Acrylic fiber and mfg. process therefor

There is disclosed an acrylic fiber (a) consisting of an acrylonitrile polymer comprising an acrylonitrile unit in at least 80 wt% and less than 95 wt%, (b) having a monofilament dry strength of 2.5 to 4.0 cN/dtex, (c) having a monofilament dry elongation of 35 to 50 %, and (d) forming a crack with a length of 20 mu m or more in its tension rupture lateral surface along the filament axis direction when rupturing the monofilament in a tension test. The fiber has even orientation in its surface and inside; is significantly improved in dry strength, dry elongation and dyeability; and exhibits wool-like hand feeling. It is, therefore, quite suitable as a synthetic fiber for various applications such as a garment material, e.g., a sweater and a home furnishing material such as a pile.