Search

JP-2026074751-A - Fiber filter material, filtration method, and method for manufacturing fiber filter material

JP2026074751AJP 2026074751 AJP2026074751 AJP 2026074751AJP-2026074751-A

Abstract

[Problem] To provide a fibrous filter material that is excellent at capturing solids, including fine particles with a particle size of 10 μm or less, from water to be treated, allows for precision filtration, and can be reused after washing; a filtration method using the same; and a method for manufacturing the fibrous filter material. [Solution] A fibrous filter material comprising a main fiber and a thermoplastic elastomer, wherein at least a portion of the fiber entanglement points of the main fiber are fixed by the thermoplastic elastomer, the fibrous filter material has a maximum length of 3 mm to 20 mm, and an apparent density of 0.02 g/ cm³ to 0.10 g/ cm³ . [Selection Diagram] None

Inventors

  • 林 邦香
  • 丹下 真也
  • 氏家 秀隆

Assignees

  • 帝人フロンティア株式会社
  • 株式会社石垣

Dates

Publication Date
20260507
Application Date
20241021

Claims (9)

  1. A fibrous filter material comprising a main fiber and a thermoplastic elastomer, At least a portion of the fiber entanglement points of the main fiber are fixed by the thermoplastic elastomer. The aforementioned fibrous filter media has a maximum length of 3 mm to 20 mm and an apparent density of 0.02 g/ cm³ to 0.10 g/ cm³ . Fiber filter media.
  2. The fibrous filter material according to claim 1, wherein the thermoplastic elastomer is a polyether polyester block copolymer, in which polybutylene terephthalate-based polyester is used as the hard segment and polyoxybutylene-based polyether is used as the soft segment.
  3. The fibrous filter material according to claim 1, wherein the compressibility at 20°C is 20% to 70%.
  4. A fibrous filter material according to claim 1, for use in a device having a filtration mechanism.
  5. The fiber filter material according to claim 1, wherein the main fiber comprises short fibers with a fineness of 1 dtex to 4 dtex.
  6. The fibrous filter material according to claim 1, wherein the shape is columnar.
  7. A filtration method comprising filtering using a fibrous filter material described in any one of claims 1 to 6 within a device having a filtration mechanism capable of filtering while maintaining the compacted state of the filter layer.
  8. A method for producing a fiber filter material containing a main fiber and a thermoplastic elastomer, The process includes a step of processing a sliver, which comprises a main fiber and a thermoplastic elastomer, with a die at 100°C to 200°C. A method for manufacturing fiber filter media.
  9. The method for producing a fiber filter material according to claim 8, wherein the main fiber comprises short fibers with a fineness of 1 dtex to 4 dtex.

Description

This invention relates to a fibrous filter material suitable for filtering water, a filtration method, and a method for manufacturing the fibrous filter material. As a filter material for water treatment, fibrous filter media have been developed and are being used as an alternative to sand filtration (see, for example, Patent Document 1). While sand filtration can remove solid particles with a diameter of approximately 10 μm or larger, fiber filtration, which uses fiber filter media, can remove solid particles with a diameter of 5 μm or larger. However, it cannot remove solid particles with even smaller particle sizes; to remove these finer particles, it is common to separate them using microfiltration membranes. Patent No. 2672780 The following describes the fibrous filter media, the filtration method, and the manufacturing method of the fibrous filter media. In this specification, numerical ranges indicated using "~" represent a range that includes the numbers listed before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. In the numerical ranges described herein, the upper or lower limits of those ranges may be replaced with the values shown in the examples. In this specification, the term "process" includes not only independent processes but also any process that cannot be clearly distinguished from other processes, provided that its intended purpose is achieved. In this specification, "fiber filter media" may sometimes be simply referred to as "filter media." <Fiber filter media> The fibrous filter material of the present invention comprises a main fiber and a thermoplastic elastomer, wherein at least a portion of the fiber entanglement points of the main fiber are fixed by the thermoplastic elastomer, and the fibrous filter material has a maximum length of 3 mm to 20 mm and an apparent density of 0.02 g/ cm³ to 0.10 g/ cm³ . The above configuration provides excellent capture of solid particles, including those with a particle size of 10 μm or less, enabling precise filtration, and allowing for repeated use after washing. (Main fiber) The fibrous filter material of the present invention includes a main fiber. Preferably, the main fiber includes polyester short fibers. The polyester staple fibers may be polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polytrimethylene terephthalate, polycyclohexylenedimethylene terephthalate, polypivalolactone, or copolymers thereof. However, from the viewpoint of the elasticity and resilience of the final fiber filter material, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, or polycyclohexylenedimethylene terephthalate are preferred. The polyester staple fibers may also be, for example, heat-bondable composite fibers in which polyethylene terephthalate is used as the core component, with polyethylene and polypropylene arranged around it as sheath components. The fineness of the main fiber is preferably 1 dtex to 4 dtex, more preferably 1.2 dtex to 3.6 dtex, even more preferably 1.5 dtex to 3.2 dtex, and particularly preferably 1.6 dtex to 3 dtex, from the viewpoint of improving filtration performance and the ability to capture fine particles. When the fineness of the main fiber is within this range, the compression characteristics required for a microfiltration fiber filter media are also easily achieved. Regarding the length of the main fibers, from the viewpoint of increasing the number of fiber entanglement points between the main fibers and improving the strength and durability of the fiber filter material, it is preferably 30 mm to 100 mm, more preferably 40 mm to 70 mm, and even more preferably 50 mm to 60 mm. The ratio of fineness to length (mm/dtex) of the main fiber is preferably 5 to 100, more preferably 10 to 50, and even more preferably 15 to 25. When the ratio of fineness to length (mm/dtex) of the main fibers is 5 or higher, filtration performance tends to improve, and the number of fiber entanglement points between the main fibers increases, which tends to improve the strength and durability of the fiber filter media. On the other hand, the ratio of fineness to length (mm/dtex) of the main fiber is 100 or less, making it easier to procure the main fiber. In the fibrous filter media of the present invention, the content of the main fiber is preferably 20% to 90% by mass, and more preferably 30% to 70% by mass, based on the total mass of the fibrous filter media. When the content of the main fiber is within this range, the main fiber can effectively exhibit its properties in the fibrous filter media, and the desired properties can be easily obtained. The specific gravity of the main fiber is preferably in the range of 1.1 to 2. Since the specific gravity of w