Abstract: Provided are an amorphous polyetherimide fiber having not only a small single fiber fineness suitable for producing fabrics, and a fabric comprising the amorphous polyetherimide fiber. The fiber comprises an amorphous polyetherimide polymer having a molecular weight distribution (Mw/Mn) of less than 2.5, and having a shrinkage percentage under dry heat at 200° C. of 5% or less, and a single fiber fineness of 3.0 dtex or less. The fiber may have a tenacity at room temperature of 2.0 cN/dtex or greater.

Abstract: Provided are a heat-fusible fiber having excellent heat resistance, flame retardancy and dimensional stability; a fiber structure comprising the heat-fusible fiber; and a molded article produced by applying a heat fusion treatment to the fiber structure and having excellent heat resistance. The heat-fusible fiber comprises an amorphous PES type polymer (A) not substantially having a melting point and an amorphous PEI type polymer (B) in the mixture ratio (weight) of (A)/(B)=5/95 to 95/5, the fiber having a single glass transition temperature in the range between 80° C. and 200° C., and being amorphous. The fiber structure comprises 10% by weight or higher of the amorphous heat-fusible fiber. The molded article comprises at least a fiber structure comprising 10% by weight or higher of the amorphous heat-fusible fiber, to be fusion-bonded at a temperature higher than the glass transition temperature of the amorphous heat-fusible fiber.

Abstract: Provided are an amorphous polyetherimide fiber having not only a small single fiber fineness suitable for producing fabrics, and a fabric comprising the amorphous polyetherimide fiber. The fiber comprises an amorphous polyetherimide polymer having a molecular weight distribution (Mw/Mn) of less than 2.5, and having a shrinkage percentage under dry heat at 200° C. of 5% or less, and a single fiber fineness of 3.0 dtex or less. The fiber may have a tenacity at room temperature of 2.0 cN/dtex or greater.