JP6858426B1 - filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a number of times of reuse which greatly exceeds that of a filter paper alone, in which the deterioration of filtration performance is small, wrinkles are not generated, and flatness is maintained. SOLUTION: A filter 10 is formed by laminating a reinforcing layer 12 on the surface of a filter skeleton 11 and winding it in a roll shape, and is continuously fed out so as to block a flow path of a liquid to be treated and continuously. The filter 10 is a filter 10 that allows the liquid to be treated to flow through the mesh holes in a moving state to capture solid impurities in the liquid to be treated, is made of a mesh web in which the filter frame 11 is wound in a roll shape, and the reinforcing layer 12 is Cellulose nanofibers that are fixed to one or both surfaces of the filter skeleton 11 by cationic starch that enhances the adhesion strength. They are provided in a thin and strong network structure of the required thickness to reinforce the strength of the filter skeleton 11. At the same time, it is a cellulose nanofiber layer that imparts high and stable capture performance. [Selection diagram] Fig. 1

Description

The present invention relates to a reusable filter that allows an aqueous liquid to pass through and captures solid impurities in the aqueous liquid.

The coolant liquid, which is supplied to the surface to be processed of a metal workpiece in grinding work, etc. and used for lubrication, cooling, rinsing, etc., contains metal chips, solids such as abrasive grains, and lubricating oil. It contains impure oil such as rust preventive oil. For this reason, continuing to use the coolant in a circulating manner causes a decrease in grinding accuracy and, in turn, a decrease in the quality of the workpiece.

Therefore, the filter is set from the rolled state to the state of blocking the flow of the aqueous liquid containing solid impurities, and the filter is continuously moved in the plane direction. Then, the aqueous liquid is passed through the filter and solid impurities are trapped (see Patent Documents 1 and 2).

The reference numerals used in the following description of Patent Documents 1 and 2 are the reference numerals used in the respective patent documents.

In the continuous filtration device shown in Patent Document 1, the filtration filter 4 drawn out from the roll body 3 is wound around the outer peripheral surface of the filtration drum 10 via the supply roller 20, and then the pollution tank is passed through the discharge roller 30. It is guided to the outside of No. 2, and by rotating the filtration drum 10 and the discharge roller 30, the filtration filter 4 is continuously wound around the filtration drum 10 and moved, and the pollutant liquid is caused by the negative pressure of the vacuum pump 5. The solid matter of 1 and the purification liquid can be separated by using the filtration filter 4 as a boundary surface, and the solid matter adhering to the filtration filter 4 can be collected together with the filtration filter 4 in the collection container 70 via the guide roller 60.

As described above, according to the continuous filtration device shown in Patent Document 1, the used filtration filter 4 is collected from the collection container 70 and incinerated in a state where solid matter is attached, and provides a technique for not reusing. There is.

If the filtration filter 4 must be disposed of after being used only once due to clogging, the cost of the filtration filter 4 increases, the environmental load increases, and the like. In order to repeatedly use the used filtration filter 4, the solid content adhering to the filter is separated and removed by brushing on the adhering surface, and then the cleaning water is vigorously sprayed from the side opposite to the adhering surface by nozzle injection. By doing so, it is necessary to clear the clogging of the filter and then separate / remove the impure oil adhering to the filter from the filter.

The cutting fluid filtration device shown in Patent Document 2 receives coarse-grained cutting debris in the liquid to be treated, which settles in the process of ascending between the bath plates 12, and slides it down. , It is received on the discharge conveyor 14 running on the inner bottom surface of the filtration tank 1, transported to the folded-back portion 14a, scraped off by the scraper 15, collected in the slurry box 16, and the liquid to be treated that has passed upward between the particle plates 12 is a screen belt. The lower traveling portion of the filter medium 27 is passed upward, and at this time, cutting chips having a fine particle size are captured by the screen belt filter medium 27.

When the screen belt filter medium 27 is used repeatedly, the mesh holes of the screen belt filter medium 27 are clogged with fine-grained cutting chips and the filter accuracy is lowered. Therefore, in order to remove the cutting chips, the screen belt filter medium 27 is brushed with the brush roller 40 during non-filtration. At the same time, the backwash nozzle 39 sprays the purifying liquid onto the back surface of the screen belt filter medium 27.

