KR20020040550A - Cylindrical cartridge filter with improved filtering capacity - Google Patents

Abstract

PURPOSE: Provided is a cylinder-shaped cartridge filter which is made of non-woven fabric and has improved filtering capability while maintaining intrinsic mechanical properties of a resin. CONSTITUTION: The cartridge filter is prepared in a cylinder form from synthetic resins through melting, forming and spinning processes by an extruder. During drawing when cylindrical filter is formed, prominences and depressions are formed on the surface of the filter through compression by a drawing road and shaping grooves provided on the shaping roller at prescribed intervals. The distance from the top of the prominence and the bottom of the depression is 1 to 10 mm and the repeating interval of the prominences and depressions is at least 5mm.

Description

Cylindrical cartridge filter with improved filtering capacity

The present invention relates to a cylindrical cartridge filter with improved filtration capability, and more particularly, when manufacturing a cylindrical cartridge filter by winding a synthetic resin melted and extruded by an extruder into a nonwoven fabric with a winding rod, to form a cylindrical cartridge filter. The present invention relates to a cylindrical cartridge filter having an improved filtration capacity, having a wider filtration surface area and having a larger center of density than the surface by forming a concave-convex shape by winding a shape groove provided in the roller.

Steam, dust, and various pollutants are present in the air and water, and homes and industries are always required to remove them, which can lead to the failure of various machines and devices. It is a big threat to your health.

Therefore, the filter can gradually filter fine foreign matter, and the filter that can selectively filter according to the type of foreign matter has been developed in various ways.

Such filters are classified into ceramics, activated carbon, celluloses, resin filters, and the like depending on the material, and are selected and used according to their purpose. Among these resins, the resin filters are generally used as filters made of polyolefin resins such as polyethylene and polypropylene, polyurethanes, or mixtures thereof, and these resin filters have a small pressure loss due to compression and molding. This is used when the filtration flow rate is large.

In general, polyolefin resin is a general-purpose resin having excellent mechanical, thermal, and electrical properties, excellent chemical resistance, and moldability, and is widely used for making films and containers.

Filters made using these resins as a material are resins, in addition to the advantages that the pores are uniform in size, can be manufactured without a special core, and do not require end-cap processing. Due to its properties, mechanical strength and chemical resistance are excellent. Such resin filters are used in a variety of industrial applications such as air filters, oil filters, paint industry.

Efforts have been made to obtain desired properties by using polyolefin resins having such excellent physical properties as filter materials.

Korean Patent Laid-Open Publication No. 2000-6029 discloses a method of forming a pleat in a nonwoven filter manufactured from a resin, and removing or compressing a material in the form of burning and / or melting of fibers by an energy head. However, these methods only aim at the flexibility of the filters and use expensive energy heads such as laser beams or ultrasonic welding devices. In addition, Korean Patent Laid-Open Publication No. 1998-14011 discloses a method of simultaneously forming an embossed pattern on the surface of a synthetic resin floor mat, but this method is only for the purpose of aesthetics of the floor mat.

In addition, Korean Patent Laid-Open Publication No. 1998-701834 discloses a gradient density filter made of sheets of three or more blown polypropylene microfibers to improve gradient density characteristics compared to a filter having a uniform pore diameter. A complicated process of laminating sheets having different pore diameters together with a cover layer in a stack structure is included.

In addition, as a method for increasing the filtration surface area of the cartridge filter, conventionally, after manufacturing a cylindrical raw filter, a method of forming irregularities by post-processing such as a separate lathe is known, but this method is a filter according to the lathe Destruction of the surface tissue, thereby lowering the mechanical strength, results in deterioration of product quality.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention found that the synthetic resins melted and extruded by the extruder and formed into a nonwoven fabric by simultaneously forming the shape of the irregularities by the shape grooves provided in the shape rollers of the winder. The present invention has found that a cylindrical cartridge filter having an improved filtration capability, having a wide filtration surface area and having a higher density inside the filter than the surface, can be produced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cylindrical cartridge filter in the form of a nonwoven fabric, in which the mechanical properties of the resin are maintained and the filtration ability is improved.

