Polynosic fibres

T. Nagata, "New Process Developments foi Polynosic Fibres," Proceedings of the 28 th Dombim International Man Made Fibres Conference, Austria, Sept. 1989. 

The viscose process has some variants depending on the quality of the cellulose and the composition of the regenerating bath, special high added value products can be obtained so-called modal-polynosic fibres, or modal-high wet modulus fibres, for instance. 

Fig. 6.15 Polynosic fibre after compression following swelling in nitric acid...

The early methods of spinning viscose continuous filament were based upon rapid coagulation and regeneration after extrusion. This procedure is reversed in the preparation of polynosic fibres because the coagulating liquor only decomposes the xanthate slowly so that considerable stretching... 

Polynosic fibres have a fibrillar structure to which many of their properties are attributed. This feature is illustrated in Fig. 6.15 which shows a fibre magnified 400 times after compression following swelling in nitric acid. 

Originally the name polynosic was applied to fibres extruded by methods based on the Tachikawa patent taken out in Japan. The essentials consisted of using an unaged alkali cellulose in the preparation of the xanthate which in turn was dissolved in only water giving a viscose with a low content of sodium hydroxide. The unripened viscose was then extruded into a very dilute solution of sulphuric acid containing no salt. The term... 

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