JPH04146082A - Nonwoven fabric polishing material - Google Patents

Abstract

PURPOSE:To prevent the occurrence of blinding by covering resin or rubber on which thermosetting resin belonging to one of phenol, epoxy and urethane radicals or these mixed resin is making-coated as a size-coat layer on the fabric surface of forming basic material. CONSTITUTION:A random web is formed of a high rigid hard hemp fiber 1 such as Manila hemp and sisal, and previously tacked using thermosetting resin or synthetic rubber 2 to display the characteristic of the fiber 1, and improved in fiber density by thermocompressedly forming to improve coupling force between the fibers, and thereby shortened in distance between fibers to execute size-coating for composing polishing material. The resin can therefore prevent adhesion caused by heat generation during high speed rotation, and can have high rigidity and excellent polishing ability, and its multi-cavity structure can prevent the occurrence of blinding and make polishing grains 4 distribute uniformly inside for no unevenness on the polished surface. Thus an unwoven polishing material which has excellent polishing glossiness, thickness being within 2-6mm1% and modulus above 3kg/5cm can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an abrasive nonwoven fabric using hard hemp fibers such as abaca and sisal as base fibers, and in particular, the present invention relates to an abrasive nonwoven fabric that uses hard hemp fibers such as abaca and sisal as a base fiber. The purpose is to achieve a glossy polished surface with excellent uniform polishing of corners and edges without resin welding.

(Prior Art and its Problems) Polishing and grinding processes are used in all industrial fields, and a grindstone, abrasive cloth paper, or a nonwoven abrasive material is used depending on the object to be polished and the required finish.

Recent trends in polishing and grinding have shifted from conventional hard polishing to soft polishing due to improvements in machining. Therefore, the current situation is that the use of nonwoven abrasive materials suitable for soft grinding is increasing significantly.

In general, non-woven abrasive materials are made by fixing abrasive particles to the fibers using a thermosetting resin such as phenol or epoxy on a fiber aggregate made of synthetic fibers such as nylon or polyester, and processing them into the shape of a flat plate, roll, flap, etc. It is used.

Compared to a whetstone, it is flexible and elastic, conforms well to the shape of the workpiece, and has a soft surface that prevents wild scratches.

On the other hand, there is a demand for improved productivity when it comes to polishing rolls, etc.
Roll rotation speed tends to be set high, usually 120
0~+500r, p, m, in some cases 2500
Polished at ~3000 r, p, m.

The heat generated by the polishing roll due to high-speed rotation causes the fibers and resin in the abrasive material to melt, causing resin, etc. to adhere to the surface of the material to be ground. In addition, as the speed becomes higher, since the skeleton fibers of the abrasive are made of synthetic fibers, the abrasive tends to escape, leading to insufficient polishing of edges, etc., resulting in a decrease in polishing accuracy. There are drawbacks.

In addition, there are abrasive materials using hemp fibers that use woven fabric as a base material and have abrasive particles attached to it, but they tend to get clogged, and the abrasive particles are not evenly attached to the inside, making it difficult to polish. There were drawbacks such as unevenness.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned drawbacks, and involves forming a random web using hard hemp fibers with high rigidity such as abaca and sisal, and exhibiting the characteristics of the fibers. Therefore, the abrasive material is constructed by temporarily fixing it with thermoplastic resin or synthetic rubber in advance, increasing the fiber density by thermo-press molding to increase the bonding strength between the fibers, shortening the distance between the fibers, and applying a size coat. The above problems were solved by eliminating the adhesion of resin due to heat generated during rotation, high rigidity, excellent abrasive power, no clogging due to the multi-void structure, and a non-woven abrasive material with a uniformity or better inside. It is something.

The configuration of the present invention will be explained below.

The fibers used in the nonwoven abrasive material of the present invention are hard hemp fibers represented by abaca, sisal, etc.
%, but in addition to hard hemp fibers, hard fibers such as coir can also be used, and must contain at least 50% of the fibers. , which does not melt due to heat, such as vinylon,
Fibers such as acrylic, carbon, and aramid are preferred.

These hard hemp-based fibers are used to form a randomly arranged fiber web using a land univer machine, and the formed web is pre-sprayed or impregnated with a binder such as a thermoplastic resin emulsion or synthetic rubber latex. A primary raw fabric is formed in which the fibers are temporarily fixed to each other by means of applying a binder.

