JPH02265615A - Filter for liquid filtration and its preparation - Google Patents

Abstract

PURPOSE:To prevent a fibrous activated carbon from dropping at a time of use by placing a sheet of the fibrous activated carbon in the upper stream side in a housing and a material to capture removed substances from the sheet of the fibrous activated carbon in the down stream side. CONSTITUTION:A sheet 3 of a fibrous activated carbon is placed in the upper stream side in a housing 7 and a material 2 to capture removed substances from the sheet of the fibrous activated carbon is placed in the down stream side. The capturing material 2 is preferably a porous material or a woven cloth with a sponge or honeycomb structure and having voids, and as its composing material, various kinds of resins e.g. polypropylene, polyethylene are available. The thickness of the capturing material 2 is preferably 0.1-2mm and the diameters of the fine pores are preferably 20-200mum. As a result, at the time of use, the fibrous activated carbon is prevented from dropping.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a liquid filtration filter used for purifying body fluids such as blood, and a method for manufacturing the same.

<Conventional technology> Various studies have been conducted to preserve blood for as long as possible, but when blood is preserved for a long period of time, histamine increases as well as microaggregates (fine aggregates such as platelets and white blood cells). It is clear that

Furthermore, it is known that harmful substances such as microthrombi made of cells and proteins are generated in long-term stored blood.

Therefore, histamine and other harmful substances must be removed before blood transfusion.

Therefore, a liquid purification treatment device for removing these substances has been developed (Japanese Patent Laid-Open No. 62-266073).

In this invention, a filter made of woven or nonwoven fabric of activated carbon fibers is disposed in the flow path of the housing.

However, in this body fluid purification treatment device, since the filter is installed in the housing in a naked state, there is a drawback that activated carbon fiber debris falls off from the filter during use and mixes into the body fluid.

Further, such a filter is manufactured by cutting a large filter material into a size corresponding to the inner diameter of a housing to which it is attached, but chips of activated carbon fibers are generated during this cutting. Cuts that occur during filter manufacturing adhere to the surface of the filter and fall off during subsequent use.

<Problems to be Solved by the Invention> The purpose of the present invention is to eliminate the drawbacks of the prior art described above, to prevent the fibrous activated carbon from falling off during use, and to prevent the generation of chips of the fibrous activated carbon during manufacturing. It is an object of the present invention to provide a filter for liquid filtration that does not require water filtration, and a method for manufacturing the same.

Means to solve problems Such objects are achieved by the present invention as described below.

That is, the present invention provides a filter for liquid filtration, characterized in that a fibrous activated carbon sheet material is provided on the upstream side in a housing, and a trapping material for substances released from the fibrous activated carbon sheet material is provided on the downstream side. It is.

Further, the present invention is preferably a liquid filtration filter in which the capturing material and the fibrous activated carbon sheet material are laminated and their peripheral edges are fused together.

Further, the present invention provides a method for laminating the fibrous activated carbon sheet material and the capturing material, fusing the laminate together at a portion corresponding to the outline of the desired shape, and cutting the laminate along the fused portion. , a method for manufacturing a liquid filtration filter, characterized in that the filter is housed in a housing.

<Example> Hereinafter, a liquid filtration filter and a method for manufacturing the same according to the present invention will be described in detail with reference to preferred examples shown in the accompanying drawings.

FIG. 1 is a sectional view showing an example of the configuration of a liquid filtration filter of the present invention. As shown in the figure, a liquid filtration filter (hereinafter simply referred to as a filter) 1 has a three-layer laminated structure in which a fibrous activated carbon sheet material 3 is sandwiched between two sheet-like capture materials 2.2. , whose peripheral portions are integrally fused.

The capture material 2 is a desorbed material from the 1a fibrous activated carbon sheet material 3 (
It mainly captures activated carbon fibers), and is preferably made of a porous material such as a sponge or a honeycomb structure, or a material with voids such as a woven fabric or a non-woven fabric. In addition, examples of its constituent materials include various resins such as polypropylene and polyethylene.

The thickness of the trapping material 2 is preferably about 0.1 to 2 mm, and the pore diameter is preferably about 20 to 200p.

In the filter of the present invention, it is sufficient that the trapping material 2 only has the function of trapping detached substances, but by selecting the constituent materials and pore diameter of the trapping material 2, blood cells (especially white blood cells) can be absorbed.
It is also possible to provide a function of removing micro-aggregates and the like. Thereby, leukocytes, microaggregates, histamine, etc. can be removed in one operation.

