| 摘要 |
520,951. Bleaching. TOMASZOWSKA FABRYKA SZTUCZNEGO JEDWABIU SPOLKA AKCYJNA, and BORGNIEC, A, Nov. 4, 1938, No. 31974. Convention date. June 11. [Class 15 (ii)] Artificial or natural fibres are bleached on perforated carriers by sucking or forcing, through the fibres, a hypochlorite solution of such a degree of alkalinity that in practice the said solution has no bleaching properties, and subsequently forcing an agent of acid reaction either in solution or in gaseous form through the fibres. Artificial silk wound on perforated spinning bobbins or a perforated insertion piece or within a perforated drum of a centrifuge, or any other artificial or natural fibre wound on a perforated bobbin is placed in a vat and hypochlorite solution brought to a pH of 11 to 12 by caustic soda is sucked or forced through the fibres ; when saturated, the fibres are freed from excess solution by evacuating the vat and then a diluted solution of sulphuric or nitric acid or acid gases or vapours are forced or sucked through the fibres ; the fibres are finally rinsed and may be dried or subjected to further processes such as dyeing or impregnating with a fat. Glaubers salt &c. may be added to the hypochlorite solution. The above process may be preceded by various processes such as the desulphuration of viscose artificial silk or the denitrification of collodion artificial silk. |
