JPS6045925B2 - Manufacturing method of magnetic filter element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a powder or granule of a material that generates magnetic force by applying a magnetic field or a magnet by stretching a polymer compound into a predetermined plate or film.
A perforated filter element in which fine pieces, wire pieces, fiber pieces, etc. are added and mixed and uniformly dispersed therein is manufactured without applying a magnetic field, or by applying the magnetic field in a controlled manner. , relates to a filter that is used without or with the addition of a magnetic field, or with a controlled magnetic field.

Conventionally, foams have been commonly used as filters. Also, a filter has been proposed in which a foam body with a magnetic material facing it is used under magnetic field control. These are already in practical use as perforated filters. Due to its capillary properties, magnetic properties, and magnetic field controllability, it has high efficiency and good workability in collection, filtration, cleaning, etc. However, there is no one-size-fits-all solution. For example, a plate or membrane may be suitable, which presents difficulties in supporting and occupying the foam, and does not require as complex a communication channel within the foam. If possible, it should be a porous space body rather than a foam, so that the foaming reaction can be easily carried out, and if possible, foaming using an auxiliary foaming agent is particularly preferable, even if it is unavoidable. Instead, it may be effective to use a plate or film containing a magnetic material as a filter element, in which porous and controllable fine spaces are uniformly dispersed at a predetermined ratio of 5. The present invention aims to solve the above-mentioned problems.

Also, the purpose is to utilize the strength and corrosion resistance of the polymer compound. Another object of the present invention is to provide a plate or film that provides a filter that takes advantage of both capillary properties and magnetism. Another object of the present invention is to provide a device that can replace conventional vapors and provide a significantly better filtering effect in fields where vapors have traditionally been used. When a polymeric material is stretched in a certain direction, the molecular chains can be oriented along the stretching direction. At this time, tension in the amorphous chains occurs inside the polymer material, causing tension between and within the microcrystals (accompanied by crystal destruction), rotation of the microcrystals (partially),
Unfolding (unfolding of folded molecules) occurs one after another, and the molecules become oriented in the stretching direction. However, in cold stretching (low temperature) below the polymer glass transition temperature, the stretching of amorphous polymers Elongation is not uniform;
It exhibits a so-called netting phenomenon in which a macroscopically sharp constriction occurs at the boundary between the stretched portion and the nearly unstretched portion. Such a phenomenon occurs even above the glass transition point in crystalline polymer materials.

Crystalline polymers have strong intermolecular forces, so they tend to form fibers or thin layers, and although many have a melting point, they rarely crystallize as a whole.

The degree of crystallinity varies greatly depending on the production conditions or heat treatment of the polymer solid, and is generally in the range of about 0.1 to 0.9.

In chain polymers, molecules that are stretched are oriented in the stretching direction, increasing crystallinity. In other words, this crystalline polymer material has a temperature close to the glass transition point. When stretched at the above temperature, crystallization of molecules oriented in the stretching direction is promoted and the fibers become layered.

When stretched in multiple directions, the fibers each form a network, molecules are oriented in the stretching direction, crystallized, and formed into fiber layers.

These fiber layers are intertwined with each other, and fine pores are generated between the fiber layers. The present invention utilizes the crystallization effect of stretching a crystalline polymer as described above.
A magnetic filter element is manufactured by mixing fine particles of a magnetic material into a molten crystalline polymer compound and biaxially stretching the mixture while applying a magnetic field and heating it to a temperature just above the glass transition point. Next, an outline of the present invention will be described.

The invention uses a perforated plate or membrane containing strips of magnetic material to obtain a magnetic filter element.

More specifically, a permanent magnet, a material capable of generating magnetic force by applying a magnetic field, or a combination thereof, an arbitrary amount of powder, particles, fine pieces, fibrous pieces, or a combination of these, It is added to and mixed with a polymeric compound or a highly polymerized substance, heated to melt or semi-molten, and then extruded and stretched into a plate or film. During mixing or when molten or semi-molten, extrusion, stretching and solidification can be effected without or in addition to a magnetic field, and if a magnetic field is applied, a magnetic field can be controllably applied. Next, by applying a magnetic field to the plate or membrane and controlling the stretching in two axial directions while heating it to a temperature just above the glass transition point, a filter element that is a perforated body and has a good porosity is produced. Obtainable.

