BLEACHING 375 



pressure steam is again admitted, which forces the lime-liquor through the goods to the 

 bottom of the vessel, then up the pipe o, and on to the goods in the second kier. The 

 tap is then closed, which admits steam into the first kier, and the steam is now sent 

 into the second. The same process occurs, only in this case the liquid is sent again on 

 to the top of the goods in the first kier. This process is continued about five hours. 

 In this method each 7,000 Ibs. of cloth take into the kiers 2 cwts. of lime, which is 

 equally distributed. The clear lime-water which is blown out of the steam at the 

 commencement contains only 3 to 4 Ibs. of lime in solution. At the close of the 

 operation the liquor has a specific gravity of 3| to 4 Twaddle (1017'5 to 1020), 

 instead of half that amount, or 1 to 2 Twaddle (1007'5 to 1010), as is usual. 



3. When the liming is completed the steam-pressure in the kiers is removed, the 

 manway opened, and the cloth in the kier attached to the washing-machine, which 

 draws the goods out of the kiers and washes them. 



4. The pieces are then passed by the winches through the souring machine, or soured 

 by having muriatic acid of 2 Twaddle (1010) pumped upon them. They must 

 remain with the acid two to three hours, either steeped in it, or after having passed 

 through it. 



5. Again attach the cloth to the washing-machine, and wash it well, passing it on 

 by winches, as before, into the kier. 



6. Introduce steam and drive off the air and the cold water ; these are let out by 

 the tap at the bottom : add then 210 Ibs. of soda-ash and 70 Ibs. of resin, boiled in 

 600 gallons of water, for 7,000 Ibs. of cloth. Work the kiers by driving the liquid 

 from one to the other as before ; about five hours is a sufficient time. These pro- 

 portions of soda may be varied. If the cloth is very strong a little more may be 

 used (or if the cloth has been printed upon in the grey state, from having been used 

 to cover the blanket of the calico-printing machine). 



7. After this the cloth is passed through the washing-machine, and then submitted 

 to chloride of lime. This may be done either by the machine or by pumping. In 

 either case it is an advantage to warm the bleaching-liquid up to 80 or 90 F. The 

 strength of the solution when the machine is used maybe about Twaddle, or 1002'5 

 specific gravity ; but if the pump is used it must be much weaker. When the bleaching 

 is for finishing white, milk of lime is added to the chloride, in order to retard the 

 operation ; the goods are also washed from the bleaching-liquor before souring them. 

 This causes a smaller escape of chlorine, and is a more careful method : it tends to 

 preserve the headings, or the coloured threads, which are often put into the ends of 

 pieces of cloth in order to see if the bleaching has been performed roughly or not. 

 The original use of this has almost been forgotten, but these headings are still care- 

 fully preserved. This method preserves also the cloth, which is also less apt to be 

 attacked by the chlorine. 



If the cloth has been well managed, it will be almost white when it leaves the 

 second kier containing the resinate of soda ; it will therefore require very little de- 

 colourising. If the goods have been printed on, more chloride will bo needed. The 

 cloth should lie from two to eight hours in the liquor, or after saturation with it. The 

 action is quickened if warmth is used. They are soured then, as before, in muriatic 

 and sulphuric acid, at 2 Twaddle, for three or four hours ; then wash for drying. 



The patentee claims for these kiers considerable advantages over the old, amongst 

 others that they are not more costly occupy less room, and whilst the goods are 

 more thoroughly ' bottomed ' or cleansed, considerable saving is effected in fuel, 

 water, labour, chemicals, and time. ' As regards boiling of goods in bleaching, there 

 is, as compared with the ordinary kier, a saving of three-fourths of the coal by using 

 these kiers.' They are perfectly safe in their action and the fibre is not ' tendered.' 



From what has been said, it will be seen that the operations of the bleacher are not 

 so numerous as at first sight appears, when we call every washing a separate process ; 

 and although it really is so, it is managed so rapidly that it can scarcely be said to 

 occupy time, and as it is carried on at the same time as the other processes, it scarcely 

 can be said to give trouble. The work may be divided into 



1. Singeing. 2. Bowking with lime. 3. Washing, souring, and washing. 4. Bowking 

 with resinate of soda. 5. Washing and chlorinating. 6. Souring, washing, and drying. 



Steeping. Instead of boiling in the kier at first, the goods are sometimes, though 

 now rarely, steeped from one to two days in water, from 100 to 150 F., for the pur- 

 pose of loosening the gummy, glutinous, and pasty materials attached to the cloth. 

 Fermentation ensues, and this process is dangerous, as the action of the ferment some- 

 times extends to the goods, especially if they are piled* up in a great heap without 

 being previously washed. The spots of grease on the insoluble soaps become thereby 

 capable of resisting the caustic alkalis, and are rendered in some measure indelible ; 

 an effect duo, it is believed, to the acetic and carbonic acids generated during fer- 

 mentation. Some persons throw spent lyes into the fermenting vats to counteract the 



