Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4382—Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather
  • D04H1/43835—Mixed fibres, e.g. at least two chemically different fibres or fibre blends
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/413—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties containing granules other than absorbent substances
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4382—Stretched reticular film fibres; Composite fibres; Mixed fibres; Ultrafine fibres; Fibres for artificial leather
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4391—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece characterised by the shape of the fibres
  • D04H1/43918—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece characterised by the shape of the fibres nonlinear fibres, e.g. crimped or coiled fibres

Definitions

• the present disclosure relates to a fiber article including a first fiber and a second fiber having an outer diameter smaller than that of the first fiber.
• a fiber article used for applications such as a filter of an air conditioner for example, as disclosed in Patent Document 1, a fiber article including a first fiber and a second fiber having an outer diameter smaller than that of the first fiber is known.
• Patent Document 1 WO 2021/039980
• performance of the fiber article is improved by supporting the second fibers with the first fibers and allowing the first fibers and the second fibers to exhibit their respective functions.
• strength can be improved while weight can be reduced for the fiber article.
• An object of the present disclosure is to, for a fiber article including first fibers and second fibers each having an outer diameter smaller than an outer diameter of each of the first fibers, improve strength while weight is reduced for the fiber article.
• the fiber article according to an aspect of the present disclosure is a fiber article having a sheet shape, the fiber article containing: a plurality of first fibers; and a plurality of second fibers supported in a dispersed state by the plurality of first fibers, each of the plurality of second fibers having an outer diameter that is smaller than an outer diameter of each of the plurality of first fibers, wherein the fiber article has a basis weight having a value in a range of 60 g/m 2 or greater and 300 g/m 2 or less, and a tensile strength in a minimum strength direction in which the tensile strength is minimized among directions perpendicular to a thickness direction having a value in a range of 0.8 N/10 mm or greater and 100 N/10 mm or less.
• a fiber article including first fibers and second fibers each having an outer diameter smaller than that of each of the first fibers, strength is improved while weight is reduced for the fiber article.
• the inventors of the present application focused on a basis weight of a fiber article to be produced and a tensile strength in a minimum strength direction in which the tensile strength is minimized during production of the fiber article, and found that weight reduction and strength improvement can be achieved for the fiber article by adjusting these values to a combination of predetermined ranges.
• the present disclosure solves the issues described above by allowing a fiber article to be composed in a manner that the fiber article has excellent tensile strength in spite of a relatively low value of basis weight.
• FIG. 1 is a schematic view of a fiber article 1 according to a first embodiment.
• FIG. 1 further illustrates an enlarged view schematically illustrating an internal structure of the fiber article 1.
• the fiber article 1 illustrated in FIG. 1 is a filter member that is disposed in a flow path through which a predetermined fluid flows and filters out impurities mixed in the fluid.
• the fluid passing through the inside of the fiber article 1 may be either gas or liquid.
• the gas is, for example, air.
• the fiber article 1 has a sheet shape.
• the fiber article 1 includes a plurality of first fibers 2 and a plurality of second fibers 3 each having an outer diameter smaller than that of each of the plurality of first fibers 2, the plurality of second fibers 3 being supported in a dispersed state by the first fibers 2.
• the fiber article 1 has a basis weight set to a value in a range of 60 g/m 2 or greater and 300 g/m 2 or less (an example is 152 g/m 2 ).
• the basis weight preferably has a value in a range of 60 g/m 2 or greater and 250 g/m 2 or less, and more preferably has a value in a range of 60 g/m 2 or greater and 200 g/m 2 or less, for example.
• the basis weight preferably has a value in a range of 80 g/m 2 or greater and 200 g/m 2 or less, and more preferably has a value in a range of 100 g/m 2 or greater and 200 g/m 2 or less, for example.
• the fiber article 1 has a tensile strength in a minimum strength direction (hereinafter, also referred to as "first direction”) in which the tensile strength is minimized among directions perpendicular to a thickness direction of a value in a range of at least 0.8 N/10 mm or greater.
• the unit “N/10 mm” indicates how much N of a load the fiber sheet can withstand per a measurement width of 10 mm.
• minimum strength direction refers to a width direction of a fiber sheet that is a production intermediate of the fiber article 1 before cutting (hereinafter, also simply referred to as "fiber sheet”) in a production line to continuously produce the fiber article 1.
• minimum strength direction corresponds to a width direction that is perpendicular to a conveyance direction of the fiber sheet.
• the fiber sheet when the fiber sheet is continuously produced by a wet papermaking method, a large number of the short fibers contained in the dispersion liquid as a fiber sheet material are oriented to extend in the conveyance direction of the fiber sheet in a production line.
• the plurality of first fibers included in the fiber sheet is continuously spun by a melt spinning method, an electrospinning method, a dry spinning method, or the like, the first fibers that are long fibers emitted from the spinning cabinet are oriented to extend in the conveyance direction.
• the fiber article usually has a structure in which the plurality of fibers is extended in a direction orthogonal to the minimum strength direction among directions perpendicular to the thickness direction (in other words, a direction corresponding to the conveyance direction of the fiber sheet in the production line, hereinafter, also referred to as a "second direction").