In this way, it is possible to form a perforated plate or membrane by controlling the stretching method and stretching rate that makes it possible to obtain a high porosity in a perforated body, and use it as a filter element to construct a magnetic filter. Features. In addition, if necessary, in addition to the holes and spaces in the plate or membrane, perforations can be made by mechanical needle ringing with a needle of a predetermined size and shape, and in addition to the perforated spaces, holes can be made to control the spaces. You can use it. Next, the present invention will be described with reference to some embodiments. Example 1 To polyethylene having a molecular weight of 3.5 million (melting point 135° C.), magnetic metal oxide powder particles having a size of 0.025 μm are added and mixed in an amount of 60% by volume.

Using a device such as the conceptual diagram shown in Fig. 1 showing the front view and the conceptual drawing showing a partially plan view in Fig. 2, heating and melting is carried out at a heating part (not shown) to 140'C above the melting temperature. The magnetic powder is taken out in a plate form from the nozzle of the extrusion and stretching part 3, and passed through the magnetic field forming part 2A to give polar directionality to the magnetic powder and to arrange it, to form a plate-like body 1A.
Roll 5B is stretched to 1B, roll 6A is stretched to 1C, and then heated by heater 4 between roll 6B and roll 6C, and both poles 2N and 2S of magnet 2 are stretched.
(FIG. 2), the magnetic particles contained therein are given directionality and rearranged, and stretched in the X and Y axes. For example, the image is enlarged 1.3 times in the X direction and 1.8 times in the Y direction. When the thus obtained plate is uniaxially stretched, the molecules are oriented along the stretching direction, causing crystallization and forming a fiber layer.

Since biaxial stretching is carried out in the present invention, fiber layers are generated by crystallization along each stretching axis direction, and these are entangled with each other to form a network, and minute pores are generated between the fiber layers.

By adjusting the heating temperature and stretching ratio, it was possible to precisely control the size of the holes. The diameter of the generated pore is
The 500 to 10,000 A1 void ratio could be controlled almost accurately within the range of 10 to 80%. Figure 3 shows a plan view of the model. Using the produced perforated plate as a filter element, without applying a magnetic field or with the addition of a controlled magnetic field when applied, the results of using the filter yielded very noticeable good effects.

For example, a finishing fluid mixed with extremely fine grinding powder generated during super-finishing of electric discharge machining, a machining fluid obtained by electric discharge machining of carbon steel S55C (Japanese standard) with a pulse width of 2 μs,
The results of a test using a filter (for example, the one shown in FIG. 6), which is an embodiment of the present invention, in which the strip-shaped polyethylene plate is coil-wound (as shown in FIG. 4), are 5e/M.
In the case of liquid treatment using a 3,000 cT1 area, the service life was 62 days (23Hr/field).The service life of conventional paper vapor was 24 days (23HV/day). Since it was hot for about 2 days, the improvement was achieved within the lifespan of approximately 2.5 days.Since there is an example of super-finishing, it can be said that the effect was extremely improved.Example 2 Regarding polypropylene, the effect was improved as shown in Figure 5. As shown, fine magnetic wire strips are added to polypropylene by volume of 6
0% was added and mixed, and heated and melted.

The size of the magnetic wire strip was 0.01 to 0.005μ. The heated material P melted at a temperature just above the melting point is ejected from an extrusion circular nozzle provided in the device 13, the magnetic field forming device M gives directionality to the magnet powder, and air A is blown into the inner surface along the wall W. It is then cooled and compressed between nip rolls 16A. Next, it is heated with a heater 14A and biaxially stretched.
B, tightened between nip rolls 16B, then heated and annealed to 11C, further heated and tightened between nip rolls 16
D and heated by the heater 14, the magnet 12
gives directionality to the magnetic powder, rearranges it, and forms the adhesive film 11.
E, the film was wound around roller 17, and a usage test was conducted in the same manner as in Example 1. The average pore diameter was in the range of 500 to 5,000 A, and the porosity was in the range of 10 to 80%. The filtration efficiency was almost the same as in Example 1, resulting in significantly good effects. In addition, approximately 2,
Ferrite magnet with 000 Oe coercive force and oxidized
Fine iron powder is added and mixed at 60% by volume, extruded and stretched in a semi-molten and softened state to form an extremely thin plate, and slightly foamed during the forming process, which is good as a filter element. It showed high filtration efficiency.

1 The plate or film formed in this way can be used alone or in combination, together with a mesh, without or with a magnetic field applied, and when used with a magnetic field applied.
A controlled magnetic field was used and showed good filtration efficiency (7).

