JPH06104338B2 - Method for producing resin foam molded article having surface decorative layer - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a method for producing a resin foam-molded article having a surface decorative layer in which the surface of a resin foam is made up with a decorative sheet such as a blank or a label.

[Prior art]

In order to produce a packaging container made of a resin foam having a surface decorative layer, a blank to be the surface decorative layer is preliminarily molded using a vacuum molding die or the like, and this blank is molded into a pair of male and female molding dies. After accommodating in a female mold, pre-foamed resin beads are filled in the cavity formed by clamping both male and female molds, and then steam is introduced into the cavity to heat the bead group and beads. A method is commonly used in which a blank is fused to the foam at the same time when the foams are molded by fusing each other.

[Problems to be Solved by the Invention]

Since the above-mentioned conventional method uses static electricity as a means for fixing the blank in the female mold, dust in the atmosphere is often attached to the mold to stain the molded product, and the blank is fixed. It becomes unstable and cannot fit properly on the inner wall surface of the female mold, and there is a problem that the commercial value of the product is impaired. Also, a fixing method of mounting a container-shaped vacuum forming sheet that matches the shape of the female mold in advance on the female mold is also performed.
If the blank is ring-shaped, it will not be fully fixed.

[Means for solving problems]

The present invention has solved the above problems, and its purpose is to utilize a pair of male and female molding split type steam introduction chambers (usually also serving as a cooling water introduction chamber) in which a large number of steam introduction holes are formed. To hold a blank by pulling it on the inner wall surface of one of the mold halves, and to manufacture a product with a good appearance in which the blank to be the surface decorative layer fits correctly on the molded resin foam. It is an object of the present invention to provide a method for producing a resin foam-molded article having an improved surface decorative layer. Therefore, the above object of the present invention is to store a blank serving as a surface decorative layer of a molded product in one of molds of a mold split mold composed of a female mold and a male mold each having a steam introduction hole. Then, after filling the pre-foamed resin beads in the cavity formed by clamping the male and female molds,
Steam is introduced into the cavity through the chamber of the other mold or both male and female molds to heat the beads and fuse the beads together to form a foam, and at the same time integrate the blank on the foam. In the method for producing a resin foam-molded article having the surface decorative layer fused to, the blank is evacuated through the steam introduction hole by decompressing the chamber of one mold, and the inner wall surface of the mold is evacuated by this vacuuming action. This is achieved by the method for producing a resin foam-molded article having a surface decorative layer which is made to be placed under a vacuum evacuation action until the filling of the pre-expanded resin beads into the cavity of the suction-bonded blank is completed.

【Example】

The manufacturing method of the present invention will be described below with reference to the accompanying drawings. As the molding split mold, as shown in FIG. 1, a female mold 1 having chambers 1a and 2a for introducing heating and cooling media, respectively.
And a male mold 2 are used, and a large number of steam introduction holes 3 and 4 are provided in the male and female molds 1 and 2. Steam pipes 5 and 6, cooling water pipes 7 and 8 and drain pipes 9 and 10 are connected to the chambers 1a and 2a of the male and female molds 1 and 2, respectively, and the intake pipe 1 is connected to the drain pipes 9 and 10.
1,12 are branched and connected. These tubes 5,6,7,8,9,10,1
1, 12 are all openable and closable by open / close valves 5a, 6a, 7a, 8a, 9a, 10a, 11a, 12a, and further, in the female die 1, a release pin 14 placed under the action of a spring 13 However, the pre-foamed resin bead filling guns 15 are mounted on the male molds 2, respectively. First, in the first step shown in FIG. 1, a blank 16 preformed in the female mold 1 is accommodated, and the blank 16 is
A vacuum is evacuated by a compressor through the intake pipe 11 and the chamber 1a on the female die 1 side, and the inner wall surface of the female die 1 is held by being joined by the pressure reduction through the steam introduction hole 3 communicating with the chamber 1a. In this case, the intake pipe of the female die 1
Only the on-off valve 11a of 11 is opened, and the on-off valves of other pipes are all closed. Next, in the second step shown in FIG. 2, the pre-foamed resin beads 17 are filled with the filling gun 15 into the cavity formed by clamping the male and female molds 1 and 2, and this filling is performed. At the time of completion, the on-off valve 11a of the intake pipe 11 on the female die 1 side is closed. Next, in the third step, only the opening / closing valves 5a and 6a of the steam pipes 5 and 6 of the male and female molds 1 and 2 are opened to introduce steam into the chambers 1a and 2a and to introduce the steam introduction hole 4 communicating with the chamber 2a. The steam is introduced into the cavity through the group, the pre-expanded resin beads 17 are heated, and the beads are fused to each other to form the foam, and at the same time, the blank 16 is integrally fused to the foam. In the next 4th process, the open / close valves 7a, 8 for the cooling water pipes 7, 8 and the drain pipes 9, 10
Only a, 9a and 10a are opened, and the molded product is cooled by the cooling water introduced into both chambers 1a and 2a. In the fifth step shown in FIG. 3 after the completion of this cooling step, the mold opening of the male and female molds 1 and 2 is performed with only the opening / closing valves 9a and 10a of the drain pipes 9 and 10 left under the opening operation. Then, the release pin 14 is operated to take out the product 18 to which the blank 16 is adhered, and the manufacturing operation is completed. Thus, as the blank 16 used in the production method of the present invention, a water-resistant sheet printed on a synthetic paper or a normal resin film is used, and as the pre-expanded resin beads 17, polystyrene, polypropylene, polyethylene is used. Pre-expanded resin beads having a bulk density of 8 to 100 g / l are used. In the description of this manufacturing example, the blank 16 is attached to the female die 1.
However, it may be manufactured by mounting on the male mold 2. Further, the intake pipes 11 and 12 are provided so as to be branched to the drain pipes 9 and 10, but it goes without saying that this can be directly connected to the chambers 1a and 2a. However, the latter is not economical.

