JPS5940198Y2 - Extrusion molding machine screen assembly - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a screen assembly provided at the tip of a cylinder of an extrusion molding machine when extrusion molding a thermoplastic resin or the like.

During extrusion molding of thermoplastic resin, a screen assembly consisting of a breaker plate and a plurality of screens is installed at the tip of the cylinder of an extrusion molding machine to (1) perform a rectifying effect on the flow of the resin.

(2) Pressure is increased by flow resistance to improve the degree of kneading of the resin.

(3) The filtration action of the screen assembly removes foreign matter mixed into the raw resin and altered resin, making it possible to obtain molded products without defects.

It is well known that the following effects can be achieved.

In this way, in order to mold a thermoplastic resin into a molded product by extrusion molding, the screen assembly and the play car plate that supports the screen assembly play an important role.

In order to obtain a good molded product, selection of the number of wire meshes in the screen assembly to be arranged, the size of the wire mesh mesh, etc. are important conditions.

Even the screen assembly, which was clean at the start of operation, becomes clogged over the course of one hour due to the accumulation of foreign matter mixed into the resin and foreign matter originating from various compounds added to the resin.

If the screen assembly becomes clogged, the pressure at the tip of the cylinder will increase, and the wire mesh that makes up the screen assembly will become twisted, reducing the throughput.

Therefore, it is necessary to periodically replace the screen assembly during extrusion.

To replace a screen assembly mounted on a conventional fixed play car plate, simply shut down the extruder, disassemble the cylinder tip, and replace the clogged screen assembly with a new one.

A clogged screen assembly has foreign matter attached to it, making it difficult to remove each wire mesh, and if the wire mesh is twisted, it is difficult to reuse it, making it uneconomical.

Under such circumstances, the inventors of the present invention have found that the replacement work is easy, the wire mesh that makes up the assembly does not get twisted, and
In order to provide a screen assembly in which part or all of the wire mesh constituting the assembly can be reused, the present invention was completed as a result of intensive studies.

However, the gist of this is that in the screen assembly, which is placed behind the marker plate with many small holes provided at the tip of the cylinder of the extrusion molding machine, multiple screens are combined to form the marker plate. On the side farthest from the plate, there is an outer peripheral frame that fits into the screen assembly support portion of the fighter plate, and a metal perforated thin plate with a large number of polygonal small holes bored inside the outer peripheral frame. A screen assembly for an extrusion molding machine, characterized in that:

Hereinafter, the present invention will be described in detail based on the drawings, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

FIG. 1 is a longitudinal sectional side view showing the essential parts of an example of an extrusion molding machine equipped with a screen assembly according to the present invention, and FIG. 2 is a plan view of an example of a perforated metal thin plate.

In the figure, 1 is the extruder cylinder, 2 is the screw, 3 is the cylinder tip flange, 4 is the breaker plate, 5 is the small hole, 6 is the screen assembly holding part, 7 is the screen assembly, 8 is the clamp, Reference numeral 9 indicates a clamp fixing bolt, 10 a multi-thin metal plate, 11 an outer peripheral frame, 12 a polygonal hole, and 13 an opening.

The screen assembly according to the present invention is used by being placed at the tip of a cylinder of an extrusion molding machine.

Between the tip of the cylinder 1 of the extrusion molding machine and the clamp 8,
A breaker plate 4 provided with a large number of small holes 5 is mounted.

A screen assembly support section 6 is provided at the rear of the fighter plate 4 (on the screw 2 side), and the screen assembly T is disposed on this support section 6.

The screen assembly T is composed of a plurality of wire meshes with different mesh sizes, and the assembly according to the present invention has a metal porous thin plate 10 on the side farthest from the breaker plate (screw side). Must be placed.

This perforated thin metal plate 10 has a peripheral frame 1 which fits almost exactly into the screen assembly support 6 of the breaker plate.
Must have 1.

This outer peripheral frame 11 functions to press the screen assembly 7 and prevent the wire mesh constituting the assembly from twisting even if the back pressure of the resin increases.