In conventional abrasive materials, a thermosetting resin is used to further firmly bond the fibers to the base material formed as described above, and the abrasive particles are fixed to the fiber surfaces to form a nonwoven abrasive sheet.

In the present invention, since hard hemp fibers with particularly strong rigidity are used, the fiber density is coarse and the bond distance between fibers becomes large in the above method, making it difficult to obtain practical strength as a base material. It is characterized by increasing the practical strength by further shaping the making-coated primary fabric using hot press means to increase the fiber density, shortening the distance between the fibers, and then applying a size coat.

In order to heat-press hard hemp fibers that are not plastic and have high rigidity to increase the fiber density, the binder for temporary fixation is synthetic rubber latex such as SBR or NBR, or E
Emulsions of VA, acrylic esters, vinylidene chloride, etc. are desirable, and the amount of dry solids deposited on the fibers is preferably in the range of 30 to 100%.

If the amount of adhesion is less than 30%, the stiffness of the fibers is high during hot pressing, making it difficult to obtain a hot pressing effect, and if it exceeds 100%, rubber elasticity will appear and the purpose of the present invention, such as elongation and bending, will be reduced. Physical properties are lost and the abrasive material escapes during polishing.

Furthermore, the appropriate distance between fibers that provides sufficient strength to the nonwoven abrasive material of the present invention can be expressed in terms of fiber density. The apparent density of this molded base material is 0.06g1cd to 0.1
A range of 8 g/ad is preferred.

If it is less than 0.06 g/a/, the distance between the fibers is too large and it is difficult to bond them together, and the binder film formed at the intersections between the fibers is formed in a web-like shape, resulting in an adverse effect during polishing. Moreover, if it exceeds 0.18 g/ad, the space between the fibers decreases, and there is insufficient area for the subsequent abrasive particles to stick and for holding the object to be polished during polishing, which causes clogging particles to stick. Size coating is performed by impregnation with a thermosetting resin solution containing abrasive particles.

As the thermosetting resin used for this impregnation treatment, epoxy resin, phenol resin, or polyurethane resin may be used alone or in an appropriate mixture.

Further, as the abrasive particles, aluminum oxide, silicon carbide, and metal particles are used, but the abrasive particles are not limited to these, and it is sufficient to use the abrasive particles most suitable for the object to be polished.

The size coating process described above may be applied in two or three times depending on the amount of adhesion, and is not limited to the impregnation method, but can also be carried out by spraying or electrostatic coating. 1% coated non-woven abrasive
Modulus is 3Kg15cm or more.

[For production]

The non-woven abrasive material made from hard hemp fibers according to the present invention has excellent practical strength by setting the inter-fiber bonding distance of the fiber layer of the base material to be short, and prevents resin from being applied to the polished material due to heat generated during high-speed polishing. No adhesion. Due to its high rigidity, the polishing power is strong, and it can polish every corner of the edges and part of the hooker. Density adjustment prevents clogging and provides excellent gloss after polishing.

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

[Number of implementations]

A random web with a basis weight of 200 g/nr is formed from 100% sisal hemp with a fiber diameter of 100 to 200 μm using a land univer machine.

Next, the web is attached to both sides by spraying using a binder having the following composition so that the adhesion amount to the fibers is 40% (solid content) on one side, and dried at 110°C with IO molecules to form a making coat. Forms a layer and has a basis weight of 360g
/nf, a primary fabric with a thickness of 18 m was obtained.

Solid ratio SBR (RIOX Lenone 5A-20) 4 5
Melamine resin (Konicalenone 370F)
3 3 parts Catalyst () (LCIO) 3 parts PVA resin
20 parts water
300 In the above-mentioned evil method, the temperature of the next original fabric is 15
Heat pressing was performed at 0°C, pressure of 5 kg/ad, and time of 30 seconds to obtain a molded base material having a thickness of 25 mm and an apparent density of 0.14 g/Ci.

Furthermore, the molding base material was prepared by using the liquid mixture shown below as a size coat material, solid ratio phenol (PL 2340): 40 parts, epoxy: 40 parts, hardening agent.
(H-2870) 2 0 copies
Grains (SiC11300) 3 0
Dilute with a mixed solvent of 0 parts ethyl cellosolve/Kijirol = 50150 and spray 100g/each on each side using the spray method.
Size coating was performed by adhering nf (solid content), followed by drying and curing to form a nonwoven abrasive sheet. The obtained abrasive sheet has a thickness of 3.0 m and a basis weight of 560 g/n? Met.

