JPH07329149A - Breaker plate for extrusion molding equipment - Google Patents

Abstract

PURPOSE:To obtain a breaker plate wherein a carbide does not generate even when it is operated continuously for a long time and deposition phenomenon of a resin additive hardly occurs by providing a recessed face which slants to the center from a peripheral edge in the outflow direction as an inflow side face of a melting resin, and a protruded face as an outflow side face. CONSTITUTION:A breaker plate 1 comprises an inflow side face 1A of a melting resin and an outflow side face 1B of the melting resin. The inflow side face 1A of the melting resin has a recessed face slanting to the center from a peripheral edge in the outflow direction. The outflow side face 1B of the melting resin has a protruded face slanting to the center from the peripheral edge in the outflow direction. A large number of through holes 1a and 1b are arranged ranging from the inflow side face 1A to the outflow side face 1B. An angle theta1 formed by the vertical face of the inflow side face 1A and the slanting face of the recess is set to 30 deg.. The angle of inclination 81 is adequately determined dependent on the kind and viscosity of a synthetic resin to be used, specification of an extrusion molding device, and molding condition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a breaker plate for an extrusion molding apparatus.

[0002]

2. Description of the Related Art A conventional extrusion molding apparatus will be described with reference to FIGS. As shown in the configuration diagram of the extrusion molding apparatus in FIG. 4, the extrusion molding apparatus supplies a solid thermoplastic synthetic resin molding material from a hopper 21 into a cylinder (barrel) 22 heated by a heater, and the cylinder 2
2 The resin is kneaded, heated, and plasticized by the rotation of the rotating screw equipped inside, and is sent by pressure to a molding die (die) 23 mounted on the tip of the cylinder 22, molded, continuously extruded, and cooled in a water tank 25. The take-out machine 25a is configured to cut into a predetermined length with a drawer cutter 25b.

FIG. 5 is a sectional view showing a main part of a conventional extrusion molding apparatus, in which a rotary screw 24 mounted inside a cylinder 22 is rotated by a drive gear 24a. A breaker plate 27 having a large number of through holes 26 is mounted between the cylinder 22 and the molding die 23, and the molten resin is pressure-fed by the rotary screw 24 and passes through the through holes 26 of the breaker plate 27 to form It flows into the mold 23, is molded into a predetermined shape, and is continuously drawn out from the mold 23. The breaker plate 27 straightens the molten resin kneaded and plasticized in the cylinder 22,
This is aimed at making the amount of resin supplied to each part of the molding die 23 uniform, perfecting the product formation, and improving the appearance of the product surface.

FIG. 6 is a cross-sectional view of a main portion of a conventional extrusion molding apparatus showing a mounting portion of the breaker plate 27 cited from Japanese Utility Model Publication No. 63-12985. In this example, the cylinder 22 and the molding die 23 are the breaker plate 27.
The molds 2 are connected to each other with a fixture 28 between them.
A core bar 29 is provided on the center axis of the pipe 3 so that the pipe can be continuously extruded.

In this breaker plate 27, the inflow side surface of the molten resin is a plane perpendicular to the central axis of the cylinder 22, and the outflow side surface of the molten resin is a plane perpendicular to the central axis of the molding die 23. A large number of through-holes 26 communicating with the outflow side surface are provided. Further, in the breaker plate 27, since the inflow side surface and the outflow side surface of the molten resin are parallel to each other, the distance between the both sides is the same at the peripheral portion and the central portion.

[0006]

However, as in the above example, in the conventional breaker plate 27, a large number of through holes 26 provided in the breaker plate 27 are formed at right angles to the inflow side surface and the outflow side surface of the breaker plate 27. It was penetrated. For this reason, in the portion where the through hole 26 is not provided on the inflow side surface of the breaker plate 27, the flow of the molten resin is bent at a right angle and flows into the through hole 26, so that there is a problem that the flow easily stays. Further, when the molten resin flows out from the outflow side surface of the conventional breaker plate 27, there is a problem that a portion where the through hole 26 is not provided becomes a dead space and the flow is likely to stay and the rectifying action is hindered.

Due to these problems, the surface of the molded product tends to have irregularities and gloss unevenness. Also,
In the case of a resin such as vinyl chloride resin that is easily decomposed, if it is continuously operated for a long time, the resin will be thermally decomposed to generate a carbide due to the above-mentioned retention problem, or added by being mixed in the vinyl chloride resin. There is a problem in that the agent precipitates and accumulates in the accumulation portion of the above-mentioned flow, and this phenomenon periodically adheres to the surface of the product and emerges, so-called plate-out, which is a problem.

