JPH06142422A - Filter medium - Google Patents

Abstract

PURPOSE:To obtain a filter medium having excellent mechanical strength which hardly causes clogging. CONSTITUTION:This filter has a two-layer structure consisting of wood pulp and cellulose fiber having thinner fiber than the wood pulp and is produced by paper making method in a manner that the cellulose fiber layer 2 has <1/4 thickness of the wood pulp layer 1. The liquid to be filtered is poured from the wood pulp layer side. Thereby, such a matter which causes clogging is removed by the wood pulp layer 1 and the liquid permeates through the cellulose layer 2. Thus, clogging is decreased. Moreover, both fibers are entangled with each other in the interface of the layers, so that the mechanical strength of the filter can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter medium, and more particularly to a filter medium used for filtering an aqueous solution or a beverage.

[0002]

2. Description of the Related Art As a filter material used for filtering an aqueous solution or a beverage, a material obtained by refining wood pulp to make paper and a microfiltration membrane have been used.

[0003]

The filter medium obtained by refining and making paper from the above-mentioned wood pulp is inexpensive, but since it is a natural fiber, it has a large fiber diameter and is bent. Therefore, there is a problem that even considerably large particles pass through.

Further, the above-mentioned microfiltration membrane has uniform fine pores and an excellent filtration accuracy, but since it is a screen filter, its mechanical strength is insufficient and the filtration amount per unit area is small, resulting There was a problem that clogging is likely to occur.

[0005]

In order to solve the above-mentioned problems, the present invention is a papermaking process in which wood pulp and cellulose fibers having finer fibers than the wood pulp are made into two layers to make paper, and the thickness of the cellulose fiber layer is made into wood. 1/4 of the thickness of the pulp layer
It is characterized in that the liquid to be filtered is injected from the wood pulp layer as described below.

[0006]

[Operation] Therefore, according to the present invention, the clogging material can be effectively captured by the wood pulp layer, and even the minute material can be removed accurately by the cellulose fiber layer having finer fibers than the wood pulp. it can.

[0007]

EXAMPLE FIG. 1 is a sectional view of a filter medium of the present invention.

In FIG. 1, reference numeral 1 denotes a wood pulp layer, which is made of wood pulp having an average fiber diameter of 50 μm and has a thickness of about 1 mm. Reference numeral 2 denotes a cellulose fiber layer, which is made of fine cellulose fibers having an average fiber diameter of 1 μm and has a thickness of about 0.2 mm.

The fine cellulose fibers constituting the cellulose fiber layer 2 are obtained by refining the product of Acetobacter or the outer skin of ascidian, and the cellulose fibers and wood pulp are made into two layers for papermaking. Thereby, the respective fibers can be entangled with each other near the boundary between the cellulose fiber layer 2 and the wood pulp layer 1, so that the mechanical strength of the filter medium can be increased.

The wood pulp layer 1 acts as a pre-filter, and the substance causing the clogging of the cellulose fiber layer 2 is removed in advance, and then the cellulose fiber layer 2 performs filtration with high accuracy. I am trying.

Next, by changing the ratio of the thickness of the cellulose fiber layer 2 to the thickness of the wood pulp layer 1 in the above-mentioned filter medium, the quality of filtration, the amount of filtration, and the mechanical strength are investigated, and The results are shown in FIGS. 2, 3 and 4.

From FIG. 2, the filtering accuracy is one fourth of the above.
It can be seen that there is almost no change even with the above.

Further, it can be seen from FIG. 3 that the filtration amount increases when the ratio is 1/4 or less.

Further, it can be seen from FIG. 4 that the mechanical strength is high if the ratio is 1/4 or less.

Therefore, if the thickness of the cellulose fiber layer 2 is set to 1/4 or less of the thickness of the wood pulp layer 1, good filtration accuracy can be obtained, and the filtration amount and mechanical strength are also good. Recognize.

[0016]

EFFECTS OF THE INVENTION As described above, the filter material of the present invention is less likely to cause clogging and has excellent mechanical strength, and is suitable for filtration of aqueous solutions and beverages.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a filter medium of the present invention.

FIG. 2 is a diagram showing the relationship between the ratio of the thickness of the cellulose fiber layer to the thickness of the wood pulp layer and the filtration accuracy.

FIG. 3 is a diagram showing the relationship between the filtration rate and the ratio of the thickness of the cellulose fiber layer to the thickness of the wood pulp layer.

FIG. 4 is a diagram showing the relationship between the mechanical strength and the ratio of the thickness of the cellulose fiber layer to the thickness of the wood pulp layer.

[Explanation of symbols]

 1 Wood pulp layer 2 Cellulose fiber layer

Claims (2)

[Claims] 1. A paper is made with two layers of wood pulp and cellulose fibers having finer fibers than the wood pulp, and the thickness of the cellulose fiber layer is ¼ of the thickness of the wood pulp layer.
A filter medium characterized in that the liquid to be filtered is injected from the wood pulp layer as described below. 2. The filter medium according to claim 1, wherein the cellulose fiber is obtained by purifying a product of Acetobacter or an outer coat of ascidian.