1A and 1B are schematic diagrams showing the configuration of an apparatus for manufacturing a cylindrical cartridge filter according to the present invention.

2 is an enlarged view of a wound shape of the cylindrical cartridge filter according to the present invention.

3 is an enlarged view of a filter generating unit of the cylindrical cartridge filter according to the present invention.

4 is a cross-sectional view of the cylindrical cartridge filter according to the present invention.

5 is an enlarged view of a fiber of a cylindrical cartridge filter having a conventional shape.

6 is an enlarged view of the fiber of the cylindrical cartridge filter according to the present invention.

7 is a shape of a cylindrical cartridge filter that can be produced by the present invention.

(Explanation of symbols for the main parts of the drawing)

1: extruder, 2: winding rod, 3: shape roller, 4: winding machine, 5: die,

6: gap between winding rod and shape roller, 7: spring, 8: cartridge filter.

Cylindrical cartridge filter according to the present invention for achieving the object as described above is a non-woven cylindrical cartridge filter manufactured from a synthetic resin melted, extruded, and spun by an extruder, providing irregularities on the surface to increase the filtration surface area For example, the present invention relates to a cylindrical cartridge filter having a higher density at the center than a density at the surface, thereby improving the filtration capacity.

Synthetic resins used in the present invention are mainly polyolefin resins or mixtures thereof, but polypropylene resins excellent in moldability, impact resistance, heat resistance and chemical resistance are preferably used. Moreover, in this invention, as a material of such a cylindrical cartridge filter, it does not contain other additives other than the said polyolefin resin. This is to ensure that the material component of the filter is not eluted by the fluid to be filtered.

The polyolefin resin cartridge filter can be used for food, electronics, water treatment, pharmaceutical, chemical, industrial, household and the like. Specifically, the food industry, such as alcoholic beverages, corn syrup, juice, cooking oil, IC-based, corrosive liquid, liquid crystal, magnetic medium, photoresist, ceramics, electronics industry, water treatment industry, such as water purification, ultrapure water production, dialysis machine, cosmetic, perfume It can be used in the pharmaceutical industry, adhesives, solvents, chemical industries such as surfactants, other gases, compressed air, lubricants, thermosensitive pigments, dyes and the like.

The irregularities provided in the present invention vary depending on the thickness of the cartridge filter, but the depth (depth from the top of the convex to the bottom of the concave) is 1 mm from the surface. It is preferable that it is more than 10 mm. If the depth is less than 1 mm, the improvement of the filtration capacity, which is a feature of the present invention, is insufficient, and if the depth exceeds 10 mm, the physical properties of the cartridge filter may be degraded or torn. As for the space | interval repeated between unevenness | corrugation, 5 mm or more is preferable.

Hereinafter, the cylindrical cartridge filter of the present invention will be described in detail.

The manufacturing apparatus for manufacturing the cylindrical cartridge filter of the present invention includes an extruder (1) for melting and extruding a synthetic resin, and a winding rod (2) for rotating winding a synthetic resin melted, extruded, and spun, and a gap between the winding rod and a predetermined interval. It is composed of a winding machine (4) including a shape roller (3) disposed at the top and provided with a shape groove and a removal means for removing the cylindrical cartridge filter provided with irregularities.

More specifically, the extruder includes a die 5 spinning in a predetermined shape as a normal extruder used by using the synthetic resin of the present invention as a material. At this time, the heating temperature of the extruder depends on the synthetic resin supplied, for example, in the case of polyethylene is 200 to 300 ℃, in the case of polypropylene, it is 250 to 350 ℃. The material synthetic resin may be in powder or pellet form. The molten synthetic resin is extruded and spun according to the designed melt discharging capacity of the die.

In addition, in the winding machine which can be used normally, the winding rod 2 and predetermined uneven | corrugated shape which rotate-wound the synthetic resin melted, extruded, and spun in order to form the shape groove which is the characteristic of the cylindrical cartridge filter of this invention are It is characterized in that it comprises a shape roller (3) to give a concave-convex groove in the cylindrical cartridge filter at the same time winding in the form of a nonwoven fabric. The shape roller is provided with a spring 7 which gives a constant tension to give a pressing force to the resin wound on the winding rod.