As described above, the cutting fluid filtration device shown in Patent Document 2 provides a technique for reusing the screen belt filter medium 27, and provides a technique for improving the cost performance of the screen belt filter medium 27.

Japanese Unexamined Patent Publication No. 2006-305430 Japanese Unexamined Patent Publication No. 58-170511

According to the cutting fluid filtration device shown in Patent Document 2, a technique capable of reusing the screen belt filter medium 27 is provided. However, no example of reusing the screen belt filter medium 27 shown in this technique has been found so far. Therefore, when the present inventor examined the reuse of the filter through experiments, it was found that there are the following problems.

First, the paper strength of filter paper decreases as the number of times it is reused increases. In particular, in order to reuse the filter paper, there is a process of brushing the surface to which the solid content of the filter paper is attached to sweep off the solid content, and the filter paper is wound and wound, so that the filter paper greatly reduces the paper strength. It is supposed to be done. Further, when the filter paper greatly reduces the paper strength, the mesh holes are greatly expanded, and the filtration performance is deteriorated.

Furthermore, when the filter paper reduces the paper strength, wrinkles occur and the flatness is impaired, and the initial band-like linear shape becomes meandering, and it becomes impossible to wind it into a beautiful roll shape, and when the filter paper reduces the paper strength, , The side edge of the filter cracks during filtration, and in addition to cracking once, wrinkles occur, which causes the filter paper to be wrapped around and the tension that changes significantly when running is not smooth, causing stress concentration in the cracks. There is a danger that the paper will burst when it suddenly develops into a large crack.

If the filter paper bursts during filtration, not only is it time-consuming to replace the filter paper, but the filtered liquid is mixed with the unfiltered liquid, and the filtration must be restarted from the beginning. It becomes a big problem.

Therefore, there is a demand to keep the number of times the filter paper reused small from the viewpoint of safety that the filter paper does not burst. Therefore, it is possible to collect data on the required number of reuses for each type of filter, which may cause small cracks on the side edges, and use it with the number of reuses smaller than the minimum number of reuses. This is a problem-solving method.

On the other hand, one other problem-solving method is to improve the cost performance of the filter material by devising a method for increasing the number of times of reuse of commercially available filter paper and filter cloth. In the above situation, conventionally, no improvement proposal has been found to significantly increase the number of times the filter paper can be reused.

The present invention has been made to solve such a problem. By laminating a reinforcing layer on a filter paper or the like as a base, the strength of the filter as a whole is increased, the strength is less deteriorated, and wrinkles are not generated. It is an object of the present invention to provide a filter in which flatness is maintained, mesh holes are less likely to be enlarged, filtration performance is less deteriorated, and the number of reuses is significantly higher than that of a filter paper alone.

In the filter of the first aspect according to the present invention, in order to achieve the above object, a filter skeleton having mesh holes and a reinforcing layer laminated on the surface of the filter skeleton and containing cationic starch as a binder are wound in a roll shape. In a state where the flow path of the liquid to be treated containing fine-grained solid impurities is blocked and continuously moved, the liquid to be treated is allowed to flow through the mesh holes, and the solid impurities in the liquid to be treated are downstream. It is a filter that captures without passing through to the side.

The filter according to the present invention is particularly required to be a cellulose nanofiber in which the filter skeleton is made of a mesh web wound in a roll shape and the reinforcing layer is fixed to one or both surfaces of the filter skeleton. A cellulose nanofiber layer provided in a thin film with a thickness and having a network structure, which reinforces the strength of the filter skeleton and imparts stable capture performance higher than the capture performance of the mesh holes of the filter skeleton. Cationic starch intervenes as a fixing agent between the filter skeleton and the cellulose nanofibers, and also intervenes as a binder so that the cellulose nanofibers form a layered network structure to maintain a flat surface that does not easily wrinkle. It is characterized by imparting sex.

The filter of the second aspect according to the present invention is characterized in that, in addition to the configuration of the first aspect, the cellulose nanofibers invade the filter skeleton together with the cationic starch.

