JP3455099B2 - Net paper support member - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic member which abuts and supports a paper making machine in a former part of a paper machine.

[0002]

2. Description of the Related Art As shown in FIG. 2, the structure of a conventional paper machine comprises a former part 1 and a press part 2. And, the former part 1 is a paper making machine 12 rotated by a roll 11 in an arrow direction.
And a plurality of supporting members 10 arranged below the paper making net 12.
The slurry made of pulp raw material 14 is supplied from the head box 13 to the upper part of the paper making net 12 so that the supporting net 10 is supported by the supporting member 10 and the edge 10a thereof is formed.
The slurry was dehydrated.

The supporting member is, for example, as shown in FIG.
A hydrofoil as shown in (A) and a suction box as shown in FIG. 3 (B) are used. The hydrofoil is designed to drain water at the leading edge 10a and to generate negative pressure when the papermaking net 12 slides on the rear slope portion 10b to dehydrate. Further, the suction box is designed to drain water at the edge 10a and perform vacuum suction through the suction hole to perform dehydration.

Next, the dehydrated pulp raw material 14 is sent to the press part 2, and this portion is composed of a felt 22 which is rotated by a roll 21 in the direction of the arrow and a support member 20 which supports the felt 22. There is. Then, the pulp raw material 14 that has been dehydrated to some extent by the former part 1 is pressed against the felt 22 to further absorb moisture, and then sent to the next drying step. The felt 22 that has absorbed water is dehydrated by vacuum suction while sliding on the support member 20.

The support member 20 is called a felt suction box, and has a glossy surface 20a with rounded corners and a suction hole 20b for vacuum suction, as shown in FIG.

The material of the supporting members 10 and 20 of the paper making machine 12 or the felt 22 constituting the paper machine is as follows.
Since plastic materials such as ultra-high molecular weight polyethylene are inexpensive, they have been widely used before. However, the presence of clay or talc in the pulp raw material 14 or the contact sliding with the papermaking machine causes abrasion in a short time. Therefore, the support members 10 and 20 are removed from the paper machine and the surface is polished. Maintenance such as modification or replacement work had to be performed frequently.

Therefore, in recent years, ceramics containing alumina, zirconia, silicon nitride or the like as a main component have been often used as the material of the supporting members 10 and 20. (For example, JP-A-5
5-80591, JP-A-58-208485, etc.). Support member 1 made of these ceramics
Nos. 0 and 20 are widely used because they have great abrasion resistance and have a long life.

On the other hand, such support members 10 and 20 are usually fixed to a support base (box) made of stainless steel or the like with bolts or inserted into a fitting portion provided on the support base to be fixed. The method is adopted. Further, in particular, in the ceramic support member 10 in the former part, it is possible to smoothly run the paper mesh to be contacted and supported without damaging the paper mesh 1.
In order to properly perform the dehydration (water scraping) action from 2, or to prevent cracks or chips from occurring in the edge portion of the support member 10, the design is made with attention to the cross-sectional shape and the outer peripheral shape. In particular, the tip end of the support member 10 that first comes into contact with the papermaking net 12 and contributes to the dewatering operation is formed at an acute angle, and its surface is subjected to careful finishing.

[0009]

However, in recent paper machines, the speed of paper making is greatly increased from the viewpoint of improving productivity, and especially abrasion resistance and heat resistance to the supporting member in the former part are increased. Impact resistance, heat distortion resistance, etc. are required even more. On the other hand, the conventional supporting members made of ceramics such as alumina, zirconia, and silicon nitride have some inferior characteristics, so that this requirement cannot be sufficiently satisfied. In particular, with the trend of increasing the speed of the above-mentioned paper making, it has become a serious problem that the paper making is rapidly worn.

Further, when the support member is made of alumina or silicon nitride, a chip is likely to occur at the tip edge of the supporting member, and this chipping or the like shortens the life of the papermaking machine or causes a dehydration action from the papermaking machine. There is a problem in that the size of the paper becomes smaller and the uniform quality of the papermaking cannot be maintained, leading to deterioration of the paper quality.

[0011]

SUMMARY OF THE INVENTION In view of the above, the present invention can improve the Vickers hardness of the base material drastically, rather than
The means is to coat the leading edge of the paper making support member with the most suitable material.

Specifically, in the present invention, a ceramic material having a relatively large Vickers hardness or a very large Vickers hardness is used as the base material. Specifically, alumina, zirconia, zirconia dispersion strengthened alumina, Si
₃ N ₄ and SiC are used. Then, a coating of a diamond film or a hard carbon film, which has excellent smoothness and wear resistance and is particularly hard to wear a plastic material, is applied to the tip edge of such a base material. The coating also has the function of reinforcing the Vickers hardness of the base material. In addition, by applying this coating to the upper and lower surfaces of the tip edge, the peeling of the coating is less likely to occur.

