JPS6332490B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present application relates to an air filter material mainly used in an air cleaner for an internal combustion engine, and a method for manufacturing the same.

Air filter materials consist of sheets of paper made of natural and synthetic fibers and are usually pleated before use. Some of these materials, as shown in Japanese Patent Publication No. 46-13917, include those made by impregnating paper with a certain oil in order to improve the excess properties (particularly dust retention capacity), or those made by impregnating paper with a certain oil to improve paper strength. It is known that paper is impregnated with a resin such as phenol to enhance the strength.

In this way, paper impregnated with only one of oil or resin has the characteristics of only one of them, so it would be preferable to obtain a material that has both of the characteristics. In order to achieve this, common sense would suggest that a material should be made by bonding paper impregnated with oil and paper impregnated with resin; This is difficult, and there is a risk that the paper may peel off or a gap may be formed between the two papers during the pleating process. Furthermore, when both papers are bonded together, it is difficult to obtain a thin material and the material does not have low air permeability resistance characteristics.

Another example would be to use paper impregnated with one of oil or resin and the other, but in this case, for example, paper pre-impregnated with resin may be It becomes extremely difficult to impregnate a certain amount of oil. This is because the paper fibers are coated with resin, making it difficult for oil to be impregnated into the paper fibers. It is also difficult to impregnate oil-impregnated paper with resin for similar reasons.

Therefore, the present application uses a material in which a uniform paper mixed with fibers is provided with a resin-impregnated part on one side and an oil-impregnated part not impregnated with resin on the other side, and the entire paper is impregnated with a resin liquid. The above-mentioned drawbacks have been solved by using a manufacturing method in which only one side of the sheet is heated and then impregnated with oil.

To explain by way of an example, FIG. 1 shows an air filter material 10 of the present invention, in which a resin-impregnated part 2 in which one side of a paper 1 made of a mixture of natural and synthetic fibers is impregnated with a resin such as phenol or vinyl acetate. , has an oil-impregnated part 3 impregnated only with oil without impregnating such a resin on the other side. paper 1
is a sheet-like material, not two sheets of paper joined together, but a uniform material in which fiber pieces are mixed in a three-dimensional network, and the resin-impregnated portion 2 At the interface between the oil-impregnated portion 3 and the oil-impregnated portion 3, fiber pieces are continuously entangled. Further, the oil impregnated in the oil-impregnated portion 3 is lubricating oil such as motor oil.

The air filter material 10 is manufactured through a resin impregnation process, a one-sided heating process, and an oil coating process. That is, in FIG. 2, the paper 1 that has been made is immersed in a resin solution 5 made of a solution of, for example, phenol resin in a solvent, and the entire paper is impregnated with the resin solution 5 (resin impregnation step). Next, the resin-impregnated paper 1 is sent to the heating furnace 7 by the roll 6, and only one side of the paper 1 is heated (single-sided heating step). Furthermore, the paper 1 is immersed in the oil liquid 8 by the roll 6 (oil application step). In the one-sided heating process, the solvent of the resin liquid 5 rises toward the heated one side, and the resin component also moves toward the one side (Fig. 3), causing the resin-impregnated portion 2 on the one side to rise. and a non-impregnated part on the other side where the resin has moved away. In the oil application step, this non-impregnated portion is impregnated with oil. Note that oil also adheres to the surface of the fibers coated with the resin in the resin-impregnated portion 2, but the fibers are not impregnated. The oil in the material 10 is extracted by, for example, a centrifuge and controlled to a predetermined value.

The fibers at the boundary between the resin-impregnated portion 2 and the oil-impregnated portion 3 are continuously entangled.

The air filter material 10 is, for example, folded into an annular body, which is placed in a predetermined case and used. In this case, the material 10 is used with the oil-impregnated portion 3, which is not impregnated with resin, as the air inflow side. When dust-containing air flows through the material 10, dust particles separate and accumulate on the surface of the oil-impregnated portion 3, forming a relatively coarse cake layer. Fine dust particles in the dust-containing air are internally filtered out while flowing through the cake layer, the oil-impregnated section 3, and the resin-impregnated section 2. As dust particles are captured, flow resistance increases and a large differential pressure acts on the material 10, but the paper strength is increased due to the presence of the resin-impregnated portion 2, and there is no fear of breakage. Also, when folding,
Cracks on the paper are also prevented.

As described above, the air filter material of the present invention can improve both the dust retention capacity characteristics due to oil impregnation and the paper strength characteristics due to resin impregnation using a single layer of paper without laminating multiple layers.
Furthermore, according to the manufacturing method of the present invention, a resin density gradient can be formed in a single layer of paper by heating only one side of the resin-impregnated paper, and the oil-impregnated portion and the resin-impregnated portion can be integrally formed. It is very easy to produce materials that have

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the air filter material of the present invention, FIG. 2 is a diagram showing a method of manufacturing the air filter material, and FIG. 3 is a cross-sectional view showing the movement of resin within the material in a single-sided heating process. 1...Paper, 2...Resin-impregnated part, 3...Oil-impregnated part, 10...Air filter material.

Claims (1)

[Claims] 1. A uniform filter paper made by mixing fibers, having a resin-impregnated part impregnated with a paper strength-strengthening resin on one side,
A filter medium for air filters that has oil-impregnated parts that are not impregnated with resin continuously on multiple sides. 2. A filter medium for air filters comprising the steps of immersing a uniform filter paper made of a mixture of fibers in a resin liquid to impregnate the entire part with the resin, then heating only one side of the resin-impregnated filter paper, and further impregnating the entire part with oil. manufacturing method.