• a direction corresponding to the conveyance direction of the fiber sheet in the production line hereinafter, also referred to as a "second direction"
• entanglement of the plurality of fibers is relatively small in the minimum strength direction.
• the strength of the fiber article is minimized among the plurality of directions perpendicular to the thickness direction.
• the fiber article 1 of the present embodiment has improved tensile strength in the minimum strength direction because the tensile strength in the minimum strength direction is set to a value in a range of at least 0.8 N/10 mm or greater.
• the fiber article 1 of the present embodiment is formed in a manner that the second fibers 3 that are abundant extend in the width direction of the fiber sheet at the time of production.
• the entanglement of the first fibers 2 and the second fibers 3 in the minimum strength direction is increased.
• the tensile strength in the minimum strength direction is further improved by the abundant first fibers 2 and second fibers 3.
• the tensile strength of the fiber article 1 in the minimum strength direction has a value in a range of 100 N/10 mm or less. This prevents the tensile strength of the fiber article 1 from increasing excessively and facilitates the production of the fiber article 1.
• the tensile strength of the fiber article 1 of the present embodiment in the minimum strength direction has a value in a range of 0.8 N/10 mm or greater and 100 N/10 mm or less.
• the range of the tensile strength in the minimum strength direction preferably has a value in a range of 1 N/10 mm or more and 100 N/10 mm or less, and more preferably has a value in a range of 5 N/10 mm or more and 100 N/10 mm or less, for example.
• the range of the tensile strength in the minimum strength direction preferably has a value in a range of 8 N/10 mm or more and 100 N/10 mm or less, and more preferably has a value in a range of 10 N/10 mm or more and 100 N/10 mm or less, for example.
• the fiber article 1 of the present embodiment has a tensile elongation rate in the minimum strength direction with respect to a natural state of a value in a range of at least 5% or greater. Furthermore, the fiber article 1 of the present embodiment has the tensile elongation rate of a value in a range of 250% or less. That is, the tensile elongation rate of the fiber article 1 of the present embodiment has a value in a range of 5% or greater and 250% or less.
• the fiber article 1 is configured in a manner that the fiber article 1 is less likely to be broken even when an external force is applied in the minimum strength direction.
• the tensile elongation rate preferably has a value in a range of 10% or more and 250% or less, and more preferably has a value in a range of 20% or more and 250% or less, for example. In another example, the tensile elongation rate preferably has a value in a range of 30% or more and 250% or less, and more preferably has a value in a range of 40% or more and 250% or less, for example.
• the fiber article 1 of the present embodiment has a thickness set to a value in a range of less than 3.0 mm (an example is 1.1 mm).
• the thickness of the fiber article 1 has, for example, a value in a range of 0.1 mm or greater and less than 3.0 mm.
• This thickness preferably has a value in a range of 0.1 mm or greater and 2.5 mm or less, and more preferably has a value in a range of 0.1 mm or greater and 2.0 mm or less, for example.
• this thickness preferably has a value in a range of 0.5 mm or greater and 2.5 mm or less, and more preferably has a value in a range of 1.0 mm or greater and 2.5 mm or less, for example.
• the "thickness" of the fiber article 1 referred to herein refers to a thickness of the fiber article 1 in a natural state.
• the fiber article 1 of the present embodiment has a PF value set to a value in a range of 16 or greater and 84 or less (an example is 64.
• the PF value referred to herein refers to a value calculated based on Equations 2, 3, and 4 described below.
• a transmittance (%) described in Equation 2 NaCl particles having a particle size of 0.4 ⁇ m generated according to a method described in JIS B9928, Annex 5 (stipulation), Method for Generating NaCl Aerosol (Pressure Spray Method) are used.
• the number of NaCl particles before and after passing of the fiber article 1 when air containing the NaCl particles is caused to pass through the fiber article 1 in the thickness direction at a flow rate of 5.3 cm/sec is measured with a particle counter.
• CO is the number of NaCl particles after passing of the fiber article 1.
• CI is the number of NaCl particles before passing of the fiber article 1.
• the PF value is, for example, preferably a value in a range of 16 or more and 70 or less, and more preferably a value in a range of 16 or more and 60 or less. In another example, for example, the value is preferably in a range of 20 or more and 84 or less, and more preferably in a range of 25 or more and 84 or less.
• pressure loss when air is caused to pass through the fiber article 1 in the thickness direction at a flow rate of 5.3 cm/sec is set to a value in a range of 3 Pa or greater and 35 Pa or less (an example is 6 Pa).
• This pressure loss preferably has a value in a range of 3 Pa or greater and 25 Pa or less, and more preferably has a value in a range of 3 Pa or greater and 15 Pa or less, for example.
• the pressure loss preferably has a value in a range of 6 Pa or greater and 35 Pa or less, and more preferably has a value in a range of 9 Pa or greater and 35 Pa or less, for example.
• This pressure loss is measured by, for example, the following procedure. Set a measurement sample in a holder having an inner diameter of 113 mm (an effective area of 100 cm 2 as a filter medium). Adjust a flow rate of air flowing through the measurement sample to 5.3 cm/sec with a flow meter. At this time, the pressure loss generated between an upstream side and a downstream side in an air flowing direction of the measurement sample is measured by a manometer.
• the fiber article 1 of the present embodiment is set to have a trapping efficiency calculated by Equation 3 of a value in a range of 35% or greater and 95% or less (an example is 61%).