【The invention's effect】

The present invention is as described above, and since the blank held in one mold is held inside the mold by vacuuming using the chamber of the mold, the blank is a bottomed container. In addition, even if it is a cylindrical body without a bottom, the suction force effectively acts on the blank and its holding state is stable, completely preventing the molding deviation that tends to occur with the foam and improving the quality. Good products can be manufactured, and for example, a foamed product such as a label having a different shape can be effectively bonded and molded. Further, there is an advantage in practice that a vacuum box does not need to be specially provided in the chamber for evacuating the blank and only the intake pipe is connected to the chamber.

[Brief description of drawings]

The drawings explain the manufacturing method of the present invention. FIG. 1 is a sectional view showing a blank mounting step, FIG. 2 is a sectional view showing a bead filling step by mold clamping, and FIG. 3 is a mold opening and product removal. It is sectional drawing which shows a process. In the figure, 1 is a female mold, 1a is a chamber, 2 is a male mold, 2a is a chamber, 3 and 4 are steam introduction holes, 5 and 6 are steam pipes,
7 and 8 are cooling water pipes, 9 and 10 are drain pipes, 11 is an intake pipe, 15 is a filling gun, 16 is a blank, and 17 is pre-expanded resin beads.

Front page continued (72) Inventor Koji Iwanami Marunouchi 2-5-2, Chiyoda-ku, Tokyo Sanryo Yuka Co., Ltd. (72) Inventor Mitsuo Ochiai 2-5-2 Marunouchi, Chiyoda-ku, Tokyo Hishiwasan (72) Inventor Junichi Yasuda 1-5-1, Marunouchi, Chiyoda-ku, Tokyo Oji Petrochemical Synthetic Paper Co., Ltd. (72) Inventor Hiroyuki Yamaji 1000 Kawajiri-cho, Yokkaichi-shi, Mie (56) References JP 60-46229 (JP, A) JP 56-109732 (JP, A) JP 55-73532 (JP, A) JP 49-45169 (JP, A)

Claims (1)

[Claims] 1. A blank serving as a surface decorative layer of a molded product is mounted on one of molds of a female mold having a steam introduction hole and a male mold, and then the male and female. After filling the pre-foamed resin beads into the cavity formed by clamping both molds, steam is introduced into the chamber of the other mold or both male and female molds, and the beads are heated by this steam. At the same time, the beads are fused together to form a foam, and at the same time, in the method for producing a resin foam-molded article having a surface decorative layer in which the blank is integrally fused on the foam, depressurizing one of the mold chambers. By doing so, the blank is evacuated through the steam introduction hole, and the blank is suction-bonded to the mold wall surface by this evacuation action, and the filling of the pre-expanded resin beads into the cavity is completed. To the point, method for producing a resin foam molded article having a surface decorative layer, characterized in that placed under vacuum action.