In the filter of the third aspect according to the present invention, in addition to the configuration of the first or second aspect, the cellulose nanofiber layer is pierced and locked to the filter skeleton, and the cellulose nanofiber fiber is the filter. It is characterized by the fact that the fibers of the skeleton are entwined with each other.

In the filter of the fourth aspect according to the present invention, in addition to the configuration of the first to third aspects, the cellulose nanofiber layer has an affinity for the surface to be fixed to the filter skeleton, and the surface to be fixed to the filter skeleton. It is characterized in that the surface on the opposite side of the surface has amphipathic properties that make it water repellent.

In the filter of the fifth aspect according to the present invention, in addition to the configuration of the first to fourth aspects, the size of the mesh holes of the filter skeleton is larger than the diameter at which the desired capture performance can be obtained, and the cellulose nanofibers The network structure of the layer covers the mesh holes, and desired capture performance can be obtained according to the thickness of the network structure.

In the filter of the sixth aspect according to the present invention, in addition to the configuration of the first to fifth aspects, the filter frame is any one of filter paper, filter cloth, non-woven fabric, or single-layer mesh film.

According to the present invention, by laminating a reinforcing layer on a filter paper or the like as a base, the strength of the filter as a whole is increased, the strength is less deteriorated, the flatness is maintained without wrinkles, and the mesh holes are enlarged. It is possible to provide a filter that is difficult to deteriorate in filtration performance and can be reused much more frequently than a filter paper alone.

FIG. 1 is a block diagram in which impurity removing devices to which the filters according to the present embodiment are applied are arranged in the order of processing steps. FIG. 2A shows a perspective view of the filter according to the present embodiment, FIG. 2B shows a partially enlarged cross-sectional view of the filter skeleton, and FIG. 2C shows a reinforcing layer on one side of the filter skeleton. A partially enlarged cross-sectional view of the fixed filter is shown, and FIG. 2 (D) shows a partially enlarged cross-sectional view of the filter in which reinforcing layers are fixed on both sides of the filter frame. FIG. 3 (A) is a schematic manufacturing process diagram relating to an example of a filter in which a reinforcing layer is laminated on one surface of the filter frame, and FIG. 3 (B) shows a reinforcing layer on one surface of the filter frame. It is a schematic manufacturing process diagram which concerns on another example of a laminated filter. FIG. 4 is a schematic manufacturing process diagram of a filter in which reinforcing layers are laminated on both surfaces of the filter frame.

Hereinafter, the filter according to the embodiment of the present invention will be described with reference to the drawings.

[Filter application example]
FIG. 1 is a block diagram showing an example of an impurity removing device to which the filter according to the present embodiment is applied in a symbolic diagram and arranged in the order of processing steps. The impurity removing device includes, for example, a filter supply unit 1, a filtration tank unit 2, a brushing unit 3, a mesh hole clogging elimination unit 4, a drying unit 5, and a filter winding unit 6.

Next, the processing process of the impurity removing device will be described. The filter 10 according to the present embodiment is wound in a roll shape, is continuously fed out from a state supported by the filter supply unit 1 at a constant speed, and is guided to the filtration tank unit 2 to be an aqueous liquid containing solid impurities. It is set in a state of blocking the flow of and moves in the direction of the surface. Then, in the filtration tank unit 2, the filter 10 has a pressure difference between the hydraulic pressure on the upstream side and the hydraulic pressure on the downstream side acting on the blocking surface of the filter (whether the hydraulic pressure on the upstream side is increased or increased). Alternatively, reduce the hydraulic pressure on the downstream side) to actively flow through the mesh holes, and capture solid impurities in a state where they are in close contact with each other due to the pressure difference of the hydraulic pressure without passing through the mesh holes. Next, the filter 10 moves from the damming position to the brushing unit 3 and sweeps away the solid impurities captured by brushing. Subsequently, the filter 10 is moved to the mesh hole clogging clearing unit 4, and fluid pressure is applied to the mesh hole from the surface opposite to the trapping surface to remove fine solid impurities that are clogging of the mesh hole from the trapping surface. By separating it, the clogging of the mesh hole is eliminated. After that, the filter 10 can be used repeatedly by being dried by the drying unit 5 and then wound again in a roll shape by the filter winding unit 6.