The diameter of the winding rod (2) can be replaced according to the inner diameter of the cartridge filter to be obtained, preferably having a diameter of 20 to 30mm, in the embodiment of the present invention uses a winding rod having a diameter of 27mm .

In addition, the shape roller (3) can replace the roller to give a variety of shapes, that is, uneven size or uneven pattern depending on the degree of expansion of the filtration surface area. In the embodiment of the present invention, although the depth of the concavities and convexities is 1 ~ 10mm, and the repeating interval between the concavities and convexities is 5mm or more, it is used, but not limited to the conventional wedge-shaped roller. The diameter of the roller is usually 100mm, and it is installed at regular intervals from the winding rod. When the wound resin reaches a certain thickness, the roller is rotated in the opposite direction by the friction force between the resin wound on the winding rod and the convex portion of the roller. While giving a constant compressive force. At this time, the recessed portion of the shape roller is loosely wound to produce a cartridge filter having a smaller density than the center of the surface of the filter.

In addition, the manufacturing method of the cylindrical cartridge filter according to the present invention,

(1) melting, extruding and spinning a synthetic resin in an extruder;

(2) winding the synthetic resin melted, extruded and spun in the form of a nonwoven fabric in a winding rod, and manufacturing a cartridge filter in which the uneven groove is formed while being wound;

(3) recovering the manufactured cylindrical cartridge filter from the winding rod.

In the step (1), the extruder uses a conventional extruder, and the supplied synthetic resin is melted in the extruder and extruded and spun through a die.

In the step (2), the spun molten synthetic resin reaching the winding rod is naturally cooled by air and wound up into a nonwoven fabric. At this time, until reaching the shape roller which maintains a certain distance from the winding rod, the nonwoven fabric is wound to have a uniform pore in a state of being heat-bonded, the degree of filtration of the cartridge filter is determined at this time. When the wound resin reaches a certain thickness, the wound roller comes into contact with the roller and rotates the roller by friction. The depth of concavities and convexities of the shape roller is 1 to 10 mm. In addition, the convex portion of the roller has a cylindrical cartridge filter pressurized by a spring having a certain tension provided on the roller to improve the adhesive state, thereby maintaining mechanical strength without causing the removal of the filter. The concave portion of the shape roller provides a predetermined space with the rolled resin, and serves to loosely stack the resin to be emitted, and at the same time, provide the shape of the cartridge filter. The cartridge filter produced in this way has a uniform pore inside which determines the degree of filtration, and the portion pressed by the convex portion of the shape roller improves the adhesion state of the spun resin to the cartridge filter. The mechanical strength is maintained, and the shape formed by the concave portion of the shape roller increases the surface area of the filtration and at the same time, the density is smaller than the inside, thereby increasing the dirt holding capacity of the cartridge filter. Let's do it. Uneven grooves of the cartridge filter may be embossed or intaglio in various shapes, and the shape of the cylindrical cartridge filter that can be manufactured by the present invention is shown in FIGS. 4 and 7.

In the step (3), to remove the cylindrical cartridge filter prepared by providing a detachable device of the winding rod.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1A and 1B are schematic diagrams showing the configuration of an apparatus for manufacturing a cylindrical cartridge filter according to the present invention. The extruder 1 extrudes the resin supplied in the form of powder or pellets by heating it to a molten state. A die 5 is provided at the end of the extruder to spin the molten resin onto the winding rod 2 that rotates. The synthetic resin in the spun molten state is naturally cooled while being wound in the form of a nonwoven fabric along the circumferential surface of the rotating winding rod. A cartridge filter having the shape of a groove is obtained. At this time, the protrusion of the roller is applied to the resin wound on the winding rod to maintain the mechanical strength of the cylindrical cartridge filter, and the resin is loosely laminated to the depression of the roller to make the density smaller than the inside of the filter. The density inside the filter is gradually increased from surface to center, resulting in a cylindrical cartridge filter with improved filtration capability.

