JPH0355272B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to nonwoven abrasive products that partially contain abrasive grains. Conventionally, this type of abrasive product has been created by impregnating or spraying synthetic resin containing abrasive grains on a non-woven mat.This type of low-density abrasive product is suitable for finishing metals, wood, etc. Although it is effective for polishing, heavy grinding and high speed cutting are not possible. Furthermore, because it is not possible to obtain a flat surface with a uniform depth on the ground surface, its uses are currently limited. In other words, a surface finished with a low-density abrasive product has uneven depth of abrasion and also has undulations that prevent a glossy finish. Currently, abrasive cloth belts and cloth buff assemblies are used in these fields, but abrasive cloth belts have a high initial grinding force, but the abrasive force rapidly decreases, and they have difficulty adapting to the object to be ground. It has no properties and cannot be used on uneven shapes. In addition, cloth buff assemblies are made by forming a resin layer containing hard abrasive grains similar to that of a grinding wheel on a flexible base material, and the entire surface of the wheel does not contain abrasive grains. It had the disadvantage that it had to be replaced. The present invention solves the above-mentioned drawbacks, and utilizes the difference in melting point of synthetic fibers and the properties of thermoplastic synthetic resin for temporary fixing to create a synthetic material in which fibers are bonded together in advance with a binder mainly composed of thermoplastic resin. A heat embossing roll whose surface is engraved with a certain pattern or a random pattern with unevenness is used to press the fibrous nonwoven fabric by the convex portions of the embossing roll, and the thermoplastic synthetic resin is softened and melted to form a compressed resin. A flat concave portion and a bulky convex portion that is not pressed corresponding to the concave portion of the embossing roll are formed, an embossed nonwoven fabric having an uneven pattern is formed on the entire surface, and the convex portion is impregnated with a resin binder containing abrasive grains. The present invention provides a nonwoven abrasive material containing abrasive grains only in the fiber layer. Next, the structure of the nonwoven abrasive material of the present invention will be explained with reference to the drawings. Figure 1 is a schematic sectional view of the main part of a nonwoven abrasive material according to an embodiment of the present invention, and Figure 2 is a partially enlarged sectional view of the convex portions and concave portions. Table of fiber webs made of vinylidene chloride, nylon 66-nylon 6 composite fibers, polyester composite fibers, polypropylene-polyethylene composite fibers, polyester-ethylene vinyl acetate composite fibers, etc., either singly or by appropriately mixing them. A temporarily fixed synthetic fiber nonwoven fabric whose back surface has been sprayed and adhered with a thermoplastic resin binder is pressed by a pair of embossing rolls consisting of a heated embossing roll and a flat roll with a certain uneven pattern engraved on the surface. A concave portion a1 in which the portion pressed by the convex portion is resinized and crimped by softening and melting the thermoplastic resin.
Form an embossed nonwoven fabric 3 with an uneven pattern having approximately resinized fused concave portions with an area of 5 to 20% and an area of bulky convex portions b2 that are not pressed corresponding to the concave portions of the embossing roll of 95 to 80%. do. The above-mentioned non-woven fabric mats include alundum, carborundum, emery, diamond sand, etc., as well as commercially available abrasive grains, and in some cases, resin binders containing abrasive particles such as aluminum powder, glass beads, and resin grains (e.g., phenol). By impregnation, drying, and heat treatment of resins, epoxy resins, polyurethane resins, NBR, SBR, etc., individually or in appropriate mixtures,
The abrasive grains or abrasive particles 4 are uniformly contained and fixed only in the fibers constituting the bulky convex portion b2, and the abrasive grains or abrasive particles 4 are contained only in a small amount on the surface of the pressed resin concave portion a1. A nonwoven abrasive material 5 is constructed in which portions are arranged in regular or irregular dots. In addition, the area of the recess formed in the embossed nonwoven fabric is suitable to be 5 to 20%, and if it is less than 5%, it is not much different from a nonwoven abrasive product made by impregnating a normal nonwoven mat, and if it is more than 20%, it will contain abrasive grains. The problem is that there are fewer protrusions to remove and wear out more quickly, so 10 to 15% is preferable. In addition to being able to properly edge grind the surface to be ground, it also has a moderate amount of resinized concavities, so it is difficult to fall off. , it has the advantage of less wear and tear. In addition, when forming a simple laminate product or a roll, it is also possible to make a molded product by impregnating an uneven patterned nonwoven fabric mat with an abrasive grain-containing resin binder and then winding it in a spiral shape. Because complete voids are formed between the laminated mats, when molded into a wheel, heat dissipates quickly, the heat load on the wheel is small, clogging is less likely to occur, and the voids provide immediate cushioning effect. You can obtain innovative non-woven abrasive products such as Next, the present invention will be explained in more detail with reference to Examples. A composite fiber of 15 de x 38 mm, with a core made of 66 nylon and a sheath made of 6 nylon, was spun using a Landweber machine to form a web weighing 100 g/m ² . Next, apply the following binder solution to the front and back sides of the web at 30 g/m ² each.
It is sprayed and dried to obtain a temporarily fixed nonwoven fabric in which the fibers on the front and back surfaces of the web are bonded to each other. SBR latex containing a scattering binder: 100 parts Melamine resin: 35 parts Catalyst: 3.5 parts Next, this temporarily fixed nonwoven fabric was placed between a pair of heated rolls (220°C), the upper part of which was an embossed roll engraved with a predetermined uneven pattern, and the lower part made of silicone rubber. By softening and melting the thermoplastic resin binder pressed by the convex part of the embossing roll, the area of the flat heat-sealed concave part is about 10%, and the other part is not pressed by the convex part. An embossed nonwoven fabric having a continuous uneven pattern was formed. The thickness of the convex portions of the embossed nonwoven fabric was 5 mm, and the thickness of the concave portions was 1 mm. Next, this embossed nonwoven fabric was impregnated with the following binder, and the weight of the product was adjusted to 800 g/m ² . Urethane prepolymer with dipping binder 100 parts MEK pigment Small amount of aluminum oxide 300 parts The nonwoven abrasive material obtained by drying and heating weighs 800 g/m ² and has a convex fiber layer with a thickness of 5 mm for convex parts and 1 mm for concave parts. A nonwoven abrasive material having an uneven pattern was formed, which uniformly contained and fixed abrasive grains inside and on the surface, and had locally abrasive grain-containing areas. Next, as a comparative example, a nonwoven fabric with the same fiber composition and the same fabric weight as in the example without embossing was used as the raw material, and the same resin processing as in the example was performed, and the product weight was
A nonwoven abrasive material weighing 800 g/m ² and having a thickness of 5 mm was obtained. A grinding test was conducted to compare the performance of the uneven patterned nonwoven abrasive material obtained in the above example and a conventional nonwoven abrasive material used as a comparative example. Grinding conditions In both Examples and Comparative Examples, four pieces of the nonwoven abrasive material obtained above were punched out into a donut shape with a wheel outer diameter of 305 mm and an inner diameter of 25.4 mm, and these were laminated and glued to form a wheel with a width of 40 mm.
Create a wheel with a load of 1Kg/cm, 6Kg/cm,
The rotation speed was 3000 r.pm, a stainless steel plate was used as the object to be ground, and the machine was traversed at a rate of 10 m/〓. The grinding time was 10 minutes. The results are shown in the table below.

