JP2012000559A - Method of producing filter medium for use in microcylindrical filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem associated with a prior art filter medium for use in a cylindrical filter, of having an insufficient uniformity in its filtration capability caused by unevenly wound fibers or tapes constituting a cylinder or by an uneven surface appearing upon forming a cylinder by directly winding nonwoven fabric, which uneven surface results from overlaying nonwoven fabric of poor texture and an uneven thickness inherent thereto.SOLUTION: Nonwoven fabric 1 constituted of a fiber having a low melting point and a fiber having a high melting point and/or a fiber not having a melting point is first subjected to preheating at a temperature of 30 to 50°C, is subsequently subjected to drying b at a temperature of 70 to 90°C to remove moisture absorbed therein if the nonwoven fabric 1 comprises a hygroscopic fiber such as rayon and nylon, is finally subjected to pressing c on a heated plate or a rotary roll reheated in a range of up to +10°C above the melting point of the fiber of a low melting point to make the surface thereof smooth, and is directly wound around a core member 2 to produce a filter medium 3 for use in a cylindrical filter, having excellent surface smoothness with the interface of the layers of the nonwoven fabric 1 sufficiently thermally bonded. The core member 2 is subsequently extracted, and the filter medium 3 removed of the core member 2 is slit by an intended length in the width direction thereof.

Description

  The present invention relates to a method for producing a filter medium for filtering and purifying a gas containing impurities, particularly in a small apparatus such as a vacuum adsorption conveyance member or a personal computer used in a recent adsorption / desorption automatic conveyance apparatus. The present invention relates to a method of manufacturing a filter material for a micro cylindrical filter suitable for obtaining a predetermined filtration performance for supplying clean air.

  Conventionally, a method for producing a filter material for a cylindrical filter is a method in which a multifilament yarn of silica fiber is wound around a porous core to form a filter cartridge (see, for example, Patent Document 1), or a fabric is slit into a tape shape Is wound around the core material to a predetermined thickness and then heated and cooled to extract the core material to produce a cylindrical filter medium (see, for example, Patent Document 2). Further, the non-woven fabric is wound around the core material to a predetermined thickness. A method of heating after laminating and extracting a core material to obtain a cylindrical filter medium (see, for example, Patent Document 3) is known. In Patent Documents 4 and 5, the filter medium is heated before winding the filter medium around the core material, and a part of the filter medium is melted and wound around the core material to a predetermined thickness. After the filter medium is sufficiently fused and fixed, the filter medium is cooled. A method for obtaining a cylindrical filter medium by extracting a core material is disclosed.

JP 2003-117321 A JP 2001-327817 A Japanese Patent Publication No.56-41290 Japanese Patent No. 2717805 JP 61-102470 A

  However, the filter media manufactured by these conventional methods are finished in a cylindrical shape by laminating the wound groups such as fibers or tapes, or when the nonwoven fabrics are directly wound, the poor texture and thickness of the nonwoven fabric. There was a problem that irregularities appeared on the surface. Moreover, although the size of the cylindrical filter cartridge obtained by these conventional methods is not disclosed clearly, the overall length is 250 mm and the thickness of the filtration layer is 5 to 50 mm when all the descriptions are taken together. All of them are relatively large, and it is almost impossible to assemble and use them in small devices such as vacuum suction transfer members and personal computers used in recent automatic adsorption / desorption type automatic transfer devices.

  In the present invention, in view of the actual situation as described above, the surface of a cylindrical cartridge wound up by heating on a heated plate or a rotating roll to cope with this is made a smooth finished surface, and the size thereof is further reduced. It is an object of the present invention to provide a filter material for a fine filter suitable for supplying air purified by various apparatuses and machines that have been reduced in size by being cylindrical.

  That is, the present invention suitable for the above-mentioned purpose is prepared by blending a fiber containing a heat-fusible low-melting fiber, cooling a nonwoven fabric heat-bonded through card-wrapping, slitting to a width of 10 to 50 cm, preheating and drying After smoothing the thickness of the nonwoven fabric while heating and pressing in the range of + 10 ° C. from the melting point of the low-melting fiber, winding the nonwoven fabric to a desired thickness, cooling, and then removing the core material, Further, the method is characterized in that a filter medium made of a cylindrical non-woven fabric from which the core material has been removed is slit into a desired narrow width in the axial direction of the cylinder and formed into a micro cylindrical filter medium having the narrow width as the axial length. To do.