In this way, the filter 10 is continuously fed out from the rolled state at a constant speed, and is stretched in a film shape so as to block the flow path of the liquid to be treated containing fine particle-like solid impurities. In addition, in the state of continuous movement, the hydraulic pressure difference positively generated between the upstream filter surface and the downstream filter surface at the damming position (increase the hydraulic pressure on the upstream side or reduce the hydraulic pressure on the downstream side). This is a filter that allows the liquid to be treated to flow through the mesh holes and captures the solid impurities in the liquid to be treated without flowing to the downstream side.

[Outline structure of filter]
FIG. 2A shows a perspective view of a roll form of the filter 10 according to the present embodiment. FIG. 2B shows a partially enlarged cross-sectional view of the filter skeleton 11 having the mesh holes 11a constituting the filter, and FIG. 2C shows the filter 10 having the reinforcing layer 12 fixed to one side of the filter skeleton 11. A partially enlarged cross-sectional view is shown, and FIG. 2 (D) shows a partially enlarged cross-sectional view of the filter 10 in which the reinforcing layer 12A is fixed to one surface of the filter frame 11 and the reinforcing layer 12B is fixed to the other surface. Shown. The filter 10 shown in FIGS. 2 (C) and 2 (D) is not limited to the manufacturing methods shown in FIGS. 3 (A), (B) and 4 (D).

[Two manufacturing process examples of the outline of the filter]
FIG. 3A shows an example of a manufacturing process according to the first example, and is a schematic manufacturing process diagram of the filter 10 in which the reinforcing layer 12 is laminated on one surface of the filter frame 11. The filter manufacturing device 20 includes a filter frame supply unit 21, a reinforcing layer forming unit 22, a drying unit 23, and a filter winding unit 24. The reinforcing layer forming unit 22 is a coating processing tank 22a for storing the cellulose nanofiber layer forming liquid, a rotating drum 22b having a cylindrical net surface, and a circle partially in close contact with the lower side of the inner peripheral surface of the rotating drum 22b. The peripheral surface is a mesh surface, the other portion is closed, and the suction box 22c has a spout port and the spout port is connected to the pump.

The cellulose nanofiber layer forming solution is a solution in which a predetermined ratio of cationic starch is added to water and stirred to obtain an aqueous solution, and this aqueous solution is further mixed with cellulose nanofibers having amphipathic properties. The method of making a cellulose nanofibers having amphiphilic, there is a chemical treatment method and the mechanical processing method, cellulose nanofibers having amphiphilic application, be those made by any of the processing methods Good.

For example, the underwater counter-collision method (ACC method) for obtaining amphipathic cellulose nanofibers from Chuetsu Pulp Industry Co., Ltd. is a mechanical treatment method. Specifically, the pulp suspended water put into the sample tank is used as a plunger. Pressurization is performed by injecting and colliding with the opposing nozzles arranged in the chamber at high speed, and the energy generated at the time of collision cleaves the weak bonds between the fibers to promote the miniaturization. Amphiphile can be obtained by exposing the hydrophobic surface inside the cellulose fiber structure by cleavage.

In the manufacturing process example according to the first example, the filter skeleton 11 wound in a roll shape around the filter skeleton supply unit 21 is a thin film having a cellulose nanofiber layer 12 on one side (lower surface) of the reinforcing layer forming unit 22. It is laminated by adsorption as a layer.

The filter skeleton 11 is in close contact with the lower portion of the cylindrical mesh surface of the rotary drum 22b and moves in synchronization with the rotation of the rotary drum 22b, and the suction box 22c becomes a negative pressure by pump suction, and the negative pressure of the rotary drum 22b The outer cellulose nanofiber layer forming liquid is sucked into the suction box 22c and is attracted to the filter skeleton 11 in which the cellulose nanofibers continuously move by negative pressure suction force to form the cellulose nanofibers 12.

Next, after the moisture is removed by the drying unit 23, a roll pressure is applied, and the product is further dried by a heater roll or the like. Finally, the filter winding unit 24 winds the water into a roll shape, thereby reinforcing one side of the filter frame 11. A filter 10 in which the layers 12 are laminated and fixed is manufactured.

