Textile fibers that are composed of ester cellulose are called acetate fibers. Acetate is a manufactured fiber in which the forming substance is cellulose acetate. Where not less than 92% of the hydroxyl groups are acetylated may be used as a generic description of the fiber. Acetate filament yarns are referred to as “Fibers of Beauty” . Because they have a luster and tactile feeling as silk fibers. It’s frequently used for women’s dresses and exhibit their beauty in the form of women’s formal wear, suits, coats, or knitwear. Acetate (staple tow) is used for almost all cigarette filters. Manufacturing Process Flow Chart of Acetate Fiber is as follows:
Purification of cellulose
Hydrolysis (for acetate)
Washing & drying
Spinning Solution or Dope
Acetate rayon is manufactured by dry spinning. It is dissolved in a volatile solvent. From Acetone to its form the spinning solution or dope. This solution is forced through a spinnerette into a chamber. Where hot air is circulated. The solvent evaporates leaving filaments of acetate rayon.
Dried acetate flakes are mixed with three times the weight of acetone in enclosed tanks. That’s provided with powerful stirrers. The acetate dissolves slowly in the solvent. It takes about 24 hrs for the complete dissolution to give a thick clear liquid called dope. The solution is filtered and deaerated.
The dope is spun into acetate rayon filaments on the dry spinning process. It’s fed from a spinning tank into spinning cabinets. The dope coming out of the spinnerette travels a distance of 2 to 5 meters vertically downwards to a feed roller. From where it’s guided onto a bobbin at a much greater speed than the speed of spinning. This imparts a twist to the filaments.
Author of this Article: Rana Sohel Executive Engineer Sunman Textile Mills Ltd. Chittagong Cell: +8801912-420118 Email: [email protected]