• This trapping efficiency preferably has a value in a range of 35% or greater and 85% or less, and more preferably has a value in a range of 35% or greater and 75% or less, for example.
• this trapping efficiency preferably has a value in a range of 40% or greater and 90% or less, and more preferably has a value in a range of 45% or greater and 90% or less, for example.
• the fiber article 1 of the present embodiment has a nonwoven fabric structure.
• the first fibers 2 are, for example, short fibers.
• the first fibers 2 each have a length in a range of 10 mm or greater and 100 mm or less.
• the first fibers 2 have strength (e.g., tensile strength) larger than that of the second fibers 3.
• the plurality of first fibers 2 is used as a backbone of the fiber article 1.
• the first fibers 2 of the present embodiment are crimped. By use of the plurality of crimped first fibers 2, the fiber article 1 has a reduced fiber density compared to a case where a plurality of uncrimped first fibers 2 is used. Furthermore, as an example, the first fibers 2 are longer than the second fibers 3. As a result, even when the number of the first fibers 2 is relatively small, the abundant second fibers 3 can be stably supported by the first fibers 2.
• the outer diameter D2 of the second fiber 3 is thinner than the outer diameter D1 of the first fiber 2.
• the fiber article 1 has a fiber composite structure with fibers having different diameters.
• the second fibers 3 are supported in a dispersed state by the first fibers 2 in the fiber article 1.
• the second fibers 3 are at least partially attached to the first fibers 2.
• a ratio D1/D2 of the outer diameter D1 of the first fiber 2 to the outer diameter D2 of the second fiber 3 is set to a value in a range of 15.0 or greater and 1666.7 or less.
• the fiber article 1 of the present embodiment contains, for example, the first fibers 2 each having the larger outer diameter D1 and the second fibers 3 each having the outer diameter D2 significantly smaller than the outer diameter D1.
• the ratio D1/D2 is, for example, preferably in a range of 15.0 or greater and 1300.0 or less, more preferably in a range of 15.0 or greater and 714.3 or less, and still more preferably in a range of 15.0 or greater and 300.0 or less.
• the ratio D1/D2 is, for example, preferably in a range of 60.0 or greater and 1666.7 or less, more preferably in a range of 60.0 or greater and 1300.0 or less, still more preferably in a range of 60.0 or greater and 714.3 or less, and still more preferably in a range of 60.0 or greater and 300.0 or less.
• the ratio D1/D2 is 15.0 or greater, for example, the functions of the first fibers 2 and the second fibers 3 having outer diameters different from each other are easily exhibited in the fiber article 1.
• the ratio D1/D2 is 1666.7 or less, for example, a network of the second fibers 3 is easily spread around the first fibers 2 while an increase in the outer diameter D1 of the first fiber 2 is suppressed.
• the second fibers 3 can be easily formed by maintaining the outer diameter D2 at a certain value.
• the ratio D1/D2 is set to a value in a range of 60.0 or greater and 1666.7 or less, an amount of use of the second fibers 3 can be reduced and a production cost of the fiber article 1 can be suppressed while a filter performance of the fiber article 1 is improved.
• the outer diameter D1 for example, a value in a range of 5.0 ⁇ m or greater and 50.0 ⁇ m or less is preferable, and a value in a range of 20.0 ⁇ m or greater and 30.0 ⁇ m or less is more preferable. According to this configuration, the plurality of second fibers 3 can be easily disposed abundantly around the first fibers 2 while the second fibers 3 are stably supported by the first fibers 2.
• the outer diameter D2 for example, a value in a range of 30.0 nm or more and 1.0 ⁇ m or less is preferable, a value in a range of 30.0 nm or more and 800 nm or less is more preferable, and a value in a range of 30.0 nm or more and 166.7 nm or less is still more preferable.
• the outer diameter D2 preferably has a value in a range of 50.0 nm or more and 800.0 nm or less, for example. This configuration makes it possible to increase the ratio D1/D2 while an excessive decrease in the outer diameter D2 of the second fiber 3 is avoided. As a result, the fiber article 1 abundantly containing the plurality of second fibers 3 can be stably formed.
• a ratio V1/V2 of the total volume V1 of the first fibers 2 to the total volume V2 of the second fibers 3 and resin particles 4 is set to a value in a range of 1.9 or greater and 124.0 or less.
• the ratio V1/V2 is further preferably set to a value in a range of 20.0 or greater and 124.0 or less. Setting the ratio D1/D2 and the ratio V1/V2 to values in the ranges described above makes the outer diameter D1 of the first fiber 2 be different from the outer diameter D2 of the second fiber 3, and thus the functions of the first fibers 2 and the second fibers 3 can be easily exhibited.
• the fiber article 1 has fiber gaps between the plurality of crimped first fibers 2 and fiber gaps between the plurality of second fibers 3.
• the fiber article 1 has a network of the plurality of crimped first fibers 2 and the plurality of second fibers 3. Because the second fibers 3 are fixed to the first fibers 2 in the fiber article 1 of the present embodiment, even when an external force is applied to the fiber article 1, the network is less likely to be broken.
