JPH01314122A - Method of molding long-sized material made of synthetic resin - Google Patents

Abstract

PURPOSE:To prevent generation of breaking and damage of a long-sized material and separation between single bodies at a connecting part after connection of the single bodies with each other, by a method wherein an end part of the rear of the single body is heated, the next single body is fused and integrated with the end part of the rear of the single body and the long-sized material is molded. CONSTITUTION:A stationary mold 1 and movable mold 2 are closed and a molten material 8 of resin is injected into cavity 9 through a material injection port 3 and a single body 4 made of synthetic resin whose end part 10 of the rear is projected in a sheetlike state on a bottom side is molded. Then a top side is formed by projecting in a sheetlike state so that the top side is fittable in the end part 10 of the single body 4 after release of the movable mold 2. Moreover, an extrusion part 12 with a built-in heater is heated, the extrusion part 12 is fitted into the end part 10 of the single body 4 and the same is shifted up to a position directly below the injection port 3. Then the mold is closed again and the molten material 8 of the resin is injected again through the injection port 3. With this construction, a temperature difference between the end part 10 and the material to be injected does not become great, fusing of the material to the end part 10 of the single body 4 becomes favorable and molding to the end part 10 of the single body 4 can be performed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of molding a long synthetic resin object, and more specifically, to a method of molding a long article made of synthetic resin, and more specifically, a method for fusing the ends of mutually adjacent single objects in a mold. This invention relates to an improvement in a molding method for molding a long synthetic resin object by arranging a large number of units in series.

(Prior art) Conventionally, as a method for molding a long object made of synthetic resin,
For example, there is an invention disclosed in Japanese Patent Publication No. 59-23550 by the present applicant.

That is, the present invention has a fixed mold 1b as shown in FIG.
When the movable mold 2b is closed, a molten synthetic resin material is injected into the cavity Sb of the mold from the material injection port 3b formed on the fixed mold 1b side to form the rear end 10 as the melted end. The single body 4 in which is formed is injection molded, and after the injection molding, the single body 4 is moved so that the rear end 10 is located under the material injection port 3b in the mold cavity 9b, and then While injecting material from the material injection port 3b and melting the rear end 10 of the single body 4, the next single body 4a is molded backward, and the front end of the rear single body 4a is molded to the rear of the front single body 4. This is a molding method in which a long object is molded by fusing and integrating with the end portion 10, and then repeating the molding, movement, and fusing and integrating of the single body, and then arranging a large number of single bodies in series.

(Problem to be solved by the invention) However, in the conventional molding method described above,
After the molding, while the unit 4 is being moved, the rear end 10 of the unit 4 is
The surface temperature of the single piece 4 may drop, or the difference between the temperature of the rear end 10 and the material after molding may become large, resulting in
There was a problem in that the material 8b was extremely poorly fused to the rear end 10 of the holder.

Therefore, in a long object in which the single bodies 4, 4a, etc. are molded in series, the welding force at the long distance between the single bodies becomes weak, resulting in breakage, breakage, and even detachment of the single bodies. This had the fatal drawback of causing problems such as

In particular, the above-mentioned situation occurs particularly when the synthetic resin used as the molten material is a hard type, or when a long object with a thin wall thickness is to be molded.

Therefore, the present invention was invented in order to solve the above-mentioned conventional problems, and its purpose is to suitably fuse and integrate the respective fusion surfaces of the joint ends of a single unit and connect them. It is an object of the present invention to provide a method for molding a long synthetic resin object, and to suitably prevent the occurrence of bending or damage of the long object at the connecting portion after connecting the single bodies, separation of the single bodies, etc.

(Means for Solving the Problems) Therefore, the present invention has been made to achieve the above object, and the gist of the structure of the method for molding a long synthetic resin article according to the present invention is to A molten synthetic resin material 8 is injected into a cavity 9 of the mold from a material injection port 3 formed in the mold to mold a single body 4 with the rear end 10 as the melted part, and after the molding, the rear end 10 is moves the single body 4 so that it is located directly below the material injection port 3, and then injects the material 8 from the material injection port 3 to melt the rear end 10 of the single body 4 while forming the next single body 4a. The unit 4 is fused and integrated with the rear end 10, and then the unit is molded and moved.

In a method of molding a long object made of synthetic resin, in which a long object is formed by repeatedly fusion-integrating a large number of single objects, the rear end 10 of the single object 4 is heated, and in a heated state. The point is to fuse and integrate the next single unit 4a.

(Function) Therefore, in the method for molding a long synthetic resin article characterized by the above configuration, the rear end portion 10 of the single body 4 is heated, and the next single body 4a is fused and integrated in the heated state. In order to become
There is a large temperature difference between the rear end 10 and the material 8b injected from the material injection port 3b, and the material can be well fused to the rear end 10 of the single body 4. ,4
(a) The connection of the mutually fused surfaces becomes reliable and strong, and it is possible to suitably prevent the occurrence of bending or damage of the long object at the connected portion after the unites are connected, and the occurrence of separation between the units.

(Example) An example of the present invention will be described below with reference to the drawings.

