JPH0572998U - Doctor blade for papermaking roll - Google Patents

Abstract

(57) [Summary] [Structure] As a material of the doctor blade 2 for a papermaking roll 1 having a thermal spray coating formed on the surface thereof, resin materials such as epoxy resin, polyethylene resin, Teflon resin, and phenol resin are mainly used. A composite resin molded plate formed by mixing fibers or particles such as glass fibers, carbon fibers, and carbon particles, and molding is used. [Effect] The composite resin molded plate has extremely excellent wear resistance to the thermal spray coating due to the fibers and particles mixed in the resin material acting as a lubricant and a reinforcing material, and therefore, it can be used as a doctor blade made of stainless steel. Compared with this, it has a much longer life and the frequency of replacement can be greatly reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is provided in various papermaking rolls such as press rolls, dryer rolls, paper rolls, size press rolls and coater rolls in a paper machine, and removes deposits such as paper dust adhering to the roll surface. About Doctor Blade to do.

[0002]

[Prior Art]

 As is well known, a so-called stone roll made of natural granite is widely used as the above roll in a paper machine because it is necessary to ensure good paper separation from the roll of wet paper. Then, the deposits such as paper dust attached to the roll surface are removed by keeping the tip of the doctor blade in contact with the roll surface. In this case, as the material of the doctor blade, a stainless plate (SUS440A etc.) is generally used in consideration of corrosion resistance and wear resistance.

[0003]

[Problems to be solved by the device]

 By the way, in recent years, due to the fact that high-quality natural granite is being depleted, the development of so-called thermal spray rolls, which have a thermal spray coating of ceramics such as alumina or cermet on the surface, has been promoted as an alternative to ston rolls. ing.

Such a thermal spraying roll has a surface particle hardness of about 2500 Hv and a coating hardness of about 1000 Hv, and quartz (hardness of about 1000 Hv), feldspar (about 700 Hv) and mica (about 100 Hv). The hardness is remarkably higher than that of natural granite, which is an aggregate of coarse crystals. Therefore, if a conventional stainless steel plate (which has a hardness of only 450 Hv or so) is used as it is as a doctor blade provided to remove such deposits on the surface of the thermal spray roll, the doctor blade will be There is a risk that the doctor blade will need to be replaced frequently, resulting in a drop in production efficiency.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an effective doctor blade that can have a long life even when applied to a thermal spray roll for papermaking on which a high-hardness thermal spray coating is formed. Has a purpose.

[0006]

[Means for Solving the Problems]

 The present invention is formed by mixing fibers or particles into a resin material as a material for a doctor blade that is pressed against the surface of a papermaking roll on which a thermal spray coating is formed to remove deposits on the surface. It is characterized by using a composite resin molded plate.

[0007]

[Action]

 By using a composite resin molded plate made by mixing fibers or particles into the resin material, the doctor blade of the present invention is excellent not only in corrosion resistance but also in abrasion resistance against the sprayed coating. It is a thing. That is, in the composite resin molded plate, the friction resistance value of the resin material itself, which is the main component, with respect to the thermal spray coating is smaller than that of metal materials such as stainless steel, and in addition, the mixed fibers and particles are lubricated. Since it acts as a material, the frictional resistance is further reduced, and in the case of fibers mixed, it also acts as a reinforcing material and suppresses the generation of minute cracks. And exhibits excellent wear resistance.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, reference numeral 1 is a papermaking roll, and 2 is a doctor blade for removing deposits on its surface. The roll 1 is a so-called thermal spray roll having a high-hardness thermal spray coating made of ceramics or cermet on its surface. The doctor blade 2 has its base end attached to the mount 4 via the holder 3 with its tip pressed against the surface of the roll 1, and the surface of the doctor blade 2 is rotated by the rotation of the roll 1. Adhesive matter such as paper dust that has adhered to the surface of the doctor blade 2 is scraped off and removed by the tip of the doctor blade 2. The front end portion of the doctor blade 2 is processed into a shape in which the front surface side is obliquely cut off, for example, at about 45 ° so that the adhered matter on the surface of the roll 1 can be easily peeled off.

The holder 3 is composed of a mounting plate 5 and a fixed plate 7 connected to the mounting plate 5 by rivets 6, and the mounting plate 5 and the fixed plate 7 form a doctor blade. The doctor blade 2 is supported with the base end of 2 being sandwiched from the front and back. Reference numeral 8 is a retaining pin attached to both sides in the width direction of the doctor blade 2 in order to prevent the doctor blade 2 from falling off the holder 3. The mounting plate 5 of the holder 3 is attached to the mounting base 4 by means of machine screws 9 that are screwed into the mounting base 4. The machine screws 9 loosely insert the base of the mounting plate 5 and A hexagon socket set screw 10 is attached to the most proximal end of the plate 5. Then, by adjusting the screwing amount of the set screw 10 into the mounting plate 5, the mounting plate 5 is rotated at the tip side with the position of the small screw 9 as a fulcrum, whereby the tip of the doctor blade 2 is rotated. The pressing force on the roll 1 can be adjusted.

