JPH0420768B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a process for producing a synthetic resin molded body by filling a thermosetting synthetic resin foam into a hollow part of a gutter-shaped thermoplastic synthetic resin extrusion molded material. A thermosetting liquid foam is continuously injected into the cavity of a thermoplastic synthetic resin molding material that is extruded from a mold of a molding machine and is in a high temperature state, and the heat retention of the molding material is utilized to create a foam. Based on rapid foaming of the liquid foam, the foaming of the liquid foam can be completed in a short time, improving the molding speed, significantly shortening the molding line, and simplifying the entire equipment. The present invention relates to a continuous manufacturing method for synthetic resin molded bodies filled with foam, which can reduce manufacturing costs.

Conventionally, in manufacturing a synthetic resin molded body by filling a thermosetting foam into a cavity of a thermoplastic synthetic resin molded material having an opening over the entire length in the longitudinal direction, steps 4 to 6 are performed. As shown in the figure, a gutter-shaped molding material c extruded from a mold b of an extrusion molding machine a and in a high temperature and flexible state is guided into a molding passage d.
After solidifying and molding using a vacuum device or the like, a thermosetting liquid foam f is continuously injected into the cavity e of the molding material c, and then the molding material c is heated in a heating furnace. g, and the liquid foam f was foamed therein. As shown in FIG. 1, the heating furnace g has a caterpillar type molding device h, and the entire device is used to foam the liquid foam f using hot air, for example.
It was designed to be heated to a predetermined temperature necessary for curing. As shown in FIG. 6, the mold device h consists of a lower mold member i and an upper mold member j, and by sequentially facing each other, a mold k for guiding the molding material c is formed. The molded material c was taken up and transferred, and during the transfer, the molded material c was pressurized with an extrusion force that could withstand the foaming pressure. In addition, the heating furnace g has a considerably long length (for example, about 10 to
It was set at about 15m). The reason for this is that in order to prevent the molding material c from softening when foaming the liquid foam f in the heating furnace g,
It is necessary to limit the temperature to 40°C to 60°C. At such a relatively low temperature, the liquid foam f will foam and harden slowly, so it will take quite a long time to foam and harden. This is because it required time.

The reason why the large-scale caterpillar type mold device h was used in the heating furnace g is because the length of the heating furnace g is quite long as described above, so that the mold k and the molding material c are This is because the frictional resistance between them is so great that it is virtually impossible to take off the molded material c in front of the outlet end of the heating furnace g using a taking off device consisting of, for example, a roller.

For this reason, conventional molding equipment not only requires a fairly large installation space, but also requires a very large heating furnace, and special molding equipment such as a vacuum unit is installed in the molding passage. This led to a rise in equipment costs and was one of the causes of increased manufacturing costs.

The present invention provides a method for producing a molded body that can solve these problems, based on the principle of rapidly foaming a liquid foam by utilizing the retained heat of the molding material. That is, the present invention extrudes a gutter-shaped thermoplastic synthetic resin molding material, which has an opening communicating with a cavity over the entire length in the longitudinal direction, from a mold of an extrusion molding machine, and immediately after being extruded from the mold. A thermosetting liquid foam is continuously injected into the cavity of the molded material which is in a high temperature and flexible state, and immediately thereafter,
A foamed material, characterized in that the molding material is introduced into a molding passage, and in the molding passage, the liquid foam is foamed to fill a cavity with the foam, and at the same time, the molding material and the foam are hardened. This is a continuous manufacturing method for synthetic resin molded bodies filled with
One embodiment will be described below based on the drawings.

In FIG. 1, 1 is an extrusion molding machine, 2 is a liquid foam injection device, 3 is a molding passage, and 4 is a take-off device.

The extrusion molding machine 1 extrudes thermoplastic synthetic resin such as vinyl chloride in a molten state from a mold at a high temperature (approximately 160°C to
(approximately 180°C) and extruded as a flexible molding material 6. The molding material 6 is, as shown in FIG. 2a,
It is formed as a gutter-like body having a U-shaped cross section and having an opening 9 that communicates with the cavity 7 over the entire length in the longitudinal direction.

The injection device 2 is disposed immediately before the mold 5 of the extrusion molding machine 1, and as shown in FIG. 2b,
A thermosetting liquid foam 10, for example, a liquid polyurethane resin, is continuously injected from the opening 9 into the cavity 7 of the molding material 6 which is in a high temperature state immediately after being extruded from the mold 5. The injected liquid foam 10 starts foaming rapidly at the same time as the injection.

