JPH07329088A - Painting method in compression molding - Google Patents

Abstract

PURPOSE:To paint the outside of a molded product simultaneously with compression molding by holding a foil within a side mold face of a cavity mold. CONSTITUTION:A recessed part 4 having a necessary depth is provided in a side mold face 2a of a cavity mold 2 performing compression molding of a molded product such as tableware or a dish. A foil 5 is held in the recessed part 4 by turning a printed face to a surface side. Simultaneously with compression molding of a molded product, by casting a molding material of a thermosetting resin within a cavity, setting off of the foil 5 to the outside of the molded product is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for painting an outer surface of a molded article such as tableware made of thermosetting resin simultaneously with compression molding of the molded article.

[0002]

2. Description of the Related Art In order to paint a surface of melamine tableware and the like at the same time as compression molding, first, in a cavity of a mold composed of a cavity mold and a core mold set to a predetermined molding temperature,
A molding material of thermosetting resin such as melamine resin that has been preheated is put in, and the molding material is primary molded by clamping.

[0003] Next, the mold is opened to move the core mold upward, and then a pattern or the like is offset printed on the surface of the titanium-free natural pulp paper (overlay paper) and impregnated with a melamine resin. A printed paper called a foil is placed on the edge of the primary molded product in the cavity mold with the printing surface facing up. After that, the core mold is lowered again and the mold is clamped, the primary molded product is compressed and the secondary molding is performed, and the foil is transferred to the surface of the molded product for painting.

Further, when painting on the rising surface inside the molded product, since the foil cannot be placed on the rising surface, the foil is placed so as to be located over both the edge surface and the rising surface. By doing so, the foil of the portion placed on the edge surface during the secondary molding is sandwiched between the core molds, the deviation of the foil on the rising surface is prevented, and painting is performed from the edge surface to the rising inner surface. . After painting, the core mold is opened again, an appropriate amount of glaze coating material is put therein, and the surface of the molded product is subjected to glaze coating treatment by pressurization.

When painting on the outer rising surface of the molded product, the cavity mold is arranged so that it can be moved up and down with the core mold facing downward, and the outer surface exposed by molding the primary molded product in a lying state. Place the foil on, and perform the secondary molding as well as the tertiary molding as in the inside.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In conventional compression molding, painting on the molded product is limited to the surface of the primary molded product that faces the core mold, and the side that is in contact with the side mold surface of the cavity mold cannot be painted. Since it is either the inner surface or the outer surface and it is extremely difficult to paint both the inner and outer surfaces, double-sided painting of a plastic container or the like by compression molding has not been actually carried out.

For the painting of the outer rising surface, it has been considered to use an insert which is formed by injection molding of a thermoplastic resin, but the viscosity of the molding material is significantly higher than the melt viscosity of the thermoplastic resin, Due to the strong flow force of the molding material pushed around the cavity by the compression of the core mold, the foil was easily pushed from the insert position and painting could not be performed.

The object of the present invention is to make it possible to easily paint the outer surface of tableware or the like with thermosetting synthetic resin at the time of compression molding by an extremely simple means, and to rub the pattern or the like due to contact with other objects. It is an object of the present invention to provide a new painting method in compression molding, which is less likely to fall off, and which can maintain a pattern or the like applied during molding for a long time.

Another object of the present invention is to make it possible to paint on the outer rising surface of the primary molded product during compression molding of the primary molded product, and by means of the conventional means after compression molding of the primary molded product. It is an object of the present invention to provide a new painting method in compression molding that allows painting on the inner rising surface and thereby enables painting on both the inner and outer surfaces of a molded product.

[0010]

The features of the present invention according to the above-mentioned object are that a molded article such as a tableware or a deep dish made of a thermosetting synthetic resin is compression molded in a mold, and at the same time, an image is formed on the outer surface of the molded article. When attaching, make a recess of the required depth on the side surface of the cavity mold, accommodate the foil on which the pattern etc. is printed, and then put the thermosetting resin molding material in the cavity. At the same time as the compression molding of the molded product, the foil is transferred to the outer surface of the molding material.
Another feature of the present invention is that the wall surface of the recess is formed into a gentle convex curved surface, and the painting surface of the molded product is formed into a concave curved surface by the wall surface.

[0011]

[Operation] In the above configuration, since the foil is positioned so as to be retracted inward from the side surface of the cavity mold, even if the molding material flows along the cavity surface due to compression by the core mold, the end of the foil flows. Since the molding material does not roll up due to the force and flows over the upper surface of the foil, the foil maintains its position without being swept away.

Further, the foil transfer surface of the molded product is formed into a concave curved surface, and it is difficult for the pattern etc. on the surface to come into surface contact with other objects, so there is little disappearance due to abrasion and the initial state is maintained for a long time. To do.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. In the figure, reference numeral 1 is a mold for compression molding, which comprises a cavity mold 2 which forms the outer shape of a deep dish-shaped molded product having a rising peripheral surface, and a core mold 3 which forms the inner surface.
Although not shown in the figure, the cavity mold 2 is attached to the fixed plate of the vertical mold clamping device, and the core mold 3 is attached to the movable plate above the fixed plate. It is configured so that the molding material put in the cavity mold 2 can be compression-molded.

