Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 edition. Excerpt: ...placed in the steam box they should be passed through a bath containing i oz. of caustic soda and 1 oz. of sodium sulphide per gallon. In some cases, instead of steaming the development may be satisfactorily accomplished by squeezing the yarn out evenly then hanging it up on sticks and exposing it to the air at the ordinary temperature for several hours. In the case of warps and loose cotton the goods are simply allowed to lie in the warm moist condition until properly oxidized. hand is both inconvenient and harmful to the workmen as the sodium sulphide liquor is quite corrosive to the hands and skin. It is best to have the dyevat provided with a yarn wringer through which the skeins are passed before being rinsed. It should be so arranged that the dye liquor that is squeezed out runs back into the bath. If it is not feasible to squeeze the yarn in this manner, the hanks should be put in a centrifugal hydro-extractor and the excess liquid removed. The yarn may then be washed in the hydro-extractor before being removed. Many of the sulphur dyes resemble the vat colors in that they may be reduced to a soluble leuco-compound by the action of reducing agents in the presence of strong alkaline solutions. Under these circumstances they may be used practically as vat dyes, similar to Indigo or the indanthrene colors. This process, so far, has been but slightly studied and its practical feasibility has not been thoroughly established. According to Ganswindt (Theorie und Praxis der modernen Farberei, p. 306) the only form of this process which has been discussed is the glucose-caustic soda vat. It may be prepared as follows: Sulphur Black (or Sulphur Blue), for example, is mixed with an equal weight of caustic soda (40 Be) which has been...
