JPH06136680A - Campus stretch roll for paper machine - Google Patents

Abstract

PURPOSE:To provide a campus stretch roll prevented in attachment of a resin, etc., excellent in durability and having long life. CONSTITUTION:The surface of a metallic roll body 25 is covered 27 with low- hardness rubber material having heat resistance and abrasion resistance, and where a spiral groove 29 formed in reverse direction in the center part of the roll body and having nearly V-shaped cross section enlarged from the bottom toward the opening is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a canvas stretch roll for a paper machine used in a drying section during a paper making process.

[0002]

2. Description of the Related Art Conventionally, in a papermaking process, a paper making machine is provided with a plow mesh part for forming a paper layer from a paper raw material obtained by fibrating pulp, a compression part for compressing and dehydrating the paper layer, and a drying part for drying the paper layer. is made of. Generally, the drying unit is composed of a plurality of dryers arranged vertically, a dryer canvas for pressing a paper layer against the dryer, a canvas roll for transferring the dryer canvas, and a canvas stretch roll for adjusting the tension of the dryer canvas. ing.

FIG. 3 is a front view for explaining a part of the drying section. First, the drying section is composed of a large number of dryers arranged in two stages, an upper stage dryer 1 and a lower stage dryer 3.
And are arranged with a half pitch offset. Canvas rolls are provided in the upper and lower dryers 1 and 3, respectively. The canvas roll includes canvas rolls 5 and 7 provided between the dryers and canvas rolls 9 and 10 provided above or below the dryer. Further, canvas stretch rolls 11 and 13 are provided at appropriate positions on each of the canvas rolls 9 and 10 in order to adjust the tension of the dryer canvas. And in the arrangement configuration of these rolls,
The paper layers are pressed against the dryers 1 and 3, and dryer canvases 15 and 17 which are woven belts are wound.

That is, the dryer canvas 15 is placed between the dryer 1 and the canvas roll 5 in the dryer 1.
Are alternately wound in a zigzag manner so as to press the upper surface side (outer side), and the canvas roll 9 is wound in contact with an arbitrary surface. Then, the tension of the canvas 15 is adjusted by changing the position of the canvas stretch roll 11. The paper layer 19 to be dried is alternately wound between the dryers 1 and 3 as shown by a dotted line,
It is transferred while being pressed by the canvases 15 and 17, and is sequentially dried. The ambient temperature of the drying section composed of these rolls and canvas reaches about 90 ° C, and the temperature of the dryer reaches about 120 ° C. The dryer, the canvas roll and the canvas stretch roll are all metal rolls.

[0005]

Various wood pulps are used as a raw material for paper, and the pulp contains a resin (pitch tars). Particularly, the low-grade pulp used for newsprint contains a relatively large amount of resin. In addition, when a cardboard box or the like is used as a waste paper, in addition to the resin originally impregnated in the paper, an adhesive tape adhesive or the like is included. These resins and pressure sensitive adhesives adhere to the dryer canvases 15 and 17 because the resin or the like melts because they become hot when they pass through the dryers 1 and 3 in the drying section in the paper manufacturing process.

The resin or the like adhered to the dryer canvases 15 and 17 becomes a high temperature of about 100 ° C. during the transfer of the dryer canvases 15 and 17, and therefore is adhered to the canvas rolls 9 and 10 and the canvas stretch rolls 11 and 13. . Particularly, since the pressing surfaces of the dryer canvases 15 and 17 against the dryers 1 and 3 are wound around the canvas stretch rolls 11 and 13, the resin and the like attached to the dryer canvases are scattered on the canvas stretch rolls 11 and 13 in a scattered manner. Become stacked. Then, the lumps of these resins and the like finally fall off and adhere to the paper layer through the dryer canvas. When a lump of resin or the like adheres to the paper layer 19, it causes a break of the paper layer and troubles of the apparatus.

Therefore, the canvas stretch roll 1
In order to prevent the resin etc. stuck to 1 and 13 from falling off,
The roll surface must be cleaned frequently. Cleaning the roll surface is not only labor intensive, it also reduces productivity. On the other hand, in order to prevent the resin or the like from sticking to the canvas stretch rolls 11 and 13, a Teflon tape is wound around the metal roll surface,
Coating with a high hardness rubber material is performed. Figure 4
FIG. 7 is a front view of a conventional canvas stretch roll wrapped with Teflon tape. Since the Teflon tape 20 is heat resistant, it is possible to prevent adhesion of resin or the like to some extent, but there is a problem that resin or the like is adhered to the stepped portion of the seam 21.

Further, as the high hardness rubber material, a mixture of ebonite with a releasing powder such as fluorine powder, silicone oil, and high molecular weight polyethylene powder is used, and a canvas stretch roll is formed by coating a metal roll. To be done. Canvas stretch rolls coated with these high hardness rubber materials are less likely to be adhered with a resin or the like as compared with metal rolls, but once the adhesion is started, the progress of the solidification is further accelerated. Further, since static electricity is generated, there is a problem that cracks occur in the coating layer.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a canvas stretch roll which prevents sticking of a resin or the like and has excellent durability and a long life.