2 is an enlarged view of a winding portion of a cylindrical cartridge filter according to the present invention. The winding rod 2 and the shape roller 3 are separated by a predetermined interval 6, and when a resin having a predetermined thickness or more is wound on the winding rod, it is in contact with the wound resin and rotates in the opposite direction to the winding rod by frictional force. The shape roller is provided with a spring 7 having a certain tension in order to apply a constant pressing force to the wound resin.

3 is an enlarged view of a filter generating unit of the cylindrical cartridge filter according to the present invention.

The cylindrical cartridge filter has a uniform pore inside which determines the degree of filtration, and the portion pressed by the convex portion of the shape roller improves the adhesion state of the spun resin to improve the mechanical strength of the cartridge filter. The portion formed by the concave portion of the shape roller expands the filtration surface area and is formed smaller in density than the inside, thereby increasing the dirt holding capacity of the cartridge filter.

4 is a cross-sectional view of the cylindrical cartridge filter according to the present invention.

The shape of another cylindrical cartridge filter that can be produced by the present invention other than that of FIG. 4 is shown in FIG.

5 is an enlarged view of a fiber of a cylindrical cartridge filter having a conventional shape.

This is a method to increase the surface area of filtration after manufacturing cylindrical raw filter, and to form irregularities by post-processing. This method increases the surface area and increases the filtration efficiency, but the structure is destroyed so that the mechanical strength of the cartridge filter decreases. Caused.

6 is an enlarged view of the fiber of the cylindrical cartridge filter according to the present invention.

Unlike FIG. 5, the tissue was not destroyed and the convex portions of the cartridge filter surface were less dense than the center.

7 is a shape of a cylindrical cartridge filter that can be produced by the present invention.

Example 1

Polypropylene pellets having a melt index of 32 are added to an extruder having a barrel heating temperature of 260 ° C. and a die temperature of 300 ° C. to melt, extrude, and spun. The die is used by arranging 76 0.4 mm nozzles in a straight line at 10 cm intervals, and the discharge amount through the die is 3 kg per hour. The resin spun through the die is wound in the form of a nonwoven fabric by a winding machine provided with a winding rod having a diameter of 27 mm. The shape roller installed in the winder has a gear-shaped unevenness as shown in Fig. 4, and the depth from the top of the convex portion to the bottom of the concave portion is 5 mm. The plane width is 5 mm, the plane width of the recess is 13 mm, the repetition interval between the unevenness is 20 mm, and 12 mm is provided away from the outermost part of the winding rod. A cartridge filter having a shape is obtained with a core having an inner diameter of 27 mm and an outer diameter of 64 mm.

Example 2

In the same manner as in Example 1, the shape roller provided in the winder has a gear-shaped unevenness as shown in Fig. 4, and is formed from the top of the convex portion to the bottom of the concave portion. The depth is 1 mm, the plane width of the convex portion is 6 mm, the plane width of the concave portion is 13 mm, and the repetition interval between the unevenness is 20 mm.

Example 3

In the same manner as in Example 1, the shape roller provided in the winder has a gear-shaped unevenness as shown in Fig. 4, and is formed from the top of the convex portion to the bottom of the concave portion. The depth is 10 mm, the plane width of the convex portion is 4 mm, the plane width of the concave portion is 12 mm, and the repetition interval between the unevenness is 20 mm.

The filtration degree, water passage amount differential pressure, impurity trapping amount, and mechanical strength of the cylindrical polypropylene cartridge filters (Examples 1 to 3) thus obtained are shown in the following table.

Comparative Example 1

In the same manner as in Example 1, polypropylene chips having a melt index of 32 were added to an extruder having a barrel heating temperature of 260 ° C. and a die temperature of 300 ° C. to melt. Extrude and spin. The die is used by arranging 76 0.4 mm nozzles in a straight line at 10 cm intervals, and the discharge amount through the die is 3 kg per hour. The resin spun through the die is wound in the form of a nonwoven fabric up to an outer diameter of the cartridge filter, which is produced by a winding machine provided with a winding rod having a diameter of 27 mm, up to 64 mm.