That is, according to the present invention, alumina, zirconia, zirconia dispersion strengthened alumina, Si ₃ N ₄ , Si
A paper making contact support member having C as a base material and having a curved leading edge, wherein a diamond film or a hard carbon film is coated on the upper and lower two surfaces of the leading edge. A mesh contact support member, and in such a contact member, the radius of curvature R of the tip edge is 0.
The thickness of 1 mm or more is intended to provide a paper making contact support member for a paper machine.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, a general structure of a paper machine in which the net-making support member is used comprises a former part 1 and a press part 2. The former part 1 is composed of a paper making machine 12 which is rotated by a roll 11 in the direction of the arrow and a plurality of paper making machine support members 10 arranged below the paper making machine 12, and the upper part of the paper making machine 12 above. A slurry made of pulp raw material 14 is supplied from the head box 13 to the paper making support member 10 to support the paper making net and the slurry is dewatered at the edge 10a.

Next, the dehydrated pulp raw material 14 is sent to the press part 2, and this part is composed of a felt 22 which is rotated by a roll 21 in the direction of the arrow and a support member 20 which supports the felt 22. There is. Then, the pulp raw material 14 that has been dehydrated to some extent by the former part 1 is pressed against the felt 22 to further absorb moisture, and then sent to the next drying step. The felt 22 that has absorbed water is dehydrated by vacuum suction while sliding on the support member 20.

FIG. 1 shows a mesh support member 10 of this embodiment used in such a paper machine. In FIG. 1, a hydrofoil support member is shown. Also shown).

The net-making support member 10 as a hydrofoil shown in FIG. 1 drains water at the leading edge 10a, and also generates negative pressure when the net 12 slides on the sloped portion 10b at the rear portion for dehydration. It is like this.

Further, the above-mentioned paper making support member 10 is composed of the base material 10
c is alumina, zirconia, zirconia dispersion strengthened alumina, Si ₃ N ₄ , SiC Vickers hardness 1200k
A ceramic material having a relatively large Vickers hardness of g / mm ² or more or a very large Vickers hardness of 1800 kg / mm ² or more is used, and a high hardness material is used for the tip edge 10a of the base material 10c. Since the coating 10d of the diamond film or the hard carbon film is applied, the fracture resistance is reinforced, and the coating 10d of the diamond film or the hard carbon film is very excellent in smoothness and wear resistance, and particularly, a plastic material is used. Hard to wear. Further, by coating 10d of a diamond film or a hard carbon film on both the upper surface 10e and the lower surface 10f of the tip edge 10d,
It is hard to peel off the coating and has great durability. Further, the radius of curvature R of the tip edge 10a is set to 0.1.
When the thickness is not less than mm, the peeling of the coating is less likely to occur. As a result, the occurrence of chipping of the tip edge 10a can be reduced, and the amount of wear of the netting due to chipping can be reduced. Therefore, the net can be protected and the life of the net can be extended.

As described above, in the wire making support member of the present invention, a ceramic material of alumina, zirconia, zirconia dispersion strengthened alumina, Si ₃ N ₄ or SiC is used as the base material 10c, and the Vickers hardness of the coating 1
The base material 10c preferably has a high hardness, if possible.

Therefore, if SiC is used, it is preferable to use the one obtained by liquid phase sintering containing a metal oxide as a sintering aid. Since such SiC has liquid phase sintering, it has stable sinterability, becomes dense, has high hardness, and has a high fracture toughness value (K1C).
The occurrence of chipping a can be reduced. In addition, Si ₃ N
_{As 4} , it is preferable to add a metal oxide such as alumina or yttria and perform liquid phase sintering. Such Si
₃ N ₄ has a large fracture toughness value (K1C) because the crystal has a needle-like shape with an aspect ratio of about 2 to 20, so chipping of the tip edge 10a can be reduced.

Further, in the present invention, the above coating 1
0d is composed of a diamond film or a hard carbon film mainly containing diamond. The diamond film or the hard carbon film mainly containing diamond has a coefficient of thermal expansion of 4.0.
To 4.4 × 10 ⁻⁶ / ° C. (40 to 800 ° C.), Young's modulus of 4.2 × 10 ⁶ Kg / cm ² or more, Vickers hardness of 1
500 ~ 2500kg / mm ² and heat distortion resistance, high rigidity,
It has high hardness and great abrasion resistance, and since it has excellent slidability, it can reduce the abrasion of the mesh made of plastic or the like.

Regarding the method of forming the coating 10d, a plasma CVD method or a filament CVD method can be used for these films. In the plasma CVD method, it is preferable to coat the film by a so-called electron cyclotron resonance plasma CVD method (hereinafter referred to as ECR plasma CVD method) in which a magnetic field is applied to the plasma generation region. According to this ECR plasma CVD method, high-density plasma can be obtained at a low pressure (1 torr or less), so that the plasma can be uniformly generated in a wide area, and it is possible to generate a plasma with a high density. It is possible to uniformly form a film in an area of about 10 times.

When the coating 10d is made of a hard carbon film, the coating thickness is 0.1 to 1.0.
On the other hand, the coating thickness of the diamond film is preferably 1.0 to 10.0 μm. Here, if the coating thickness is too thick, the coating will be easily peeled off and the cost will be increased. On the other hand,
If it is too thin, it will wear out and wear out quickly.

