Snia Viscosa Societa Nazionale Industria Applicazioni Viscosa S.p.a.

Novello Leoncini

Ugo Paoletti

Tommaso Benai

Gianfranco Angelini

Bice Pallesi

Process for the continuous production of viscose rayon yarns having a high egree of whiteness, comprising extruding a viscose solution into a coagulating bath, drawing and coagulating the extruded filaments, advancing said filaments in a substantially helical path while they undergo all the treatments required for the production of the finished yarn, which process is characterized by, after the exit of the filaments from the spinning bath, completion of the coagulation to a coagulation index not higher than 1 and a treatment with water having a non-alkaline pH.

Process for the continuous production of viscose rayon yarns having high

A process is described for the continuous spinning of viscose rayon. Said ocess is characterized by the fact that after the coagulation and drawing of the yarn, a two-stage setting is carried out, the first stage being at higher temperature and acidity than the second stage. The two-stage setting permits one to obtain a yarn which is not only perfectly set but is also substantially desulphurated and the classic desulphuration operation is thus eliminated. The setting is followed by at least one washing and by the other conventional treatments, with the exception of the desulphuration. The viscose rayon continuous spinning process is carried out while the yarn travels in a substantially helical path.

Process for the continuous spinning of viscose rayon

A process is provided herein for continuously spinning viscose yarns by euding viscose into a coagulating bath to form filaments and partially coagulating these filaments to a coagulation index of between 15 and 18, while concurrently stretching said filaments to the desired stretch ratio and then subjecting the filaments to a 2-stage coagulation treatment in which (1) the filaments are advanced without further chemical treatment onto e.g. a first advancing roller where partial spontaneous coagulation occurs such that the coagulation index is between 5 and 8 and (2) a second stage coagulation which comprises contacting the filaments with an acid bath at a temperature between 50.degree. and 100.degree. C. until complete coagulation occurs such that the coagulation index is between 0 and 1. The aforementioned process permits the spinning operation to occur at a much greater speed than was hitherto possible without increasing dimensions of the treatment zones or apparatus.

Growing community of inventors

Limbiate, Italy

Novello Leoncini