• the second fibers 3 are supported by the first fibers 2 with the second fibers 3 intertwined with the first fibers 2. Accordingly, even when the outer diameter D2 of the second fiber 3 is smaller than the outer diameter D1 of the first fiber 2, the second fibers 3 can be supported by the first fibers 2 while damage such as cutting of the second fibers 3 is prevented. Therefore, the function of the second fibers 3 can be maintained over a long period of time.
• the plurality of second fibers 3 is arranged dispersed in a wide region extending in an extension direction of the plurality of the first fibers 2 in the fiber article 1 having a sheet shape.
• the fiber article 1 abundantly contains fiber gaps formed by the plurality of first fibers 2 and the plurality of second fibers 3.
• occurrence of unevenness of fiber gaps between the plurality of first fibers 2 and the plurality of second fibers 3 is suppressed in the first direction and the second direction that are extending orthogonally to each other within a plane perpendicular to the thickness direction.
• the fluid when a fluid is allowed to flow in the fiber article 1 by arranging the flow path in the fiber article 1, the fluid is brought into contact with the first fibers 2 and the second fibers 3 evenly to facilitate exhibition of the functions of the first fibers 2 and the second fibers 3. Furthermore, due to the formation of the network in the fiber article 1, the form of the fiber article 1 can be maintained, and the filter performance of the fiber article 1 can be stably maintained.
• the second fibers 3 of the present embodiment are formed from resin particles 4 attached to first fibers 2 in the production of the fiber article 1.
• the resin particles 4 are extrusion-molded bodies produced by a paste extrusion method.
• the resin particles 4 contain a polymer that is fiberizable.
• the second fibers 3 are formed from the resin particles 4 by applying a first external force, to the resin particles 4 attached to the plurality of first fibers 2, in such a direction that fiber gaps between the first fibers 2 are compressed (reduced) and then by applying a second external force in a direction that allows relaxation of the first external force.
• the second fibers 3 are also formed by expansion of fiber gaps between the plurality of first fibers 2 as a result of relaxation of the first external force applied to the resin particles 4.
• the abundant second fibers 3 are actively formed by application of the second external force to the resin particles 4.
• the resin particles 4 slightly remain in the manufactured fiber article 1. In some cases, the resin particles 4 do not remain in the fiber article 1 due to the method of manufacturing the fiber article 1 or the like.
• the resin particle 4 internally includes a lamellar structure.
• the "lamellar structure” herein refers to a structure in which polymer chains constituting a resin of the resin particles 4 are linked and folded.
• the lamellar structure contained in the resin particle 4 is formed of fine fibers, in which the polymer chains are linked in millions and formed into a ribbon shape.
• the fine fibers are folded and contained in the resin particle 4.
• the fiber article 1 by applying the first external force to the plurality of resin particles 4 attached to the plurality of first fibers 2 and then applying the second external force to the conveyance direction and the width direction, the plurality of second fibers 3 extending in the conveyance direction and the plurality of second fibers 3 extending in the width direction are formed.
• unevenness of fiber gaps in at least the first direction and the second direction is suppressed, and a fiber article 1 having a tensile strength in a minimum strength direction, which is perpendicular to the thickness direction, having a value in a range of 0.8 N/10 mm or greater and 100 N/10 mm or less can be produced.
• the fiber gaps are properly expanded, and a fiber article 1 having a basis weight having a value in a range of 60 g/m 2 or greater and 300 g/m 2 or less can be produced.
• the material of the first fibers 2 can be selected as appropriate.
• the resin particles 4 are attached to the first fibers 2 by allowing an aqueous dispersion containing the resin particles 4 (hereinafter, simply referred to as aqueous dispersion) to attach to the first fibers 2.
• aqueous dispersion an aqueous dispersion containing the resin particles 4
• the raw material of the first fibers 2 is preferably a raw material having a low water contact angle ⁇ 1 to some extent immediately after a water droplet is dropped on a surface of the first fibers 2.
• the first fibers 2 contain at least one of rayon, polypropylene (PP), polyethylene terephthalate (PET), polyethylene (PE), or cellulose acetate. With such a raw material, the water contact angle ⁇ 1 can be suppressed to a relatively low value.
• the first fibers 2 of the present embodiment are cellulose acetate fibers.
• the fiber article 1 includes the plurality of first fibers 2 produced by crimping and opening a tow (band) including cellulose acetate fibers. As a result, the fiber article 1 is configured to readily have a desired bulkiness.
• the first fibers 2 and the second fibers 3 have good affinity with each other.
• the second fibers 3 of the present embodiment are attached to the first fibers 2 by, for example, van der Waals force.
• the second fibers 3 contain a polymer that is fiberizable.
• the second fibers 3 are attached to the first fibers 2 in a state where the second fibers 3 intersect the first fibers 2.
• the second fibers 3 preferably contain, as polymers that is fiberizable, at least one of polytetrafluoroethylene (hereinafter, also referred to as PTFE), polypropylene (PP), polyethylene (PE), or polyamide (PA).
• PTFE polytetrafluoroethylene
• PP polypropylene
• PE polyethylene
• PA polyamide
• the second fibers 3 of the present embodiment contain PTFE as a main component. In other words, the second fibers 3 contain PTFE in an amount of greater than 50 wt.% of the total weight of the second fibers 3.
• the second fibers 3 of the present embodiment are ultrafine fibers of PTFE.
