JP2014210231A - Method of manufacturing filter element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a filter element which does not cause deformation of any of a pleated unwoven filter material and a resin frame without taking time and effort.SOLUTION: A method of manufacturing a filter element includes (1) a process of manufacturing a pleated filter material by pleating an unwoven filter material so as to have fold lines extending in parallel to a production direction, (2) a process of manufacturing a precursor filter element by fixing a periphery of the pleated filter material by a resin frame formed by injection molding, and (3) a process of manufacturing the filter element by heating the precursor filter element.

Description

  The present invention relates to a method for producing a filter element in which the periphery of a pleated nonwoven filter material is fixed with a resin frame by injection molding.

  Conventionally, as a method for producing a filtration element, a method of inserting a pleated nonwoven filter material into a mold and molding a resin frame by injection molding and fixing the pleated nonwoven filter medium is known. .

  However, since the resin frame contracts during injection molding, there is a problem in that pressure loss increases as a result of deformation of the pleated nonwoven filter material. In order to prevent such deformation of the non-woven filter material, it was considered to strengthen the non-woven filter material, but on the contrary, as a result of preventing the resin frame from contracting, the resin frame was deformed and filtered. There was a problem that the dimensional accuracy of the element deteriorated.

  As a method of manufacturing a filter element that can solve such problems, the applicant of the present application stated that “the frame side in the crease line direction of the filter medium is molded with the synthetic resin material first and then the other frame side is molded after a while. The manufacturing method of the filter with a frame "(patent document 1) was proposed. According to this method, the above-mentioned problem can be solved, but it is a time-consuming and troublesome method because it is necessary to perform molding twice. In particular, in the case of injection molding, it is a time consuming and laborious method for setting the nonwoven fabric filter material in the mold so that the resin does not leak.

Japanese Patent Laid-Open No. 06-218208

  The present invention has been made under such circumstances, and provides a method for producing a filtration element without deformation of either a pleated nonwoven filter material or a resin frame without taking time and effort. With the goal.

  The invention according to claim 1 of the present invention includes: (1) a step of producing a pleated filter medium by pleating a non-woven filter medium so as to have a crease line extending in parallel with the production direction; ) Fixing the periphery of the pleated filter material with a resin frame by injection molding to manufacture a pre-filter element; and (3) heating the pre-filter element to manufacture the filter element. It is provided with the manufacturing method of the filtration element characterized by comprising. "

  The invention according to claim 1 of the present invention is that a nonwoven filter material is pleated so as to have a crease line extending in parallel with the production direction to produce a pleated filter material, which is fixed by a resin frame by injection molding. Then, since it is heated and manufactured, it is possible to manufacture a filtration element without deformation in any of the pleated nonwoven filter material and the resin frame without taking time and effort.

  In other words, in general, when continuously producing a nonwoven filter medium, since tension tends to work in the production direction and residual strain tends to remain in the production direction, the non-woven filter medium pleated by heating is used. It was found that the deformation of the non-woven filter material generated by the resin frame by injection molding can be corrected by generating shrinkage that relaxes the strain.

Conceptual diagram of the process of manufacturing pleated filter media Front view of the prefilter element Front view of filter element Front view of another filtration element

  The manufacturing method of the filtration element of this invention is demonstrated referring FIGS.

  First, in this invention, as shown in the conceptual diagram of the process which manufactures a pleat type | mold filter medium (2) in FIG. 1, the crease line (2a) which extends a nonwoven fabric filter medium (1) in parallel with the production direction. Pleating so that the pleated filter medium (2) is produced.

  The pleating process is performed after the nonwoven filter material (1) is cut into a desired size so that the processability is excellent.

Moreover, a conventionally well-known thing can be used for the nonwoven fabric filter material (1), and it can select suitably according to desired performance. For example, a nonwoven fabric filter material used for dust removal with a basis weight of 30 to 100 g / m ² can be used.