Comparative Example 2

The cartridge filter manufactured in the same manner as in Comparative Example 1 was subjected to lathe processing to have a depth of 5 mm from the top of the convex portion to the bottom of the concave portion, and the plane width of the convex portion was 14 mm, The plane width of the recess is 6 mm, and the repetition interval between the unevenness is 20 mm.

The filtration degree, water passage amount differential pressure, impurity trapping amount, and mechanical strength of the cylindrical polypropylene cartridge filter (Comparative Examples 1 and 2) thus obtained are shown in the following table.

Test Example

The physical property of the propylene resin cartridge filter of this invention was measured by the following method.

(1) Filtration degree measurement

To measure the filtration efficiency of the cartridge filter, add 40 g of carborundum # 800 for 5 minutes at 5 g per 5 minutes as a contaminant while passing distilled water at a flow rate of 30 L / min to the 250 mm cartridge filter to be tested. The filtrate passed through the cartridge filter is collected every 10 minutes and analyzed by measuring the number of contaminant particles per unit volume.

Filtration degree measurement (%) Particle size 4㎛ 6 μm 8㎛ 10 μm Example 1 93 97 99 100 Example 2 94 98 100 100 Example 3 90 94 96 98 Comparative Example 1 94 98 100 100 Comparative Example 2 92 96 98 99

As shown in Example 1 and Comparative Example 1 of Table 1, when the depth of the uneven groove was 1 mm (Example 2), the degree of filtration was the same as that of the cartridge filter (Comparative Example 1) which provided no uneven groove at all. If the depth is 10mm (Example 3) it can be seen that the length of filtering the contaminants is relatively small, so that the degree of filtration is slightly reduced. It is found that the filtration degree is slightly superior to that of the groove having the same depth as that of the uneven groove of 5 mm (Example 1), and that there is no uneven groove (Comparative Example 1). Can be. In any case, it can be seen that the removal efficiency of the 4 μm-sized contaminants is 90% or more.

(2) Measurement of differential pressure against water flow

The pressure difference between the inlet and the outlet of the cartridge filter is measured according to the change of the water flow rate of the cartridge filter. The differential pressure is measured using a differential pressure gauge while passing distilled water at a constant flow rate through a 250 mm cartridge filter.

Differential pressure (psid) measurement relative to the flow rate (LPM) Water flow rate (LPM) 10 20 30 40 50 Differential pressure (psid) Example 1 1.0 2.0 3.0 4.5 6.5 Example 2 1.0 2.5 3.0 4.5 6.5 Example 3 1.5 3.0 4.5 6.0 9.0 Comparative Example 1 1.0 2.5 3.5 4.5 7.0 Comparative Example 2 1.0 2.0 3.0 4.5 6.0

It can be seen that Examples 1 to 3 and Comparative Examples 1 and 2 both have excellent pressure-bearing characteristics versus differential pressure. It can be seen that only when the depth of the grooved grooves is 10 mm (Example 3), the differential pressure is increased than when the grooves are not provided (Comparative Example 2).

(3) Determination of Impurity Collection

Carborundum # 1200 is applied at a differential pressure of up to 40 psid while passing distilled water at a flow rate of 30 L / min through a 250 mm cartridge filter. After maintaining the same flow rate for 30 minutes under this differential pressure, the cartridge filter is collected and dried in an oven at 60 ° C for 3 days. The outer surface of the dried cartridge filter is well shaken and weighed to determine the weight of carborundum # 1200 used as a contaminant.

Determination of Impurity Collection (g) Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Capture amount (g) 145 50 73 48 32

In the cartridge filter having the shape of the uneven groove, when the convex portion of the cartridge filter has a low density capable of collecting a large amount of impurities, it can be seen that the amount of impurity collection is rapidly increased.