FIG. 3B shows an example of a manufacturing process according to the second example, and is a schematic manufacturing process diagram of the filter 10 in which the reinforcing layer 12 is laminated on one surface of the filter frame 11. The filter manufacturing device 20A includes a filter frame supply unit 21, a reinforcing layer forming unit 22A, a drying unit 23, and a filter winding unit 24.

In the filter skeleton 11 wound in a roll shape around the filter skeleton supply unit 21, the cellulose nanofiber layer 12 is applied to one side (lower surface) of the reinforcing layer forming unit 22A as a thin film layer having a required thickness.

The reinforcing layer forming unit 22A employs a roll coating method. According to the roll coating method, the filter skeleton 11 is passed between the gravure roll 22e immersed in the cellulose nanofiber layer forming liquid stored in the tank 22d and the rolling roll 22f on the gravure roll 22e, and the cell of the gravure roll 22e is passed. This can be achieved by transferring the cellulose nanofiber layer forming liquid pumped up to the filter frame 11.

Next, after the moisture is removed by the drying unit 23, a roll pressure is applied, and the product is further dried by a heater roll or the like. Finally, the filter winding unit 24 winds the water into a roll shape, thereby reinforcing one side of the filter frame 11. A filter 10 in which the layers 12 are laminated and fixed is manufactured.

FIG. 4 is a schematic manufacturing process diagram relating to an example of the filter 10 in which the reinforcing layer 12 is laminated on both surfaces of the filter frame 11. The filter manufacturing device 30 includes a filter frame supply unit 31, a first reinforcing layer forming unit 32 (same structure as the reinforcing layer forming unit 22 in FIG. 3), a first drying unit 33, and a second reinforcing layer forming. It includes a unit 34, a second drying unit 35, and a filter winding unit 36.

The filter skeleton 11 wound in a roll shape around the filter skeleton supply unit 31 has a required thickness of the cellulose nanofiber layer 12A on one surface (lower surface) of the first reinforcing layer forming unit 32 due to the cellulose nanofiber layer forming liquid. Is adsorbed as a thin film layer of the above, then the moisture is removed by the first drying unit 33, a roll pressure is applied, and the mixture is further dried by a heater roll or the like.

Subsequently, in the second reinforcing layer forming unit 34 (same structure as the reinforcing layer forming unit 22 in FIG. 3), the cellulose nanofiber layer 12B is formed on the other surface (lower surface) by the cellulose nanofiber layer forming liquid to form a thin film having a required thickness. It is adsorbed as a layer, then the moisture is removed by the second drying unit 35, a roll pressure is applied, and the mixture is further dried by a heater roll or the like, and finally, it is wound into a roll by the filter winding unit 36. , A filter 10 in which reinforcing layers 12A and 12B are laminated and fixed on both sides of the filter skeleton 11 is manufactured.

[Detailed configuration of filter]
As the filter skeleton 11, a mesh web is prepared in which the form before the reinforcing layer 12 is laminated is wound in a roll shape. Specifically, as the filter skeleton 11, any one of filter paper, filter cloth, non-woven fabric, and single-layer mesh film can be used. As for the filter skeleton 11, there are several types of filter skeletons 11 having different fineness, for example, quantitative filter papers and quantitative filter cloths having φ1, 2, 4, 6, 8, 10 μm, etc., which are commercially available. Therefore, an appropriate one can be selected according to the purpose such as the size of the object to be filtered and the amount of filtration per unit time.

As the filter paper, cotton fiber (cellulose) can be generally used, or a biologically inert mixture of cellulose acetate and cellulose nitrate, a glass fiber filter paper, and a hydrophilic PTFE membrane. A treated product or a quartz filter paper using high-purity fine silica fiber can be used.

The filter cloth is a yarn made from any of polyethylene terephthalate, polypropylene, polyamide, polyester, acrylic, heat-resistant nylon, polyimide, PPS, glass, PTFE, and glass PTFE, and is a spun yarn (short fiber yarn) or a multifilament. Any yarn of (long fiber yarn) or monofilament (long single fiber yarn) may be processed as a plain weave, a twill weave, a red weave, a double weave, or a needle punching felt to form a mesh filter.

