JPS62227610A - Foam slush molding apparatus - Google Patents

Abstract

PURPOSE:To obtain a foam slush molding device, throughout which almost no temperature difference develops in hot air, by a structure wherein a hollow heat insulating body is provided along the mold surface of a slush mold and a large number of vent holes are made on the hollow heat insulating body. CONSTITUTION:Along the mold surface 10a of a slush mold 10, a hollow heat insulating body 12 is provided so as to have the predetermined space interval between the surface and the body. In addition, hot air passages 13 are formed between the hollow heat insulating body 12 and the mold surface 10a of the slush mold 10. A vent wall 12a, which consists of a passage forming surface opposite to the mold surface 10a, of the hollow heat insulating body 12 is made of porous electroformed material. At the same time, on a barrier 12a, which is not opposite to the mold surface 10a, a hot air supply port 14 is opened in order to supply air therethrough. Because a large number of vent holes are made on the passage forming surface of the hollow heat insulating body as described above, hot air is uniformly spread over the whole area in the hollow heat insulating body and uniformly strikes against resin so as to heat the resin uniformly.

Description

Detailed Description of the Invention (Industrial Application!?) The present invention relates to a slush molding device that performs foaming at the same time as molding.

(Prior art) Slush molding is a process in which a highly viscous liquid, generally called plastisol, consisting of a mixture of plastic particles and a plasticizer, is injected into a heated mold and adhered to the surface of the mold. The process involves recovering excess plastic by rotating the mold, then further heating the sol stuck to the surface of the mold to melt it into a gel, and then cooling it to make a product. , such a molding method is usually called sol slush.

In addition to the sol slush, slush molding includes a type called powder slush. This is a molding method that uses powdered resin. ' Foaming slush molding as referred to in the present invention is a process in which a foaming agent is added to the above-mentioned sol or powdered resin to cause gelation and foaming to occur simultaneously.

In the automobile manufacturing industry, it is often used to manufacture thin-walled products such as flexible polyvinyl chloride, such as the skin of dash panels.

By the way, a hot air oven or infrared rays are usually used to foam a resin containing a foaming agent that decomposes when heated. For example, conventionally, when molding foamed PVC sheets, etc., a resin roll is placed in a hot air oven at about 200°C. I try to pass it continuously.

However, in the above molding method, if the resin to be heated is in the form of a sheet, it may not be heated uniformly, or if it has a complicated shape, the hot air may not be applied evenly.
There is a problem that excessive foaming occurs in areas where the foam is slender, while insufficient foaming occurs in areas that are not well exposed to hot air, making it impossible to obtain a satisfactory foamed slush skin.

Furthermore, in the case of infrared heating, since radiant heat is used, there is a drawback that areas not hit by infrared rays, such as undercuts, are not heated.

To deal with this, as shown in FIG. 3, a heat insulating cover 2 is provided along the mold surface of the slush mold l at a predetermined distance from the mold surface.

A hot air passage 3 is formed between the cover 2 and the mold surface of the slush mold l, and after a slush skin 4 to be heated is attached to the mold surface, a hot air passage is supplied from a hot air generator 6 via a hose 5. It has been proposed to uniformly heat the slush skin 4 over all parts by supplying hot air to the slush skin 3.

Furthermore, as shown in FIG. 4, it is proposed to provide a heating element small piece 7 on the surface of the hot air passage 3 side of the heat insulating cover 2, and to control the amount of foaming of the slush skin 4 by the amount of infrared rays irradiated from the small piece 7. has been done.

(Problems to be Solved by the Invention) In any of the conventional examples as described above, a temperature difference occurs in the hot air between the inlet 3a and the outlet 3b of the hot air passage 3.
For example, in the former case, a temperature difference of about 20° C. will occur, and in the latter case, a temperature difference of several degrees will occur.

In the former case, if the heat insulating cover 2 is at room temperature,
Since the heat of the hot air is taken away by the cover 2, a heater is required to keep the heat insulating cover 2 warm.