• PTFE that is a raw material of the second fibers 3 is, for example, a high molecular weight PTFE produced by emulsion polymerization or suspension polymerization of TFE.
• the high molecular weight PTFE may be at least any of modified PTFE or homo PTFE.
• the modified PTFE contains, for example, TFE and a monomer other than TFE such as a modified monomer.
• the modified PTFE is uniformly modified by the modified monomer or is modified at an early or end stage of the polymerization reaction, but the modified PTFE is not particularly limited.
• the modified PTFE includes a TFE unit based on TFE and a modified monomer unit based on the modified monomer.
• modified monomer unit is a part of a molecular structure of the modified PTFE, and is a part derived from the modified monomer. As long as the modified monomer can be copolymerized with TFE, the modified monomer is not particularly limited.
• the "high molecular weight" of the high molecular weight PTFE herein refers to a molecular weight at which PTFE is easily fiberized at the time of producing the fiber article 1 and at which a fibril having a long fiber length is produced.
• the high molecular weight has a value of a standard specific gravity (SSG) in a range of 2.130 or greater and 2.230 or less, and indicates a molecular weight at which melt flow substantially does not occur because of high melt viscosity.
• SSG standard specific gravity
• the water contact angle ⁇ 2 immediately after dropping a water droplet on a surface of the fiber article 1 is preferably a value that is low to a certain extent.
• the water contact angle ⁇ 2 is preferably a value in the range that is the same as or similar to that of the water contact angle ⁇ 1.
• the water contact angles ⁇ 1, ⁇ 2 can be measured, for example, by observing the surface of a target object on which water droplets have been dropped, from the side of the water droplets with a microscope.
• the water contact angles ⁇ 1, ⁇ 2 are calculated as an average value of measurement values obtained, for example, by using a commercially available contact angle meter (contact angle meter "DMs-401" available from Kyowa Interface Science Co., Ltd.), dropping water droplets onto a target object, and measuring the contact angles by five-point measurement.
• the water contact angles ⁇ 1, ⁇ 2 are set to relatively low values in order to increase the affinity of the first fibers 2 to the aqueous dispersion, but the water contact angles ⁇ 1, ⁇ 2 may be set to relatively high values, for example, in accordance with characteristics of a dispersion that disperses the resin particles 4.
• the dispersion liquid containing the resin particles 4 in a dispersed state may be adjusted, whereby, for example, the contact angle to the surface of the first fibers 2 is low.
• the water contact angles ⁇ 1, ⁇ 2 can be set to somewhat free values.
• the fiber article 1 contains the plurality of first fibers 2 and the plurality of second fibers 3 each having an outer diameter D2 smaller than that of the first fiber 2, the plurality of second fibers 3 being supported in a dispersed state by the plurality of first fibers 2, and the basis weight is set to a value in a range of 60 g/m 2 or greater and 300 g/m 2 or less.
• the fiber article 1 contains abundant fiber gaps formed by the first fibers 2 and the second fibers 3 together with the basis weight set to a relatively low value. Therefore, the weight of the fiber article 1 can be easily reduced.
• the fiber article 1 has a tensile strength in a minimum strength direction among directions perpendicular to a thickness direction set to a value in a range of 0.8 N/10 mm or greater and 100 N/10 mm or less. As a result, strength of the fiber article 1 is improved. Thus, for example, even when an external force is applied to the fiber article 1 at the time of use, the form of the fiber article 1 can be maintained. Therefore, stable filter performance of the fiber article 1 can be achieved.
• the range of external forces that can be applied to the fiber sheet in the minimum strength direction of the fiber article 1 during the production of the fiber article 1 improves.
• the fiber gaps can be more abundantly provided in the produced fiber article 1. Therefore, the weight of the fiber article 1 can be easily reduced.
• the resin particles 4 containing a polymer that is fiberizable to attach to the first fibers 2 and applying an external force to the resin particles 4 adjustment of the external force applied to the resin particles 4 can be facilitated in a case where the second fibers 3 are made from the resin particles 4. This makes it easy to form the second fibers 3 abundantly.
• the fiber article 1 of the present embodiment has a tensile elongation rate in the minimum strength direction with respect to a natural state of a value in a range of 5% or greater and 250% or less. According to this configuration, the strength of the fiber article 1 can be further improved. Thus, for example, even when the external force reaches the fiber article 1 during use, fracture and damage of the fibers 2 and 3 in the fiber article 1 can be prevented. Furthermore, breakage of the fiber article 1 can be prevented.
• the fiber article 1 of the present embodiment has a thickness in a natural state in a range of less than 3.0 mm. This makes it possible to make the fiber article 1 thin. Therefore, size reduction of the fiber article 1 can be further achieved.
• the fiber article 1 includes the first fibers 2 and the second fibers 3 each having an outer diameter D2 smaller than that of the first fiber 2, the plurality of second fibers 3 can be supported by the plurality of first fibers 2 in a state where the first fibers 2 and the second fibers 3 are dispersed each other. Accordingly, the plurality of second fibers 3 can be stably maintained by the plurality of first fibers 2 while cutting of the second fibers 3 is prevented.
• the strength of the fiber article 1 can be improved, and the filter performance can be improved by bringing the first fibers 2 and the second fibers 3 in the fiber article 1 into contact with a fluid stably and efficiently during use.