  More specifically, when a non-woven fabric composed of low-melting fibers and high-melting fibers and / or fibers having no melting point is first preheated at a temperature of 30 to 50 ° C. and then contains fibers that easily absorb moisture such as rayon and nylon. Is dried at 70-90 ° C in order to remove the moisture absorption, and is finally wound again around the core while smoothing the surface by heating and pressurizing again within the range of the melting point of the low melting point fiber to + 10 ° C, and smoothing the surface. The filter material for cylindrical filters which is excellent in the property and the interlayer of the nonwoven fabric is sufficiently fused is obtained, and then the core material is removed and further slit to a desired length in the width direction.

  Here, the fiber including the heat-fusible low-melting fiber constituting the nonwoven fabric is preferably 40 to 90% by weight of the low-melting fiber having a melting point of 100 to 200 ° C., and the melting point is 50 ° C. or more higher than the low-melting fiber. It is a fiber in which 60 to 10% by weight of fibers and / or fibers having no melting point are blended, and the nonwoven fabric is constituted by heating and bonding the fibers through card-wrapping.

  In addition, as a method for drying and heating the nonwoven fabric, it is preferable to heat and press at least one of a heating roll, a heated cylinder drum, and a hot plate to smooth the thickness of the nonwoven fabric. In order to finally make a filter material for a micro cylindrical filter, a non-woven fabric having a thickness of 0.1 to 1 mm is wound around a core material in a cylindrical shape, and then the core material is removed and then slit and wound to have a thickness of 0.5 to 6. A filter medium for a cylindrical filter having a width of 0 mm, a wound outer diameter of 5 to 20 mm, and a cylinder axis length of 5 to 50 mm is used. In addition, the cross-sectional shape of the cylindrical filter medium to be rolled up is not limited to a circle, and may be a polygonal shape such as an ellipse or a square.

  Thus, a micro cylindrical filter medium having a predetermined outer diameter, thickness, and slit length is obtained, and is effectively used to supply purified air in various miniaturized devices and machines.

  As described above, the method of the present invention has a smooth finish as described above, and can obtain a smooth micro-filter material for a filter, so that it can fit in the outer cylinder without any gaps when used in various miniaturized devices. Performance is obtained and has a very significant effect on gas cleaning.

It is process outline | summary figure of this invention manufacturing method. It is a partially-omission perspective view which shows the filter medium for cylindrical filters after winding up. It is a perspective view which shows the filter material for micro cylindrical filters finally obtained.

  Hereinafter, specific embodiments of the production method of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a process example of a manufacturing method according to the present invention. In the figure, reference numeral 1 denotes a non-woven fabric to be a base fabric, which is sequentially processed in the order shown in the figure and wound on the core material 2 to a predetermined thickness. It is important that the non-woven fabric 1 serving as the base fabric is a non-woven fabric composed of at least a fiber including a low-melting fiber having thermal adhesiveness, and in particular, a fiber that is 50 ° C. higher than the melting point of the low-melting fiber and the low-melting fiber and / or Nonwoven fabrics made of a blend of cellulosic fibers such as rayon having no melting point are most effective.

  Here, the low melting point fiber is a fiber having a melting point of 100 to 200 ° C., and the high melting point fiber is a fiber that is 50 ° C. higher than the melting point of the low melting point fiber. , Modified nylon, that is, low-melting polyester, high-melting polyester, low-melting nylon, and high-melting nylon are used.

  In addition, as the fiber having no melting point, a cellulosic fiber such as rayon fiber is used. The blending ratio in blending the low melting point fiber with a fiber having a melting point higher than the melting point of the low melting point fiber by 50 ° C. or higher or a cellulose fiber such as rayon having no melting point is 40 to 90% by weight for the former and the latter Is preferably in the range of 60 to 10% by weight, and when the ratio of the low melting point fiber is 40% by weight or less, the shape stability and tensile strength as a nonwoven fabric are inferior, and there is a risk of breaking in the subsequent steps of heating and winding. Absent. On the other hand, if it exceeds 90% by weight, the heat resistance is inferior, and fusing or unplugging may occur in the heating process, which is not preferable.

  As described above, a fiber containing a low melting point fiber and a fiber having a high melting point or no melting point is heated and bonded through carding and wrapping to form a nonwoven fabric. The present invention is based on the obtained nonwoven fabric. And proceed to subsequent steps. The base fabric 1 in FIG. 1 is the above-mentioned non-woven fabric. First, as the first step a, the present invention once cools the non-woven fabric 1 and then preheats it at 30-50 ° C. while slitting it to a width of 10-50 cm and feeding it by a cylinder. Then, when there is a fiber containing moisture such as cellulosic fiber as the second step b, after drying the moisture absorption at 70 to 90 ° C., as the final step c, a hot plate, a rotary heating roll, a cylinder drum At least one is heated and pressed in the range of + 10 ° C. from the melting point of the low-melting fiber, and the nonwoven fabric is rolled up to a desired thickness while smoothing the thickness and surface irregularities of the nonwoven fabric. FIG. 2 shows the rolled filter medium 3 for a cylindrical filter.