Furthermore, in both the former and latter cases, the hot air from both sides of the heat insulating cover 2 hits the convex part formed on the mold surface of the slush mold l, so that the foaming in the part 7E is partially excessive. There is a problem with becoming

The present ff1lJJ was developed in order to solve this problem, and its purpose is to obtain a foaming slush molding apparatus in which almost no temperature difference occurs in hot air.

(Means for Solving the Problems) In the present invention, a hollow heat insulator is provided along the mold surface of a slush mold, and a large number of ventilation holes are formed in the hollow heat insulator.

(Function) The hot air supplied to the hollow heat insulator flows out into the hot air passage from a large number of ventilation holes and heats the resin adhered to the mold surface of the slush mold.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, lO is a slush mold,
On the mold surface 10a of the mold 10, a resin 11 to be heated,
In other words, a slush skin consisting of a solid PVC layer (0.3~0.5+o+w) molded by the usual slush molding method and an unfoamed PVC layer (0.5~0.8cm) containing a foaming agent is attached. .

A hollow heat insulator 12 is provided along the mold surface 10a of the slush mold lO at a predetermined distance from the mold surface 10a, and the hollow heat insulator 12 and the slush mold 10
A hot air passage 13 is formed between the mold surface 10a and the mold surface 10a. The ventilation wall 12a constituting the passage forming surface facing the mold surface 10a of the hollow heat insulating body 12 is formed of porous electroforming and does not face the mold surface 10a. A hot air supply port 14 is opened in the non-defining blocking wall 12b, and hot air is supplied from the supply port 14. The hot air introduced from the supply port 14 passes through the blocking wall 12
It is preferable that the wind pressure at this time is uniform, and from this point of view, the hollow heat insulating body 12 is formed with a concave cross section as shown in FIG. The opening 14 is provided at a position facing the recess 12c of the hollow heat insulator 12. By the way, when the hollow heat insulator 12 is configured in this way, the corner 12d of the recess 12c is hit by more hot air than other parts, so if no measures are taken, one localized excessive foaming will occur. It turns out. Therefore, only the corner portion 12d is made non-ventilated so that the hot air does not directly hit the resin 11.

In FIG. 1, 15 is a hose connected to the hot air supply 14, 16 is a hot air generator connected to the hose 15, 1
7 is an outlet of the hot air passage 13.

Next, to describe the operation of the apparatus according to the above configuration, liquid resin is injected into the slush mold 10 and the mold surface 10a is
After the excess plastisol or powder is collected and the hollow insulation body 12 is installed, hot air is supplied into the hollow insulation body 12, and the hot air hits the hollow insulation body 12'! The resin 11 is evenly heated by passing through the ventilation wall 12a. The hot air after heating is passed through the hot air passage 13.
It flows out from the outlet 17 of the.

(Effects of the Invention) As is clear from the above, the present invention has a large number of ventilation holes formed in the passage forming surface of the hollow heat insulating body, so hot air is evenly distributed over the entire area inside the hollow heat insulating body, and evenly spreads over the resin to be heated. , so the resin is heated evenly.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of the device according to the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIGS.
The figure is a sectional view of a conventional example. lO...Slash mold 11...Resin 12...
・Hollow insulation body 13...Hot air passage 14...Hot air supply port Patent applicant Toyota Motor Corporation? 1 at 4° and 11° Fig. 3 “4-

Claims (1)

[Claims] A hollow heat insulator is provided at a predetermined distance from the mold surface along the mold surface of the slush mold on which the resin to be heated is placed, and a hollow heat insulator is provided between the hollow heat insulator and the slush mold. In order to form a hot air passage between the mold surface and the mold surface of the slush molding mold, and further form a large number of ventilation holes in the passage forming surface of the hollow heat insulator facing the mold surface of the slush mold, and to supply hot air to the hollow heat insulator. A foam slush molding device equipped with a hot air supply port.