634 



CALICO-PRINTING 



The cisterns are kept constantly charged with extract diluted with water, in quantity 

 corresponding to that required by the piecea if dyed in the ordinary beck ; thus, the 

 Cisterns are kept up to the original strength, which, as above stated, is excessive com- 

 pared with the actual wants of the mordants. This, however, is of no consequence 

 if the arrangement be such that the issuing pieces bring away with them only a very 

 small percentage of the excess of dye. This is managed by squeezing them under 

 jx>wls and passing them through water, which is employed to fill up the cisterns. 

 fig. 381 represents a section of the 'open dye-beck 'of Mather and Platt, arranged 

 specially for this process. A, wooden cisterns ; B, wooden rollers with brass centres, 

 fixtures, &c. for immersing the cloth ; c, drawing rollers, from cistern to cistern ; D, 

 strong squeezing rollers ; E, washing-off cistern with boater F ; o, steam-boiling pipes, 

 &c., which do not inject steam into the liquor, but terminate in condensed water-pipes 

 H ; i, cloth passing through the machine ; K, drawing pullies and spur wheels. In 

 reference to this open dyeing process, it is obvious that unless the extract of madder 

 used is very pure and free from fine particles of woody fibre and chemical salts, 

 the constant addition of it, without drawing anything off, -would result in time 

 in the cisterns being loaded with impurities which would weaken and eventually stop 

 the dyeing power of the extract, no matter in what quantity added. The extract 

 made by Tennants and Co., of Scotland, specially for this purpose, is claimed to be 

 pf the degree of purity required. It is probable, however, that the artificial aliza- 

 rine now made in perfect purity, and consequently entirely free from woody fibre and 

 resinous colouring matters, will be found most suitable for this process, if it becomes 

 a well-established one in calico-printing works. Much will, of course, depend on the 

 prices of the artificial and the natural alizarine as delivered to consumers. It may 

 be here stated that the value of the open and quick dyeing process as an economiser 

 of material and time has been somewhat reduced by the discovery that several sets of 

 pieces may be dyed with artificial alizarine in the ordinary dye-beck without letting- 



382 



off between each set, but merely adding after the withdrawal of a set (of say 30 pieces) 

 the quantity of alizarine necessary for the next set, entering these at once in the 

 boiling hot liquor, which becomes cooled down by the wet pieces to about 130 F., 

 and recommencing the dyeing ; the becks being brought to boil in an hour, and the 

 pieces withdrawn. As many as 5 sets can be done in this way, and as the .dyeing with 

 artificial alizarine in an ordinary beck need not last above an hour, the economy in 

 time of the open dyeing would appear somewhat doubtful. 



Maddored goods, on issuing from the dye-beck, are far from possessing the beauty 

 that they afterwards show, the colours are dull and heavy, and the white part stained 

 with a reddish shade ; various clearings are required, in which soap plays a principal 

 part. Garancined goods show pretty nearly the colour they are intended to be ; but as 

 the white is also stained, a peculiar clearing is given them, which will be described 

 further on. Madder goods are cleared with soap in a beck similar to a dye-beck. 

 They receive generally two soapings at boil of about half-an-hour each, with from \ 

 to Ib. of soap per piece each time, washing between. If the white is not sufficiently 

 good, the pieces are spread out on the grass for a day or two, and are afterwards 

 winced in hot water to which a little solution of chloride of lime or soda is added. 

 They are then washed and dried. 



The success of the spiral system of dyeing led printers to adopt a similar system for. 

 soaping, and at the principal print-works this operation is now performed in a series 

 of becks, generally 7 or 8. The pieces enter at one end of the first beck of the series, 

 and after passing spirally through this, traverse successively the remainder of the 



