An Optical Method for the Analysis of Gel Particles in Viscose

Abstract

Gel particles generally are understood as highly transparent spheroidal objects that arise within the viscose polymer dope mainly due to thermodynamic instability and related loss of solubility within cellulose xanthate solutions. A certain variation of physical and chemical behaviour of these particles is predicted. Most importantly, the presence of particles sized within observability by photo-optical methods is undesired for product quality reasons. Thus, particle content and size distribution are crucial. The standard practice for particle counting in this environment is contamination analysis of the spinning solution. Several techniques are known and have well-proved their importance for process monitoring. As of yet, statements regarding particle parameters within the ready-made polymer are not possible. Relating to that, an investigation was conducted to gain knowledge on whether particles were contained in effective amounts within the regenerated cellulose. Morphology, size and size distribution were examined. This article aims at demonstrating the applicability of the optical method introduced. For the study, viscose samples were drawn at a fibre production site. Thin films were made from each sample. These were then specifically prepared and subjected to optical analysis. Particles likely of originating according to existing theories are present within the regenerated cellulose as expected. Shape and size differ on a considerably large scale; general characteristics can be specified, though. Absolute values regarding particle size, quantity and size distribution were gathered by direct ascertainment within the product samples analysed.