METHOD FOR THE PRODUCTION OF FIBRES BY MEANS OF EXTRUSION WITH A FOCUSING GAS IN SUBSONIC REGIME

摘要

The invention relates to a method which is intended for the production of fibres and which combines two operations. According to the invention, the first operation comprises the formation of the material of the fibre (referred to hereafter as fibre material or constituent fluid) in the fluid or ductile phase thereof using another fluid (referred to hereafter as focusing fluid) which is immiscible with said fluid or ductile phase, e.g. a gas. For said purpose, the focusing fluid is made to flow concentrically with the fibre material through a small converging nozzle. The second operation, which is performed simultaneously with the aforementioned coaxial flow, comprises the solidification of the fibre material leaving the nozzle in the form of a jet, using one of the following three methods: cooling, evaporation of the solvent or reaction of the components. The invention is essentially characterised in that the focusing fluid flows through the nozzle in the subsonic regime, the precise velocity limits permitted for the focusing fluid in the nozzle being specified in order to prevent irregular fluctuations in the jet.