Acetate fibres are chemical compounds of cellulose and not the pure cellulose as in rayon fibres. These chemical com-pounds have their own unique properties and in fact the various types of cellulose acetate fibres differ from each other in properties. In 1865, Pant Schutzenberger discovered the reaction of cellulose ace-tate. Later in 1903, the German chem-ists Arthur Eiechengeun and Theodore Becker invented the fast soluble form of cellulose acetate.
In 1904, cellulose acetate was developed by Camille Dreyfus and his younger brother Henri in England, during World War I. It was used as a non flam-mable lacquer for the fabrics used for cov-ering the wings and fuselage of aircrafts. In 1918, they perfected the technique of spinning this substance into lustrous fil-aments of “artificial silk”. Subsequently, British Celanese Ltd. started the produc-tion of this fibre. In 1924, the commercial production of acetate fabric started in the United States by Celanese Corp. In 1954, The Celanese Corp. of America undertook the production of a variation of this chem-ical called cellulose triacetate. This prod-uct is marketed by the Celanese Fibres Marketing Co. under the trademark Arnel.
The different types of acetate are
Pure cellulose is formed by converting cotton linters or wood sheets. This pure cellulose is steeped in glacial acetic acid and aged under controlled temperature for a period of time. It is then mixed with acetic anhydride and a small amount of sulphuric acid as a catalyst to facilitate the reaction which produces a thick and clear liquid solution of cellulose acetate. This liquid is then passed through the spin-neret to form these fibres which is solidi-fied and rolled on the bobbins for later use (Figure 3.2).
Shape : Can be modified as per requirement
Size : Thin long filament
Luster : Variation from brightness to dullness
Strength : Good
Elongation : Good up to 25%
Elastic recovery : Good
Resiliency : Low for acetate, but for triacetate it is good.
Dimensional stability: Good
Resistance to acids : Fair resistance to dilute acid, but cannot withstand concentrated acid.
Resistance to alkalis : Good resistance to dilute alkalis but cannot withstand concentrated alkalis.
Resistance to flame : Burns easily
Depending upon the kind of yarns used and the final effect desired, different fin-ishes can be given to acetate fabrics. The most common finishes are :
Embossing : For pattern or design
Heat setting : For crease and shape retention
Moireing : For permanent watermarking effect
Napping : On spun acetate for softness and warmth
Sizing : For better appearance
Water repellency : For resistance to water and rain
Wrinkle resistance : For better shape retention
The uses of acetate are :
· The breathable nature of the fabric makes it suitable for use as a lining fabric for apparels.
· Acetate is used for making cigarette filters and other filters, ink reser-voirs for fibre tip pens.
· It is used for making high absor-bency products like diapers and sur-gical products.
· It is also used for making eyeglass frames.