JPH0724903A - Screen mesh for rubber and plastic extruder and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a screen mesh for a rubber and plastic extruder with fine corrosion resistance and abrasion resistance, and a manufacture thereof. CONSTITUTION:The screen mesh for a rubber and plastic extruder is characterized in that a screen mesh for a rubber and plastic extruder consists of meshed wire materials, and the wire materials are of ones that are deposition-hardening process, and the method of a screen mesh for a rubber and plastic extruder is featured such that a deposition-hardened stainless steel wire materials are woven into a mesh prior to a deposition hardening process and thereafter the woven mesh is given a heat treatment in order to allow the wire materials to be deposition-hardened. As a consequence of this process, such mesh is durable for a long period of use because it has an excellent strength, anticorrosion and abrasion resistance. Thus, there is readily manufactured a screen mesh consisting of deposition-hardened stainless steel wire materials made by deposition hardening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen mesh used in a rubber / plastic extruder for the purpose of removing foreign matters in a rubber / plastic material and a method for producing the screen mesh.

[0002]

2. Description of the Related Art Conventionally, for the purpose of removing foreign substances in rubber / plastic materials, a screen mesh is arranged at the tip of a rubber / plastic extruder to remove foreign substances in rubber / plastic materials. Generally, SUS304 and SUS31 are used for the wire rods of the screen mesh.
A stainless steel wire rod such as 6 was used. In recent years, the higher voltage of electric wires / cables has been advanced, and in order to improve the electrical characteristics of the insulating materials used for the electric wires / cables, the requirement for highly removing foreign substances in the rubber / plastic materials used has become more severe, The screen mesh placed at the tip of the rubber / plastic extruder is becoming more porous. Traditionally, this screen mesh has
About 200 to 400 mesh is used,
In this case, the opening diameter is about 80 to 35 μm, and the wire diameter of the constituent wire is 50 to 30 μm. In order to make the screen mesh fine, it is necessary to reduce the wire diameter of the wire material forming the mesh. For example, in the case of 1000 mesh, the opening diameter is 25 μm and the wire diameter of the wire is 20 μm.
m.

[0003]

When a rubber / plastic material is extruded by an extruder using the screen mesh thus pored, the ability to remove foreign matters is improved, but the following problems occur. Is occurring. The pressure during material extrusion rises sharply and the screen mesh breaks. When a material such as ethylene-vinyl acetate copolymer (EVA) that generates a small amount of acid during extrusion is extruded, the acid corrodes the constituent wire of the screen mesh and breaks the screen mesh. When a material containing a filler such as carbon in addition to the base polymer is extruded, the filler wears the constituent wire of the screen mesh and breaks the screen mesh. These problems are due to the increase in the amount of material extruded due to the higher voltage of electric wires / cables and the thinner wire material of the screen mesh.Thus, conventional screen mesh materials lack strength, corrosion resistance, and abrasion resistance. It is caused by doing.

As a countermeasure against this, it is effective to improve the wear resistance of the wire constituting the screen mesh, and therefore various studies have been conducted. If the wire constituting the screen mesh is made hard, the wear resistance is improved. It has become clear that However, when the hardness of the constituent wire of the screen mesh is increased so that the abrasion resistance thereof is improved, the workability of the wire is poor and it is difficult to weave the wire into a mesh. In particular, when the screen mesh is made fine, the wire diameter of the wire becomes thin, and it is extremely difficult to achieve both improvement in wear resistance of the wire and improvement in mesh workability by weaving the wire. The purpose of the present invention is to
A rubber that solves the above problems and has excellent corrosion resistance and wear resistance.
A screen mesh for a plastic extruder and a method for manufacturing the same.

[0005]

In order to achieve the above object, in the present invention, in a screen mesh for a rubber / plastic extruder in which a wire is woven in a mesh shape, the wire is precipitation hardened After weaving the screen mesh for rubber / plastic extruder, which is a hardened stainless steel wire rod, and the precipitation hardened stainless steel wire rod before the precipitation hardening treatment into a mesh shape, the woven mesh is heat treated. There is provided a method for producing a screen mesh for a rubber / plastic extruder, which comprises depositing and hardening the wire rod.

The precipitation hardening stainless steel referred to in the present invention is
By heat-treating to finely disperse precipitates in the matrix, the stainless steel has increased strength and hardness without impairing the original corrosion resistance of stainless steel. Note that precipitation hardening is the phenomenon in which another new solid phase appears from the solid phase, and this precipitation occurs due to the diffusion of atoms using the supersaturation degree as a driving force to move the supersaturated solid solution to a more stable state. It is a reaction and refers to the phenomenon of hardening due to the formation of a precipitation phase. As this precipitation hardening stainless steel, any material may be used as long as it is precipitation hardened by heat treatment. For example, SUS630 (C: 0.07) of martensite precipitation hardening stainless steel.
% Or less, Si: 1.00% or less, Mn: 1.00%,
P: 0.04% or less, S: 0.03% or less, Ni: 3.
0.00 to 5.00%, Cr: 15.00 to 17.50%,
Cu: 3.0 to 5.00%, Nb: 0.15 to 0.4
0%) or austenite / ferrite (two-phase) precipitation hardening stainless steel NAS45 (C: 0.05%, B
i: 0.5%, Ni: 4.0%, Cr: 20.0%, C
u: 2.0%, Mo: 3.75%) and austenitic precipitation hardening stainless steel ASTMA461 (C: 0.05%).
055%, Si: 0.6%, Ni: 25.2%, Cr:
14.8%, Mo: 1.3%, Al: 0.22%, V:
0.28%, B: 0.004%). These heat treatments are appropriately selected according to the material type.

