Teijin Limited

Tetsuo Yamauchi

Shingo Emi

Tsutomu Kiriyama

Susumu Norota

Tadasi Imoto

Yasuhiko Segawa

Yasuhiko Sagawa

A process and apparatus for producing a fibrous assembly. At least one fiber-forming polymer is extruded through a spinneret having numerous small openings. The process uses a die equipped with a spinneret having numerous closely spaced small openings and an opening ratio (.alpha.) of at least 30%. At least one fiber-forming polymer in the form of a shaped mass having a specified compression resistance is continuously stuffed into said die. Said shaped mass has a shape such that it measures more in one direction than in another. There is passed through the spinneret an electric current sufficient to give said fiber-forming polymer Joule heat required for cutting said polymer by partitioning members defining the numerous small openings of the spinneret. The cut fiber-forming polymer is taken up as fine streams. The present invention provides ultrathick aromatic polyamide fibers having an average cross-sectional area of about 0.01 mm.sup.2 to about 5 mm.sup.2 and comprising at least one fiber-forming aromatic polyamide and an inorganic or metallic fine powder or a fibrous material.

Process for producing fibrous assembly

The present invention provides a process for producing a fibrous assembly, which comprises extruding a melt of a fiber-forming polymer through a mesh spinneret, said spinneret including many closely arranged small openings and having an opening ratio (.alpha.), represented by the following formula, of at least about 10% ##EQU1## V.sub.a is the total apparent volume of the spinneret which is taken within a unit area of its mesh portion, and V.sub.f is the total volume of partitioning members defining the small openings which is taken within a unit area of the mesh portion of the spinneret; said extrusion being carried out while generating Joule heat in the partitioning members of the spinneret and cooling the vicinity of the extrusion surface of the spinneret by supplying a cooling fluid, whereby the melt is stably converted into fine streams by the partitioning members; and taking up and solidifying the fine streams; and also provides the process wherein the extrusion surface of the spinneret is turned upward so that the normal vector of the extruding surface is reverse to the direction of gravity, and the fine streams extruded from the extrusion surface are taken up against gravity. The present invention provides a molding apparatus for production of a fibrous assembly having a mesh spinneret which has many closely arranged small openings having an opening ratio .alpha. defined by the above formula of at least 10% and the extrusion surface of the spinneret being turned upwardly such that the normal vector of the extrusion surface is reverse to the direction of gravity.

Process for producing a fibrous assembly

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Iwakuni, Japan

Tetsuo Yamauchi