The non-woven fabric may be a mesh filter formed by non-woven processing from spun yarn (short fiber yarn) made of any one of polyethylene, polypropylene, polyamide, polyester and the like.

The single-layer mesh film is a biaxially stretched film such as polyethylene, polypropylene, polyamide, polyester, etc., which is provided on the entire surface in a distributed state in which pinholes are close to each other by needle punching or laser processing.

The reinforcing layer 12 has a thickness of 1 to 100 nm, an unspecified length, various orientations, and intricately entangled cellulose nanofibers dispersed in water on one or both surfaces of the filter frame 11. For example, it is laminated by a roll coater, and flattened by removing water with a water absorbing roll or the like and being pressurized. At that time, the cellulose nanofibers pierce the filter skeleton 11 and firmly adhere to the filter skeleton 11, so that the filter skeleton 11 is curved. Even if it is brushed, adhesion strength that does not easily peel off can be obtained.

In the manufacturing process shown in FIG. 3A, the cellulose nanofibers were impregnated into the filter frame and the cellulose nanofibers were impregnated so as not to use cationic starch as the cellulose nanofiber layer forming liquid stored in the coating treatment tank 22a. A layer is formed, and subsequently, only water is stored in the coating treatment tank 22a and the suction box 22c is made a negative pressure to allow water to flow through the filter, whereby the thickness of the cellulose nanofiber layer is not changed. Cellulose nanofibers impregnated in the filter skeleton of the above can be transferred to the deeper inside of the filter skeleton.

[Adhesion force of reinforcing layer 12]
The fact that the cellulose nanofibers invade the filter skeleton 11 and pierce it by the roll pressure is based on the fact that the cellulose nanofibers are needle-shaped bodies having a strength of about 5 times that of iron. In both FIGS. 3 (A) and 3 (B), cellulose nanofibers invade the filter skeleton 11 together with cationic starch, but in FIG. 3 (A) in particular, they invade under reduced pressure, and the inclusion amount and The depth of invasion becomes large.

When the filter skeleton 11 is stacked as a cellulose nanofiber layer 12 in the process of moving in close contact with the lower side portion of the cylindrical net surface of the rotating drum 22b, by suction box 22c is negative pressure, rotary drum 22b The cellulose nanofiber layer forming liquid on the outside of the is sucked into the suction box 22c, and a large number of cellulose nanofibers are oriented in the direction of the filter skeleton 11, and these cellulose nanofibers invade the filter skeleton 11 by negative pressure suction force. Also, since it is adsorbed, the strength of the filter skeleton 11 is increased, and the cellulose nanofibers oriented toward the filter skeleton 11 pierce and lock diagonally and deeply into the hole wall of the mesh hole of the filter skeleton 11. , Cellulose nanofibers oriented substantially perpendicular to the surface portion of the filter frame 11 other than the mesh holes are deeply pierced and locked, and further, these pierced cellulose nanofibers are rolled for flattening after application. as well as deeper pierce locking by pressure, the fibers of cellulose nanofibers in which entangles with fiber維同Shi between the fibers of the filter skeleton.

For even amount of cellulose nanofibers pierce the filter skeleton 11, since the number of alignment to the filter skeleton 11 of cellulose nanofibers (CNF) by the action of vacuum in FIG 3 (A) becomes larger than in FIG. 3 (B) cellulose The number of nanofibers that pierce the filter skeleton 11 increases, and the adhesion is enhanced. Thus, the cationic starch is strongly entangled with each other CNF, the cationic starch becomes larger impregnation to strength the filter paper, the cationic wearing tangled strongly cationic starch and CNF each other are impregnated filter paper that the starch have a close contact force between the filter paper and CNF by being connected together.

In particular, in the manufacturing process shown in FIGS. 3A and 4, the suction box 22c becomes negative pressure and the cellulose nanofiber layer forming liquid outside the rotating drum 22 is sucked into the suction box 22c. box 22c is sticks-out collision numbers rather multi cellulose nanofiber cellulose nanofiber layer formed liquid suction force is oriented in a direction substantially perpendicular to the surface portion other than the mesh holes of the filter skeleton 11 by the negative pressure, further The piercing becomes deeper due to the pressure applied by the roll, so that the cellulose nanofiber layers 12 (12A, 12B) are strongly locked to the filter skeleton 11.