[0007]

Function The precipitation hardening stainless steel has a low hardness in the solid solution state, but the hardness can be increased by heat treatment and precipitation hardening. In the present invention, by utilizing the characteristics of the precipitation hardening stainless steel as described above, the precipitation hardening stainless steel is used as a base material, and after drawing this, solid solution treatment is performed once to suppress the hardness and toughness. The wire rod in the held state is formed and the mesh is woven. Next, after the completion of the mesh, the mesh is heat-treated to precipitate and harden it to obtain a mesh having high hardness and strength.

[0008]

EXAMPLES The performance of the screen mesh for a rubber / plastic extruder of the present invention will be described below with reference to examples. (Example 1) SUS630 (C: 0.07% or less, Si: 1.00) of martensitic precipitation hardening stainless steel
% Or less, Mn: 1.00%, P: 0.04% or less, S:
0.03% or less, Ni: 3.00 to 5.00%, Cr:
15.00 to 17.50%, Cu: 3.00 to 5.00
%, Nb: 0.15 to 0.40%), the base material made, wire diameter 20
Wire drawn to μm, and the wire obtained is 30 at 1060 ℃
After performing a solution treatment for a minute, air cooling was performed. The wire rod after air-cooling treatment was woven into 1000 mesh (opening diameter 25 μm), aged at 480 ° C. for 1 hour, and then air-cooled to obtain a screen mesh for a rubber / plastic extruder of the present invention.

(Example 2) Austenite-ferrite (two-phase) precipitation hardening stainless steel NAS45 (C:
0.05%, Bi: 0.5%, Ni: 4.0%, Cr:
The base material made of 20.0%, Cu: 2.0%, Mo: 3.75%) was drawn into a wire diameter of 20 μm, and the obtained wire material was 1
After solution treatment at 050 ° C. for 30 minutes, rapid cooling was performed.
1000 mesh (opening diameter 2
(5 μm), aging treatment at 450 ° C. for 4 hours, and air cooling to obtain a screen mesh for rubber / plastic extruder of the present invention.

(Example 3) Austenitic precipitation hardening stainless steel ASTM A461 (C: 0.055%,
Si: 0.6%, Ni: 25.2%, Cr: 14.8
%, Mo: 1.3%, Al: 0.22%, V: 0.28
%, B: 0.004%) was drawn into a wire having a diameter of 20 μm, and the obtained wire was subjected to solution treatment at 980 ° C. for 30 minutes and then rapidly cooled. 1 using wire rod after quenching
After weaving to 000 mesh (opening diameter 25 μm), 718
After aging treatment at 16 ° C. for 16 hours, air cooling was performed to obtain a screen mesh for a rubber / plastic extruder of the present invention.

(Comparative Example 1) A base material made of SUS304 has a wire diameter of 2
1 using a wire rod that has been drawn to 0 μm (without heat treatment)
A screen mesh woven into 000 mesh (opening diameter 25 μm) was obtained. (Comparative Example 2) A screen mesh woven into 1000 mesh (opening diameter 25 µm) was obtained using a wire material (without heat treatment) obtained by drawing a SUS316 base material into a wire diameter 20 µm. (Comparative Example 3) A screen mesh woven into 1000 mesh (opening diameter 25 µm) was obtained by using a wire material (without heat treatment) obtained by drawing a SUS630 base material into a wire diameter 20 µm.

The above-mentioned six kinds of 1000-mesh screen meshes were used, with a cylinder diameter of 150 mmφ and L / D = 2.
Used for 2 extruders, low density polyethylene (LDPE) 10 tons (material), LDPE 60Wt% + carbon 4
1 ton (material) of 0 Wt% mixture, LDPE30W
t% + ethylene-vinyl acetate copolymer (EVA) 70W
5 tons of t% mixture (material), LDPE 20Wt%
+ 1% mixture of EVA 45 Wt% + carbon 35 Wt%
Tons (materials) and the like were extruded at an extruder preset temperature of 130 ° C., and then the screen mesh was observed with a microscope to examine the fracture state of the wire constituting the mesh. The results obtained are shown in Table 1.

[0013]

[Table 1]

As is clear from Table 1 above, in the rubber / plastic extruder screen mesh of the present invention, the constituent wire rods of the screen mesh have not been broken in any of the materials 1 to 3. On the other hand, in the rubber / plastic extruder screen mesh of the comparative example, the material, that is, a single material of LDPE, is worn out of the constituent wire of the screen mesh. The constituent wire of the screen mesh was broken.

[0015]

INDUSTRIAL APPLICABILITY The screen mesh for rubber / plastic extruder of the present invention is excellent in strength, corrosion resistance, and abrasion resistance, and therefore can withstand long-term use, and its practical value is extremely large. is there. Further, according to the production method of the present invention, a screen mesh made of a precipitation-hardened stainless steel wire rod that has been precipitation-hardened can be easily manufactured, and its industrial value is extremely large.

Claims (2)

[Claims] 1. A screen mesh for a rubber / plastic extruder, in which a wire material is woven in a mesh shape,
A screen mesh for a rubber / plastic extruder, wherein the wire is a precipitation-hardened stainless steel wire that is precipitation hardened. 2. A rubber / plastic extruder characterized by woven a precipitation hardening stainless steel wire rod before precipitation hardening treatment into a mesh shape, and then subjecting the woven mesh to heat treatment to precipitate and harden the wire material. Screen mesh manufacturing method.