JPS6130894B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a breaker plate 2 in which the extrusion side end surface 4 of the melt 3 is projected so as to gradually become thinner in the extrusion direction of the extrusion molding machine 1, and the mold 8 is attached to the breaker plate 2. The breaker plate 2 is placed so as to face the extrusion side end surface 4 of
A breaker plate device for an extrusion molding machine is characterized in that a pressure passage 25 is formed between the mold 8 and the mold 8, into which the melt 3 that has passed through the breaker plate 2 is filled and pumped. The purpose of this invention is to provide a breaker plate device for an extrusion molding machine that prevents large particles of compounding agents from being mixed into the molded product.

The present invention will be described in detail below with reference to Examples. The melt 3 is made by melting pellets and compounding agents, and has a high viscosity. The extruder 1 is used to extrude the melt 3 to obtain a molded product of a desired shape. A filter 7, a breaker plate 2, and a mold 8 are attached to an extrusion port 6 at the tip of the extrusion molding machine 1. A filter 7 is installed between the extrusion port 6 and the breaker plate 2, and is used to filter out dust in the melt 3. The breaker plate 2 has a countless number of minute holes 9 perforated on its entire surface, and the end surface 4 of the breaker plate 2 on the extrusion side of the melt 3 protrudes so as to become gradually narrower in the extrusion direction of the extrusion molding machine. . The mold 8 is attached to the extrusion port 6 of the extrusion molding machine 1, and the filter 7 and the breaker plate 2 are connected to the filter insertion part 11 on the front surface 10 of the extrusion port 6 and the rear surface 12 of the mold 8.
It is fitted into a cavity 14 formed by a breaker plate insertion portion 13 of the breaker plate. Mold 8
A first recess 15 is provided from the breaker plate insertion portion 13, which gradually becomes thinner in the extrusion direction.In this first recess 15, the mold 8 faces the breaker plate 2, and the mold 8 and the breaker A pressure channel 25 through which the melt 3 is pumped is configured between the plate 2 and the first recess 15, starting from the narrowest diameter neck 16 at the front end, gradually increasing in diameter in the extrusion direction, and then gradually increasing in diameter toward the middle. A second recess 18 is provided, which has a cylindrical shape with an unchanging diameter at the end, and whose diameter gradually becomes narrower near the outlet 17. A core mold 19 matching the shape of the second recess 18 is fitted into the second recess 18 . This core mold 19 is the second
It is supported by a support arm 21 bored in a cylindrical portion 20 of the recess 18 . Further, the mold 8 is split into a mold for inserting or removing the core mold 19. The first concave portion 15 of the mold 8 and the extrusion side end surface 4 of the breaker plate 2 are aligned with each other with a constant interval. The extrusion molding machine 1 melts the pellets and compounding agents to form a molten material 3, which is then extruded through the breaker plate 2 into the mold 8 for extrusion molding. The melted material 3 flows along the extrusion side end surface 4 of the breaker plate 2. In this case, breaker plate 2
Negative pressure is created on the extrusion side end surface 4 of the partition wall 22 between the through holes 9, and small particles of the compound adhere to the extrusion side end surface 4 of the partition wall 22.
Since the extrusion side end surface 4 of the molded product is always wiped away by the melt 3, the small particles of the compounded compound do not grow and the large particles 24 of the compounded compound do not mix into the molded product. be.

In the conventional example, since the extrusion side end surface 4 of the breaker plate 2 was flat, even if small particles of the compounding agent adhered to the extrusion side end surface 4 of the partition wall 22 between the through holes 9, they were not wiped away, and the compounding agent gradually The grains grow to become large grains 24, and when they become large grains 24, they separate from the extrusion side end surface 4 of the partition wall 22, are extruded from the mold 8 together with the melt 3, and mix in the molded product, causing the molded product to be defective. It had the disadvantage of being

In the present invention, the mold is placed approximately parallel to the extrusion side end surface of the breaker plate, which protrudes so that the extrusion side end surface of the melt is gradually tapered in the extrusion direction of the extrusion molding machine. Since the breaker plate and the mold are opposed to each other, and a pressure passage is formed between the breaker plate and the mold, which is filled with the molten material that has passed through the breaker plate and is pumped, The melt is then extruded, and even if small particles of the compounding agent of the melt adhere to the extrusion side end face of the partition wall between the through holes, they are sequentially wiped away by the melt that is pumped in the pressure channel, and the compounding agent is removed. This has the advantage that small particles of the compounding agent do not grow into large particles, and that large particles of the compounding agent do not get mixed into the molded product and cause the molded product to be defective. Since it does not adhere to and grow on the extrusion side end face, there is no need to clean the mold or breaker plate, which has the advantage of improving the operating rate. The length of the hole is the shortest at the periphery of the breaker plate, which has the greatest resistance to the flow of the melt, and the length of the hole in the center, where the resistance is the least. This has the advantage that the length of the through hole is increased, and the extrusion of the melt can be made uniform, resulting in uniform quality of the molded product.

[Brief explanation of the drawing]

Fig. 1 is a partial longitudinal sectional view of an embodiment of the present invention, Fig. 2 is a longitudinal sectional view of an embodiment of the breaker plate shown above, Fig. 3 is a front view of the same as the above, and Fig. 4 is a partially enlarged view of the same as the above. 5 shows a conventional example, in which 1 is an extrusion molding machine, 2 is a breaker plate, 3 is a melt, and 4 is an extrusion side end face.

Claims (1)

[Claims] 1. A mold is opposed to a breaker plate whose extrusion side end face of the melt protrudes so as to become gradually thinner in the extrusion direction of the extrusion molding machine so as to be substantially parallel to the extrusion side end face of the breaker plate, A breaker plate device for an extrusion molding machine, characterized in that a molten material passing through the breaker plate is filled between the breaker plate and a mold to form a pressure passage for the molten material.