• relatively large fiber gaps formed by the plurality of first fibers 2 and relatively small fiber gaps formed by the plurality of second fibers 3 can be both formed abundantly in the fiber article 1.
• the functions of the first fibers 2 and the second fibers 3 that have a predetermined outer diameter difference are easily exhibited for a fluid flowing inside the fiber article 1.
• the second fibers 3 each having an extremely thin outer diameter D2 that is 1.0 ⁇ m or less are supported by first fibers 2 each having a relatively thick outer diameter D1.
• first fibers 2 each having a relatively thick outer diameter D1.
• the fiber article 1 has the outer diameter D1 set to a value in a range of 5.0 ⁇ m or greater and 50.0 ⁇ m or less.
• the first fibers 2 can be formed in a manner that the first fibers 2 each have proper thickness.
• the strength of the first fibers 2 can be further improved.
• the strength of the fiber article 1 can be improved to achieve stable filter performance by allowing exhibition of the functions of the first fibers 2 and the second fibers 3 for a long period of time.
• the outer diameter D1 is set to a value in a range of 20.0 ⁇ m or greater and 30.0 ⁇ m or less.
• the first fibers 2 are crimped.
• the first fibers 2 are configured to be bulkier compared to an uncrimped state.
• the fiber gaps formed by the plurality of first fibers 2 can be abundantly disposed in the fiber article 1.
• the weight reduction and size reduction of the fiber article 1 can be facilitated, and exhibition of the functions of the first fibers 2 and the second fibers 3 can be further facilitated by bringing the first fibers 2 and the second fibers 3 into contact with a fluid.
• the first fibers 2 of the present embodiment contains at least one of rayon, polypropylene, polyethylene terephthalate, polyethylene, or cellulose acetate.
• a selection range of the material of the first fibers 2 can be expanded.
• a degree of freedom in designing the fiber article 1 can be improved.
• the second fibers 3 contain a polymer that is fiberizable.
• the second fibers 3 can be efficiently produced by fiberization of the polymer by allowing a material containing the polymer to attach to the first fibers 2.
• the second fibers 3 of the present embodiment include at least one of polytetrafluoroethylene, polypropylene, polyethylene, or polyamide. By this, a selection range of the material of the second fibers 3 can be expanded. Thus, a degree of freedom in designing the fiber article 1 can be further improved.
• the second fibers 3 contain polytetrafluoroethylene as a main component.
• the main component refers to a component whose content exceeds 50 wt.% of the second fibers 3.
• the function of polytetrafluoroethylene can be stably achieved by the fiber article 1.
• the fiber article 1 of the present embodiment includes the resin particles 4 that are attached to the first fibers 2 and made of a composition that is the same as or similar to that of the second fibers 3.
• the ratio V1/V2 of the total volume V1 of the first fibers 2 to the total volume V2 of the second fibers 3 and the resin particles 4 is set to a value in a range of 1.9 or greater and 124.0 or less.
• the second fibers 3 each having the small outer diameter D2 and small volume can be stably supported by the first fibers 2 each having the large outer diameter D1 and large volume.
• the function of the second fibers 3 can be more stably and easily exhibited.
• the filter performance can be improved even for the fiber article 1 having a basis weight set to a relatively small value.
• the pressure loss of the fiber article 1 when air is passed through the fiber article 1 at a flow rate of 5.3 cm/sec in the thickness direction is set to a value in a range of 3 Pa or greater and 35 Pa or less.
• a fluid can be efficiently flown inside the fiber article 1. Therefore, performance deterioration along with the use of the fiber article 1 can be prevented.
• a fluid can be brought into contact with the first fibers 2 and the second fibers 3 in the fiber gaps of the fiber article 1, and thus exhibition of the functions of the first fibers 2 and the second fibers 3 is facilitated.
• the PF value of the fiber article 1 is set to a value in a range of 16 or greater and 84 or less.
• FIG. 2 is a cross-sectional view of a fiber composite 10 according to a second embodiment.
• the fiber composite 10 includes a first sheet 6, a second sheet 7, and a third sheet 8.
• the first sheet 6 and the second sheet 7 are each a fiber article 1 of the first embodiment.
• the first sheet 6 and the second sheet 7 are disposed overlapping each other.
• the thicknesses of the first sheet 6 and the second sheet 7 are the same but may be different.
• the third sheet 8 is disposed overlapping the first sheet 6 and the second sheet 7 in between the first sheet 6 and the second sheet 7.
• the third sheet 8 includes nonwoven fabric.
• the third sheet 8 contain an identical or different material from that of the fiber article 1.
• the third sheet 8 of the present embodiment may contain at least one of a resin fiber or a pulp fiber.
• the fiber composite 10 has improved strength and bulkiness compared to those of a single fiber article 1 because the plurality of sheets 6 to 8 is disposed overlapping.
• a fiber composite 10 having improved strength can be produced by using the first sheet 6 and the second sheet 7 that are the fiber articles 1 of the present embodiment. Furthermore, the weight of the fiber composite 10 is reduced because the basis weights of the first sheet 6 and the second sheet 7 are reduced. Furthermore, for example, by adjusting at least the thickness of any of the plurality of sheets 6 to 8, adjustment of the total thickness of the fiber composite 10 can be facilitated. By this, size reduction of the fiber composite 10 can be achieved.