As shown in the drawing, the nonwoven abrasive material thus formed has thermoplastic synthetic rubber (SBR) (2) selectively adhered to the cross-contact areas of hard hemp fibers (1), and the fibers are formed by thermo-press molding. The synthetic rubber is coated on the fiber surface of the molded base material, which has increased density and shortened interfiber distance, and is size-coated with phenol and epoxy resin (3), and simultaneously sawed abrasive grains (4).
are fixed with the phenol-epoxy.

[Example 2] Vinylon fiber 2, 80% sisal, 13 denier x 51 m fiber diameter 100-200μ, cut length 50-70
A random web with a basis weight of 240g1rd consisting of 0% was formed, and it was attached to the fibers by a spray method using a binder having the same composition as in Example 1 so that the amount of adhesion (solid content) to the fibers was 100% on both sides, and then dried. Conditions 120℃X I 5m
A making coat layer was formed by pre-drying at 1N to form a primary fabric having a basis weight of 480 g/nf and a thickness of 2 (1 m).

The above original fabric was heated and pressed at 150°C and 4 kg/cd for 20 seconds to give a thickness of 4.0 m and an apparent density of 0.12 g.
/aIr molding base material and size coated with a phenol-epoxy thermosetting resin solution containing abrasive grains of the same composition as in Example 1 using a spray method so that the amount of solid content deposited is the same as in Example 1. After drying and curing, the abrasive grains were fixed to the surface of the making-coated fibers with the thermosetting resin to form a nonwoven abrasive material.

[Comparative example]

6-6 nylon fiber 15dX force length 38m.

A random web with a basis weight of 200 g/rd formed using 100% solids has a solid content of 80 g on one side.
/n(), a synthetic rubber solution having the same formulation as in Example 1 was applied, dried, and cured to form a making coat layer.

The obtained primary fabric has a thickness of 12 m and a basis weight of 360 g/nf.
Met. Next, the second original fabric was coated with a size coating agent of the same composition and resin as in Example I, with a solid content coating amount of 10% on each side.
0g/rd' and fixed the abrasive grains on the surface of the making coated fibers with thermosetting resin.
60g/n? , a nonwoven abrasive material with a thickness of 12 m was constructed.

Performance comparison tests were conducted on the nonwoven abrasive materials obtained in the above Examples and Comparative Examples, and the results are shown in the table below.

Test results showed that the nonwoven abrasive material of the present invention has superior surface gloss, no adhesion of molten resin, and a 40 to 80% improvement in grinding ratio compared to conventional comparative examples, making full use of the heat-resistant rigidity of hemp fibers. became possible.

〔Effect of the invention〕

Since the present invention is constructed as described above, clogging is difficult to occur, the heat dissipation effect is excellent, and the abrasive particles are evenly distributed throughout the interior, so that uneven polishing does not occur. In addition, by increasing the fiber density, shortening the bonding distance between fibers, and applying a size coat to form the abrasive material, it is possible to prevent the formation of a web-like film of the binder at the intersections between fibers during size coating, and to reduce the bonding distance between fibers. This eliminates the adhesion of resin due to heat generated during rotation, making it possible to efficiently utilize the high rigidity of hard hemp fibers.
It has excellent effects such as being able to uniformly polish every corner of the edge portion, producing a glossy polished surface, and having excellent grinding effects.

[Brief explanation of the drawing]

The drawing is a schematic plan view of a nonwoven abrasive material according to an embodiment of the present invention. (1)...Hard hemp fiber (2)...Thermoplastic synthetic rubber (3)...Phenol-epoxy resin (4)
...abrasive grains

Claims (2)

[Claims] (1) At least 5 pieces of hard hemp fiber such as abaca or sisal
At least the cross-contact parts between the fibers of the random fiber web containing 0% by weight or more are coated with a thermoplastic resin or synthetic rubber, and the fiber surface of the molded base material is formed by thermoforming to a predetermined thickness. , a thermosetting resin such as epoxy, urethane, or a mixed resin thereof is used as a size coat layer to cover the making-coated resin or rubber and to which abrasive particles are fixed, the thickness is 2 mm to 6 mm, and the modulus is 1%. A nonwoven abrasive material having a weight of 3 kg/5 cm or more. (2) Amount (d
．． p. u. ) is 30-100% and the apparent density is 0.06
The nonwoven abrasive material according to claim 1, characterized in that a molded base material of 0.18 g/cm^3 to 0.18 g/cm^3 is used.