What is Acetate Fiber?
The development of manufactured fibers created new opportunities for producing textile materials with attractive aesthetics at a lower cost than natural fibers such as silk. Among these fibers, acetate became an important innovation because of its silk-like appearance, good draping qualities, and versatility in apparel and interior textiles. Although its development involved several technical challenges, acetate eventually established itself as a valuable textile fiber with unique properties and applications.
History and Origins
Acetate originated in Europe in the early years of the 20th century. The Dreyfus brothers experimented with acetate in Switzerland, using a technique that produced a spinning solution for a silk-like fiber. During World War I, they went to England and perfected the acetate dope as a varnish for airplane wings. After the war, they perfected the process of making acetate fibers for textile use. In 1924, acetate became the second manufactured fiber to be produced in the United States.
Early Challenges
More problems had to be solved with the acetate process than with the rayon processes. Acetate is a different chemical compound compared to other manufactured and natural cellulosic fibers. It has few components that form bonds with dyes. Because of this unique chemistry, acetate could not be dyed with any existing dyes. Disperse dyes were developed especially for acetate.
Acetate was also the first thermoplastic, or heat-sensitive, fiber. Consumers suddenly had fabrics that melted under a hot iron, something they had never experienced before. This was at a time when consumers tended to iron all apparel. The problem was further compounded when manufacturers introduced acetate as a kind of rayon, creating false expectations about how it should be handled.
Still another problem was fume or pollution fading, a condition in which some disperse dyes changed color when exposed to atmospheric fumes, now known as atmospheric pollutants. Blue shifted to pink, green to brown, gray to pink. Solution-dyeing corrected this problem and is now used for many manufactured fibers. In 1955, an inhibitor greatly improved dye performance under all conditions that cause fading. However, fume or pollution fading continues to be a problem.
Production of Acetate Fiber
Acetate is produced from cellulose, the same raw material used for rayon and lyocell. While several steps in the process appear similar to rayon production, acetate uses a different solvent, is extruded into warm air as a dry-spun fiber, and the solvent is evaporated, recovered, and reused. Because acetate is dry-spun, it is easier for producers to reclaim and reuse the solvent. With current environmental regulations and economic pressures, solvent recovery and reuse is standard practice in acetate production.
Physical Structure
Acetate is available as staple or filament. Much more filament is produced because it gives a silk-like look. Staple fibers are crimped and usually blended with other fibers. The cross section of acetate is lobular or flower petal-shaped. This shape results as the solvent evaporates when the fiber solidifies after extrusion. The lobes may sometimes appear as a false lumen. The cross-sectional shape can be varied, and flat filaments give a glitter effect to fabrics.
Chemical Composition and Molecular Arrangement
The Federal Trade Commission defines acetate as a manufactured fiber in which the fiber-forming substance is cellulose acetate. Where not less than 92% of the hydroxyl groups are acetylated, the term triacetate may be used as a generic description of the fiber.
Acetate is an ester of cellulose and has a different chemical structure from rayon or cotton. In acetate, two hydroxyl groups are replaced by bulky acetyl groups that prevent highly crystalline areas. There is less attraction between the molecular chains due to a lack of hydrogen bonding. Water molecules do not penetrate as readily, which contributes to acetate’s lower absorbency and dye affinity. In triacetate, all three hydroxyl groups are replaced with the bulky acetyl group. Both acetate and triacetate are thermoplastic.
Properties of Acetate Fiber
Acetate has a combination of properties that make it a valuable textile fiber. It is low in cost and has good draping qualities. Triacetate is similar in performance to acetate, though where the differences are significant, triacetate’s performance is noted separately below.
Aesthetics
Acetate has excellent aesthetics. It is widely used in satins, brocades, and taffetas, where fabric luster, body, drape, and beauty are more important than durability or ease of care. It has high luster, good drape, and a smooth texture and hand. Acetate also maintains a good white color, which is an advantage over silk.
Durability
Acetate has poor durability. It is a weak fiber, with a low breaking tenacity of 1.2 to 1.4 g/d, and it loses some strength when wet. Other weak fibers have compensating factors, such as wool’s good elastic recovery or rayon’s high absorbency, but acetate does not. Its breaking elongation is moderate at 25%. Since acetate has poor resistance to abrasion, a small percentage of nylon is sometimes combined with acetate to produce a stronger fabric.