  The purpose of gradually increasing the temperature when heating, melting, pressurizing and winding the nonwoven fabric is to heat the low melting point fiber at one time, in most cases it is heated above the melting point. In some cases, there is a high possibility of occurrence of melt holes due to the poor texture inherent in the nonwoven fabric. Also, when used together with cellulosic fibers such as rayon and hygroscopic fibers such as nylon, moisture in the environment is absorbed, and once heated, moisture cannot be completely released and the temperature does not rise partially, resulting in poor fusion. This is because it may occur and is not preferable.

  Therefore, as a result of diligent efforts, the present inventor first preheated at 30 to 50 ° C. as a preferred heating condition as described above, and then 70 to 90 to remove moisture absorption of fibers that easily absorb moisture such as rayon and nylon. It is found that it is preferable to dry at a temperature of 0 ° C., and finally wrap around the core material 2 while smoothing the surface by applying pressure on a hot plate or rotating roll heated to a range of + 10 ° C. from the melting point of the low melting point fiber. It was. The contact time with the hot plate, heating roll, cylinder drum, etc. is selected according to the type of fiber constituting the filter medium, the amount of fiber used, the thickness, and the like. In the case where hygroscopic fibers such as cellulosic fibers are not used, it is possible to omit the preheating and drying steps, or to set all of them to a high temperature and increase the processing speed as appropriate.

  Thus, the filter material 3 for a cylindrical filter wound around the core material, excellent in surface smoothness and fused between the layers of the non-woven fabric is then pulled out of the core material 2 and desired as indicated by a dotted line in FIG. Is formed into a minute filter medium 4 for a cylindrical filter as shown in FIG.

  In order to form the minute filter medium 4 for the cylindrical filter, it is necessary to have a size that can be adapted to the small apparatus to be used, and the most common range is a winding outer diameter of 5 to 20 mm, a winding thickness of 0. It is made into a cylindrical shape of 5 to 6.0 mm, and it is slit by a length unit of 5 to 50 mm in the width direction in contact with the slit after the core material is removed, so that it becomes a minute cylindrical shape of a desired length. The obtained filter material 4 for a micro cylindrical filter has a micro cylindrical shape as shown in FIG. 3, has an outer diameter of 5 to 20 mm, a thickness of 0.5 to 6.0 mm, and a cylinder axial length of 5. It is a small cylindrical shape in the range of ~ 50mm, it can be easily used for various types of downsized devices and machines, and it can fully meet the requirements of the downsized devices and machines that have been purified gas, It is preferably used for air cleaning of a small apparatus such as a vacuum suction member or a personal computer used in an automatic conveyance device.

Hereinafter, although an example is given and the concrete mode of the present invention is explained, the present invention is not limited to these examples. In the examples,% is based on weight unless otherwise specified.
Example 1
The low melting point fiber has a melting point of 130 ° C., a thickness of 22 dtex, and 60% by weight of a modified polyester fiber having a length of 64 mm, and a melting point of 200 ° C., a thickness of 4.4 dtex, and a length of 51 mm. A 20% by weight polyester fiber having a melting point of 264 ° C., a thickness of 17 dtex, and a length of 51 mm was blended and blended to form a card web having a normal basis weight of 65 g / m ² . Subsequently, the thermocompression-bonding type nonwoven fabric was obtained through a calender roll heated to 210 ° C.

And after leaving the said thermocompression-bonding type | mold nonwoven fabric to cool, after slitting to 20 cm in width and passing through the calender roll heated at 205 degreeC, it is 2 mm in thickness to the core material for winding of diameter 10mm heated to 150 degreeC I rolled it up. After winding, both the core material and the nonwoven fabric were cooled to room temperature, and then the core material was extracted to obtain a cylindrical filter medium. The filter medium was further slit in units of 10 mm in the width direction according to the application, and a minute filter medium for a cylindrical filter was obtained. In the conveying apparatus using the obtained filter medium, it could be used stably for a long time.
Example 2
As a low melting point fiber, melting point 130 ° C., thickness 22 dtex, length 64 mm of modified polyester fiber 70% by weight and melting point 200 ° C., thickness 4.4 dtex, length 51 mm of modified polyester fiber 15% by weight, melting point 264 ° C., After blending 15% by weight of a normal polyester fiber having a thickness of 17 dtex and a length of 51 mm and blending, a card web having a normal basis weight of 80 g / m ² was formed. Subsequently, the calender roll heated at 210 degreeC was passed, and the thermocompression-bonding type nonwoven fabric was obtained.

