KR20070020359A - Abrasive disks and preparation thereof - Google Patents

Abstract

The present invention relates to a polishing disk and a method for manufacturing the same, nonwoven fabric; One or more glass fiber paper layers formed by mixing resin-impregnated glass fibers with wood fibers; And the abrasive disc of the present invention, which in turn includes abrasive cloth, has excellent flexibility, elasticity, dimensional stability and rotational fracture strength, is light in weight, convenient to use, and inexpensive.

Description

Abrasive disk and its manufacturing method {ABRASIVE DISKS AND PREPARATION THEREOF}

1 and 2 are cross-sectional views of a conventional abrasive disc,

3 is a cross-sectional view of a glass fiber paper layer-containing abrasive disk according to the present invention;

4 is a schematic of a coater used to impregnate a substrate with a resin,

5 is a schematic view of a steel holder used to make an abrasive disk according to the present invention.

The present invention relates to a glass fiber paper layer-containing abrasive disk and a method for producing the same, which are economical because of their excellent flexibility, dimensional stability and rotational fracture strength and inexpensive price.

Conventional abrasive discs based on vulcanized fiber plates, as shown in FIG. 1, apply an adhesive resin on the vulcanized fiber plate substrate to form a primary adhesive layer, spray the abrasive thereon and pre-dry it. After making it, it is manufactured by apply | coating an adhesive resin on it, drying, and forming a secondary adhesive layer.

At this time, since the moisture contained in the vulcanized fiber is released by the heat of the drying process, the size of the abrasive disc may be deformed or the abrasive disc may be easily broken even by a small impact, thereby providing moisture to the abrasive disc to improve dimensional stability and impact resistance. There was a problem that the humidification process and the aging process must be performed.

Accordingly, as a method of manufacturing an abrasive disc without a humidification process, Korean Patent No. 10-046922 discloses a back pad made of a nonwoven fabric and a fabric layer (carbon fiber fabric layer, glass fiber fabric layer, or a laminate thereof). After applying the adhesive, there is disclosed a technique for bonding and heat-pressing a back sheet of coated abrasive, wherein the backing sheet consists of a back sheet and an abrasive layer comprising an abrasive. One embodiment of the abrasive disc produced by the is shown in FIG.

However, the abrasive disc produced by this method has the problems of excellent dimensional stability and rotational fracture strength, but low flexibility and high price.

Accordingly, it is an object of the present invention to provide an economical abrasive disc, and a method of manufacturing the same, which are excellent in flexibility, dimensional stability and rotational fracture strength and are inexpensive.

In the present invention to achieve the above object,

(1) nonwovens;

(2) one or more glass fiber paper layers formed by mixing resin-impregnated glass fibers with wood fibers; And

(3) an abrasive paper comprising a back sheet bonded to the glass fiber paper layer and an abrasive layer containing an abrasive

To provide an abrasive disc, which in turn comprises.

Hereinafter, the present invention will be described in more detail.

The abrasive disc according to the present invention is characterized in that it has a structure in which a nonwoven fabric, a resin-impregnated glass fiber paper (a mixture of glass fibers and wood fibers) layers, and abrasive cloth are sequentially stacked. The cross-sectional structure of the abrasive disc according to the present invention is as shown in FIG.

The nonwoven fabric used in the present invention is suitably having a weight of 20 to 30 g / m ² and a thickness of 0.1 to 0.3 mm, and may have a flat form or an embossed form.

Glass fiber paper used in the present invention is formed by mixing 70 to 90% by weight, preferably 70 to 80% by weight of glass fibers and 10 to 30% by weight, preferably 20 to 30% by weight of wood fibers. Before use, the adhesive resin is impregnated for a certain time and then dried at, for example, 80 to 100 ° C. for 1 to 3 minutes.

Prior to the impregnation of the resin, the fiberglass paper may have a weight of 45 to 80 g / m ² and a thickness of 0.25 to 0.65 mm, suitable in flat form. Glass fiber paper can be obtained by applying the glass fiber fragment which cut | disconnected 5-20 micrometers thick glass fiber to 5-10 mm, and powdery wood fiber to a conventional papermaking process.

As the adhesive resin impregnating the glass fiber paper, phenol resin, epoxy resin, urea melamine resin, polyester resin, polyvinyl butyral, acrylonitrile-butadiene-rubber, modified thermosetting resin, and mixtures thereof may be used. Can be. As the phenol resin, a Rezole type having a solid content of 40 to 60 wt% and a viscosity (at 25 ° C.) of 400 to 700 cps is preferable. At this time, the adhesive resin may be impregnated into the glass fiber paper in an amount of 90 to 200 g / m ² . A schematic of the coating machine used to impregnate the fiberglass paper in the resin is shown in FIG. 4.