First, as shown in FIGS. 1 and 2, the fixed mold 1 and the movable mold 2, which have been previously formed into a desired shape, are closed, and in this state, the material injection molded on the side of the movable mold 2 is closed. A molten resin material 8 is injected from the outlet 3 into the cavity 9 formed by each of the molds. As a result, the single body 4 made of synthetic resin is molded according to the shape of the mold.

That is, as shown in FIG. 6, this unit 4 has a rear end 10 as a part to be melted, which is formed in a plate-like manner protruding from the lower surface side.

Next, as shown in FIG.
After being released, the upper surface side is formed to protrude into a plate shape so as to be able to fit into the rear end portion 10 of the unit 4 as shown in FIG.
Moreover, the extrusion part 12 with a built-in heater is heated and moved forward by a piston rod, and the extrusion part 12 is fitted into the rear end part 10 of the unit 4 molded as described above, and while heating the extrusion part 12, the extrusion part 12 is heated. The movable mold 2 is moved to a position directly below the material injection port 3.

Thereafter, the extrusion section 12 is moved back, the movable mold 2 is moved to the fixed mold 1 side as shown in FIG. inject molten material.

In this case, in order to fit the rear end 10 of the molded unit 4 into the extrusion part 12 heated by a heater and move it, the residual heat causes the rear end 10 and the material injection port 3b to be moved. The temperature difference between the material 8b and the injected material 8b is not large, so that the material can be well fused to the rear end 10 of the single body 4, and the single body 4 can be easily molded to the rear end 10. Become.

Therefore, the joint part of the single body 4 can be formed reliably and firmly, and as a result, the strength of the joint part of the molded long object is significantly improved, and there is no possibility of bending or breakage of the long object at the joint part.
This makes it possible to suitably prevent the occurrence of detachment between the single units.

Then, by repeating the injection of the material, the movement of the single pieces after injection molding, and the fusion and integration of the single pieces as described above, and joining a large number of single pieces, a desired long synthetic resin object is molded. becomes.

In the above embodiment, the rear end 10 of the unit 4 is formed into a protruding plate shape, but the shape of the rear end 10 of the unit 4 is by no means limited to this.

Further, in this embodiment, in order to heat the rear end portion 10 of the molded unit 4, the extrusion portion 1 is equipped with a heating function.
2 was reciprocated and fitted into the rear end 10 of the single body 4, and thus the single body 4 could be moved while being heated, and a favorable advantage was obtained in that the efficiency of the molding work could be improved. , it is not a condition that the rear end 10 of the unit 4 be moved in a heated state. In short, it is sufficient that the rear end portion 10 of the front unit 4 is heated when molding the next unit 4a.

Therefore, the heating means for the rear end 10 of the unit 4 is not limited to the above embodiment, and may be a heating means such as holding the rear end 10 with a chuck having a heater, for example.
It does not question its specific structure.

Further, the shape of the rear end portion 10 of the unit 4 is not limited to the above embodiment, and its specific shape is not limited.

In addition, the shape of the mold, the number of material injection ports 3, the single unit 4...
The specific structure of the moving means and the like can be freely changed within the scope of the present invention.

(Effects of the Invention) As shown above, the present invention provides a molding method for molding a long synthetic resin object by fusion-bonding adjacent single bodies at their joint ends and connecting a large number of single bodies. In this method, the rear end of the unit is heated, and the next unit is fused to the rear end of the unit in the heated state to form a long object. There is no large difference between the temperature of the end and the temperature of the material injected from the material injection port as in the conventional case, and therefore the material is well fused to the rear end of the unit, and the rear end of the unit is This allows for easy molding.

Therefore, the joints of single units can be reliably and firmly formed, and the strength is significantly improved compared to conventional ones, making it suitable for preventing bending or damage of long objects at the joints of single units, separation of units, etc. A particularly remarkable effect has been achieved in that it can prevent

[Brief explanation of the drawing]

1 to 7 show an embodiment of the present invention, in which FIG. 1 is a cross-sectional view of the material injection process after the mold is closed, FIG. 2 is a cross-sectional view after material injection molding, and FIGS. Figure 4 is a cross-sectional view of the unit moving after opening the mold, Figure 5 is a cross-sectional view of the material injection process after the unit is moved, Figure 6 is an enlarged perspective view showing one end of the unit, and Figure 7
The figure is a sectional view showing a state in which a single unit is connected. FIG. 8 is a sectional view showing a conventional example. 3...Material injection port 4...Single body 4a...Single body 8...Melted material 9...Cavity 10...
Rear end applicant Kitai Seisakusho Co., Ltd. Agent Patent attorney Noboru Fujimoto Figure 1 Figure 3 Figure 5 Figure 8

Claims (1)

[Claims] A molten synthetic resin material 8 is injected into a cavity 9 of the mold from a material injection port 3 formed at a predetermined position of the mold to mold a single body 4 with the rear end 10 as the melted part, and after molding. The unit 4 is moved so that the rear end 10 is located directly below the material injection port 3, and then the material 8 is injected from the material injection port 3 to melt the rear end 10 of the unit 4. The next single body 4a is fused and integrated with the rear end portion 10 of the single body 4, and then the molding, movement, and fusion of the single body are repeated to form a long object by arranging a large number of single bodies in a row.Synthetic resin A method for molding a long product made of synthetic resin, characterized in that the rear end portion 10 of the single body 4 is heated, and the next single body 4a is fused and integrated in the heated state. .