In the breaker plate 27, since the inflow side surface and the outflow side surface of the molten resin are parallel to each other, the distance between the both sides is the same in the peripheral portion and the central portion, and the through hole 26 and the central portion of the peripheral portion are the same. The through holes 26 have the same flow resistance. For this reason, the flow rate in the center portion where the flow is fast becomes larger than the flow rate in the peripheral portion, and the rectifying action of the breaker plate 27 becomes insufficient. Therefore, it has been a cause of problems such as unevenness on the surface of the molded product and uneven gloss. In order to improve the rectifying action and improve these problems, the diameter of the through hole 26 is made smaller by the conventional method, but if it is made smaller, the load on the rotary screw 24 for pumping the molten resin increases. Another problem was that the amount of synthetic resin extruded decreased.

The object of the present invention is to prevent the unevenness and uneven gloss which are apt to occur on the surface of the product without increasing the load on the rotary screw 24, and the thermal decomposition of the resin even during continuous operation for a long time. It is an object of the present invention to provide a breaker plate of an extrusion molding apparatus which does not generate a carbide due to the above and does not easily cause a precipitation phenomenon of a resin additive called plate-out and which is excellent in continuous operability for a long time. Another object of the present invention is to provide a breaker plate for an extrusion molding apparatus that can even more effectively prevent unevenness and uneven gloss by uniformizing the flow velocity distribution in the peripheral portion and the central portion, and is excellent in long-term continuous operation. Is to provide.

[0010]

The present invention has been made to achieve the above object, and the invention of claim 1 is a cylinder equipped with a rotary screw for feeding a molten resin and a molding. A breaker plate of an extrusion molding apparatus mounted between a die and the mold, wherein the breaker plate is a concave surface whose inflow side surface of the molten resin is inclined in the outflow direction from the peripheral edge toward the center, and the outflow of the molten resin. A breaker plate for an extrusion molding apparatus, characterized in that a side surface is a convex surface that is inclined in the outflow direction from the peripheral edge toward the center, and a large number of through-holes communicating from the inflow side surface to the outflow side surface are provided.

According to a second aspect of the present invention, in the breaker plate of the extrusion molding apparatus according to the first aspect, the distance from the inflow side surface to the outflow side surface is larger in the central portion than in the peripheral portion. It is a breaker plate of the device.

[0012]

According to the breaker plate of the invention of claim 1, since the inflow side surface of the molten resin is a concave surface inclined from the peripheral edge toward the center in the outflow direction, and a large number of through holes are provided, this concave surface It smoothly flows into many through-holes while flowing along, and the molten resin does not stay between the through-holes. Further, since the outflow side surface is a convex surface that is inclined in the outflow direction from the peripheral edge toward the center, the molten resin that flows out from the through hole flows along this inclined convex surface. There is no flow dead space between.

Therefore, the unevenness that tends to occur on the surface of the product without increasing the load on the rotary screw 24,
It is possible to prevent uneven gloss, and even after continuous operation for a long time, there is no generation of carbides due to thermal decomposition of the resin, and the precipitation phenomenon of resin additive called plate-out hardly occurs.

In the conventional breaker plate, the flow rate at the central portion is higher than the flow rate at the peripheral portion, so that the rectifying action is insufficient, but the invention of claim 2 is the extrusion molding apparatus of claim 1. In the breaker plate, the distance from the inflow side surface to the outflow side surface is larger in the central part than in the peripheral part, so that the flow velocity at the peripheral part and the central part of the breaker plate is made uniform, and a uniform resin is formed in the entire molding die. Since a flow can be formed and pressure-fed, unevenness and uneven gloss can be better prevented.

[0015]

Embodiments of the present invention will now be described with reference to the drawings. 1 and 2 show an embodiment of the present invention,
FIG. 1 is a front view of a breaker plate according to the present invention in which a molten resin inflow side surface is a concave surface and a molten resin outflow side surface is a convex surface. FIG. 2 is a sectional view of the breaker plate shown in FIG. FIG. 3 is a sectional view of a breaker plate according to another embodiment of the present invention, in which the distance between the inflow side surface and the outflow side surface of the molten resin is larger in the central portion than in the peripheral portion.

