KR101159160B1 - Abrasive disks with an improved durability and productivity and preparation method thereof - Google Patents

Abstract

PURPOSE: An abrasive disc for improving the durability and productivity and a manufacturing method thereof are provided to maintain a grinding force and to improve the dimensional stability and rotational breaking strength. CONSTITUTION: An abrasive disc comprises a water proof paper(1), one or more first mesh woven fabric layers(20), a first abrasive layer(10), and one or more second mesh woven fabric layers(30). The first mesh woven fabric layer is impregnated with first thermosetting resin. The first abrasive layer is coated with a second thermosetting resin and agglomerated. A second abrasive coated with third thermosetting resin is dispersed and applied on.

Description

Abrasive Disc with Improved Durability and Productivity and Manufacturing Method Thereof {ABRASIVE DISKS WITH AN IMPROVED DURABILITY AND PRODUCTIVITY AND PREPARATION METHOD THEREOF}

The present invention relates to a polishing disk and a method for manufacturing the same, which are excellent in durability, productivity, dimensional stability, rotational breakdown strength, impact resistance, rotational balance and economy of products, and can reduce worker fatigue.

General polishing disks with porosity have good polishing power in the form of mesh, but the impact strength and rotational breakdown strength are weak, and the rotational balance is non-uniform, which is likely to cause a safety accident and the replacement cycle is short, resulting in low productivity. Most of these abrasive discs include a common fiberglass fabric layer as a constituent layer, and the cross-sectional structure of the fiberglass fabric layer-containing abrasive disc according to the prior art is shown in FIG.

In the conventional abrasive disc shown in FIG. 2 as a reinforcing material, a glass fiber coated with an abrasive is dispersed by applying an abrasive-containing slurry onto a disc layer of a glass fiber fabric impregnated with a thermosetting resin and then pre-dried. After the fabric layer is obtained, black paper and two glass fiber fabric layers are placed on a curved mold calcined plate, followed by heat pressing.

 However, such a conventional grinding disk has a low impact strength and rotational breakdown strength during the polishing process, which is likely to cause debris by the edge or sharp impact of the polishing surface, causing a safety accident of the operator. In order to solve the above problems, the abrasive disc prepared by dispersion coating the abrasive impregnated with the thermosetting resin on the carbon fiber and the chemical fiber layer (Fig. 3) was developed, but the carbon fiber is expensive (about 5 times higher than glass fiber and chemical fiber). ), There is a problem that serious contamination of the polishing surface is expressed due to the decrease in the heat resistance of the chemical fiber.

Korean Patent No.794297 combines at least one of bonded abrasives and resin-treated abrasives or secondary abrasive coated products with a thermoplastic adhesive on the back of a substrate of general coated abrasives. It is disclosed that the polishing force and the durability can be increased by doing so. However, the abrasive discs produced in this way have a thick layer of grindstones and resin impregnation-abrasives, which reduce the polishing efficiency, make the polishing surface coarse, and reduce the heat-resistant adhesion, thereby causing a safety accident for the operator.

In addition, the porous abrasive disc disclosed in Korean Patent No. 937857 has excellent stability, dimensional stability, rotational breakdown strength and impact resistance, but it is low in economic efficiency because carbon fiber and chemical fiber are expensive, and it is resistant to surface contamination by chemical fiber layer. There is a problem.

[Patent Document 1] Korean Patent No.794297

[Patent Document 2] Korean Patent No. 937857

Accordingly, it is an object of the present invention to provide an abrasive disk having excellent durability and productivity.

Another object of the present invention is to provide a method of manufacturing the above abrasive disk.

The present invention to achieve the above object

1) water proof paper;

2) a first thermosetting resin-impregnated, one or more first mesh woven cloth layers;

3) a first abrasive layer cohesively bonded after the second thermosetting resin-coated; And

4) Provided is an abrasive disc comprising a layered form of at least one second network woven cloth layer, dispersion coated with a third thermosetting resin-coated second abrasive.

In order to achieve the above another object, the present invention includes laminating a moisture proof paper, at least one first mesh woven cloth layer, a first abrasive layer and at least one second mesh woven cloth layer and heat pressing to bond the constituent layers to each other. It provides a method for producing the abrasive disk.

