首页>
外国专利>
Device for producing voltage-impulses of short-duration, wherein a discharge-path, which is conductive in a negative direction with respect to the pulses, is connected in parallel with the load
Device for producing voltage-impulses of short-duration, wherein a discharge-path, which is conductive in a negative direction with respect to the pulses, is connected in parallel with the load
展开▼
机译：用于产生短时电压脉冲的装置，其中，相对于脉冲在负方向上导电的放电路径与负载并联连接
展开▼
页面导航
摘要
著录项
相似文献
摘要
In the manufacture of regenerated cellulose threads, films and like products from viscose, the cellulose xanthogenate still present in the products after they leave the spinning bath is decomposed by first treating the products with an aqueous solution containing an inorganic acid and at least one inorganic salt, in which the molar ratio of acid to neutral salt is below 1, and thereupon, after freeing the products from the bath liquid, e.g. by washing with water, treating the products with an acid aqueous solution containing no or very little salt. The process is characterized by the first treatment reducing the xanthogenate ratio of the products to about 0.10, by the second treatment taking place at not over 60 DEG C., preferably at room temperature, and by the second treatment being followed by a treatment with steam until the xanthogenate ratio of the products has decreased to 0.003 or less. Finally the products are desulphurized, e.g. by washing with water. The xanthogenate ratio is defined as the ratio of the total number of xanthogenate groups still present in the products to the total number of anhydro-glucose units therein. In the example threads from a spinning bath containing 8 per cent. of sulphuric acid and 14 per cent. of sodium sulphate are passed through a decomposition bath at 80 DEG C. containing 4 per cent. of sulphuric acid and 7 per cent. of sodium sulphate. The threads are stretched about 50 per cent. in this bath, then passed through a water bath at 20 DEG C. and thereafter through a 1 per cent. aqueous sulphuric acid solution at 25 DEG C. The threads are then passed through a long chamber supplied with saturated steam and finally washed with water at 50 DEG C. The low xanthogenate ratio of the thread substance after the treatment with steam enables a more rapid and complete desulphurizing and bleaching of the threads to be accomplished than in prior art processes, and the total steam consumption is reduced. Specification 692,023 is referred to.
展开▼
