Sound-absorbing material nonwoven fabric, sound-absorbing material, and method for producing sound-absorbing material nonwoven fabric
AssigneeToray Industries, Inc.
InventorsMakoto Nakahara, Hiroshi Kajiyama
Life of this patent
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Abstract
A sound-absorbing material nonwoven fabric includes: 30 to 80 mass % of short fibers A having a fineness of 0.4 to 0.9 dtex; and 20 to 70 mass % of short fibers B having a fineness of 1.1 to 20.0 dtex. A carding passage coefficient of the short fibers A calculated from equation (1) is in a range of 15 to 260. The equation (1) is carding passage coefficient=(fineness×strength×√elongation percentage×√number of crimps×√crimping degree)/(fiber length).
Claims11
A sound-absorbing material nonwoven fabric comprising:
- 30 to 80 mass % of short fibers A having a fineness of 0.4 to 0.9 dtex;
- and
- 20 to 70 mass % of short fibers B having a fineness of 1.1 to 20.0 dtex,
- a carding passage coefficient of the short fibers A calculated from following equation (1) being in a range of 15 to 260,
- carding passage coefficient=(fineness×strength×√elongation percentage×√number of crimps×√crimping degree)/(fiber length) (1)
- <fineness (dtex), strength (cN/dtex), elongation percentage (%), number of crimps (peaks/25 mm), crimping degree (%), fiber length (cm)>.
A method for producing a sound-absorbing material nonwoven fabric, the method comprising:
- a step of opening short fibers A and short fibers B and obtaining a mixed fiber web comprising the short fibers A and the short fibers B;
- and
- a step of passing the mixed fiber web through a water jet punching nozzle three or more times,
- the short fibers A having a fineness of 0.4 to 0.9 dtex and a carding passage coefficient calculated from equation (1) below in a range of 15 to 260,
- the short fibers B having a fineness of 1.1 to 20.0 dtex,
- a content of the short fibers A being 30 to 80 mass % and a content of the short fibers B being 20 to 70 mass % of the whole of the mixed fiber web,
- carding passage coefficient=(fineness×strength×√elongation percentage×√number of crimps×√crimping degree)/(fiber length) (1)
- <fineness (dtex), strength (cN/dtex), elongation percentage (%), number of crimps (peaks/25 mm), crimping degree (%), fiber length (cm)>.
A method for producing a sound-absorbing material nonwoven fabric, the method comprising:
- a step of opening short fibers A and short fibers B and obtaining a mixed fiber web comprising the short fibers A and the short fibers B;
- and
- a step of needle punching the mixed fiber web with a needle density of not less than 200 needles/cm2,
- the short fibers A having a fineness of 0.4 to 0.9 dtex and a carding passage coefficient calculated from equation (1) below in a range of 15 to 260,
- the short fibers B having a fineness of 1.1 to 20.0 dtex,
- a content of the short fibers A being 30 to 80 mass % and a content of the short fibers B being 20 to 70 mass % of the whole of the mixed fiber web,
- carding passage coefficient=(fineness×strength×√elongation percentage×√number of crimps×√crimping degree)/(fiber length) (1)
- <fineness (dtex), strength (cN/dtex), elongation percentage (%), number of crimps (peaks/25 mm), crimping degree (%), fiber length (cm)>.
Dependencies are inferred from the claim text.