[0010]

Therefore, according to the present invention, the surface of the metal roll body is covered with a low hardness rubber material having heat resistance and wear resistance, and the direction is reversed at the central portion of the roll body, and the bottom portion is From the above, a spiral groove having a substantially V-shaped cross section which is enlarged toward the opening is formed. It is desirable to mix fluorine powder, silicone oil, high-molecular polyethylene, or the like, which has a peeling property, as an adhesion preventive agent in the rubber material. The spiral groove has a pitch of 5 to 8 mm,
It is desirable that the groove width of the opening is 2 to 5 mm and the groove depth is 2 to 4 mm.

[0011]

Since the hardness of the coated rubber material is low, the surface is displaced by the tension of the dryer canvas,
Prevents adhesion of resin and the like, and also works to peel off the adhered resin and the like. The spiral groove increases the action of the tension of the dryer canvas, and the spiral groove serves to prevent the mass of resin or the like from spreading in the lateral direction.

[0012]

EXAMPLES The present invention will be described in detail below based on examples. In the canvas stretch roll according to the present invention, a coating layer 27 coated with a low-hardness rubber material is provided on the surface of a conventional metallic roll body 25, and the surface of the coating layer 27 has opposite directions at the central portion of the roll body. Cross section V
A spiral groove 29 having a character shape is formed. Roll body 2
5 may be a conventionally used pipe-shaped roll core. A feature of the present invention resides in that the coating layer is formed of a low hardness rubber material and a spiral groove having a substantially V-shaped cross section which is enlarged from the bottom toward the opening is formed.

As the low hardness rubber material, EPDM, CSM, H-NBR or the like having heat resistance and wear resistance is used, and fluorine powder, silicone oil or high molecular polyethylene having peelability is used as an adhesion preventive agent. -30% by weight, preferably 15-20% by weight. The rubber hardness is 50 to 85 degrees, preferably 60 to 70 degrees. The method of forming the coating layer 27 made of the low hardness rubber material is not particularly limited, and may be formed by a conventionally known method. Contrary to the conventional case, the coating layer 27 is formed of a low hardness rubber material, so that the coating layer 27 is displaced by the tension of the dryer canvas, which makes it difficult to attach the resin or the like.

In the present invention, the coating layer 27 has a cross section of approximately V.
A V-shaped spiral groove 29 is formed. The spiral grooves 29 are opposite in direction at the central portion of the roll, and one spiral groove 29 is distributed at the central portion. The groove depth F ₁ at the center of the spiral groove 29 is 1.0 mm, and the groove width W _{1 at the} opening is 1.2 mm. Further, the groove depth F ₂ is 3 mm and the groove width W ₂ of the opening is 3.5 mm from the first round onward.
It is said that. The pitch P of the spiral groove 29 is 6.5.
The groove depth and the groove width are gradually increased from the distributed portion of the central portion to the first round. Here, the groove having a substantially V-shaped cross section is not limited to the shape shown in the drawing, and it is sufficient that the opening is larger than the bottom. Therefore, a U-shaped groove having curved bottoms and side surfaces,
Alternatively, an inverted trapezoidal shape is also included.

Due to the small surface area of the spiral groove 29, it is difficult for resin or the like to adhere, and lateral spread of the block is prevented by the groove. Further, the coating layer 27 is formed of a low hardness rubber material so as to be easily displaced, and further, the displacement is further increased due to the formation of the spiral groove 29 to prevent sticking of resin or the like. Further, since the spiral groove 29 is formed so that the direction thereof is reversed at the central portion of the roll, the spiral groove 29 acts so as to push the adhered material such as resin to both ends of the roll.

[0016]

As described above in detail, in the canvas stretch roll of the present invention, contrary to the conventional case, the coating layer is formed of the low hardness rubber material and the spiral groove having the opposite direction is formed in the central portion of the roller. Therefore, it prevents the sticking of the resin or the like adhering to the dryer canvas and prevents the spread of the stuck mass. Therefore, not only a durable canvas stretch roll having a long life can be obtained, but also the quality and productivity of paper can be improved.

[Brief description of drawings]

FIG. 1 is a front view of a canvas stretch roll according to an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing the shape of a spiral groove.

FIG. 3 is an explanatory front view showing a part of a drying unit in a paper manufacturing process.

FIG. 4 is a front view showing an example of a conventional canvas stretch roll.

[Explanation of symbols]

 25 roll body 27 coating layer 29 spiral groove

Claims (2)

[Claims] 1. A cross-section of a metal roll body whose surface is covered with a low-hardness rubber material having heat resistance and wear resistance, the directions of which are reversed at the central portion of the roll body, and which is enlarged from the bottom toward the opening. A canvas stretch roll for a paper machine, which is characterized by forming a V-shaped spiral groove. 2. The low hardness rubber material is mixed with a peelable fluorine powder, silicone oil or high molecular weight polyethylene as an anti-sticking agent, and the spiral groove pitch is 5 to 8 mm and the opening groove width is 2-5 mm, groove depth 2
The canvas stretch roll for a paper machine according to claim 1, wherein the stretch roll is 4 mm.