• the configuration of the fiber composite using the fiber article 1 is not limited to that of the second embodiment.
• the fiber composite may have a structure in which the third sheet is disposed on at least one of the both sides of the first sheet 6 in the thickness direction.
• the fiber composite may have a structure in which the plurality of first sheets and the plurality of third sheets are disposed alternately.
• a fiber article 1 of Example 1 was produced.
• Cellulose acetate fibers having a plurality of crimped short fibers each having an outer diameter D1 of 20 ⁇ m were used as first fibers 2.
• PTFE fibers each having an outer diameter D2 of 70 nm were used as the second fibers 3.
• fiber articles 1 of Examples 1 to 7 were produced.
• fiber articles of Comparative Examples 1 to 6 were produced.
• the second external force was applied to a fiber sheet, which was a production intermediate, at the time of production of Examples 1 to 7.
• no second external force was applied to a fiber sheet at the time of production of Comparative Examples 1 to 6.
• the basis weight and thickness were measured.
• the pressure loss, trapping efficiency (using NaCl particles having a particle size of 0.4 ⁇ m), and PF value of each of the fiber articles were measured based on the methods described in Embodiments.
• the tensile strength and elongation rate in the minimum strength direction (first direction) of each of the fiber articles were measured based on the methods described in Embodiments.
• the tensile strength and elongation rate in an orthogonal direction that is orthogonal to the minimum strength direction (second direction) of each of the fiber articles were measured.
• a J-ePM1 trapping efficiency (%) was measured based on a method in accordance with an item 7.2 "Calculation of particulate matter trapping rate (J-eMPx)" in a general ventilation filter test (JIS B 9908-1:2019).
• J-eMPx particulate matter trapping rate
• JIS B 9908-1:2019 general ventilation filter test
• a particulate matter obtained by reducing the particulate matter by 50% with a classifying device at an aerodynamic particle size of 1 ⁇ m was used as a particulate matter (PM1) for testing.
• the measurement results and the evaluation results are shown in Tables 1 and 2.
• the tensile strength of the fiber article 1 in the minimum strength direction had a value in a range of 1.5 N/10 mm or greater and 100 N/10 mm or less. In another example, the tensile strength of the fiber article 1 in the minimum strength direction had a value in a range of 9.9 N/10 mm or greater and 100 N/10 mm or less. In another example, the tensile strength of the fiber article 1 in the minimum strength direction had a value in a range of 10.5 N/10 mm or greater and 100 N/10 mm or less.
• the tensile strength of the fiber article 1 in the minimum strength direction had a value in a range of 10.8 N/10 mm or greater and 100 N/10 mm or less. According to an embodiment, the tensile strength of the fiber article 1 in the minimum strength direction had a value in a range of 0.8 N/10 mm or greater and 100 N/10 mm or less.
• the elongation rate of the fiber article 1 in the minimum strength direction had, for example, a value in a range of 24.1% or greater and 250% or less. In another example, the elongation rate of the fiber article 1 in the minimum strength direction had a value in a range of 28.4% or greater and 250% or less. In another example, the elongation rate of the fiber article 1 in the minimum strength direction had a value in a range of 99.7% or greater and 250% or less. In another example, the elongation rate of the fiber article 1 in the minimum strength direction had a value in a range of 120.7% or greater and 250% or less. In another example, the elongation rate of the fiber article 1 in the minimum strength direction had a value in a range of 171.8% or greater and 250% or less.
• the tensile strength of the fiber article 1 in the minimum strength direction had a value in a range of at least 0.8 N/10 mm or greater. Furthermore, in Examples 1 to 7, the elongation rate of the fiber article 1 in the minimum strength direction had a value in a range of at least 24.1% or greater.
• the tensile strength in the minimum strength direction and the elongation rate in the minimum strength direction were unmeasurable in each of Comparative Examples 1 to 6.
• the tensile strength in the orthogonal direction was 14.2 N/10 mm, which was higher than the tensile strength in the orthogonal direction of each of Examples 1 to 4.
• Comparative Examples 1 to 6 each had a tensile strength, which was small and unmeasurable, in the minimum strength direction. Thus, it is likely that the fiber articles of Comparative Examples 1 to 6 had inferior strength overall compared to the fiber articles of Examples 1 to 7. The results described above confirmed that Examples 1 to 7 each had improved strength compared to Comparative Examples 1 to 6.
• the basis weight of the fiber article 1 had, for example, a value in a range of 60 g/m 2 or greater and 92 g/m 2 or less. In another example, the basis weight of the fiber article 1 had a value in a range of 60 g/m 2 or greater and 82 g/m 2 or less. In another example, the basis weight of the fiber article 1 had a value in a range of 60 g/m 2 or greater and 70 g/m 2 or less.
• Examples 1 to 7 each had the basis weight adjusted to a value in a wider range than those of Comparative Examples 1 to 6 and also had the thickness reduced to lower than those of Comparative Examples 1 to 6. Accordingly, it was confirmed that, in Examples 1 to 7, weight reduction and size reduction were facilitated compared to Comparative Examples 1 to 6.
• the J-ePM1 trapping efficiency (%) had a value of 50% or greater.