As a material for the doctor blade 2, a composite resin molded plate formed by mainly molding various resin materials with various fibers and particles mixed therein is used instead of the conventional general stainless steel plate. Has been. As the above resin material, for example, epoxy resin, polyethylene resin, Teflon resin, phenol resin, etc. can be adopted, and as the above fibers and particles, for example, glass fiber, carbon fiber, carbon particles, etc. are adopted. It is possible. Various combinations of these resin materials with fibers and particles are conceivable, and typical composite resin molding plates include, for example, epoxy resin mixed with glass fiber, epoxy resin mixed with carbon fiber, A polyethylene resin mixed with carbon particles, a Teflon resin mixed with glass fiber, or the like can be used.

As described above, it goes without saying that the composite resin molded plate in which the resin material is mixed with fibers or particles is superior in corrosion resistance to the stainless steel plate which is a material of conventional doctor blades. The wear resistance to a high hardness sprayed coating is remarkably excellent. This is because the friction resistance value of the resin material itself against the thermal spray coating is smaller than that of metal materials such as stainless steel, and in addition, the fibers and particles mixed in the resin material act as a lubricant, so that the friction resistance is This is because the amount is further reduced, and in the case where the fiber is mixed, it also acts as a reinforcing material and suppresses the generation of minute cracks. Therefore, when the doctor blade 2 formed of such a composite resin molded plate is applied to the roll 1 having the sprayed coating, the life can be remarkably extended as compared with the case of using a conventional doctor blade made of a stainless steel plate, and the replacement thereof can be performed. The frequency can be greatly reduced.

“Experimental Example” In order to verify the effectiveness of the doctor blade of the present invention, the following experiment was conducted.

(Experimental conditions) After preparing doctor blades (Sample 1 to Sample 5) made of the following five types of materials including conventional products made of stainless steel plate, after using them under the same conditions for 100 hours respectively, The wear amount (volume) of each was measured. As a roll for experiment, a roll having a diameter of 140 mm and a body length of 90 mm was used, and the rotation peripheral speed thereof was 110 m / min. The surface of the roll was sprayed with gray alumina (alumina mixed with about 2% by weight of titania) and then subjected to polishing finish to form a sprayed coating. The dimensions of each of the samples 1 to 5 were 1.5 mm in thickness, 85 mm in width and 85 mm in length, and the pressing force per unit length against the roll was 160 g / cm. Sample 1 Stainless steel plate (conventional product) Sample 2 Composite resin molding plate in which glass fiber is mixed in epoxy resin Sample 3 Composite resin molding plate in which carbon fiber is mixed in epoxy resin Sample 4 Composite resin molding plate in which carbon particles are mixed in polyethylene resin Specimen 5 Composite resin molded plate with glass fiber mixed in Teflon resin

(Experimental Results) When the wear amount of the conventional sample 1 is 1.000, the specific wear amounts of the samples 2 to 5 are 0.046, 0.040, 0.029, and 0.006, respectively. In other words, the amount of wear after 100 hours of use is 1/20 or less for sample 2 and 1/100 or less for sample 5 compared to the conventional product made of a stainless steel plate, and both have a significantly long life. It was confirmed that

[0015]

[Effect of the device]

 As described above, according to the present invention, the composite resin molding plate formed by mixing fibers or particles into the resin material is used as the material for the doctor blade for the papermaking roll on which the thermal spray coating is formed. In addition to being excellent in corrosion resistance, the mixed fibers and particles act as a lubricant and a reinforcing material, resulting in extremely excellent wear resistance to the sprayed coating. Compared with the case of using a doctor blade made of stainless steel, it has a much longer life, and as a result, it is possible to significantly reduce the frequency of replacement and contribute to the improvement of production efficiency.

[Brief description of drawings]

FIG. 1 is a diagram showing a usage example of a doctor blade according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a tip portion of the doctor blade.

[Explanation of symbols]

 1 roll (paper making roll) 2 doctor blade 3 holder 4 mounting base

Claims (1)

[Scope of utility model registration request] 1. A doctor blade for removing deposits on the surface of a papermaking roll by pressing the sprayed coating of ceramics or cermet on the surface of the papermaking roll. A doctor blade for a papermaking roll, which is a composite resin molding plate formed by mixing fibers or particles into a resin material and molding.