Therefore, the thin plate must have a certain degree of thickness and strength.

Furthermore, since it comes into contact with high-temperature molten resin and high-temperature additives, it is preferably made of a material that is resistant to corrosion.

In consideration of strength, corrosion resistance, etc., the metal thin plate 10 is particularly preferably made of a stainless steel thin plate with a thickness of 0.5 to 3 mm.

A large number of polygonal small holes must be bored inside the outer peripheral frame 11 of the thin metal plate 10.

The shape of the small holes may be square, pentagonal, hexagonal, hexagonal, etc.

The size of one of these small holes is approximately 5 mm in apparent diameter.
A range of 30 mm is preferable, and it is preferable that the average width of the portion separating the holes is 1 to 10 mm.

The apparent diameter here refers to the largest distance between the vertices of a polygon.

It is preferable to provide the torch 13 on the outside of the outer peripheral frame 11, since this makes it easier to remove the screen assembly 7 according to the present invention from the screen assembly support part 6.

The screen assembly 7 according to the present invention has the metal porous thin plate 10 as described above arranged behind the player plate 4 (on the screw side), but the size of the other screens, the number of screens, etc. There are no restrictions.

In an extrusion molding machine equipped with a screen assembly according to the present invention, back pressure of molten resin is applied to the screen assembly 7 during extrusion work.
However, the back pressure is first applied to the perforated thin metal plate 10, thereby pressing the plurality of screens toward the player plate.

As a result, the plurality of wire meshes constituting the screen assembly 7 will not be twisted even if the back pressure of the resin increases.

The screen assembly for an extrusion molding machine according to the present invention has the following effects, and its practical value is extremely large.

(i) In the screen assembly according to the present invention, even if the back of the resin rises during extrusion work, the wire mesh that makes up the screen assembly does not twist, and therefore the problem of a decrease in extrusion amount due to twisting does not occur. (11) In conventional screen assemblies, a wire mesh with a large mesh was placed on the side farthest from the breaker plate (screw side).

Wire mesh with a large mesh has a large wire diameter, and there is a problem in that resin accumulates in the areas where the wires intersect, and this discolors due to heat, resulting in discolored resin coming out during extrusion molding.

In the screen assembly according to the present invention, a metal perforated thin plate is disposed instead of a wire mesh, so that the above-mentioned problems of the conventional method are not present.

Q10 The assembly according to the present invention is economical because the screen constituting the assembly does not twist and can be reused by cleaning the assembly with foreign matter.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing an example of an extrusion molding machine equipped with a screen assembly according to the present invention, and FIG. 2 is a plan view of an example of a perforated metal thin plate. In the figure, 1 is the extruder cylinder, 2 is the screw, 3 is the cylinder tip flange, 4 is the breaker plate, 5 is the small hole, 6 is the screen assembly holding part, 7 is the screen assembly, 8 is the clamp, Reference numeral 9 indicates a clamp fixing bolt, 10 indicates a metal porous thin plate, 11 indicates an outer peripheral frame, 12 indicates a polygonal hole, and 13 indicates a notch.

Claims (3)

[Scope of utility model registration request] (1) In the screen assembly placed behind the marker plate with many small holes provided at the tip of the cylinder of the extrusion molding machine, multiple screens are combined and placed on the side farthest from the marker plate. The device comprises an outer peripheral frame that fits into the screen assembly support portion of the breaker plate, and a metal perforated thin plate having a large number of polygonal small holes is arranged inside the outer peripheral frame. Screen assembly for extrusion molding machine featuring features. (2) The screen assembly for an extrusion molding machine according to claim 1, wherein the metal thin plate is a stainless steel thin plate having a thickness of 0.5 to 3 mm. (3) Extrusion molding according to claims 1 or 2 of the utility model registration claim, characterized in that a plurality of notches are provided on the outside of the outer peripheral frame of the perforated thin metal plate. Machine screen assembly.