Fibers, Acrylic

Abstract

Acrylic fibers are spun from copolymers in which acrylonitrile is the major component. The fibers are solution‐spun from solvents such as dimethylformamide, dimethyl sulfoxide, and sodium thiocyanate–water either by wet (extrusion into a nonsolvent) or dry (extrusion into a hot inert gas) technologies. The basic technologies were developed in the 1950s and first commercialized in the United States. Expansion to Europe and Japan soon followed. In the twenty‐first century, the locus has shifted to Asia, with significant down‐sizing in the United States. An extensive table lists producer capacities. Acrylic fibers occupy market niches such as sweaters, half‐hose, upholstery, hand knitting yarns, and carbon fiber precursor. The technology that adapts the basic polymer and fiber for each of these products is described. The physical properties of standard acrylic fiber is compared to that of other synthetic and natural fibers in a table. Stress–strain curves are shown under differing conditions. Chemical properties of the fiber such as resistance to acids and bases and flame retardancy is detailed and compared. Commercial polymer and spinning technologies are explained in detail, including processes for bicomponent and producer‐dyed fiber.