[Table] As is clear from the table, the product of the present invention has an excellent grinding effect, and the ground surface of the product of the present invention is flat, whereas that of the conventional product had undulations. Since the present invention is constructed as described above, the abrasive grain-containing convex portion acts on the surface of the material to be ground at an acute angle, thereby making it possible to finish grinding the surface of the material to be ground to a flat surface with a uniform grinding depth and no undulations. Furthermore, only the convex portions come into sliding contact during the polishing operation, and the concave portions serving as spaces improve heat dissipation and extend the service life. In addition, it has excellent effects such as less clogging and excellent cushioning effect.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a main part showing one embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view of a convex portion and a concave portion. 1... Concave portion, 2... Convex portion, 3... Embossed nonwoven fabric, 4... Abrasive grain or abrasive particle, 5... Nonwoven abrasive material.

Claims (1)

[Claims] 1. Temporarily bonded bulky synthetic fiber nonwoven fabric made by bonding cross-contact areas between fibers on the front and back surfaces of a synthetic fiber web with a binder mainly composed of thermoplastic resin, and then using an embossing roll with unevenness on the surface. It is heated and pressed by a pair of embossing rolls made of flat rolls, and the area pressed by the convex part of the embossing roll is 5 to 20% of the area of the flat concave part which is resinized and pressed by softening and melting the thermoplastic resin. The base material is an embossed nonwoven fabric having a regular or irregular uneven pattern in which 95 to 80% of the area of unpressed bulky protrusions corresponding to the depressions is applied, and abrasive grains are applied to the protrusions of the embossed nonwoven fabric. Or a nonwoven abrasive material characterized by containing and fixing abrasive particles with a resin binder.