It can be seen that there is almost no difference in the amount of collection when the grooves of the concave-convex portion are 1 mm (Example 2) and there is no groove (comparative example 1). If the shape is given, it can be seen that the collection amount is three times higher than without the groove. In the case of lathe machining of uneven grooves of the same depth, it can be seen that the collection amount is reduced by being cut by the lathe processing as compared with the case of the uneven groove (Comparative Example 1). If the uneven groove is 10 mm (Example 3), the differential pressure reaches 40 psd quickly, as can be seen from the result of the differential pressure versus the flow rate, despite the relatively large surface portion having a low density capable of collecting a large amount of impurities. As a result, a smaller collection amount is obtained than in Example 1. According to the present invention, it can be seen that the collection amount increases when the shape of the uneven groove is given to the cartridge filter (Examples 1 to 3) than when the shape is not given (Comparative Example 2).

(4) mechanical strength measurement

Measure the mechanical strength of the cartridge filter using a universal meter. Visually observe the strain for longitudinal strain and lateral front load. Longitudinal strain should be 1mm after removing 560kg static load on 250mm cartridge filter and less than 1mm strain in longitudinal direction. The deformation of the lateral front load should not cause cracking even if the external shape is changed when a static load of 1000 kg is applied.

Mechanical strength measurement Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Longitudinal deformation immutability immutability immutability immutability transform Deformation against lateral front load Crackless Crackless Crackless Crackless Crackless

In all cases, no crack occurred in the deformation test for the lateral face load. It can be seen that the strength decreases only when the uneven groove is given by lathe machining in the longitudinal deformation (Comparative Example 2). When the uneven groove is provided by the method of the present invention (Examples 1 to 3), it can be seen that the mechanical strength is maintained as in the case of not providing the uneven groove (Comparative Example 1).

As a result of measuring the four physical properties of the above experimental example, the cartridge filter having the shape manufactured according to the present invention has uniform pores for determining the degree of filtration, and the part pressed by the protrusion of the shape roller is formed of the spun resin. The adhesive state is improved to maintain the mechanical strength of the cartridge filter, and the shape formed by the recess of the shape roller increases the surface area of the filtration and at the same time, is formed to be less dense than the inside so that the impurity collecting amount of the cartridge filter (dirt By increasing the holding capacity, it can be seen that the cylindrical cartridge filter with improved filtration capability.

The inside of the cylindrical cartridge filter according to the present invention has a uniform pore (pore) to determine the degree of filtration, and the portion pressed by the convex portion of the shape roller is improved by the adhesion state of the spun resin core (core) No), no dropping of the filter media, and improved mechanical strength of the cartridge filter. In addition, in the cylindrical cartridge filter according to the present invention, the shape formed by the concave portion of the shape roller has a wider filtration surface area and a smaller density than the inside, so that depth filtration of the cartridge filter is possible. Thereby increasing the dirt holding capacity and increasing the service life.

In addition, since the cylindrical cartridge filter according to the present invention is made of pure polypropylene and has excellent chemical compatibility, and is manufactured by thermal bonding without using an adhesive, there is no dissolution of a surfactant, a lubricant, and the like, and thus safety is excellent.

The manufacturing method of the cylindrical cartridge filter according to the present invention is to form the grooves on the surface of the membrane filter to widen the filtration surface area, and at the same time to form the grooves at the same time molding without the need for additional lathe machining or additional process, It is possible to prevent breakage and to reduce production and manufacturing costs, thereby maintaining economical and material-specific properties of the resin.

Claims (3)

A cylindrical cartridge filter manufactured from a synthetic resin melted, molded and spun by an extruder, wherein the cylindrical cartridge filter is formed at the same time as the cylindrical filter at the time of winding and is pressed by a shape groove provided in the shape roller positioned at a predetermined distance from the winding rod to form irregularities on the surface of the filter. A cylindrical cartridge filter, characterized in that. The cylindrical cartridge filter according to claim 1, wherein a depth from a top of the convex portion of the uneven portion to a bottom of the concave portion is 1 to 10 mm. The cylindrical cartridge filter according to claim 1 or 2, wherein a repetition interval between the unevennesses is 5 mm or more.