Development of rayon staple produced by viscose having high degree of polymerization and some rheological properties of such viscose
INTRODUCTION We have been engaged for more than 20 years into the investigation of the viscose fibres having a high degree of polymerization. The original viscose fibre developed by us was named Toramomen. Thereafter, T—51, T—6l, etc. were made public snecessively by improving the original Toramomen fibre. The speciality of the Toramomen process lies in that a high viscosity viscose having highly polymerized cellulose is spun into a low acid and low salt concentration bath. (Hereafter, such a viscose is abbreviated to Polynosic viscose.) Its spinning feature is fairly different from that of conventional viscoses to which the Muller's bath is applied. At first, the Toramomen process was established through comprehensive experimentation. However, to make further progress in this process, it will be quite important to make clear its theoretical meaning. With this aim we are studying the rheological properties of the Polynosic viscose. These properties are also important for the engineering, because the behaviours of a viscose in the spinnerets, viscose distributors, viscose pipes, etc. are controlled by such properties.