Cupro fiber

Another process for the manufacture of regenerated cellulosic fibers is the cuproam-monia (cuoxam) process (Kulter et al, 1990b). The resulting fiber is called a cupro fiber. The production scheme for cupro fibers is depicted in Fig. 2.32 and the process is shown in Fig. 2.33. 

In a later process, the cupro fibers are cleaned for example, acids and salts and copper are removed and recycled. The fibers are coated and dried. The further processing into staple fibers or filaments is similar to the processing of viscose. 

Cupro fibers are of high fineness in their single filaments and have a silky shine and good handle. Cupro hollow fibers are especially suitable for membranes used in blood dialysis. The properties of cupro are summarized in Table 2.8. 

In the direct methods, cellulose is dissolved and spun into fibers by using special solvent systems without chemical modification of the polymer strac-ture. For example, Lyocell fibers are produced by using an organic solvent, N-methylmoipholine N-oxide, to dissolve cellulose. Cupro fibers are manufactured by dissolving cellulose in a mixed solution of copper salts and ammonia. (Some researchers consider Cupro fibers to be produced by a derivative method because interaction is formed between cellulose and the cuprammonium ions in the solution, as discussed in Chapter 10.) More recently, researchers also are using ionic liquids as the solvent to fabricate manufactured cellulose fibers. 

Some researchers consider Cupro fibers to be produced by a derivative method because interaction is formed between cellulose and the cuprammonium ions in the solution. 

Regenerated cellulosic fibers are made out of cellulose from wood or cotton lint. The most used fibers are viscose, acetate, cupro (very small quantity), and lyocell. These fibers are produced in various titers as filament (endless fiber) or staple fiber. 

Manufactured cellulose fibers are man-made fibers. To make manufactured cellulose fibers, the cellulose component of the plant is dissolved in a solvent, which then is spun into fibers in the same ways that synthetic polymer fibers are made. Examples of manufactured cellulose fibers are rayon, acetate, triacetate, Lyocell, and Cupro. 

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