Acrylic fibers are synthetic fibers made from a polymer
(Polyacrylonitrile) with an average molecular weight of 100,000, about
1900 monomer units. To be called acrylic in the U.S, the polymer must
contain at least 85% acrylonitrile monomer. Typical comonomers are vinyl
acetate or methyl acrylate.
Production of Acrylic
The polymer is formed by free-radical
polymerization in aqueous suspension. The fiber is produced by
dissolving the polymer in a solvent such as N,N-dimethylformamide or
aqueous sodium thiocyanate, metering it through a multi-hole spinnerette
and coagulating the resultant filaments in an aqueous solution of the
same solvent (wet spinning) or evaporating the solvent in a stream of
heated inert gas (dry spinning). Washing, stretching, drying and
crimping complete the processing. Acrylic fibers are produced in a range
of deniers, typically from 1 to 15 as cut staple or as a 500,000 to 1
million filament tow. End uses include sweaters, hand-knitting yarns,
rugs, awnings, boat covers, and upholstery; the fiber is also used as a
precursor for carbon fiber. Production of acrylic fibers is centered in
the Far East, declining in Europe and now shut down (except for
precursor) in the U.S. Former U.S. brands of acrylic were Acrilan
(Monsanto). Creslan (American Cyanamid) and Orlon (DuPont).
Textile Uses of Acrylic
Acrylic is lightweight, soft, and
warm, with a wool-like feel. It dyes very well and has excellent
colorfastness. It is resilient, retains its shape, and resists shrinkage
and wrinklesAcrylic has recently been used in clothing as a less
expensive alternative to cashmere, due to the similar feeling of the
materials. The disadvantages of acrylic is that it tends to fuzz (or
pill) easily and that it does not insulate the wearer as well as
cashmere. Many products like fake pashmina or cashmina use this material
to create the illusion of cashmere to the consumer. Acrylic is
resistant to moths, oils, and chemicals, and is very resistant to
deterioration from sunlight exposure. However, static and pilling can be
a problem. Acrylic fiber is a synthetic polymer fiber that contains at
least 85% acrylonitrile.