The fibrous activated carbon sheet material 3 preferably has a thickness of 0.
．． One or more woven or nonwoven fabrics made of activated carbon fibers having a diameter of 1 to 2+ nm are used. The term "activated carbon fiber" as used herein refers to a carbon fiber whose carbon portion is activated.

The activated carbon fibers may be in any form, such as one or more long fibers, or one in which many short fibers are entangled, and the fiber diameter is preferably 5 to 3.
It is about 0μ, more preferably 7 to 15μ.

Further, the bulk density of the fibrous activated carbon sheet material 3 is preferably 0.01 to 0.2 g/cm", more preferably 7 (0.01 to 0.2 g/cm").
04-0. 06 g/am'', and in order to achieve such a bulk density, the shape of the activated carbon fibers may be straight or bulky.

As a specific example of the fibrous activated carbon sheet material 3, it is also possible to use the novoloid fibers disclosed in JP-A-62-266073, which are activated and fired under steam.

The fused portion 4 formed at the peripheral edge of the filter 1 is formed by integrally fused two capture materials 2.2 including a fibrous activated carbon sheet 1 material.

In this fused portion 4, the molten material of the capture material 2 penetrates into the gaps between the fibers of the fibrous activated carbon sheet material 3, and is in a solidified state.

In the illustrated example, the filter 1 has a 3N structure of capture material/fibrous activated carbon sheet material/capture material, but the structure is not limited to this, and for example, fibrous activated carbon sheet material (
2-layer structure of upstream side) / capture material (downstream side), 5-layer structure of capture material / fibrous activated carbon sheet material / porous body for leukocyte removal / fibrous activated carbon sheet material / capture material, or other functions in addition to these Any type of material may be used, such as a material having a layer having the following properties.

The planar shape (target shape) of the filter 1 is appropriately determined depending on the purpose of use of the filter, the shape of the housing to be mounted, etc., and examples thereof include a circle, an ellipse, a triangle, a quadrilateral, and other polygons. .

The filter of the present invention, as shown in FIG.
The filter 11 may be sandwiched between two sheets of capturing material 12, 12, and the peripheral edges of the capturing materials 12 are fused together.

According to the above filter=1, as shown in FIG.
When fixed in the housing 7, since the fibrous activated carbon sheet material 3 exists up to the fused portion 4, all liquids to be filtered such as blood will pass through the fibrous activated carbon sheet material 3. As a result, compared to the case where the filter 11 is used, the removal rate of substances adsorbed by the fibrous activated carbon sheet material 3 (for example, histamine, serotonin, etc. in blood) becomes higher.

In addition, since the fibrous activated carbon sheet material 3 is fixed to the capture material 2 at the fused portion 4, the fibrous activated carbon sheet material 3 may move inside the capture material, causing displacement or due to movement. This prevents fiber waste from coming out.

The housing 7 can have any shape and structure. A flow path through which a liquid passes is formed inside the housing 7, and a liquid inlet is formed at one end of the flow path, and a liquid outlet is formed at the other end.

The filter 1 described above is installed so as to block the flow path within the housing 7.

Next, a method for manufacturing the filter will be explained. Second
FIG. 3, and FIG. 4 are perspective views showing a process example of the filter manufacturing method of the present invention.

First, as shown in FIG. 2, a trapping material 2, a fibrous activated carbon sheet material 3, and a trapping material 2 having substantially the same shape are prepared, and these are laminated in this order to form a laminate 5.

Next, as shown in FIG. 3, a portion corresponding to the contour (a portion including the contour) of the desired shape of the filter (the shape of the filter to be obtained) is fused to the laminate 5. As a result, a band-shaped fused portion 4a (shaded portion in the figure) is formed.

The width of the fused portion 4a is preferably about 5 to 10 nm in consideration of ease of cutting, which will be described later.

Further, the welding method may be any method such as thermal welding or high frequency welding, but it is preferable to perform the welding by impulse heat sealing because after pressure welding, it can be cooled while maintaining the pressure.

In addition, in the illustrated example, one filter is obtained from one laminate 5, but the invention is not limited to this.
Alternatively, two or more filters of the same or different shapes may be fused together.

Next, as shown in FIG. 4, the laminate 5 is cut along a cutting line 6 (indicated by a dotted line in the figure) along the fused portion 4a, and unnecessary portions on the outside are removed. As a result, a filter 1 whose outline is the cutting line 6 is obtained.

Note that the cutting line 6 may be placed at any position within the range of the fused portion 4a, but preferably at a position approximately half the width of the fused portion 4a.