Figure 4 shows a coil 1 of the sheet, plate, or film of the present invention.
It is.

Scattered are holes 8 and magnetic powder 9. In addition, if the mixing ratio of magnetic materials, etc. is too small, the magnetic susceptibility when a magnetic field is applied will be low and the function as a magnetic filter element will be inhibited, so the volume ratio should be at least 40%.
The above is necessary.

In the present invention, the size of the ferromagnetic material or permanent magnet mixed into the polymer compound is ultrafine material with a size of 0.01 to 0.005μ, so the upper limit can be mixed up to 70% by volume. .

FIG. 6 shows an embodiment of a filter 10 incorporating the filter element of the present invention.

Insert the element 1 wound into a cylindrical shape into the pressure container 10,
The inner and outer surfaces of the element 1 are reinforced with rigid mesh, and field forming magnets N and S are provided to form a high gradient magnetic field. The fluid to be filtered flows under pressure from the outer periphery A of element 1, and magnets N and S
The filtered and purified fluid that passes through the layers of the element 1 under the action of is collected in the central passage 5 B and flows out to the outside. During this period, the filter of the present invention showed effective filtration efficiency due to its capillary properties, magnetic properties, and physical and mechanical selection properties using meshes and the like. Of course, the fluid may be filtered by flowing through the filter element 1 from the center B toward the periphery A. As already mentioned, the filter using the magnetic element of the present invention exhibits significantly good filterability, has a depth as a filter body, and due to the capillary nature of the filter element and the high gradient magnetic force, it is possible to prevent the presence of particles in the fluid. It collects substances well and even filters ionized substances.

In addition, it is possible to change the type or amount of magnetic material added, control the effect of the magnetic field during extrusion and stretching, and control the effect of the magnetic field when using it as a filter, resulting in good filtration. Demonstrated efficiency. Also, for beat pipes,
It can also be used by incorporating it into a heat exchanger, and it can also be used as a gas filter, in which case it is clear that it can be used for multiple purposes as a dust removal filter. As described above, the present invention exhibits a wide variety of usefulness and can raise many expectations.

[Brief explanation of the drawing]

FIG. 1 is a conceptual front view of manufacturing the filter element of the present invention. Figure 2 is a partially enlarged conceptual plan. FIG. 3 is an exemplary plan view of the element. FIG. 4 is a perspective view of the element coil of the present invention. FIG. 5 is a conceptual front view of manufacturing the element of the present invention. FIG. 6 is a plan sectional view of a filter incorporating the element of the present invention. 1, 11, 11E...Element plate or membrane, 3
, 13...Extrusion stretching nozzle part, 1S, 1N,
2S, 2N, S, N... Magnet pole, 1A, 1B
, 1C, 1D, 11A, 11B, 11C, 11D...
・Intermediate body, 6A, 6B, 6C...Stretching roll, 16
A, 16B, 16C, 16D...Nip roll, 4
, 14, 14A, 14B... Heater, 2A, 2
, 12, 14, M... Device that provides a magnetic field.

Claims (1)

[Claims] 1 By stretching in two axial directions at a temperature just above the glass transition point, the molecules are oriented in the respective stretching directions and crystallized to form fibrous layers, and the fibrous layers are mutually separated. A crystalline polymer compound in which minute pores are formed is mixed with a ferromagnetic material, a permanent magnet, or a combination of these materials in the form of powder, granules, fine pieces, fibers, or a combination of these materials in a volume ratio. 40% to 70% of the mixture is mixed in and heated and melted, and the molten material is extruded into a film of a desired thickness, while applying a magnetic field to the film and heating at a temperature just above the glass transition point. A method for producing a magnetic filter element, characterized in that pores with a porosity of 10% to 80% and a pore diameter of 100 Å to 10,000 Å are formed in the film-like body by controlling the stretching in two axial directions. 2. Claim 1, characterized in that a predetermined amount of foaming material is added to the crystalline polymer compound, and the desired number of pores and porosity are imparted to the crystalline polymer compound by biaxial stretching, and the degree of foaming is controlled. A method for manufacturing a magnetic filter element as described in . 3. A patent characterized in that the size of the ferromagnetic material, permanent magnet, or a combination of these materials in the form of powder, granules, strips, or fibers, or a combination thereof, is 0.01 to 0.005μ. A method for manufacturing a magnetic filter element according to claim 1.