KR100436682B1 - Preparation of a combined backing for abrasive belt - Google Patents

Abstract

The present invention relates to a bonding base for abrasive belts and a method of manufacturing the same, and after applying a self-crosslinking resin solution to kraft paper or reinforced kraft paper according to the present invention, cotton fibers By combining with a woven fabric made of polyester fiber, polyester and cotton blend yarn or nylon yarn, it is possible to produce a substrate having excellent physical properties such as tensile strength, tear strength, elongation and adhesion in a shortened process, the bonding according to the present invention When the polishing belt is manufactured using the substrate, the grinding performance can be greatly improved.

Description

Manufacturing method of bonding base for abrasive belts {PREPARATION OF A COMBINED BACKING FOR ABRASIVE BELT}

The present invention relates to a bonding substrate for a polishing belt and a method of manufacturing the same. Specifically, tensile strength is obtained by directly bonding a woven fabric to a kraft paper coated with a self-crosslinkable resin solution without a separate impregnation and heat setting process. The present invention relates to a method for producing a bonding substrate having excellent physical properties such as tear strength, elongation and adhesion, and a bonding substrate manufactured thereby.

Polishing belts are commonly used for polishing plywood, MDF (medium density fiber board), and the like, in order to increase the efficiency of polishing and the rotational stability of the belt, etc., a bonding material in which cotton woven fabric is laminated on kraft paper is used.

Commercially available abrasive belt substrates include, for example, a bonding substrate in which warp and weft yarns are woven into cotton fabrics on kraft paper, such as SIAPAN 3718 from SIA, Switzerland. However, this bonding base has insufficient tensile strength, impact durability, elongation, and adhesion of woven fabric to kraft paper, so that the tearing of the belt is likely to occur when the abrasive belt is manufactured, and the belt stretches well, resulting in poor rotational stability and poor separation of woven fabric and kraft paper. There is a problem that the cotton fabric used is easy to occur and the chemical resistance is bad.

In order to improve this, Korean Patent No. 193350 proposes a method of manufacturing a bonding base by mixing polyester blend yarns with cotton fibers. Specifically, in the Korean patent, as shown in Figure 1, the woven fabric woven with polyester / cotton blend yarn is impregnated in the mixed solution of the thermosetting resin and latex 7: 3, and then stretched in the warp and weft direction When heated at 150 ° C. for 2 minutes and heat-treated at 230 ° C. for 30 seconds to obtain an impregnated polyester / cotton woven fabric, and when adhesive is imparted by applying an adhesive mixed with a phenolic resin and an inorganic filler in a 5: 5 weight ratio to kraft paper After drying to, the impregnated polyester / cotton woven fabric bonded to the kraft paper under pressure and cured, after applying and filling the adhesive on the surface of the woven fabric prepared by drying at 90 to 120 ℃ 1 hour A bonding base for abrasive belts is disclosed. However, this method requires a process of impregnating and heat-fixing the woven fabric using a thermosetting adhesive to satisfy the properties of the bonding base, which is complicated in the manufacturing process of the bonding base, and is used as a polishing belt for the polishing process. Polishing efficiency and productivity are still low.

Accordingly, it is an object of the present invention to provide a method for producing a substrate for a polishing belt by a simple process which can provide a polishing belt having excellent polishing productivity while having excellent physical properties.

1 is a schematic diagram showing a manufacturing process of a bonding base for a polishing belt according to the prior art,

Figure 2 is a schematic diagram showing a manufacturing process of the bonding substrate for the abrasive belt according to the present invention,

3 is a view showing a cross-sectional structure of the polishing belt.

In order to achieve the above object, the present invention includes applying a self-crosslinking resin solution to kraft paper or reinforced kraft paper, and then bonding the cotton fabric, polyester fiber, a blend of polyester and cotton or a woven fabric made of nylon yarn. To provide a manufacturing method of the bonding base for the polishing belt.

In addition, the present invention provides a bonding base for a polishing belt manufactured by the method of the present invention.

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

The present invention is characterized by applying a self-crosslinking resin solution to the kraft paper as an adhesive component, and then directly bonding the kraft paper to an unimpregnated woven fabric using the same.

Kraft paper or reinforcing kraft paper used in the present invention can be used as the conventional one used in the art, examples of the reinforced kraft paper is that reinforced with polyester yarn or glass fiber.

