GB279888A - Improvements in spinning artificial silk - Google Patents

Abstract

279,888. I. G. Farbenindustrie Akt.- Ges. Oct. 30, 1926, [Convention date]. Grant of Patent opposed. Apparatus for making filaments; cellulose xanthates, processes for making filaments from.- When spinning viscose silk, according to the bobbin system, the thread is projected upwardly in a substantially vertical direction, an upper bath is not used, and the thread in its passage to the collecting bobbin is either not bent at all or at most through an angle of 150‹. Spinning speeds lower than the normal are advantageously employed. All the above features are directed to reducing the strain to which the partly-coagulated thread is subjected, and they serve to give a product of uniform dyeing properties and of an extensibility of 18 per cent or higher. The method may be employed when spinning viscoses of high viscosity and low cellulose content, such as unripened viscose or viscose prepared from unripened alkali cellulose; and it may be used for the spinning of fine filaments, that is, below 3 deniers, good results being obtained with a sulphuric acid bath and a length of immersion which may be reduced to less than 60 centimetres to a few centimetres. The Specification as open to inspection under Sect. 91 (3) (a) refers to an arrangement comprising an upwardly-projecting nozzle g, Fig. 3 (Cancelled), a reciprocating thread guide c, and bobbins f arranged vertically above the spinning bath; and it refers to constructions of the guide c, which is provided with rear limbs a, a<1>, Figs. 1 and 2 (Cancelled), and free limbs b, b<1>, the gap between the rear and free limbs being of such a width that the thread rubs against them, the limbs b, b<1> being either bent down as shown in Fig. 1 (Cancelled) or bent upwardly and provided at the points b<2>, Fig. 2 (Cancelled) with projections so as to allow acid stripped from the thread to flow away. This subject-matter does not appear in the Specification as accepted.