Reference numeral 4 denotes a recess for painting which is partially recessed in a required portion of the side mold surface 2a of the cavity mold 2. The wall surface 4a is formed into a gentle convex curved surface. A foil 5 is contained. This foil 5 has a printing surface 5b on which a pattern, color, pattern, etc. are offset-printed on the back surface of an overlay paper 5a impregnated with a melamine resin.
The printed surface 5b is exposed on the front side, and the overlay paper 5 is exposed.
The a is brought into contact with the wall surface 4a and accommodated. As a result, the foil 5 is attached to the wall surface 4a by the melamine resin of the overlay paper 5a melted by the heat of the cavity mold 2 and the recess 4 is formed.
Maintain its position without leaving.

The compression molding using the above-mentioned mold is carried out after the foil 5 is housed in the recess 4. Mold is 165 ℃ ~ 1
The mold material 6 is heated to a temperature of about 70 ° C., the molding material 6 of melamine resin preheated as in the conventional case is put in the bottom of the cavity mold 2 of the mold, and the core mold 3 is lowered to form the molding material 6 in the cavity. It is compressed in the mold with a molding pressure of 160 kg to 180 kg.

In this case, the method of putting the molding material 6 is not in a lump state, but as shown in FIG. 3, the molding material 6 is put in a certain amount so that the end of the molding material 6 is positioned on the foil 5. Is preferred. In this way, the flow of the molding material 6 during compression molding starts not on the lower side of the recess 4 but on the surface of the foil 5, so that the foil 5 of the molding material 6
The flow force acting on the lower edge is reduced, the phenomenon of the lower edge curling due to the flow force, and the phenomenon such as drifting away are prevented, and the immobility of the foil 5 in the recess is further ensured.

By the compression, the molding material 6 extends from the bottom to the periphery of the cavity 7 formed by the core mold 3 and the cavity mold 2, and is molded into a deep dish-shaped molded product 8 having a rising surface and at the same time. The foil 5 is transferred to the outer surface of the molded product 8 by the molding pressure and the heat of the mold to be cured and integrated. Further, the transfer portion is formed in a convex portion 9 corresponding to the concave portion 4, the surface thereof becomes a concave curved surface due to the transfer of the side wall surface 4a, and the pattern of the printing surface 5b of the foil 5 is impregnated with the resin on the concave curved surface. It is painted in a state of being covered with the transparent overlay paper 5a.

The molded product 8 shown in FIG. 5 has a painting 11 on the inner rising surface 8b. In this case,
Using the molded product 8 as a primary molded product, secondary molding and further tertiary molding are performed by the above-mentioned conventional method, and painting 11 and glaze coating are performed. During this time, since the molded product 8 is not released from the cavity mold 2, the painted portion of the outer rising surface 8 is not damaged during the painting process of the inner rising surface 8b.

Although the above-mentioned embodiment describes the partial painting on the outer rising surface 8a, the painting surface is not limited to a specific size, and the cavity mold 2 is used.
This is possible within the range in which the recess 4 for painting can be provided on the side mold surface 2a of the above, and in some cases, the recess 4 may be formed in a laterally long groove of a required width for painting. it can.

[0020]

As described above, according to the present invention, the foil is housed in the required recess provided on the side surface of the cavity mold, and the foil is transferred to the outer surface of the molded product during compression molding of the molded product. As a result, the foil is positioned so as to be retracted inward from the side mold surface of the cavity mold, which allows the molding material to flow on the upper surface of the foil, which may cause curling of the lower edge of the foil due to flow force. It is possible to prevent the washout and the like, and it is possible to surely perform the painting without causing the positional deviation on the outer rising surface of the molded product facing the recess.

Since the transfer of the foil depends on the molding pressure, no special operation is required for the transfer, and in combination with the conventional painting method, it is not found in molded articles such as tableware by compression molding. Further, a product having painting on both the inside and outside can be easily formed, and a product having a higher added value than a conventional product having only one painting can be manufactured.

Furthermore, since the foil transfer surface of the molded product can be formed into a concave curved surface, it is possible to prevent surface contact with other objects on the painting surface, and the painting surface is covered with overlay paper. Since it is possible to eliminate the loss of patterns etc. due to abrasion, it has excellent features such as maintaining the initial state for a long time even if glaze coating processing is not performed, and it is easy to use conventional compression molding means. Since painting can be performed, the cost does not increase, and it has an advantage that it can be applied immediately.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a mold used for carrying out a painting method in compression molding according to the present invention.

FIG. 2 is a vertical cross-sectional view of a side mold surface of a cavity mold.

FIG. 3 is a partial vertical cross-sectional view showing a state in which a molding material is put into a cavity mold.

FIG. 4 is a vertical cross-sectional view of a mold in a compression molding state.

FIG. 5 is a perspective view of a compression molded product.

FIG. 6 is a partial vertical cross-sectional view of a molded product showing a painting state of an outer rising surface.

[Explanation of symbols]

 1 Mold 2 Cavity Mold 2a Side Mold Surface 3 Core Mold 4 Recess 4a Wall 5 Foil 5a Overlay Paper 5b Printing Surface 6 Molding Material Mold 7 Cavity 8 Molded Product 9 Projection

Claims (2)

[Claims] 1. When molding a molded article such as tableware or a deep dish made of thermosetting synthetic resin in a mold, and simultaneously painting the outer surface of the molded article, the side mold surface of the cavity mold is coated. After forming a recess of the required depth and accommodating a foil with a pattern printed on it, put the thermosetting resin in the cavity to compression-mold the molded product, and at the same time, apply the foil to the outer surface of the molded product. A painting method in compression molding, characterized by being transferred. 2. The painting method in compression molding according to claim 1, wherein the wall surface of the recess is formed into a gentle convex curved surface, and the painting surface of the molded product is formed into a concave curved surface by the wall surface.