Next, after leaving the above-mentioned thermocompression bonding type nonwoven fabric to cool, slit to 20 cm, pass through a calender roll heated to 205 ° C., and then fixed to a winding core material having a diameter of 10 m heated to 150 ° C. After winding up to 2 mm, both the core material and the nonwoven fabric were cooled to room temperature, and then the core material was extracted to obtain a cylindrical filter medium. The filter medium was further slit in units of 10 mm in the width direction according to the application, to obtain a minute filter medium for a cylindrical filter. In the conveying apparatus using the obtained filter medium, it could be used stably for a long time.
Example 3
As a low melting point fiber, melting point 130 ° C., thickness 22 dtex, length 64 mm of modified polyester fiber 50% by weight and melting point 200 ° C., thickness 4.4 dtex, length 51 mm of modified polyester fiber 10% by weight, melting point 264 ° C., After blending 10% by weight of a normal polyester fiber having a thickness of 17 ° C. and a length of 51 mm, a rayon fiber having a thickness of 1.4 dtex and a length of 51 mm, a card web having a normal basis weight of 80 g / m ² was formed. Subsequently, the thermocompression-bonding type nonwoven fabric was obtained through a calender roll heated to 210 ° C.

Next, the obtained thermocompression-bonded non-woven fabric was allowed to cool, then slit to a width of 20 cm, passed through two cylinder rolls preheated to 50 ° C., and further absorbed moisture with two cylinder drums heated to 90 ° C. After the removal, it was passed through a calender roll heated to 205 ° C., and then fixed to a winding core material having a diameter of 10 mm heated to 150 ° C., and wound to a thickness of 2 mm.
After winding, both the core material and the nonwoven fabric were cooled to room temperature, and then the core material was extracted to obtain a cylindrical filter medium. The filter medium was further slit in units of 10 mm in the width direction according to the application, to obtain a minute filter medium for a cylindrical filter. In the transport device using the obtained filter medium, it can be used stably for a long time.

  The filter material for a micro cylindrical filter according to the present invention is used in an apparatus for carrying out vacuum adsorption conveyance, vacuum adsorption fixation, and the like for conveying various parts, paper, etc. in the assembly process of semiconductors, automobiles, etc., and the printing process.

1: Substrate nonwoven fabric 2: Core material 3: Filter medium for tubular filter 4: Filter medium for minute tubular filter

Claims (6)

  After blending fibers containing heat-melting melting point fibers, cooling the non-woven fabric that has been heat-bonded via card-wrapping, slitting to a width of 10-50 cm, preheating and drying, the range of + 10 ° C from the melting point of the low melting point fibers A filter comprising a cylindrical nonwoven fabric from which the core material is removed by smoothing the thickness of the nonwoven fabric while heating and pressurizing and winding the nonwoven fabric to a desired core material, cooling, and then removing the core material. A method for producing a filter material for a micro cylindrical filter, wherein the filter medium is slit into a desired narrow width in the axial direction and formed into a micro cylinder having the narrow width as an axial length.   When a non-woven fabric composed of low-melting fibers and high-melting fibers and / or fibers having no melting point is first preheated at a temperature of 30 to 50 ° C. and then contains moisture-absorbing fibers such as rayon and nylon, the moisture absorption Dry at 70 to 90 ° C to remove the component, and finally, heat and press again in the range from the melting point of the low melting point fiber to + 10 ° C to smooth the surface and wrap it directly around the core material, providing excellent surface smoothness and non-woven fabric A method for producing a filter material for a micro cylindrical filter according to claim 1, wherein a filter material for a cylindrical filter in which the layers are sufficiently fused is obtained, and thereafter the core material is removed and further slit to a desired length in the width direction. .    40 to 90% by weight of a low melting point fiber having a melting point of 100 to 200 ° C., 60 to 10% by weight of a fiber having a melting point higher by 50 ° C. than the low melting point fiber and / or a fiber having no melting point, and a card The method for producing a filter material for a micro cylindrical filter according to claim 1 or 2, wherein the nonwoven fabric is heated and bonded through lapping.   3. The micro cylindrical filter according to claim 1, wherein the nonwoven fabric is dried and heated using at least one of a heating roll, a heated cylinder drum, and a hot plate to heat and pressurize and smooth the thickness of the nonwoven fabric. Method for producing filter media.   A non-woven fabric having a thickness of 0.1 to 1 mm is wound on a core material, wound to an outer diameter of 5 to 20 mm and wound thickness of 0.5 to 6.0 mm, and after the core material is removed, it is slit to a width of 5 to 50 mm in the cylinder axis direction. Item 5. A method for producing a filter material for a micro cylindrical filter according to Item 1, 2, 3 or 4.   The method for producing a filter material for a micro cylindrical filter according to any one of claims 1 to 5, wherein the cross-sectional shape of the filter material for a cylindrical filter is a polygon such as a circle, an ellipse, or a square.

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