Thanks to this fiberglass paper, the abrasive disc of the present invention has excellent flexibility while maintaining excellent dimensional stability and breaking strength, and in particular, it has an excellent competitiveness in terms of price.

The abrasive cloth used in the present invention is composed of a backing sheet and an abrasive layer containing an abrasive, and may be conventionally used in manufacturing an abrasive disc. The back sheet is preferably cotton fabric, polyester fabric, rayon fabric, cotton / polyester blended yarn or polyester film (PET film), and the abrasive component is alumina (Al ₂ O ₃ ), silicon carbide (SiC). ), Alumina zirconia (AZ), ceramic (sol-gel), cubic boron nitride (CBN), diamond or mixtures thereof are suitable. The abrasive is suitably having an average particle diameter of 15 to 400 mu m, preferably 60 to 250 mu m.

Thus, the abrasive disk of the present invention, in which the nonwoven fabric, one or more glass fiber paper layers and the abrasive cloth are sequentially laminated, has a nonwoven fabric, one or more resin-impregnated glass fiber papers and abrasives from below in an iron holder as shown in FIG. After placing the forge in turn, applying a pressure of 5 to 7 kgf / cm ² using a tightening tool and heated to 120 to 150 ℃ for 5 to 8 hours to melt the adhesive resin impregnated in the glass fiber paper constituent layer By combining them with each other. In this case, the abrasive cloth should be positioned so that the back sheet of the abrasive cloth is in contact with the glass fiber paper surface, and each of the nonwoven fabric, the glass fiber paper, and the abrasive cloth is cut into a disc of a desired size.

The glass fiber paper-containing abrasive disk of the present invention prepared as described above has the advantages of excellent flexibility, elasticity, dimensional stability and rotational fracture strength, light weight, easy to use, and especially low price and economical. It can be usefully used for rusting of steel plates, removing old paint films of automobiles, and grinding of welded portions and cut surfaces of metals.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1

One nonwoven fabric (Toray Saehan) having a weight of 25 g / m ² and a thickness of 0.15 mm; One glass fiber paper (manufactured by Carbon Korea) having a weight of 45 g / m ² and a thickness of 0.28 mm; And one piece of abrasive cloth P628 # 36 Ywt (manufactured by Solar Grinding Co., Ltd.) were cut into sizes of 180 mm outside diameter and 23 mm inside diameter. The glass fiber paper is as obtained by mixing of 10 ㎛ diameter glass fibers of 80% by weight of wood fiber powder 20 wt%, the phenol resin (Kolon Chemical, Ltd.) at 90 ℃ was impregnated in an amount of 90 g / m ² 1 Drying was used for minutes.

The cut nonwoven fabric, one phenolic resin-impregnated glass fiber paper, and one abrasive paper were sequentially laminated from below while the steel holder shown in FIG. 5 was inserted into the inner diameter, and the tightening tool was After applying a pressure of 6.0 kgf / cm ² , the laminate was placed in an electric oven at 145 ± 5 ° C. and heated for 5 hours to prepare an abrasive disk (see abrasive disc cross-sectional structure shown in FIG. 3). At this time, the abrasive cloth was laminated so that the abrasive layer was positioned upward.

Example 2

Except that the glass fiber paper (product of Korea Carbon) having a weight of 60 g / m ² and a thickness of 0.35 mm was impregnated in an amount of 120 g / m ² and dried at 90 ° C. for 1.5 minutes. In the same manner as in Example 1, a polishing disk was prepared.

Example 3

Except that the glass fiber paper (product of Korea Carbon) having a weight of 80 g / m ² and a thickness of 0.6 mm was impregnated in an amount of 200 g / m ² and dried at 90 ° C. for 2 minutes. , The same process as in Example 1 was carried out to prepare an abrasive disk.

Example 4

A polishing disc was prepared in the same manner as in Example 1, except that two sheets of glass fiber paper were used and laminated.

Comparative Example 1

One vulcanized fiber substrate (manufactured by Toyo Fiber, Japan) having a thickness of 1.0 mm was cut into sizes of 180 mm in outer diameter and 23 mm in inner diameter.

On the vulcanized vulcanized fiber substrate, after coating a primary adhesive of a 50:50 mixture of phenolic resin and CaCO ₃ in an amount of 245 g / m ² , Al ₂ O ₃ / alumina zirconia 40/60 mixture abrasive (# 36 size) ) Was sprayed in an amount of 860 g / m ² and first dried in an electric oven at 60-120 ° C. for 70 minutes. On top of that, a secondary disk of a 40:60 mixture of phenol resin and CaCO ₃ was coated in an amount of 450 g / m ² and secondary dry cured in a 60-110 ° C. electric oven for 240 minutes to prepare an abrasive disk (FIG. See the abrasive disc cross section structure shown in Fig. 1).