Further, the cationic starch further enhances the adhesive force of the cellulose nanofiber layer 12 (12A, 12B) to the filter frame 11, and also increases the strength of the network structure of the cellulose nanofiber layer 12 (12A, 12B). To do. Cationic starch has a paper strength enhancing effect (paper strength enhancing agent) as an internal paper strength and surface paper quality improving agent for the composite structure of the filter frame and the reinforcing layer of the cellulose nanofiber fibers. .. Then, since the cationic starch increases the strength of the network structure, the cellulose nanofiber layer 12 is suppressed from wrinkling and the flatness is reinforced, and the filter 10 is applied to the impurity removing device shown in FIG. Even if the number of times of repeated use is increased, the filter 10 can realize smooth movement without meandering, and there is no possibility that a large tension causing the filter 10 to burst is generated.

The amphipathic cellulose nanofiber layer 12 has an affinity for the surface fixed to the filter skeleton 11, and the surface opposite to the fixed surface with the filter skeleton 11 becomes water repellent. Since ordinary cellulose nanofiber fibers (which do not have amphipathic properties) are hydrophilic, the surface opposite to the surface to which the filter skeleton 11 is fixed is also hydrophilic, so that the fibers are melted together and become water-based. It flows out, and the entanglement with the filter frame is weak. On the other hand, since the water-repellent surface of the cellulose nanofiber layer 12 having an amphoteric nature is in contact with the liquid to be treated on the upstream side of the flow passage and the fibers are strongly entangled with each other, it corresponds to the mesh pores of the cellulose nanofiber layer 12. Since the ingress of the liquid to be treated into the portion not to be treated can be suppressed, the outflow of a part of the cellulose nanofibers from this portion can be suppressed. Furthermore, since the cellulose nanofiber fibers are negatively charged, the charge of the cationic starch is used as a binder, and the charge of the cationic starch which is positively charged in advance is used to be used between the two fibers. It becomes possible to strengthen the entanglement of the electric charge.

The reinforcing layer 12 (12A, 12B) is dried, so that the reinforcing layer 12 (12A, 12B) is a thin film having a required thickness and a network structure is obtained, and the cellulose nanofibers are laminated on the filter frame 11 with strong adhesion strength. Become a layer. The reinforcing layers 12 (12A, 12B) cover the mesh holes 11a of the filter frame 11, and can stably realize finer meshes than the size of the mesh holes 11a for a long period of time.

The filter 10 in which the reinforcing layers 12 (12A, 12B) are fixed to one side or both sides of the filter frame 11 is wound in a roll shape as a final form. This is because it is attached to the impurity removing device for reuse.

The filter 10 is provided in a network structure in the form of a thin film having a required thickness with respect to the filter frame 11, and the burst strength is significantly increased by the cellulose nanofiber layer 12, and the mesh structure is maintained for a long time to maintain the mesh holes of the filter frame 11. It will maintain stable capture performance for a long time, which is higher than the capture performance of.

In the filter 10, the size of the mesh hole of the filter frame 11 is larger than the diameter at which the desired capture performance can be obtained, the network structure of the cellulose nanofiber layer covers the mesh hole, and the desired capture is performed according to the thickness of the network structure. Performance is being obtained.

According to the filter 10 according to the present embodiment, the filter 10 is set in a state of blocking the flow of the aqueous liquid containing solid impurities, which is unwound from the rolled state, and can capture the solid impurities while moving in the plane direction. A filter that can be reused repeatedly by removing solid impurities and eliminating clogging of mesh holes. The cellulose nanofiber layers 12 (12A, 12B) have a network structure and high decay strength, and the mesh of the filter frame 11 Stable trapping performance that greatly exceeds the trapping performance of only the holes can be obtained, and the permissible number of repeated uses that greatly exceeds the permissible number of repeated uses when used only with the conventional filter frame can be obtained. Capturing performance can be controlled by controlling the thickness (thickness of the network structure), and in particular, cationic starch, which is an adhesive in which the filter skeleton and the cellulose nanofiber layer having different shrinkage rates have cushioning properties. Since it is adhered by, it is possible to suppress the occurrence of wrinkles in the filter skeleton 11, share the tensile strength and reinforce the flatness, and it is considerably larger than the allowable number of repeated uses when used only with the conventional filter skeleton. It can be used repeatedly, and even if the number of times of repeated use is increased, partial peeling does not occur, and the capture performance of partial mesh holes does not deteriorate. In particular, the trapping performance of solid impurities can be controlled, and stable trapping performance that is significantly higher than when only filter paper is used can be obtained, and the number of repeated uses is significantly higher than when only filter paper is used. ..