Comfort
Acetate is moderately comfortable. Because it is smooth and slick, it is often used for linings in coats and jackets, making them easier to put on over long-sleeved shirts and blouses while adding a finished look to the garment. With a moisture regain of 6.3% to 6.5%, it is subject to static buildup and static cling. The fiber is extremely soft with no allergenic potential. Thermal retention is moderate.
Appearance Retention
Acetate has poor appearance retention. Fabrics have poor resilience and wrinkle during use. Wrinkles from washing are extremely difficult to remove, even with a hot iron. Acetate has moderate dimensional stability. The fibers are weaker when wet and can be shrunk by excess heat. Elastic recovery is poor at 58%, so areas of stress do not recover well. Triacetate can be heat-set to improve resiliency.
Care of Acetate
Acetate should be dry-cleaned unless other care procedures are identified on the care label. It is resistant to weak acids and to alkalis. It can be bleached with hypochlorite or peroxide bleaches, but these are seldom used at home. Acetate is soluble in acetone.
Acetate cannot be heat-set at a temperature high enough to give permanent shape to fabrics or a durable embossed effect. Triacetate can be heat-set to improve dimensional stability and can be machine washed. Acetate becomes sticky at low ironing temperatures of 177 to 191 degrees Celsius (350 to 375 degrees Fahrenheit) and melts at 230 degrees Celsius (446 degrees Fahrenheit). Triacetate has a higher melting point than acetate.
Acetate has better sunlight resistance than silk or nylon but less than the cellulose fibers. It is resistant to moths, mildew, and bacteria.
Comparison with Rayon
Rayon and acetate are the two oldest manufactured fibers, filling an important need for less expensive fibers in the textile industry. They lack the easy care, resilience, and strength of the synthetics and have had difficulty competing in some end uses. Rayon, lyocell, and acetate share some similarities in performance because they are all made from the same raw material, cellulose. The manufacturing processes differ, however, so the fibers differ in their individual characteristics and end uses.
Sustainability of Acetate
Acetate is produced from cellulose and requires a significant amount of processing to produce a usable fiber. The same concerns identified in discussions of rayon apply to the wood pulp used to produce acetate. Acetate fiber is less likely to degrade naturally compared to rayon and is not currently recycled.
Acetate is usually dyed with disperse dyes that require special chemical carriers during dyeing. Acetate items usually require dry cleaning, and the solvents used in dry cleaning present additional hazards to the environment. One widely noted environmental problem involves cigarette filters, one of the largest technical uses for acetate. Since acetate is not biodegradable, discarded cigarette butts create persistent environmental pollution.
Uses of Acetate Fiber
While acetate is a minor fiber overall, it is used across apparel, interior, and technical products.
One important use is in lining fabrics. The aesthetics of acetate, its luster, hand, and body, combined with its relatively low cost and ease of handling, contribute to its wide use here. However, since acetate is not a durable fiber, the fabric must be carefully selected for the end use, or the consumer will be dissatisfied when the lining shows extreme wear while the fashion fabric remains usable.
Acetate is also very important in drapery fabrics. Sunlight-resistant modifications contribute to the fiber’s popularity here, as do its luster and soft drape. Antique-satin draperies made of blends of acetate and rayon are very common. Draperies with matching bedspreads of 50% acetate and 50% cotton are popular, and the same blend is found in lightly used upholstery. Acetate and acetate-blend fabrics come in an amazing range of colors, so nearly any decor can be matched.
In apparel, acetate appears in formalwear such as dresses and blouses in moire taffeta, satin, and brocade. Other important uses include bedspreads and quilts, fabrics sold for home sewing, ribbons, and cigarette filters. Absorbent antibacterial acetate is used in personal hygiene products, fiberfill, and filters.
Types and Kinds of Acetate
Types of acetate include solution-dyed, flame-retardant, sunlight-resistant, fiberfill, textured filament, modified cross section, antibacterial, and thick-and-thin slublike filament varieties.
Conclusion
Acetate remains an important manufactured fiber because of its attractive luster, smooth hand, and excellent draping qualities. Although it has limitations in durability, wrinkle resistance, and heat sensitivity, it continues to be widely used in apparel, interior furnishings, and technical products. Its unique chemical structure and dry-spinning process distinguish it from other cellulosic fibers. As sustainability and performance requirements continue to evolve, acetate will remain a notable fiber with specialized applications in the textile industry.
