Toho Tenax Co., Ltd.

Toho Tenax Europe Gmbh

Hidekazu Yoshikawa

Taro Oyama

Hiroshi Kimura

Shuhei Yoshida

Yosuke Nakamura

Ronny Wockatz

Takaya Suzuki

Dirk Ortmanns

Harumitsu Enomoto

Method for producing a textile unidirectional fabric, wherein at least one planar layer of multi-filament reinforcement threads arranged parallel to each other are woven with each other over transverse threads, wherein transverse threads having core-sheath structure and titer of 10 to 40 tex are used as transverse threads, wherein transverse threads have a first component, which structures sheath, and second component, which structures core, wherein first component has lower melting temperature than second component, first component is meltable thermoplastic polymer material and, via first component of transverse threads, adjacently arranged multi-filament reinforcement threads are connected to each other by hot melting, wherein alleys are formed in unidirectional fabric by interweaving multi-filament reinforcement threads together with transverse threads, by means of which a permeability of 10 to 600 l/dm2/min can be established. Preferred embodiment relates to method for producing unidirectional fabric having fleece. Further, a fiber preform, produced from unidirectional fabric.

Method for producing a textile unidirectional fabric

A carbon fiber strand obtained by bundling 20,000-30,000 carbon fibers each having, in the surface thereof, creases which are parallel to the fiber-axis direction. In an examination with a scanning probe microscope, the creases in the carbon fiber surface are apart from each other at a distance of 120-160 nm and have a depth of 12-23 nm, excluding 23 nm. The carbon fibers have an average fiber diameter of 4.5-6.5 nm, specific surface area of 0.9-2.3 m/g, and density of 1.76 g/cmor higher. The carbon strand has a tensile strength of 5,900 MPa or higher and a tensile modulus of 300 GPa or higher. When would on a bobbin at a tension of 9.8 N, the strand on the bobbin has a width of 5.5 mm or larger. When the carbon fiber strand is examined by a strand splitting evaluation method in which the strand is caused to run through three stainless-steel rods while applying a tension of 9.8 N thereto, no strand splitting is observed.

Carbon fiber strand and process for producing the same

A carbon fiber strand which is produced by obtaining a solidified-yarn strand by spinning with a spinneret having 20,000-30,000 spinning holes, passing the strand through an interlacing nozzle having an air blowing pressure of 20-60 kPa to obtain precursor fibers, oxidizing them in heated air having a temperature of 200-280&#xb0; C. to obtain oxidized fibers, subjecting these oxidized fibers to a first carbonization treatment in an inert-gas atmosphere at a temperature of 300-900&#xb0; C. in which the fibers are firstly stretched in a stretch ratio of 1.03-1.06 and then secondarily stretched in a stretch ratio of 0.9-1.01, subsequently conducting a second carbonization treatment in an inert-gas atmosphere at 1,360-2,100&#xb0; C., and then conducting a surface oxidization treatment in an aqueous solution of an inorganic acid salt in a quantity of electricity of 20-100 C per g of the carbon fibers. This carbon fiber strand has a strand tensile strength of 5,650 MPa or higher, strand tensile modulus of 300 GPa or higher, and strand width of 5.5 mm or larger. No strand crack is observed in an examination by a strand crack evaluation method.

According to the present invention, there is disclosed a carbon fiber having a strand tensile strength of 6,100 MPa or more, a strand tensile modulus of 340 GPa or more and a density of 1.76 g/cmor more and possessing, on the surface, striations oriented in a direction parallel to the fiber axis, wherein the distance between striations in a 2&#xd7;2 &#x3bc;m area of the carbon fiber surface when observed by a scanning probe microscope is 0.1 to 0.3 &#x3bc;m, the root mean square surface roughness Rms (5 &#x3bc;m) in a 5&#xd7;5 &#x3bc;m area of the carbon fiber surface when observed by a scanning probe microscope is 20 to 40 nm, and the root mean square surface roughness Rms (0.5 &#x3bc;m) when measured in a 0.5&#xd7;0.5 &#x3bc;m area is 2 to 12 nm.

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Shizuoka, Japan

Hidekazu Yoshikawa