Dry spinning of cellulose acetate and triacetate

The flake is then dissolved in acetone and water to prepare the concentrated spinning solution or dope at a concentration of 15-30% solids. As with acrylic fibers, titanium oxide may be added as a delustrant, as well as pigments to color the fibers. The dope is subsequently filtered and de-aer-ated using varied filtration technologies to remove impurities. 

A guide roU at the bottom of the spinning tube directs the fibers out to a collection device. For staple fiber, the filaments from numerous spinnerets are combined into tow form, crimped, cut to the required length, and packaged in bales. A take-up bobbin is used to insert a small amount of twist. Take-up speeds are typically between 200 and 400 m/min but can be as high as 1000 m/min. For filter tow the filaments are crimped, dried, and packaged in bales. 

Triacetate uses dichloromethane and methanol as solvents. It is increasingly used as the film for LCD displays. It is very popular in films because of its excellent optical clarity, glossy surface characteristic, and resistance to grease. It is, however, prone to degradation. Fabrics of triacetate are shrink and wrinkle resistant. They are easily washable at high temperatures because they have higher heat resistance than acetate fabrics, and can be safely ironed at higher temperatures. Triacetate fabrics that have been properly 

7 Dry spinning of other fibers poly benzimidazole (PBI), spandex and polyvinyl chloride (PVC) 

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