In the fused portion 4a, the fibrous activated carbon sheet material 3 is in a state of being solidified by the melt of the capture material 2.
Chips of activated carbon fibers do not come out from the cut end faces on the side of the filter 1 and on the side of unnecessary parts to be discarded.

Further, according to this manufacturing method, since the filter is cut into the desired shape after fusion bonding, a filter with high dimensional accuracy can be obtained without being affected by phenomena such as shrinkage due to fusion bonding.

The filter of the present invention can be used, for example, as a filter for filtering body fluids such as blood, serum, plasma, and urine, or other liquids such as drinking water.

<Experimental Example> (Example 1) Two sheets of capture material (cover sheet material) and a fibrous activated carbon sheet material having the following specifications were prepared.

[Capture material] Shape: Rectangle (12cm x 10cm) Thickness: 0.5m
m Material: Nonwoven fabric made of polypropylene (pore diameter 100μ) [Fibrous activated carbon sheet material] Shape: Same as capture material Thickness: 1mm Material: Nonwoven fabric made of activated carbon short fibers (fiber diameter: average 10μ) Bulk density: 0.05g/ cm" Next, the fibrous activated carbon sheet material is sandwiched between the two capture materials to form a laminate, and approximately 20 cm
mm positions were integrally fused into a band shape with a width of 10 mm over the entire circumference. Note that the fusion was performed by impulse heat sealing.

Next, cut around the entire circumference along the fused part at a position about half the width, remove unnecessary parts, and make a 10cm x 8cm piece.
A rectangular filter A of m was obtained.

In such a manufacturing process, no activated carbon fiber chips were generated.

(Example 2) A trapping material similar to Example 1, 10cm x 8cI1
Two rectangular pieces of No. 1 were prepared.

Further, the same fibrous activated carbon sheet material as in Example 1 was cut into a rectangular piece measuring 9.5 cm x 7.5 cm.

Next, the fibrous activated carbon sheet material is sandwiched between the two pieces of capture material so as to be approximately in the center, and the peripheral edges of the capture materials are fused together to form a strip with a width of 5 mm.
A rectangular filter B was obtained.

Note that a small amount of activated carbon fiber chips generated when cutting the fibrous activated carbon sheet material were attached to the outer surface of the filter.

In addition, the filter A (Example 1) and the filter B (Example 2) were installed in the same type of housing, a liquid (model) was passed through the flow path in the housing, and the flow of this liquid was observed by visualization. However, as shown in FIG. 6, it was confirmed that filter B had a flow indicated by arrow P that did not pass through the fibrous activated carbon sheet material.

On the other hand, in filter A, as shown in FIG. 5, since the fibrous activated carbon sheet material existed up to the fused portion, the liquid always passed through the fibrous activated carbon sheet material.

Due to this, compared to filter B, filter A is
It is presumed that the removal rate of substances removed by the fibrous activated carbon sheet material is improved.

According to this method, the fibrous activated carbon is prevented from falling off during use, and no chips of the fibrous activated carbon are generated during production.

Therefore, the adverse effects of fibrous activated carbon mixed into the liquid to be filtered are prevented.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of the configuration of a liquid filtration filter of the present invention. FIG. 2, FIG. 3, and FIG. 4 are perspective views each showing a process example of the method for manufacturing a liquid filtration filter of the present invention. FIG. 5 and FIG. 6 are sectional views each showing a state in which the liquid filtration filter of the present invention is attached to a housing. <Effects of the Invention> Description of the liquid filtration filter of the present invention and its manufacturing code 1.11...Liquid filtration filter 2.12...Capture material 3.13...Fibrous activated carbon sheet material 4.4a , 14... Fusion part 5... Laminated body 6... Cutting line 7... Housing FIG, 1 / / FIG, 2 IGF i G, 4

Claims (3)

[Claims] (1) Fibrous activated carbon sheet material on the upstream side inside the housing,
A filter for liquid filtration, characterized in that a trapping material for substances released from the fibrous activated carbon sheet material is disposed on the downstream side. (2) The filter for liquid filtration according to claim 1, wherein the capturing material and the fibrous activated carbon sheet material are laminated and their peripheral edges are fused together. (3) The fibrous activated carbon sheet material and the capture material are laminated, the part of this laminate that corresponds to the outline of the desired shape is fused together, and after cutting along this fused part, the inside of the housing is A method for manufacturing a filter for liquid filtration, characterized in that the filter is housed in a liquid filtration filter.