Man-made cellulosic fibers via the viscose process - new opportunities by cellulose carbamate

Viscose fibers have an ever increasing market share with over 5 million tons p.a.. Main application area for viscose fibers is the textile industry. Nevertheless the broad variability of the viscose process allows realizing even technical man-made cellulose fibers, like Supe 3 tyre cord yarn with tenacities of more than 50 cN/tex. This broad variability of fiber qualities is not reached by any other cellulose shaping process. However since decades there is a strong focus on decreasing the input of highly toxic CS2 for the viscose fiber manufacturing and keeping the quality of spinning solutions at the same time, which allows the known processing behavior and resulting in a high fiber quality. The cellulose carbamate process is by far the most intense investigated option to substitute the viscose technology. By different reasons this didn´t happen up to today, despite the fact that the cellulose carbamate spinning was already shown on industrial scale. This paper discusses the opportunity of combining both spinning routes, carbamate and viscose. This enables to realize fiber properties known from the viscose process and at the same time a significant lower CS2 input for so produced man-made cellulose fibers. The paper will give an overview about the technology, different fiber properties and structural characterization of the same by varying the processing conditions.