First, the embodiment shown in FIG. 1 and FIG. 2 will be described. 1 is a steel disk-shaped breaker plate, and this breaker plate 1 has a molten resin inflow side surface of 1 A and an outflow of molten resin. The side surface is 1B. The inflow side surface 1A of the molten resin is a concave surface inclined from the peripheral edge toward the center in the outflow direction, and the outflow side 1B of the molten resin is a convex surface inclined from the peripheral edge toward the center in the outflow direction. A large number of through holes 1a and 1b communicating from the side surface 1A to the outflow side surface 1B are provided. θ1 is the inflow side 1
The inclination angle between the vertical surface of A and the concave surface is shown, but in this embodiment, it is set to 30 degrees. The inclination angle θ1 is appropriately determined according to the type and viscosity of the synthetic resin used, the specifications of the extrusion molding apparatus, the molding conditions, etc., but is preferably in the range of 20 degrees to 45 degrees.

If the inclination angle θ1 is smaller than 20 degrees, the molten resin is likely to stay on the inflow side surface 1A, and if it is larger than 45 degrees, the thickness of the breaker plate 1 becomes large, which is not preferable. L1 indicates the length of the through hole 1a in the peripheral portion, and L2
Indicates the length of the through hole in the central portion. In this embodiment, the length L1
And the length L2 are the same. The number and the arrangement of the through holes 1a and 1b are not limited to the example shown in the drawing, but are determined in accordance with the specifications of the extrusion molding apparatus and the size and shape of the molded product.

Next, the operation of the breaker plate 1 will be described. Using a vinyl chloride resin compound as a raw material synthetic resin, the above breaker plate 1 is attached to an extrusion molding device, and pressure-fed by a rotary screw,
The mixture was kneaded, heated, plasticized, and rectified by passing through the large number of through holes 1a and 1b of the breaker plate 1, and the resin was uniformly supplied to each portion of the die cross section. At this time, in the breaker plate 1 of the present embodiment, since the inflow side surface 1A of the molten resin is a concave surface, a flow occurs along this concave surface, and the molten resin stays between the through hole 1a and the adjacent through hole 1b. There is no such thing. Further, since the outflow side surface 1B of the molten resin is a convex surface, a flow along the convex surface occurs, and a dead space of the flow does not occur between the through hole 1a and the adjacent through hole 1b.

As a result, since a smooth and uniform resin flow can be formed and pressure-fed in the entire molding die, the aesthetic appearance of the product surface without unevenness or uneven gloss can be further increased. In addition, when the extruder was operated continuously for a long time, color burns and pyrolytic carbides caused by the retention of molten resin did not flow out, and the additives of lubricants and stabilizers added to the vinyl chloride resin compound were The plate-out phenomenon of precipitation and outflow did not occur.

Next, another embodiment shown in FIG. 3 will be described. Reference numeral 2 denotes a steel breaker plate, and the breaker plate 2 has a molten resin inflow side surface of 2A and a molten resin outflow side surface of 2B. Inflow side 2A of molten resin
Is a concave surface inclined in the outflow direction from the peripheral edge toward the center, and the outflow side surface 2B of the molten resin is a convex surface inclined in the outflow direction from the peripheral edge toward the center, and from the inflow side surface 2A to the outflow side surface 2B. Through holes 2a, 2b leading to the
Is provided. Although θ2 indicates the inclination angle between the vertical surface of the inflow side surface 2A and the concave surface, it is set to 30 degrees in this embodiment. L3 indicates the length of the through hole 2a in the peripheral portion, and L4 indicates the length of the through hole 2b in the central portion. In this embodiment, the length L
4 was 1.5 times the length L3.

This breaker plate 2 is mounted on the same extrusion molding apparatus as in the above-mentioned embodiment, and a vinyl chloride resin compound is used as a raw material synthetic resin, and is pressure fed by a rotary screw to knead / heat / plasticize the breaker plate. The resin was rectified by passing through a large number of two through holes 2a and 2b, and the resin was uniformly supplied to each part of the die cross section. Next, the operation of the breaker plate 2 will be described. Since the inflow side surface of the molten resin is a concave surface in the breaker plate 2, a flow along this concave surface occurs,
The molten resin does not stay between the through hole 2a and the adjacent through hole 2b. Further, since the outflow side surface of the molten resin is a convex surface, a flow occurs along this convex surface, and a dead space of the flow does not occur between the through hole 2a and the adjacent through hole 2b.

