JPS6122946A - Sandwich molding machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

TECHNICAL FIELD The present invention relates to a sandwich molding machine for manufacturing a sandwich molded product by extrusion molding an inner layer and an outer layer formed around the outer periphery of the inner layer.

BACKGROUND ART In a conventional sandwich molding machine, the same or different types of inner layer molding materials and outer R4 molding materials are plasticized so as not to be mixed, and are then molded through the same nozzle channel and nozzle hole. The sandwich molded product is obtained by injection filling into the molding space.

In such prior art, in order to inject the inner layer molding material and the outer layer molding material of the molded product through the same nozzle flow path, the pressure of the heated and melted molding materials is reduced at the confluence of the nozzle flow paths. As a result, the injection rate becomes low, which causes the thickness of the relatively expensive outer layer of the molded product to become unbalanced, creating the problem that it is impossible to reduce production costs. In the case of a combination of a molding material with good thermal stability and a molding material with poor thermal stability, one molding material may flow back into the supply path of the other molding material, which has a different set temperature condition, at the point where the supply paths meet. This causes the molding material to thermally decompose or its viscosity to increase, causing an imbalance in molding shrinkage, which leads to a deterioration in the quality of the molded product.

Purpose An object of the present invention is to provide a sandwich molding machine that solves the above-mentioned technical problems, prevents pressure loss of the molding material at the meeting point of the supply route, and improves the quality of the molded product. It is.

Embodiment $1 FIG. 1 is a sectional view of a sandwich molding machine 1 according to an embodiment of the present invention. To improve the sandwich molding, a fixed mold 2 and a movable mold 3 are provided, by which a molding space 4 is defined.

The molding space 4 is selected depending on the form of the molded product.

A sprue 7 is formed in the fixed mold 2 and extends through the molding space 4 and faces the nozzle hole 6 via the gate 5.

One end of the sprue 7 on the side opposite to the molding space 4 communicates with the nozzle hole 6 of the nozzle 8 . A nozzle flow path 9 is formed in the nozzle 8 and is connected to the nozzle hole 6.
is arranged in line with the sprue 7. Nozzle 8
is fixed to the cylinder 11 by screws 10. Inside the cylinder 11, there is a first supply path 12 that communicates with the nozzle flow path 9, and a screw 14 serving as a supply means that supplies the inner layer molding material 13 to the first supply path 12 and is inserted into the first supply path 12. That will be punished. The screw 14 is rotationally driven around its axis by a driving means (not shown). .

There is a shilling 1 between the first supply path 12 and the nozzle flow path 9.
The second supply path 16 formed in the second supply path 5 joins the second supply path 16 formed within the second supply path 16 . The second supply route 16 contains the outer layer molding material 1;
A supply means for supplying said merging point 20 via 6 and a screw 19 at 1 are inserted into the second supply channel 16 . Screw 1! ] is rotationally driven around its axis by a driving means (not shown).

Confluence point-2 of first supply route 12 and second supply route 16
0 is provided with a valve element Fi21, and the valve means 21 includes a hinge 22 and a valve body 23 that is angularly displaceable around the axis of the hinge 22. This valve means 21 is connected to the inner layer molding material 13.
is configured to prevent the outer layer molding material 18 from entering the second supply path 16 and to prevent the outer layer molding material 18 from entering the first supply path 12 . By this valve means 21, the inner layer molding material 13 is supplied to the nozzle flow path 9 via the first supply path 12, and the outer layer molding material 18 is supplied to the nozzle flow path 9 via the first supply path 12.
6 to the nozzle channels 9 respectively.

When performing sandwich molding, the heated and melted outer layer molding material 18 is caused to flow into the second supply path 16. At this time, the screw 19 is moved backward to the right in FIG. 1 so that only the required amount of the outer layer molding material 18 flows into the second supply path 16.

Next, the screw 14 is driven to rotate to cause the heated and melted inner layer molding material 13 to flow into the first supply path 12 . At this time, the inner layer molding material 13 and the outer layer molding material 18 are prepared in the fIS1 supply path 12 and the second supply path 16 while being kept under pressure. In addition, screws 14 and 19 include
An external thread is provided, thus making it possible to perform so-called screw-in-line injection and molding.