• each of Examples 1 to 7 corresponded to a filter group classified as "JIS-ePM1" in the item 7.3 "Classification" of JIS B 9908-1:2019.
• the fiber article of the present disclosure can be said to be a filter having a high-quality filter function classified as "JIS-ePM1".
• the J-ePM1 trapping efficiency (%) had a value of 50% or more.
• Comparative Examples 1 to 6 had lower performances than those of Examples 1 to 7 as described above.
• a fiber article having a sheet shape the fiber article containing:
• the fiber article contains abundant fiber gaps formed by the first fibers and the second fibers together with the basis weight set to a relatively low value. Therefore, the weight of the fiber article can be easily reduced. Furthermore, the strength of the fiber article can be improved by setting the tensile strength in the minimum strength direction among directions perpendicular to the thickness direction to a value in the range described above. Thus, for example, even when an external force is applied to the fiber article at the time of use, the form of the fiber article can be maintained. Therefore, stable filter performance of the fiber article can be achieved.
• the fiber article according to Aspect 1, wherein a tensile elongation rate in the minimum strength direction with respect to a natural state has a value in a range of 5% or greater and 250% or less.
• the strength of the fiber article can be further improved.
• fracture and damage of the first fibers and the second fibers in the fiber article can be prevented.
• breakage of the fiber article can be prevented.
• the fiber article can be made thin. Therefore, size reduction of the fiber article can be further achieved.
• the configuration described above makes it possible to increase the ratio D1/D2 while an excessive decrease in the outer diameter D2 of the second fibers is avoided. As a result, the fiber article abundantly containing the plurality of second fibers can be stably formed.
• the fiber article according to Aspect 4 wherein the outer diameter D1 is set to a value in a range of 20.0 ⁇ m or greater and 30.0 ⁇ m or less.
• the plurality of second fibers can be easily disposed abundantly around the first fibers while the second fibers are stably supported by the first fibers.
• the first fibers are configured to be bulkier compared to an uncrimped state.
• the fiber gaps formed by the plurality of first fibers can be abundantly disposed in the fiber article.
• the weight reduction and size reduction of the fiber article can be facilitated, and exhibition of the functions of the first fibers and the second fibers can be further facilitated by bringing the first fibers and the second fibers into contact with a fluid.
• a selection range of the material of the first fibers can be expanded.
• a degree of freedom in designing the fiber article can be improved.
• the second fibers can be efficiently produced by fiberization of the polymer by allowing a material containing the polymer to attach to the first fibers.
• a selection range of the material of the second fiber can be expanded.
• a degree of freedom in designing the fiber article can be further improved.
• the second fibers each having the small outer diameter D2 and small volume can be stably supported by the first fibers each having the large outer diameter D1 and large volume.
• the function of the second fibers can be more stably and easily achieved.
• the filter performance can be improved even for the fiber article having a basis weight set to a relatively small value.
• a pressure loss when air is passed through the fiber article at a flow rate of 5.3 cm/sec in a thickness direction is set to a value in a range of 3 Pa or greater and 35 Pa or less.
• clogging of the fiber article during use can be prevented, and a fluid can be efficiently flown inside the fiber article. Therefore, performance deterioration along with the use of the fiber article can be prevented. Furthermore, when the pressure loss of the fiber article is suppressed to the value in the range described above, a fluid can be brought into contact with the first fibers and the second fibers in the fiber gaps of the fiber article, and thus exhibition of the functions of the first fibers and the second fibers is facilitated.
• the fiber article of the present disclosure can be used as a high-quality filter classified into the filter group of "JIS-ePM1".
• a fiber composite including a first sheet, a second sheet, and a third sheet, the first sheet and the second sheet being the fiber articles described in any one of Aspects 1 to 12 and being disposed overlapping each other, and the third sheet being disposed overlapping the first sheet and the second sheet in between the first sheet and the second sheet.
• a fiber composite having improved strength can be produced by using the first sheet and the second sheet. Furthermore, the weight of the fiber composite can be reduced because the basis weights of the first sheet and the second sheet are reduced. Furthermore, for example, by adjusting at least one of the thicknesses of the first to third sheets, adjustment of the total thickness of the fiber composite can be facilitated. By this, size reduction of the fiber composite can be achieved.
• the configurations in the embodiments and combinations thereof are examples. Addition, omission, substitution, and other changes of the configurations can be appropriately made without departing from the gist of the present disclosure.
• the present disclosure is not limited by the embodiment, and is limited only by the claims.
• the aspects disclosed in the present specification can be combined with any other feature disclosed herein.
• the size of the fiber article 1 is not limited. Additionally, the fiber article 1 may be used in a state where a plurality of the fiber articles 1 is combined.

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• Textile Engineering (AREA)
• Filtering Materials (AREA)
• Nonwoven Fabrics (AREA)

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• 2024
  • 2024-04-25 JP JP2025518137A patent/JPWO2024228360A1/ja active Pending
  • 2024-04-25 CN CN202480028905.1A patent/CN121039337A/zh active Pending
  • 2024-04-25 WO PCT/JP2024/016295 patent/WO2024228360A1/ja not_active Ceased
  • 2024-04-25 EP EP24800091.1A patent/EP4707445A1/en active Pending

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