The self-crosslinking resin solution includes a self-crosslinking resin component and a hardener component selected from at least one selected from the group consisting of an epoxy resin, a urethane resin, a polyester resin, and a rubber component. The self-crosslinking resin is a resin capable of crosslinking at room temperature, and may be heat meltable or organic solvent solvent.

The coating amount of the self-crosslinking resin solution may range from 60 to 70 g / m ² based on solid content. If the coating amount is larger than the upper limit, not only it takes a lot of drying time but also costs more, and if it is less than the lower limit, the adhesive effect is insufficient. Self-crosslinking resin applied to the kraft paper is cross-linked by the curing agent component even when dried at room temperature to form a tacky coating film, the drying time is about 40 to 60 seconds.

As such, the self-crosslinking resin used in the present invention plays a decisive role in shortening the manufacturing process because crosslinking occurs at room temperature and thus may serve as an adhesive.

The woven fabric bonded to the self-crosslinked resin-coated kraft paper is woven by using cotton fibers, polyester fibers, polyester and cotton blend yarns or nylon yarns as either warp and weft yarns or both warp and weft yarns.

The bonding process of the self-crosslinked resin-coated kraft paper and the woven fabric may be performed by a pressure roller at a temperature of 65 to 75 ℃.

According to the present invention, the bonding process is performed at a low temperature below the heat deformation temperature of the polyester yarn or polyester / cotton blend yarn of the raw material of the woven fabric, it is possible to prevent the increase in elongation due to the heat shrink of the woven fabric.

An abrasive belt may be manufactured by applying an abrasive to a bonding substrate according to the present invention in a conventional manner. Specifically, after the adhesive is applied to the woven fabric surface of the substrate for the abrasive belt, the powder is usually in powder form. It can be obtained by applying phosphorus abrasive and predrying, then sizing the adhesive again to dry and cure. As the abrasive, those known in the art may be used, and specific examples thereof include alumina, silicon carbide (SiC), alumina zirconia, or a mixture thereof. The structure of the conventional abrasive paper is shown in FIG.

Bonding substrate according to the present invention is excellent in physical properties such as tensile strength, tear strength, elongation and adhesion between kraft paper and woven fabric can provide a polishing belt excellent in grinding performance and productivity.

Hereinafter, although an Example demonstrates this invention still in detail, these Examples do not limit this invention.

Comparative example

A substrate for an abrasive belt was manufactured by the method described in Korean Patent No. 193350 using the apparatus shown in FIG.

Specifically, kraft paper (3 ') and (4') were used from the container (6 ') containing the adhesive component (5') in which the phenol resin and the calcium carbonate as the inorganic filler were mixed in a 5: 5 weight ratio. 2 '), the adhesive 5' is applied, and then transferred through a roller 7 'and dried to give adhesiveness, and then impregnated with a 7: 3 mixed solution of phenol resin and latex, which is a thermosetting resin, to be stretched and heat treated ( 150 ° C., 2 minutes), joined by rollers 8 'and 9' while introducing a polyester / cotton blended woven fabric 1 ', and then the binder was passed through roller 10' and roller 12 After the adhesive 11 'was applied to the woven fabric 1' surface by ') and (13'), the bonding base for the polishing belt was manufactured by drying at 90-120 DEG C for 1 hour in the dryer 14 '. It was.

Example 1

Using the apparatus shown in Figure 2 was prepared a bonding base for a polishing belt according to the present invention.

Kraft paper (unit weight 300 g / m ² ) supplied by the unrolling roll 1 was subjected to self-crosslinking urethane resin adhesive [100 parts of 80% solution of urethane resin having an average molecular weight of 8,000 to 10,000 and an epoxy group-containing curing agent (200 to 300) Equivalent) 35 parts, containing a viscosity of 3,000 to 3,500 centipoise at 25 ± 2 ° C.] and surface-coated with adhesive (6) through calender roll (3) and gravure roll (4). After this, it was introduced into the dryer 11 via the driving roll 7 and dried at a temperature of 50 ° C. or lower, and then fed into the unwinding roll 2 to a texture of warp and weft 16s by a polyester / cotton blend yarn. The woven woven fabric was bonded together while passing through the pressure rolls 8 and 9 to obtain a woven fabric / kraft paper bonding substrate according to the present invention, and wound on a take-up roll 10.