After clamping the fixed mold 2 and the movable mold 3, move one screw to the 42 side in Figure 1 using a hydraulic ram or the like!
Ih L, the outer layer molding material 18 is injected into the molding space 4 from the nozzle channel 9 sprue 7 and date 5 via the second supply path 16 and the valve means 21.

At this time, the valve body 23 of the valve means 21 only allows the nozzle flow path 9 to enter from the second supply path 16 of the outer nine-layer molding material 18, as shown in Figure #2, and only allows the nozzle flow path 9. Inside/
Prevent the invasion of \.

Next, drive the screw 14 to move the inner layer molding material 13 to the left in FIG.
1 into the molding space 4 from the nozzle flow path 9, the sprue 7, and the date 5. At this time, ji, t, r'i2
1, the inner layer molding material 13 is only allowed to enter the nozzle flow path 9 from the first supply path 12, and
Prevent intrusion into 6.

The function of this valve means 21 reliably prevents the outer layer molding material 18 and the inner layer molding material 13 from mixing at the confluence point 20 of the first supply path 12 and the second supply path 16.

The molded product injected into the molding space 4 is cooled and solidified in the molds 2 and 3 for a certain period of time, and then taken out.

By providing the valve means 21 at the confluence point 20 of the first supply route 12 and the second supply route 16 in this manner, the following advantages cannot be obtained.

(1) The pressure loss between the outer layer molding material 18 and the inner layer molding material 13 at the confluence point can be made as small as possible. As a result, the injection rate is improved, molding shrinkage between the outer layer and the inner layer can be maintained in a well-balanced manner, and a sandwich molded product with excellent quality can be obtained.

(2) Backflow of the inner layer molding material 13 to the second supply path 16;
Also, backflow of the outer layer molding material 18 to the first supply path 12 can be prevented. Therefore, even if a combination of materials with different thermal stability is used, the material will not enter the supply route with different set temperature conditions, and problems such as thermal decomposition of the molding material and increase in viscosity will not occur.

(3) Near the confluence tM point 20, the amount of remaining molding material is reduced, thus achieving continuous and stable sand inch molding.

Although the above embodiment uses the hinge 22 and the valve body 23, the valve means 21 may be configured using other configurations. In addition, as the outer layer molding material and the inner layer molding material,
All synthetic resins can be used, such as vinyl chloride resin and acrylic resin.

Effects As described above, according to the present invention, the first supply route and the 20th (
By providing the valve means near the confluence with the supply path, backflow of the molding material can be prevented, and moreover, the confluence point 51
Minimize the pressure loss of the molding material in the vicinity as much as possible,
2), it becomes possible to obtain a sandwich molded product of good quality.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a sandwich molding machine 1 according to the present invention, FIG. 2 is a simplified diagram showing the state of communication between the nozzle ridge 9 and the second supply path Vr] 6, and FIG. 3 is a nozzle flow path. 9 is a simplified diagram showing a state of communication between the second supply path 12 and the second supply path 12. FIG. DESCRIPTION OF SYMBOLS 1...Sand inch molding machine, 12...1st supply route, 13...Inner layer molding material, 16...l 2nd supply route,
1.8... Outer layer molding material, 20... Confluence point, 22
...Hinge, 23...Valve body

Claims (1)

[Scope of Claims] A first supply path that communicates with the nozzle hole, a first supply means that communicates with the first supply path and supplies the outer layer molding material to the first supply path, and a second supply that communicates with the nozzle hole. and a second supply means for supplying the inner layer molding material to the first supply route via a passage, wherein the inner layer molding material is supplied to the first supply route near the confluence of the first supply route and the second supply route. and the outer layer molding material is prevented from entering the second supply route, and the outer layer molding material and the inner layer molding material are passed through the nozzle hole through the first supply route and the second supply route, respectively. 1. A sandwich molding machine, characterized in that it is provided with valve means for allowing the supply of water to the sandwich molding machine.