Immediately thereafter, the hot and flexible molding material 6 is introduced into the molding path 3. The molding passage 3 is formed by a passage groove 1 as shown in FIG. 2c.
1 is formed between a lower mold 12 having a recess and an upper mold 13 that covers the passage groove 11, and the molding passage 3
The cross-sectional shape of is set to be the same as the predetermined external shape of the molded body 15 (shown in FIG. 3) which is the final product. Together with the lower mold 12 and the upper mold 13, it is formed as a cylindrical body having an inner and outer double wall structure, and a cooling medium 14 is circulated therebetween. The upper mold 13 is extruded by an extrusion device (not shown) with an extrusion force that can withstand the foaming pressure of the foam. Since the molding material 6 is in a high temperature state, the injected liquid foam 10 rapidly foams in the vicinity of the entrance 3a of the molding passage 3, and as shown in FIG.
As shown in FIG. 2, the inside of the cavity 7 is rapidly filled, and foaming is almost completed at a position near the entrance 3a (FIG. 2d). Further, since the molding passage 3 is cooled by the refrigerant as described above, the molding material 6 is gradually cooled and hardened while moving through the molding passage 3. And molding passage 3
A solidified molded body 15 (shown in FIG. 3), in which the cavity 7 of the molded material 6 is filled with the foam 16, is taken up by the taking-off device 4 from the outlet part 3b and is continuously produced. . The molded body 15 is led to a cutting device (not shown) in the next step, where it is cut into a predetermined length to produce a product.

Note that in the molding passage 3, the foam 16
As it foams, the foam 16 presses the side walls 17, 17 of the molding material 6 toward the side walls 19, 19 of the molding passage 3, as shown in FIG. The molded body 15 can be automatically molded into a shape corresponding to the cross-sectional shape of the passageway 3, that is, a preset shape of the molded body 15.

In addition, in FIG. 1, 20 is a receiving groove portion for receiving the molding material 6, which is formed by extending the lower mold 12 of the molding passage 3 horizontally toward the mold 5.
A molded material 6 in a flexible state extruded from a mold 5
to prevent deflection. The liquid foam 10 is injected at an appropriate time while the molding material 6 is moving into the receiving groove 20, and in order to promote foaming of the liquid foam 10, the receiving groove 20 may be heated as appropriate. . and 21 closes the opening 9 of the molding material 6;
The lid material 21 is made of synthetic resin, paper, aluminum foil, etc.
The opening 9 is continuously closed by the method already disclosed in the publication.

As described above, the manufacturing method of the present invention involves continuously injecting a liquid foam into the cavity of a hot molding material extruded from a mold of an extrusion molding machine, and utilizing the retained heat of the molding material. As a result of rapidly foaming the liquid foam in the molding passage and filling the cavity with the foam, foaming of the liquid foam, which was conventionally carried out slowly in a very long heating furnace as described above, is achieved. The process is completed within a very short time immediately after the molding material is introduced into the molding channel. Therefore, the molding line according to the manufacturing method of the present invention can be shortened by the length of the heating furnace, which occupies about 50% of the length of the molding line, compared to the molding line in the conventional manufacturing method. Therefore, the molding line can be significantly shortened, the molding speed can be increased, and the installation space for the equipment can be drastically reduced. Furthermore, the heating furnace, which is a large-scale device as described above, can be omitted. Moreover, as mentioned above, in the molding passage, the molding material can be automatically molded into a desired shape by the foaming pressure of the foam, so a vacuum device is used to make the molding material conform to the cross-sectional shape of the molding passage. etc. are no longer necessary, which greatly simplifies the entire device and reduces the manufacturing cost of the product.

In addition, in the manufacturing method of the present invention, phenol resin, polyester resin, etc. can also be used as the thermosetting liquid foam.

[Brief explanation of drawings]

FIG. 1 is a side view of the apparatus used in the manufacturing method of the present invention, FIGS. 2 a to d are cross-sectional views showing the manufacturing steps of the manufacturing method of the present invention, and FIG. 3 is a side view of the apparatus used in the manufacturing method of the present invention. FIG. 4 is a side view of an apparatus used in the conventional manufacturing method, and FIGS. 5 and 6 are sectional views showing a part of the manufacturing process of the conventional manufacturing method. 1... Extrusion molding machine, 3... Molding passage, 5...
Mold, 6... Molding material, 7... Cavity, 9... Opening, 10... Liquid foam, 16... Foam.

Claims (1)

[Claims] 1. A gutter-shaped thermoplastic synthetic resin molded material having an opening communicating with a cavity spanning the entire length in the longitudinal direction,
A thermosetting liquid foam is continuously injected into the cavity of the molding material which is in a high temperature and flexible state immediately after being extruded from a mold of an extrusion molding machine, and immediately thereafter, Filling with foam, characterized in that the molding material is introduced into a molding passage, and in the molding passage, the liquid foam is foamed to fill the inside of the cavity with the foam, and the molding material and the foam are hardened. A continuous manufacturing method for synthetic resin molded articles.