Since the abrasive disk according to the present invention can exhibit a porous form having a network structure as a constituent layer without conventional coated abrasives, it exhibits improved dimensional stability, impact resistance and rotational fracture strength while maintaining polishing force continuously. In addition, it is possible to solve the problem of the operator's skin caused by the dust by using the existing glass fiber ("E" glass component) can maximize the work efficiency.

1 shows a cross-sectional view of an abrasive disc according to one embodiment of the invention,
2 shows a cross-sectional view of a conventional fiberglass fabric layer-containing abrasive disk,
3 shows a cross-sectional view of an abrasive disk made according to the prior art,
4 is a schematic diagram showing various types of abrasives coated with a thermosetting resin,
FIG. 5 is a schematic diagram of a net woven cloth production process in which resin impregnated coating, abrasive spraying and drying processes are continuously performed on a fabric;
6 is a schematic diagram of a curved mold stand and a mold firing plate used to make an abrasive disk according to the present invention;
Figure 7 is a schematic diagram showing the manufacturing process of the abrasive layer of the abrasive disk according to the present invention.

The present invention (1) moisture-proof paper; (2) a first thermosetting resin-impregnated, one or more first mesh woven cloth layers; (3) a second abrasive layer-coated and then cohesively bonded to the first abrasive layer; And (4) laminated at least one layer of at least one second network woven cloth, dispersion-coated with a third thermosetting resin-coated second abrasive.

Since the abrasive disk according to the present invention can exhibit a porous form having a mesh structure by the configuration including a network woven cloth without conventional coated abrasives, improved dimensional stability, impact strength and rotation while maintaining the polishing force continuously In addition to showing the fracture strength, it is possible to solve the problem of workers' skin problems due to the use of conventional glass fiber.

The abrasive disk according to the present invention has a shape of two or more curved surfaces as a whole (that is, two or more inflection points), and from the convex surface of the curved surface, a moisture resistant paper, a first mesh woven cloth layer, a first abrasive layer and a second Network woven cloth layers may be laminated sequentially.

In addition, since the abrasive disk of the present invention includes a curved shape that is bent two or more times, it is possible to perform a combination of point feathering (standing polishing) and planar polishing.

The abrasive disc according to the present invention is characterized in that when it is placed on the bottom, the connection line between the edge of the disc and the center of the inner concave surface forms an angle of 3 to 9 ° with the bottom surface, which provides the convenience of work during polishing. .

The cross-sectional structure of an abrasive disk according to one embodiment of the present invention is shown in FIG. 1 is a moisture-proof paper; 20 is a first thermosetting resin-impregnated first network woven cloth layer; 10 represents the first abrasive layer aggregated after the second thermosetting resin-coated; 30 represents a second network woven cloth layer dispersion coated with a third thermosetting resin-coated second abrasive.

According to the invention, the moisture resistant paper has a weight of 15 to 45 g / m ² and a thickness of 0.2 to 0.8 mm, the absorption rate of less than 1% when left for 24 hours at a relative humidity (RH) 40 to 80% It is preferable to show that, for example, paper impregnated in latex can be used as a moisture proof paper.

According to the present invention, the first mesh woven cloth layer can be formed by impregnating the mesh fabric with the first thermosetting resin. According to one embodiment of the invention, the first thermosetting resin is subjected to a net woven cloth (eg, a glass fiber cloth cloth of “C” glass component) in an amount of 120 to 160 g / m 2 for a predetermined time (eg, 10 To 15 minutes), followed by pre-drying at 80 to 145 ° C. for 2 to 4 minutes to prepare a first mesh woven fabric.

According to the present invention, the first abrasive layer is a mixture of the first abrasive and the second thermosetting resin to obtain a second thermosetting resin-coated first abrasive, and then, an appropriate amount is added to the mold and a smoothing (flattening) process and It may be formed by cohesive bonding in a hot press process (FIG. 7). An active filler may be added when the raw material is mixed.

According to the present invention, the second mesh woven cloth layer is prepared as described above, after the third thermosetting resin-coated second abrasive is prepared by mixing a third thermosetting resin and an optional active filler with the second abrasive. The second abrasive may be formed by dispersion coating the first thermosetting resin-impregnated mesh woven fabric (FIG. 5).