Further, in the breaker plate 2 of this embodiment, the length L4 of the through hole 2b in the central portion is 1.5 times larger than the length of the through hole 2a in the peripheral portion.
The flow of the molten resin through the through hole in the central portion is suppressed, and the resin supply amount to each portion of the mold cross section can be further uniformized and supplied. As a result, the aesthetics of the product surface could be further increased without unevenness or uneven gloss. In addition, when this extrusion molding device was operated continuously for a long time, no color burns or thermal decomposition products caused by retention of molten resin flowed out, and additives for lubricants and stabilizers added to the vinyl chloride resin compound There was no occurrence of plate-out phenomenon in which the precipitates were deposited and flowed out.

[0023]

In the breaker plate of the extrusion molding apparatus of the present invention according to claim 1, the inflow side surface of the molten resin is a concave surface inclined from the peripheral edge toward the center in the outflow direction, and the outflow side surface extends from the peripheral edge to the center. It is a convex surface that is inclined toward the outflow direction, and is provided with a large number of through holes that extend from this inflow side surface to the outflow side surface. Therefore, in the inflow side surface, the molten resin flows into the through hole while flowing along the inclined concave surface, so that the molten resin does not stay and smoothly flows out through the through hole. In addition, since the flow along the inclined convex surface also occurs on the outflow side surface, a dead space of the flow can be eliminated between the through holes.

For this reason, it is possible to form a uniform resin flow through the entire molding die and pressure-feed without increasing the load on the rotary screw, resulting in unevenness and uneven gloss which tend to occur on the surface of the product. Since it can be prevented, the appearance of the product can be improved. In addition, even after continuous operation for a long time, there is no generation of carbides due to thermal decomposition of the resin, and the precipitation phenomenon of the resin additive called plate-out does not easily occur, so product quality is uniform and stable production is continued for a long time. Can be performed, and the productivity of extrusion molding can be increased.

The breaker plate of the extrusion molding apparatus according to a second aspect of the present invention is the breaker plate of the extrusion molding apparatus according to the first aspect, wherein the distance from the inflow side surface to the outflow side surface is larger in the central portion than in the peripheral portion. Since the breaker plate has a uniform flow velocity at the peripheral and central parts, a more uniform resin flow can be formed and pressure-fed by the entire molding die, and there is no unevenness or uneven gloss, and the product's aesthetic appearance is even further enhanced. In addition to being improved, the continuous operation property for a long time is also excellent, so that the productivity of extrusion molding can be improved.

[0026]

[Brief description of drawings]

FIG. 1 is a front view of a breaker plate according to the present invention in which an inflow side surface of a molten resin is a concave surface and an outflow side surface of a molten resin is a convex surface, showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the breaker plate shown in FIG.

FIG. 3 shows another embodiment of the present invention and is a cross-sectional view of a breaker plate in which the distance between the inflow side surface and the outflow side surface of the molten resin is larger in the central portion than in the peripheral portion.

FIG. 4 is a configuration diagram of an extrusion molding device.

FIG. 5 is a cross-sectional view of a main part of a conventional extrusion molding device.

FIG. 6 is a sectional view of a main part of a conventional extrusion molding apparatus.

[Explanation of symbols]

 1, breaker plate 1a, through hole 1b, through hole 1A, molten resin inflow side surface 1B, molten resin outflow side surface θ1, concave surface inclination angle L1, peripheral through hole length L2, center through hole Length 2, breaker plate 2a, through hole 2b, through hole 2A, molten resin inflow side surface 2B, molten resin outflow side surface θ2, concave inclination angle L3, peripheral hole through hole length L4, central portion penetration Hole length 22, Cylinder 23, Mold 24, Rotating screw 26, Through hole 27, Breaker plate

Claims (2)

[Claims] 1. A breaker plate of an extrusion molding apparatus mounted between a molding die and a cylinder equipped with a rotary screw for feeding molten resin under pressure, wherein the breaker plate has an inflow side of molten resin. The concave surface is inclined from the peripheral edge toward the center in the outflow direction, and the outflow side surface of the molten resin is a convex surface inclined from the peripheral edge toward the center in the outflow direction. A breaker plate for an extrusion molding apparatus, which is provided with a through hole. 2. The breaker plate of the extrusion molding apparatus according to claim 1, wherein the distance from the inflow side surface to the outflow side surface is larger in the central portion than in the peripheral portion.