  Furthermore, pleating can also be performed by a conventionally known method. For example, it can be implemented by a pleating machine such as a reciprocating type or a rotary type, or a method of pressing with a pressing die formed in a zigzag shape. It should be noted that the mountain height and the mountain interval can be appropriately set according to the desired performance.

  Next, a step of manufacturing the precursor filtration element (4) is performed by fixing the periphery of the pleated filter medium (2) with a resin frame (3) by injection molding. When the resin frame (3) is formed by this injection molding and the periphery of the pleated filter medium (2) is fixed by the resin frame (3), the precursor filter element (4) is shown in FIG. ), The pleated filter medium (2) is deformed. For example, polypropylene or ABS resin (acrylonitrile-butadiene-styrene copolymer) is generally used as the resin constituting the resin frame (3), and these resins have a molding shrinkage of 1.0 to 2 in order. Since it is 0.5% and 0.3 to 0.8%, the pleated filter medium (2) is deformed by the shrinkage of the resin frame (3).

  And the said prefiltration element (4) is heated, the process which manufactures a filtration element (5) is implemented, and a pleat type | mold filter material (2) is shown so that the front view of a filtration element (5) may be shown in FIG. ) To produce a filter element (5) with a modified deformation. That is, as described above, the pleated filter medium (2) of the precursor filter element (4) is in a deformed state, but the non-woven filter medium (1) constituting the pleat filter medium (2) has a Since the residual strain tends to remain in the production direction due to the applied tension, heating the precursor filtration element (4) generates shrinkage that relaxes the strain of the pleated filter medium (2), and the injection. Since the deformation of the pleated filter medium (2) generated by the molded resin frame (3) can be corrected, the filter element (5) without deformation of the pleated filter medium (2) can be manufactured.

  The heating temperature and time are not particularly limited as long as the deformation of the pleated filter medium (2) can be corrected. For example, the heating can be performed at a temperature of 100 to 150 ° C. for a time of 30 to 60 seconds. In addition, in order to shorten processing time, it can also implement at still higher temperature and a short time.

  Moreover, it is preferable to carry out heating of the precursor filtration element (4) under no pressure so as not to prevent the shrinkage of the pleated filter medium (2). For example, it can be carried out in an oven.

  Thus, according to the manufacturing method of the filtration element (5) of this invention, the shrinkage | contraction which relieve | moderates the distortion | strain of the nonwoven fabric filter material (1) pleated by heating is generated, and the resin frame (3 The deformation of the non-woven filter material (1) generated by) can be corrected, so that the non-deformable filter element (5) in any of the pleated non-woven filter material (1) and the resin frame (3) Can be manufactured. Moreover, since the injection molding only needs to be performed once, the filtration element (5) without deformation can be manufactured without taking time and labor.

  FIG. 4 shows a front view of another filter element (5). The filter element (5) of FIG. 4 differs from the filter element (5) shown in FIG. 3 only in having a crosspiece (3a). Even if it has such a crosspiece (3a), a pleat type filter medium (2) can be shrunk by heating, and the filtration element (5) without a deformation | transformation can be manufactured.

  In the present invention, even when a filtration element is manufactured by fixing the periphery of a pleated filter medium with a resin frame by injection molding, a filtration element having no deformation can be manufactured. Elements can be manufactured.

DESCRIPTION OF SYMBOLS 1 Nonwoven fabric filter material 2 Pleated filter material 2a Crease line 3 Resin frame 3a Crosspiece 4 Precursor filter element 5 Filter element

Claims (1)

(1) A process for producing a pleated filter medium by pleating a non-woven filter medium so as to have a crease line extending in parallel with the production direction;
(2) A step of manufacturing a precursor filtration element by fixing the periphery of the pleated filter material with a resin frame by injection molding, and (3) a step of manufacturing the filter element by heating the precursor filtration element,
A method for producing a filtration element, comprising:

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