According to one embodiment of the invention, the first thermosetting resin has a net woven fabric (eg, a glass fiber cloth fabric of “C” glass component) in a quantity of 120 to 160 g / m 2 for a predetermined time (eg, 10 to 15 minutes) After impregnation, the first net woven fabric is prepared by predrying at 80 to 145 ° C. for 2 to 4 minutes. Subsequently, the second abrasive prepared by the compound coating of the third thermosetting resin-coated abrasive is spray coated on the first mesh woven cloth, for example, in an amount of 2000 g / m 2, and then for 5 to 10 minutes at 70 to 100 ° C. By predrying, a second net woven fabric can be produced. At this time, the first thermosetting resin-impregnated net woven cloth may be impregnated with the second thermosetting resin prior to dispersion coating the coated second abrasive.

According to the present invention, the first, second and third thermosetting resins are each independently a phenol resin, a polyester resin, an epoxy resin, a urea resin, a melamine resin, a diallyl phthalate prepolymer (DAPP) resin, a modified thermosetting resin and these And a phenol resin, an epoxy resin, a phenol-epoxy modified resin, or a urea-melamine modified resin.

Specifically, the first thermosetting resin may be a phenolic liquid resin (Resole type) having a solid content of 30 to 45% by weight and a viscosity (at 25 ° C) of 300 to 600 cps.

The second thermosetting resin may be a mixture of phenol powder resin (Novolac type) 50 to 90% by weight and phenol liquid resin (Resol type) 10 to 50% by weight, the phenol liquid resin is 60 to 75% by weight It is preferred to have a solids content of% and a viscosity (at 25 ° C.) of 300 to 600 cps.

The active filler is a material added for cooling, increasing the bonding strength of the abrasive, lowering the cost or changing the mechanical properties, or improving the color or surface texture, and in the present invention, calcium carbonate, barium carbonate, cray, iron sulfide, Components selected from the group consisting of cryolite, potassium borohydride (KBF ₄ ), organosilicon, quartz and mixtures thereof can be used, with calcium carbonate, cryolite or potassium borofluoride being preferred. The active filler may be used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the abrasive.

According to the present invention, the tissue of the mesh woven fabric may be leno plain, plain, twill, stain or mock leno, imitation leno. The fragile yarn is a combination of two yarns No. E with one weft yarn, a wide gap, and a useful structure capable of weaving a fabric having a low density of yarn without pushing; Plain weave is the most common tissue, with one warp and weft intersecting one by one, and is characterized by easy defoaming during resin impregnation; Twill weave is a more flexible structure than plain weave because it is dense and has the shape of oblique line using at least three warp and weft yarns; The runners are more flexible than twill weaves by interposing the intersection points of light and weft yarns at regular intervals. There are many kinds of runners, but there are 5 kinds and 8 kinds; A woolen yarn is an organization weaving like a plain weave by gathering the threads of the book and using them as warp and weft.

In addition, the mesh woven fabric is a glass fiber of "C" glass component, a glass fiber and polyester mixed fiber of "E" glass component, polyester fiber, nylon fiber, cotton fiber, hemp fiber and polyester mixed fiber, hemp fiber , Vinylon (polyvinyl alcohol-PVA) fiber, polyvinylidene fiber, chloride fiber, acrylic fiber, aramid fiber, acetate fiber, viscose rayon fiber, silk fiber, wool fiber, basalt fiber and mixtures thereof The glass fibers of the "C" glass component, the glass fibers and the polyester mixed fibers of the "E" glass component, or the hemp fibers and the polyester mixed fibers are preferable.

The glass fiber of the "C" glass component has a high SiO ₂ content and has excellent acid resistance and no skin irritation due to the alkali content. The glass fiber of the "E" glass component is borosilicate glass, which is an alkali-free fiber and a reinforcement. Most often used as glass fiber for plastics.

The woven fabric of the net woven fabric according to the present invention is preferably a plain weave fabric of 8 mesh (8 × 8 (inclined weft) count / inch) to 10 mesh (10 × 10 (inclined weft) count / inch). In this case, it is more preferable to include the structure of 8 mesh and 10 mesh fibers together so that the thin and the thick are mixed. The mesh represents the number of yarns that the warp yarn and the weft yarn occupy in the size of 1 "(tilt) x 1" (weft).

According to the present invention, the abrasive is alumina oxide (Al ₂ O ₃ ), silicon carbide (SiC), silicon carbide, alumina zirconia (AZ), ceramic (gel, sol), garnet, artificial diamond, cubic nitride It may be selected from the group consisting of boron (CBN), flint, flint, emery, crocus, granual, iron emulsion, silica sand, sand, and mixtures thereof, alumina oxide, alumina zirconia Preference is given to using (AZ) or a mixture of alumina oxide (Al ₂ O ₃ ) and alumina zirconia (AZ). The abrasive may have a size of # 12 to # 120, and may be a "P", "F", "JIS" or "CAMI" standard.

