Cellulose acetate or acetate rayon fiber (1924) is one of the earliest
synthetic fibers and is based on cotton or tree pulp cellulose
("biopolymers"). These "cellulosic fibers" have passed their peak as
cheap petro-based fibers (nylon and polyester) and have displaced
regenerated pulp fibers.
The Federal Trade Commission
definition for acetate fiber is "A manufactured fiber in which the
fiber-forming substance is cellulose acetate. Where not less than 92
percent of the hydroxyl groups are acetylated, the term triacetate may
be used as a generic description of the fiber."
Acetate is derived from cellulose by deconstructing wood pulp into a
purified fluffy white cellulose. The cellulose is then reacted with
acetic acid and acetic anhydride in the presence of sulfuric acid. It
is then put through a controlled, partial hydrolysis to remove the
sulfate and a sufficient number of acetate groups to give the product
the desired properties. The anhydroglucose unit is the fundamental
repeating structure of cellulose and has three hydroxyl groups which
can react to form acetate esters. The most common form of cellulose
acetate fiber has an acetate group on approximately two of every three
hydroxyls. This cellulose diacetate is known as secondary acetate, or
simply as "acetate".
After it is formed, cellulose acetate is dissolved in acetone into a
viscose resin for extrusion through spinnerets (which resemble a
shower head). As the filaments emerge, the solvent is evaporated in
warm air via dry spinning, producing fine cellulose acetate fibers.
Acetate Fiber Characteristics
- Cellulosic and thermoplastic
- Selective absorption and removal of low levels of certain organic chemicals
- Easily bonded with plasticizers, heat, and pressure
- Acetate is soluble in many common solvents (especially acetone and other organic solvents) and can be modified to be soluble in alternative solvents, including water
- Hydrophilic: acetate wets easily, with good liquid transport and excellent absorption; in textile applications, it provides comfort and absorbency, but also loses strength when wet
- Acetate fibers are hypoallergenic
Major Industrial Acetate Fiber Uses
Apparel
- Blouses, Dresses, Linings, Wedding and party attire, Home furnishings, Draperies, Upholstery and slip covers
High Absorbency Products
- Diapers, Feminine Hygiene Products, Cigarette Filters, Surgical Products, and other filters