Subsequently, in the apparatus as shown in FIG. 1, the bonding substrate was applied to the unrolling roll 1 'and coated with an adhesive comprising a 6: 4 weight ratio mixture of phenol resin and calcium carbonate as an inorganic filler, and 80 to Drying at 140 ° C. for about 5 minutes gave a substrate for the polishing belt according to the present invention.

Example 2

Except for using a woven fabric woven with 100% polyester yarn instead of polyester / cotton blend yarn in Example 1 was carried out in the same manner to prepare a polishing belt substrate.

Example 3

Self-crosslinking adhesive applied to the kraft paper in Example 1 includes 100 parts of 75% solution of epoxy resin [400-450 equivalents of 75% epoxy resin and 25 parts of amine-based curing agent (amine value 300 to 350), 25 ± 2 Viscosity at 3000 ℃ 3,500 centipoise] was carried out in the same manner to prepare a bonding base for the abrasive belt.

Test Example 1: Physical property test of substrate

Tensile strength, tear strength, adhesive strength and elongation of the abrasive belt bonding substrates prepared in Comparative Examples and Examples 1 to 3 were tested, and the results are shown in Table 1 below.

Test methods were performed according to KS K 0536, KS K 0520, and KS K 0533.

Test Items Comparative example Example 1 Example 2 Example 3 Tensile strength (kgf / in) 85 100 110 95 Tear strength (gf / 43mm) 1,800 2,500 3,000 2,300 % Elongation 14.0 12.0 13.5 12.0 Adhesive force of mating materials (kgf / 2 inch) 25 28 26 26

As can be seen in Table 1, the substrate for the polishing belt prepared in the embodiment of the present invention was superior to that according to the prior art in all aspects of tensile strength, tear strength, elongation and adhesion.

Test Example 2: Polishing ability and productivity test

An abrasive belt (belt size: 2650 mm × 3200 mm) was prepared by bonding silicon carbide (SiC) as an abrasive to the adhesive side of the substrate obtained in Comparative Examples and Examples 1 to 3 in a conventional manner. The amount of silicon carbide used was 350 g / m ² for # 60, 290 g / m ^{2 for} # 80, and 250 g / m ² for # 120.

Using the abrasive belt, the grinding performance and productivity were tested for MDF (size: 8 ft × 24 ft × 18 mm) as a grinding material in the three head grinding machine under the following grinding conditions, and the results are shown in Table 2 below. :

<Grinding condition>

1st head contact roll: # 60, 2nd head contact roll and pad: # 80, 3rd head pad: # 120

First belt speed: 2000 m / min, second and third belt speeds: 1375 m / min

Working speed: 15 m / min

First head grinding amount: 1.0 to 1.1 mm thick, Second and third head grinding amount: 0.2 to 0.3 mm thick

Test Items Comparative example Example 1 Example 2 Example 3 Effective grinding time (hours) 24 30 32 28 Number of ground abrasives per hour (sheets) 1,200 1,500 1,583 1,400 Surface roughness after polishing (center line surface roughness: R _a , μm) 7.3 6.8 6.9 6.6

As can be seen in Table 2, when grinding using the abrasive belt manufactured using the bonding substrate of the present invention, the effective grinding period is longer than the case of using the abrasive belt including the substrate according to the prior art and the productivity is also excellent In addition, the surface roughness after grinding of the grinding material can provide excellent grinding products.

According to the present invention, by directly bonding the woven fabric to a kraft paper coated with a self-crosslinking resin without a separate impregnation and heat-setting process of the woven fabric, it is possible to manufacture a bonding material having excellent physical properties in a simple process, which is used as a substrate for an abrasive belt. When used, the polishing performance and productivity are also very good.

Claims (5)

A self-crosslinking resin solution is applied to kraft paper or reinforced kraft paper, and then dried at a temperature of 50 ° C. or lower, followed by pressure bonding with a woven fabric not impregnated with a separate resin. Method of manufacturing a base material for the use. The method of claim 1, The self-crosslinking resin solution comprises a self-crosslinking resin component and a hardener component selected from the group consisting of epoxy resins, urethane resins, polyester resins and rubber components. The method of claim 1, Self-crosslinking resin coated kraft paper or reinforced kraft paper dried at room temperature. The method of claim 1, Combining the self-crosslinked resin-coated kraft paper with a woven fabric at a temperature of 65 to 75 ° C. delete