In addition, the invention includes fabricating an abrasive disk comprising laminating a moisture proof paper, at least one first mesh woven cloth layer, a first abrasive layer, and at least one second mesh woven cloth layer and thermally compressing the constituent layers to each other. Provide a method.

As a specific example, the second mesh weaving cloth, the first abrasive, the first mesh weaving cloth, and the moistureproof paper are sequentially stacked on the curved mold bent two or more times as shown in FIG. Position the curved mold firing plate bent two or more times as shown, preferably at a pressure of 5 to 15 tons, preferably 5 to 7 tons, and at 80 to 175 ° C., preferably 80 to 160 ° C. The abrasive disc of the present invention can be prepared by heat curing in an oven for 4 to 8 hours at a temperature, preferably 4 to 6 hours, to melt thermosetting resins impregnated in each fiber and abrasive and to bond the constituent layers to each other. . At this time, the size of the moisture-proof paper, the first mesh weaving cloth, the first abrasive and the second mesh weaving cloth may be processed in the form of 1 inch to 16 inches.

The mold firing plate used in the present invention necessarily has an inflection point that is bent twice at the same angle as the mold stand (FIG. 6).

The durable and productivity-enhanced abrasive disc of the present invention manufactured as described above has excellent dimensional stability, impact resistance and rotational breaking strength to protect the worker from the risk of safety accidents, increase the efficiency with strong durability and reduce the worker fatigue, especially in shipyards and heavy industries. It can be used very well for many extreme working environments in the field.

[Example]

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

Example 1

A sheet of moisture-proof paper having a weight of 45 g / m 2 and a thickness of 0.8 mm (for PFLEIDERER M16-Tissue Paper: grinding wheel) was cut into discs having an outer diameter of 178 mm and an inner diameter of 23 mm; Phenolic resin (Resol type) impregnated with KR-745FRD (Kolong Emulsified Product) in an amount of 145.0 ± 1.0 g / m2, and then pre-dried, 8 mesh “C” glass component glass fiber plain weave tissue (8 × 8 Two weave woven fabrics ("first mesh woven fabric") having a weft) count / inch structure) were cut into sizes of an outer diameter of 178 mm and an inner diameter of 23 mm to form a disc.

Next, 100 g of "F" standard alumina oxide mixed with # 20, # 24 and # 30 particles in a weight ratio of 20:20:60, 20.0 g of phenol powder resin (Novolac) KC-1364K (manufactured by Gangnam Chemical) and phenolic resin (Resol type) 9.0 g of TD-2207 (solid content 70%, Gangnam Chemical) and 5.0 g of cryolite as active filler were mixed and stirred to prepare a phenol resin-coated abrasive.

A phenolic resin-impregnated mesh woven cloth ("first mesh woven cloth") in the form of a disk prepared above was made using a glass fiber production (MC-make coating) process of "C" glass component as shown in FIG. ) Impregnated and coated phenolic resol resin TD-2207 (solid content 70%, Gangnam Chemical) in an amount of 5.0 g / 7 inch by using an MC coater in one sheet, and then 25 g of the abrasive was coated on both sides thereof. Gravity-coated in an amount of 50.0 g / 7 inches and pre-dried through a dryer to obtain a dispersion-coated mesh woven cloth (“second mesh woven fabric”).

In addition, 15.0 g of phenolic powder resin (Novolac) KC-3380 (manufactured by Gangnam Chemical, PVB modified) and 100% of phenolic alumina of "F" standard mixed # 60 and # 80 particles in a weight ratio of 50:50 Type) 40 g to 41 g of phenol resin-coated abrasive prepared by adding 6.0 g of TD-2207 (solid content 70%, Kangnam Chemical) and adding 5.0 g of calcium carbonate as the active filler to 178 mm The mold was poured into a mold to form an abrasive layer ("first abrasive layer") cohesively bonded in a flattening process and a hot press (60 ton) process.