Subsequently, in order to moisturize the back surface of the vulcanized fiber base (the part without the abrasive material), water was applied and then left in a humidity chamber at a temperature of 30 ± 2 ° C. and a relative humidity of 70 to 80% for one week to obtain a humidified abrasive disc. .

Comparative Example 2

One nonwoven fabric (Toray Saehan) having a weight of 25 g / m ² and a thickness of 0.15 mm; Fiberglass fabric with a thickness of H45 1/4 × H45 1/4 (inclined x weft) tex / yarn and 8 × 8 (inclined x weft) reno plain weave texture, dried after impregnation with phenolic resin (Korea One manufactured by Fiber Company, wherein H means an average diameter of 10.16 to 11.42 mu m; Carbon fiber fabric having a thickness of G75 1/0 × E225 1/0 (inclined x weft) tex / yarn and a main texture of 58 × 30 (inclined x weft) count / inch after impregnation with phenolic resin (Korea One manufactured by Fiber Company, wherein E and G each mean mean diameters of 6.35 to 7.61 µm and 8.89 to 10.15 µm, respectively; And one piece of abrasive cloth P628 # 36 Ywt (manufactured by Solar Grinding Co., Ltd.) were cut into sizes of 180 mm outside diameter and 23 mm inside diameter.

While the iron holder shown in FIG. 5 is inserted into the inner diameter, one cut nonwoven fabric, one carbon fiber fabric, one glass fiber fabric, and one abrasive paper are sequentially laminated from below, and using a tightening tool. After applying a pressure of 6.0 kgf / cm ² , the laminate was placed in an electric oven at 145 ± 5 ° C. and heated for 5 hours to prepare an abrasive disc. At this time, the abrasive cloth was laminated so that the abrasive layer was positioned upward.

Test Example: Property Test

Tensile strength, breaking strength, flexibility, dimensional stability and weight were measured for each of the abrasive discs prepared in Examples 1 to 4, and Comparative Examples 1 and 2, and the prices were compared. The results are shown in Table 1 below. .

From the above Table 1, the abrasive discs of the present invention prepared in Examples 1 to 4 have superior rotational fracture strength and flexibility and very stable dimensional stability according to temperature and humidity, compared to the abrasive discs prepared in Comparative Example 1. Compared with the abrasive discs prepared in Example 2, the flexibility is very excellent, and the weight is lighter and the price is about 15 to 20% cheaper than both of these comparative discs.

As described above, the abrasive disc of the present invention has excellent flexibility, elasticity, dimensional stability and rotational fracture strength, is light in weight, convenient to use, and inexpensive, and has an economic effect, and thus can be usefully used as an abrasive disc.

Claims (8)

(1) nonwovens; (2) one or more glass fiber paper layers formed by mixing resin-impregnated glass fibers with wood fibers; And (3) an abrasive paper comprising a back sheet bonded to the glass fiber paper layer and an abrasive layer containing an abrasive A polishing disk, which in turn includes. The method of claim 1, An abrasive disc, characterized in that the glass fiber paper layer is formed by mixing 70 to 90% by weight of glass fibers and 10 to 30% by weight of wood fibers. The method of claim 1, An abrasive disc, characterized in that the glass fiber paper layer before impregnation with the resin has a weight of 45 to 80 g / m ² and a thickness of 0.25 to 0.65 mm. The method of claim 1, An abrasive disc, characterized in that the glass fiber paper layer is dried at 80 to 100 ° C. after impregnating the adhesive resin in an amount of 90 to 200 g / m ² . The method of claim 4, wherein Abrasive, characterized in that the adhesive resin is selected from the group consisting of phenol resins, epoxy resins, urea melamine resins, polyester resins, polyvinyl butyral, acrylonitrile-butadiene-rubber, modified thermosetting resins and mixtures thereof disk. The method of claim 1, An abrasive disk, characterized in that the nonwoven has a weight of 20 to 30 g / m ² and a thickness of 0.1 to 0.3 mm. A method of manufacturing a polishing disk according to claim 1, comprising positioning the nonwoven fabric, the one or more glass fiber paper layers and the abrasive paper in the form of a disk in turn and thermally pressing the components to one another. The method of claim 7, wherein Heat pressing is carried out at a pressure of 5 to 7 kgf / cm ² and a temperature of 120 to 150 ° C.

Images