According to the present invention, it is composed of a filter skeleton made of mesh web and a reinforcing layer having improved adhesion strength, a network structure, and a flat surface retention that is hard to wrinkle due to cationic starch, and fine particles are formed by controlling the thickness of the reinforcing layer. It is possible to control the trapping performance of solid impurities in the form, obtain stable trapping performance that greatly exceeds that of conventional filters, and the number of repeated uses that greatly exceeds the number of repeated uses of conventional filters (filter paper). It has the effect of being obtained, and can provide a useful filter with improved cost performance.

1 ... Filter supply unit,
2 ... Filtration tank unit,
3 ... Brushing unit,
4 ... Mesh hole clogging elimination unit,
5 ... Drying unit,
6 ... Filter winding unit,
10 ... filter,
11 ... Filter skeleton,
12 ... Reinforcing layer (cellulose nanofiber layer),
20 ... Filter making device,
21 ... Filter skeleton supply unit,
22 ... Reinforcing layer forming unit,
23 ... Drying unit,
24 ... Filter winding unit,
30 ... Filter making equipment,
31 ... Filter skeleton supply unit,
32 ... First reinforcing layer forming unit,
33 ... 1st drying unit,
34 ... Second reinforcing layer forming unit,
35 ... Second drying unit,
36 ... Filter winding unit.

Claims (6)

A filter skeleton having mesh holes and a reinforcing layer laminated on the surface of the filter skeleton and containing cationic starch as a binder are wound in a roll shape to block a flow path of a liquid to be treated containing fine-grained solid impurities. A filter that allows the liquid to be treated to flow through the mesh holes and captures solid impurities in the liquid to be treated without flowing to the downstream side in a state of being stopped and continuously moving.
The filter skeleton is made of a mesh web that is rolled into a roll.
Wherein the reinforcing layer is a cellulose nanofibers is secured to one or both surfaces of the filter skeleton, provided the network structure in a thin film form, as well as reinforce the strength relative to the filter skeleton, mesh of the filter skeleton a cellulose nanofiber layer stable scavenging performance is imparted higher than performance for trapping holes,
The cationic starch is interposed as a fixing agent between the filter frame and the cellulose nanofibers, and the cellulose nanofibers are interposed as a binder so as to form a layered network structure, so that wrinkles are not easily twisted. A filter characterized by imparting retention. The filter according to claim 1, wherein the cellulose nanofibers invade the filter frame together with the cationic starch. Wherein the acquisition performance with high and stable than the capture performance of the mesh holes of the filter skeleton is applied to the cellulose nanofiber layer to the cellulose nanofiber layer is stopped engaging pierce the filter skeleton, of the cellulose nanofiber fibers One entangled with fibers between the fibers of the filter skeleton Kukoto, said cationic starch to increase the strength of the network of the cellulose nanofiber layer, the cellulose nanofiber layer are negatively charged Due to the attractive force between different charges between the fiber and the previously positively charged cationic starch,
The filter according to claim 1 or 2, wherein the filter is based on at least one of the two. The cellulose nanofiber layer is characterized in that the surface to be fixed to the filter skeleton has an affinity, and the surface opposite to the surface to be fixed to the filter skeleton has amphipathic property to be water repellent. The filter according to any of -3. The size of the mesh hole of the filter skeleton is larger than the diameter at which the desired capture performance can be obtained, and the network structure of the cellulose nanofiber layer covers the mesh hole, and the desired capture is performed according to the thickness of the network structure. The filter according to any one of claims 1-4, characterized in that performance is obtained. The filter according to any one of claims 1-5, wherein the filter skeleton is any one of a filter paper, a filter cloth, a non-woven fabric, and a single-layer mesh film.

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