JP2606561Y2 - Plastic painting mold - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a mold for molding plastic and simultaneously painting a molded product.

[0002]

2. Description of the Related Art A plastic painting molded product used for a cabinet of a home electric appliance or the like is provided with a laminated laminated decorative sheet or a transfer sheet (hereinafter, referred to as a "painting sheet") for molding. It is manufactured by molding plastic at the same time as molding by plastic molding by various molding methods such as injection molding.
At this time, as disclosed in Japanese Patent Publication No. 50-19132, it is common to pre-mold a painting sheet using a female mold prior to molding of plastic,
Therefore, many female molds are provided with a vacuum suction hole on the cavity surface.

[0003] In a conventional mold, when a painting sheet is preformed with a female mold, vacuum leakage occurs between the sheet and the parting surface of the female mold, and satisfactory preforming cannot be performed. there were. In addition, during the subsequent injection molding, the sheet for painting may be shifted due to the pressure of the molten resin.

As a countermeasure to such a problem, the applicant has already proposed a mold having a groove on the parting surface of a female mold, which at least partially surrounds the cavity portion and communicates with a vacuum means (Japanese Patent Application No. 2002-110,086). Hei 2-328251). Although this mold almost completely prevented the displacement of the painting sheet during injection molding, the solution to the problem of vacuum leakage during pre-molding was
It was not always enough.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a mold used for painting a molded article at the same time as molding a plastic, and using a cavity of a female mold to form a painting sheet. It is an object of the present invention to provide a mold for performing pre-molding, which prevents vacuum leakage during pre-molding and prevents displacement of a painting sheet at the time of injection molding.

[0006]

The mold according to the present invention is a mold for simultaneously performing plastic molding and painting, and preforms a painting sheet using a cavity of a female mold. As shown in FIGS. 1 and 2, in a mold provided with a vacuum suction hole for performing the process, the cavity part (2) is surrounded on the parting surface of the female mold (1) so as to go around the part. And a packing (3) having elasticity, and a cavity portion inside the position of the packing.
(2) at least partially surrounding and connected to vacuum means;
And a cavity part (2) on the parting surface
And a groove (5) that is not communicated with.

[0007] The packing can be arranged only by bonding to the female parting surface.
A recess surrounding and surrounding the cavity portion (2)
Preferably, (4) is provided, and the packing (3) is fitted into the recess.

The packing used in the present invention is preferably one having heat resistance enough to withstand the temperature of the plasticized plastic, for example, one made of silicone rubber. In addition, those made of metal and those made of fluororesin can also be used. The cross-sectional shape is arbitrary, but a substantially circular shape is easily available, and it is easy and convenient to attach to and detach from a concave portion provided on the parting surface. The preferred cross-sectional area varies depending on the size of the mold, usually in the range of 7~80mm ^2.
If the cross-sectional area is too small, the airtightness is low, and if it is too large, the step formed on the female parting surface becomes large and the painting sheet becomes wrinkled, or in some cases the sheet is melted at the packing part .

The painting sheet used here may be either a transfer sheet or a lamination sheet, and various known painting sheets can be formed with this mold.

[0010]

The simultaneous painting by molding using the mold of the present invention will be described by taking injection molding as an example.

As shown in FIG. 3, a painting sheet (8) is placed on a female die (1), and a hot platen (7) is overlaid thereon to heat and soften the painting sheet. Vacuum suction through the vacuum passageway (6) and, if necessary, further application of pressure from the hot plate by compressed air, deforming the painting sheet toward the cavity (4) of the female mold (1). At this time, the painting sheet is sucked at the groove (5) and adheres to the parting surface. Further, the painting sheet is sandwiched and fixed between the packing (3) and the hot platen (7), and since the airtightness is maintained at that portion, the painting sheet may be displaced or vacuum leaked. Not
The painting sheet can be preformed into the same shape as the cavity.

The injection molding after the completion of the preforming may be carried out according to a conventional method, whereby the painting is performed simultaneously with the molding.

[0013]

EXAMPLE A plastic injection mold was prepared comprising a male mold and a female mold, and provided with vacuum holes for preforming a painting sheet in the female mold cavity. On the female parting surface, an intermittent groove having a width of 5 mm and a depth of 4 mm is provided so as to surround the cavity at a position about 10 mm outside the edge of the cavity, and a vacuum passage connecting the groove to vacuum suction means is provided. Was. Further, a groove having a width of 4.5 mm and a depth of 3.0 mm is provided outside the groove so as to surround the groove, and an O-ring (manufactured by Inaba Rubber Co., Ltd.) having a diameter of 4.0 mm is fitted into the groove. The mold of the present invention was included.

A 0.15 mm thick colored semi-rigid polyvinyl chloride sheet "R type" (manufactured by Riken Vinyl) is used as a base sheet, and a pattern is printed thereon by a gravure method. .10mm clear polyvinyl chloride sheet (same as above)
Were prepared.

This painting sheet is overlaid on the female die of the above-mentioned mold, with the base sheet facing up, a hot plate is placed thereon, heated, and vacuum-sucked to apply the painting sheet. Preformed.

The hot platen was removed, the male mold was combined, the mold was clamped, and the ABS resin was injection molded to obtain a painted molded product.

[0017]

[Effects of the Invention] If simultaneous painting is performed on plastic using the mold of the present invention, displacement of the painting sheet is prevented, and the sheet is preformed with the sheet fixed at a predetermined position, and vacuum molding is performed. Since a preformed sheet conforming to the shape of the cavity can be obtained without any defects, a beautiful painting product without distortion of the pattern can be obtained.

The present invention is particularly significant when applied to a mold having a complicated cavity shape or a mold having a concave portion communicating with a vacuum means for fixing a painting sheet. Of course, if it is a female mold that preforms a sheet for painting,
It can be applied to any mold for stamping molding, RIM molding, and compression molding.

[Brief description of the drawings]

FIG. 1 is a plan view for explaining the structure of a female mold among the molds of the present invention.

FIG. 2 is a diagram in which packing is added to the AA direction cross-sectional view of FIG.

FIG. 3 is a view similar to FIG. 2, showing the preforming of the painting sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Female mold 2 Cavity 3 Packing 4 Concave part 5 Groove 6 Vacuum passage 7 Heating plate 8 Painting sheet

Continuation of the front page (56) References JP-A-3-124416 (JP, A) JP-A-63-233812 (JP, A) JP-A-57-178812 (JP, A) JP-A-63-30217 (JP, A) , A) JP-A-63-78716 (JP, A) JP-A-61-191208 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A mold for simultaneously molding and painting a plastic, wherein a vacuum suction hole for preforming a painting sheet using a cavity portion of a female mold is formed in the cavity of the female mold. In the mold provided in the above, an elastic packing (3) is arranged on the parting surface of the female mold (1) so as to surround the cavity portion (2) and make a round around the cavity portion (2). Plastic painting, characterized in that, on the inside, a groove (5) is provided which at least partially surrounds the cavity part, which is connected to the vacuum means and which is not in communication with the cavity part (2) on the parting surface. Mold for molding.