollow molded product 10 is fitted into the gap 11 of the mold 12, an elastic material such as rubber 1 is inserted into the hollow molded product 10.
5 is pushed in, and this material 15 presses the inner wall of the molded article 10 to bulge the portion corresponding to the recess 14, and a white pattern is formed in this portion due to a whitening phenomenon.

Furthermore, if the depths of the recesses 14ap, 14b, and 14c are made different, the state of bulge in each of the recesses 14a, 14bg, and 14c will be different, and the portion corresponding to the intermediate recess 14b will bulge out a lot, making the white pattern darker. On the contrary, the parts corresponding to the recesses 14a and 14c on both sides bulge out a little, so the white pattern appears thinly.By making the depth of each recess 14 different in this way, various types of white patterns can be created depending on the intensity of the white color. A pattern can be formed.

In both of the above embodiments, a linear pattern and a ring pattern have been described, but it goes without saying that the pattern can be formed in any shape, such as a flower shape, an angular shape, or an inclined line shape.

As described in detail above, the present invention forms a hollow molded article from a synthetic resin having a whitening phenomenon, forms a gap in the mold into which the molded article fits, and forms a predetermined pattern on the inner wall of the gap. A concave portion corresponding to the hollow molded product is formed, and after the molded product is fitted into the gap, the molded product is expanded within a non-destructive range to form a pattern due to a whitening phenomenon on the hollow molded product. It is something to do.

Therefore, when the hollow molded product fitted into the gap in the mold is pressed, the portion of the side wall corresponding to the recess bulges out, causing minute cracks, and a white pattern is formed due to the whitening phenomenon.
Since the recessed portions are formed in accordance with a predetermined pattern,
A gorgeous opalescent pattern can be reliably formed on the hollow molded product, and by changing the depth of the recess, the degree of whiteness can also be changed, so various patterns can be formed. Moreover, since it is only necessary to form a recess corresponding to a predetermined pattern on the side wall of the mold and bulge the hollow molded product within a non-destructive range, the work can be done very easily and efficiently.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a mold used in an embodiment of the present invention;
Figure 2 is a sectional view taken along line 1 and 2 in Figure 1, Figure 3 is a hollow molded product used in the above embodiment before pattern formation, Figure 4 is a hollow molded product with the same pattern, and Figure 5 is a hollow molded product with the same pattern formed. The figure is a schematic longitudinal sectional view of another embodiment of the invention. 1, 12... Each mold, 2, 10... Each hollow molded product, 3, 11...... Gap inner wall of each mold, 7
, 14... each recess, 8... white pattern,
9...Outer surface of the hollow molded product.

Claims (1)

[Claims] 1. A hollow molded product is formed from a synthetic resin that exhibits a whitening phenomenon, and then a recessed portion corresponding to a predetermined pattern is formed in the inner wall, which has an inner wall that matches at least the shape of the outer peripheral surface of the hollow molded product. After the hollow molded product is fitted into the mold, the hollow molded product is bulged within a non-destructive range to be temporarily elastically deformed, and a pattern is formed on the hollow molded product by a whitening phenomenon. A method for forming an opalescent pattern on a synthetic resin hollow molded product.