One layer of the second web weave cloth, the first abrasive layer, sequentially on a mold stand (an angle of 6 ° as the angle between the disc edge and the center of the inner concave surface when the disk is placed on the floor) with the bottom surface. After laminating one layer of the first fabric weave cloth and one sheet of moisture-proof paper, placing a mold firing plate therebetween and applying a pressure of 5 tons, the laminate was sequentially placed at an electric oven from 80 ° C to 165 ° C. Abrasive discs were prepared by placing and curing under heat for 7 hours. At this time, the mold baking plate used had the round shape of the same angle (6 degrees) as the mold stand (FIG. 6). The prepared abrasive disc cross section is shown in FIG.

Example 2

A polishing disk was prepared in the same manner as in Example 1, except that 9 mesh (9 × 9 (incline × weft) count / inch) structure was used as the first mesh woven fabric.

Example 3

A polishing disk was prepared in the same manner as in Example 1, except that 10 mesh (10 × 10 (tilt × weft) count / inch) structure was used as the first mesh woven fabric.

Example 4

10 mesh (10x10 (inclined x weft) count / inch) structure as the first network weave fabric, using the one having 9 mesh (9x9 (incline x weft) count / inch) texture as the second mesh woven fabric. A polishing disc was prepared in the same manner as in Example 1, except that there was used.

Example 5

10 mesh (10 × 10 (tilt × weft) count / inch) structure as the first network weave cloth, using a 10 mesh (10 × 10 (tilt × weft) count / inch) structure as the second network woven fabric A polishing disc was prepared in the same manner as in Example 1, except that there was used.

Comparative Example 1

One moisture-proof paper having a weight of 45 g / m 2 and a thickness of 0.8 mm was cut into a disc shape having an outer diameter of 178 mm and an inner diameter of 23 mm; Phenolic Resin KR-745 FRD "E" glass fiberglass fabric No.385 with 8 mesh (8x8 (inclined x weft) count / inch) texture after impregnation in 145 ± 1.0g / ㎡ Each of two pieces (manufactured by Faiba Korea Co., Ltd.) was cut into discs having an outer diameter of 178 mm and an inner diameter of 23 mm.

Next, 100 g of "F" standard alumina mixed with # 24 and # 30 particles in a weight ratio of 30:70, phenol powder resin (Novolak) 1364K (manufactured by Gangnam Chemical) and phenol liquid resin (Resol) TD-2207 ( 70% solids content, Kangnam Chemicals) 9.0% were mixed and stirred to prepare a phenolic resin-coated abrasive.

After impregnating and coating the phenolic resin KR-745FRD (KOLON Emulsified Product) in an amount of 4.0 g / 7 inches with a coater on one sheet of the phenolic resin-impregnated glass fiber fabric prepared above, the abrasive was coated on both sides thereof. Each was coated on both sides in a total amount of 60 g / 7 inches by 30.0 g and naturally dried to obtain a fiberglass fabric dispersion-coated with an abrasive.

One glass fiber cloth coated with the abrasive in a mold stand (an angle of 6 ° as the connecting line between the disk edge and the inner concave center when the disk is placed on the floor) and the bottom surface, resin- After laminating one impregnated glass fiber fabric and one moisture-proof paper, placing a molded plastic plate thereon and applying a pressure of 10 tons, the laminate was placed in an electric oven at 160 ± 5 ° C. and heat-cured for 6 hours. An abrasive disk was made. At this time, the used mold baking plate had a round inclination of the same angle (6 degrees) as the mold stand (FIG. 6). The structure of the prepared abrasive disk cross section is shown in FIG.

Experimental Example : Property Test

For each of the abrasive discs manufactured in Examples 1 to 5 and Comparative Example 1, impact strength, rotational fracture strength, dimensional stability, polishing surface state, service time (life), operator skin irritation and work fatigue were measured. The results are shown in Table 1 below.

As can be seen from Table 1, the abrasive discs prepared in Examples 1 to 5 have impact resistance, rotational breakdown strength, dimensional stability (balance), polishing surface state, use time (life time), disc replacement frequency, worker skin irritation In terms of occurrence and work fatigue, the performance of the side is very excellent, while in Comparative Example 1, not only the impact strength is weak, but also skin irritation occurs, and a significant performance decrease is confirmed in the comparison of the same items.