Example 1 In recent years, the speed of the wire of a paper machine has been increased, and the wire has come to be used under more severe sliding conditions. The characteristics of the ceramic constituting the supporting member are slidability and hardness. Is becoming more important. Therefore, in order to check the slidability with respect to the mesh and the amount of abrasion of the mesh, as shown in FIG. 4, a plastic wire 32 is hung on the rotating ceramic roll 35 as the mesh 12, and the weight is applied to the wire 32. Give a load. On the sliding portion between the ceramic roll 35 and the wire 32, a slurry 34 made of an aqueous solution of talc is dropped by a fixed amount. The ceramic roll was rotated in this state, and the wear amount of the plastic wire 32 was measured by the product of the wire contact width and the wear height. As a sample, uncoated alumina ceramic roll, hard carbon (D
LC film coating (coating thickness 0.5μ)
m) and an alumina ceramic roll with a diamond coating (coating thickness 5 μm) were used. The test conditions are: (a) Slurry: 2% talc aqueous solution, 0.7 to 0.75 liters / water (b) Wire: Plastic (c) Weight: 120 g (d) Roll size: φ60 mm (e) Roll speed: 1500 rpm ( F) Experiment period: Six months.

The results are shown in Table 1.

[0027]

[Table 1]

As is clear from Table 1, those provided with the hard carbon film or the diamond film had good slidability with the plastic and the amount of abrasion of the plastic was remarkably small.

Experimental Example 2 Next, the former part 1 of the paper machine as shown in FIG. 2 was actually incorporated with the above-mentioned paper making support member 10 coated with a hard carbon film having a thickness of 0.5 μm for operation. ,
An experiment was conducted on whether or not the coating was peeled off.
The base material 10c of the mesh supporting member 10 includes alumina 3.
SiC added at 7 wt% and 1.8 wt% was used. Also,
As the sample, the coating 10d was applied only to the upper surface 10e of the tip edge d (R0.1 mm), and the coating 1 was applied to both the upper surface 10e and the lower surface 10f of the tip edge d.
0d (R0.05 mm, 0.1 mm, 0.
3 mm) was used. The experimental conditions were as follows: (a) Machine speed: 650 m / min (b) Paper product: Fine paper (c) Net: Plastic (d) Test period: 100 days.

The results of this experiment are shown in Table 2.

[0031]

[Table 2]

As can be seen from Table 2, coating 1
Since 0d has two surfaces and R has a large value of 0.1 mm or more, it has been found that peeling of the coating 10d can be suppressed.

[0033]

As described above, according to the present invention, alumina, zirconia, zirconia dispersion strengthened alumina, Si
₃ N ₄ , SiC having a relatively large Vickers hardness or a very large Vickers hardness is used, and a diamond film or a hard carbon film made of a high hardness material is applied to the tip edge of such a base material. Since it has been applied, the fracture resistance is reinforced, and the coating smoothness and wear resistance of these diamond film or hard carbon film are very excellent, and especially the plastic material is hard to wear. Further, by coating a diamond film or a hard carbon film on the upper and lower surfaces of the tip edge, the peeling of the coating hardly occurs and the durability is very large.

As described above, according to the present invention, in addition to the abrasion resistance and durability of the paper making support member itself of the paper machine, it is also difficult to wear the sliding partner such as plastic. Therefore, it is not necessary to frequently perform the polishing and the replacement work of the member surface, and the excellent effect of being very efficient and economical is achieved.

[Brief description of drawings]

FIG. 1 is a side view of a mesh making support member of the present invention.

FIG. 2 is a schematic configuration diagram showing a general paper machine.

FIG. 3 is a side view showing a hydrofoil which is a kind of a supporting member for a paper machine, showing a conventional net-making supporting member,
(B) is a sectional view showing the suction box.

FIG. 4 is a schematic view showing a sliding test device for a ceramic roll and a plastic wire.

[Explanation of symbols]

10. Wire making support member 10a. Tip edge 10b. Slope 10c. Base material 10d. coating 10e. Top 10f. Bottom 11. roll 12. Netting 13. Head box 14. Pulp material 20. Support member 21. roll 22. felt 31. Ceramic roll 32. Plastic wire 33. weight 34. slurry R. curvature radius

─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-5-214532 (JP, A) JP-A-8-74032 (JP, A) JP-A-8-158051 (JP, A) JP-A-7- 62540 (JP, A) Actual Kaihei 6-76398 (JP, U) US Patent 3496010 (US, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D21F 1/52 C23C 16/26

Claims (2)

(57) [Claims] 1. A alumina, zirconia, zirconia dispersion strengthened alumina, Si 3 N _{4, SiC} and a抄網contact supporting member with a and tip curved leading edge as a base material, the curvature of the leading edge Set radius R to 0.1 mm or more
In addition, a mesh support member for a paper machine having a diamond film or a hard carbon film coated on the upper and lower surfaces of the leading edge . 2. The average film thickness of the diamond film is 0.1 to 10.
1.0 μm or the average thickness of the hard carbon film is 1.0
The mesh support member according to claim 1 , wherein the mesh support member has a thickness of -10.0 μm.