Acrylic

History of Acrylic Fiber

Acrylic fiber is the common name for a synthetic fiber that was the second type developed by DuPont, though it could not initially be made into a fiber. It wasn't until later, when a variety of synthetic fibers had emerged, that acrylic fiber was produced and marketed under the trade name Orlon. Other companies also produced acrylic fibers, such as Acrilan, made by Celanese, and Verel, made by Eastman—fibers that share the same basic composition but differ in manufacturing process. Acrylic is a synthetic fiber composed of a polymer of at least 85% acrylonitrile by weight, along with vinyl cyanide. Once formed into a polymer, it must be dissolved in dimethylformamide in order to be made into fiber, then extruded into filaments. Once the solvent evaporates, acrylic fiber is obtained.

Properties of Acrylic Fiber

1. Fiber Shape
    Under a microscope, viewed lengthwise, the fiber appears translucent and untwisted, with small black flecks scattered throughout. Viewed in cross-section, the shape varies by type—for example, Acrilan is fairly round, Orlon resembles a dumbbell, and Zefran is round with small dots scattered throughout, which are pigments added to reduce shine.
2. Tenacity
    Tenacity varies by type. When dry, the fiber has a tenacity of about 2-4 grams per denier; when wet, tenacity decreases. Although not very high, the tenacity is still good enough to be put to practical use.
3. Elasticity
    Elasticity varies by type, generally ranging between 20-55%. When wet, the fiber can stretch more than when dry.
4. Moisture Absorption
    Moisture absorption is low, at about 1-25% under standard conditions.
5. Heat Resistance
    Acrylic fiber belongs to the thermoplastic fiber group and should not be ironed at temperatures above 325F, as this will cause the fabric's color to fade and yellow, and the fiber to melt into a sticky, rubbery mass. It burns with a yellow flame, leaving hard, round, black ash that doesn't crumble when crushed.
6. Shape Retention
    Has good shape retention and doesn't wrinkle easily.

Chemical Properties of the Fiber

    It withstands mild alkalis well; strong alkalis cause the fiber to weaken and break. It resists dilute mineral acids and organic acids well; concentrated acids reduce the fiber's tenacity and can dissolve it. Organic solvents used for cleaning in laundering and stain removal can be used with all types.

Biological Properties of the Fiber

    Resists mold, insects, and common bacteria well.

Acrylic Fiber and Its Practical Uses

    Acrylic fiber is easy to care for and lightweight. When woven into fabric, it produces a soft-textured cloth that gives warmth similar to animal wool fiber, so it's often blended with animal wool to make faux-fur fabric, such as blankets, rugs, and winter coats.

    However, because acrylic fiber has low moisture absorption, acrylic fabric builds up static electricity, making it uncomfortable to wear. It can be cleaned by either wet washing or dry cleaning; hot water should not be used for washing, and the fabric should not be boiled, as this will cause it to shrink and lose its shape. Acrylic fabric is sold under several trade names, such as Orlon, Acrilan, Zefran, and Creslan.