Abstract: A speaker cone comprising a sheet (A) comprised of acrylic synthetic fibers, or a laminate of a sheet (A) and a sheet (B) comprised of the other fibers, in the shape of a cone, wherein the sheet (A) being comprised of acrylic synthetic fibers having a large number of long and narrow voids extending internally along the longitudinal direction, the voids have a nonspecific lateral cross-sectional shapes, the majority of the fibers present at the surface of the sheet (A) is divided into fine fibers, a large amount of undivided acrylic synthetic fibers are present in the inside of the sheet (A), and these fibers are made integral through mutual entanglement, and at least one of the surfaces of the cone shaped article has fused portions of the fibers.

Abstract: An acrylic synthetic fiber having in the transverse section thereof many openings having an indeterminate shape and a size of 0.1 to 1.6 .mu.m, wherein in the interior of the fiber, each opening forms a vein-like or straw-like void extending substantially in parallel to the longitudinal axis of the fiber and having a length of at least 60 .mu.m. This acrylic fiber is prepared by a) dissolving in a suitable solvent an acrylic polymer comprising at least 60 weight % of an acrylonitrile unit and 5 to 20 weight %, based on the weight of the acrylic polymer, of a polyalkylene glycol having a number average molecular weight of 5,000 to 50,000, b) aging the formed spinning solution for at least 4 hours, and c) extruding the spinning solution into a coagulating medium. The acrylic fiber is useful, e.g., as a frictional material comprising (a) a pulpy material made from the acrylic fiber, (b) a resin and (c) a filler.