Claims (18)

(1) water proof paper;
(2) a first thermosetting resin-impregnated, one or more first mesh woven cloth layers;
(3) a second abrasive layer-coated and then cohesively bonded to the first abrasive layer; And
(4) An abrasive disk comprising a layered form of at least one second network woven cloth layer, dispersion coated with a third thermosetting resin-coated second abrasive. The method of claim 1,
The abrasive disc has a curved shape of two or more curved surfaces as a whole, and from the convex surface of the curved surface, a moisture proof paper, a first network weave cloth layer, a first abrasive layer and a second network weave cloth layer are sequentially stacked. , Grinding disc. The method of claim 1,
And the connecting line between the edge of the disk and the center of the inner concave surface when the polishing disk is placed on the floor forms an angle of 3 to 9 degrees with the bottom surface. The method of claim 1,
After the first abrasive layer is mixed with the first abrasive and the second thermosetting resin to obtain a second thermosetting resin-coated first abrasive, the first abrasive layer is put into a mold and coagulated by a flattening process and a hot press process. The abrasive disc, characterized in that formed by. The method of claim 1,
After the second mesh woven cloth layer has mixed the second abrasive and the third thermosetting resin to produce a third thermosetting resin-coated second abrasive, the second abrasive is first thermoset resin-impregnated mesh woven cloth. An abrasive disc, characterized in that formed by dispersion coating on. The method of claim 5,
And prior to dispersion coating the coated second abrasive material, the first thermosetting resin-impregnated mesh woven cloth is impregnated with a second thermosetting resin. The method of claim 1,
The first, second and third thermosetting resins each independently consist of a phenol resin, a polyester resin, an epoxy resin, a urea resin, a melamine resin, a diallyl phthalate prepolymer (DAPP) resin, a modified thermosetting resin, and a mixture thereof. An abrasive disk, characterized in that it is selected from the group. The method of claim 7, wherein
Wherein the first thermosetting resin is a phenolic liquid resin having a solid content of 30 to 45% by weight and a viscosity (at 25 ° C.) of 300 to 600 cps. The method of claim 7, wherein
And said second thermosetting resin is a mixture of 50 to 90% by weight of phenolic powder resin and 10 to 50% by weight of phenolic liquid resin. The method according to claim 4 or 5,
The abrasive disc, characterized in that further adding an active filler (mixing) of the abrasive and the thermosetting resin. The method of claim 10,
And said active filler is selected from the group consisting of calcium carbonate, barium carbonate, cray, iron sulfide, cryolite, potassium borohydride (KBF ₄ ) organosilicon, quartz and mixtures thereof. The method of claim 1,
The first and second mesh woven fabrics each independently have a structure of leno plain, plain, twill, stain or mock leno, imitation leno. Polishing disk. The method of claim 1,
Wherein the first and second mesh woven fabrics each independently have 8 mesh (8 × 8 (inclined x weft) count / inch) to 10 mesh (10 × 10 (inclined x weft) count / inch) texture. , Abrasive discs. The method of claim 1,
The first and second mesh woven fabrics are each independently glass fiber of "C" glass component, glass fiber and polyester mixed fiber of "E" glass component, polyester fiber, nylon fiber, cotton fiber, hemp fiber and polyester Mixed fibers, hemp fibers, vinylon (polyvinyl alcohol-PVA) fibers, polyvinylidene fibers, chloride fibers, acrylic fibers, aramid fibers, acetate fibers, viscose rayon fibers, silk fibers, wool fibers, basalt fibers and mixtures thereof An abrasive disk, characterized in that selected from the group consisting of. The method of claim 1,
The first and second abrasives are each independently alumina oxide (Al ₂ O ₃ ), silicon carbide (SiC), silicon carbide, alumina zirconia (AZ), ceramic (gel, sol), garnet (garnet), artificial diamond, Cubic boron nitride (CBN), flint, fluff (emery), crocus, granular (granual), iron emulsion, silica sand, sand and mixtures thereof, characterized in that Abrasive discs. The method of claim 1,
And wherein the moisture resistant paper has a weight of 15 to 45 g / m ² and a thickness of 0.2 to 0.8 mm, and exhibits an absorption of 1% or less when left at a relative humidity of 40 to 80% for 24 hours. The method of claim 1, comprising laminating a moisture proof paper, at least one first mesh woven cloth layer, a first abrasive layer and at least one second mesh woven cloth layer and bonding the component layers to each other by thermal compression. 18. The method of claim 17,
The heat compression is applied to the pressure of 5 to 15 tons (ton) and then heat cured at a temperature of 80 to 175 ℃ for 4 to 8 hours, characterized in that the manufacturing method of the abrasive disk.

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