MANUFACTURING TESTS OF COTTON STANDARDS. 7 



TEXTILE SCHOOL TESTS. 



Bleaching : 



Scouring. — The yarn was washed in cold water for 15 minutes, 

 after which it was boiled in a 2- degree Twaddle solution of caustic 

 soda for 7 hours. It was then washed twice in cold water and 

 hydroextracted. 



Ghemicking. — The yarn was bleached in a lf-degree Twaddle 

 chlorine solution for 2 hours. It was then washed for 30 minutes 

 in cold water and hydroextracted. 



Souring. — The yarn was soured for 1| hours in a 1^-degree Twad- 

 dle solution of sulphuric acid and then washed in cold water until 

 free from chlorine. 



Soaping. — The yarn was soaped in a solution of 5 per cent Solvay 

 soda and 0.012 per cent methylene blue, which was heated to 160° F. 

 It was then washed in hot water at 120° F., then in cold water, 

 hydroextracted and dried. 



The best bleach was obtained on Good Middling Yellow Tinged, 

 followed in order by Good Middling Yellow Stained, Low Middling, 

 and Middling Yellow Stained, each of which gave a good commercial 

 white. The other four grades did not give a satisfactory white. The 

 Middling Yellow Tinged and Low Middling Yellow Tinged had a 

 bluish appearance, while the Good Middling Blue Stained and 

 Middling Blue Stained had a decided slaty or bluish cast. The 

 Middling Blue Stained came out the poorest white of all the grades 

 tested, the bleaching process having practically no effect upon the 

 blue color of this grade. The greatest improvement was noticed in 

 the case of Middling Yellow Stained, this grade having a deep yellow 

 color and considerable trash before bleaching. After processing, this 

 grade had the fourth best white and in addition had lost most of its 

 trash. A trial test was made on the blue stains by putting them 

 through the bleaching solution and acid a second time. Their white- 

 ness was not improved by this double bleach. 



Dyeing: 



Tests were made on the eight grades by dyeing them with direct 

 colors — pink and blue. 



Pink. — The bleached yarn was dyed with the following formula: 

 0.5 per cent amidine fast pink, 6 per cent Glauber's salt, and 2 per 

 cent Solvay soda. The yarn was treated in this bath for 30 minutes 

 at 140° F., washed in warm water (120° F.) , rinsed in cold water, and 

 dried. 



The best pinks were obtained on the grades that gave the best 

 bleach. The best pink was obtained on the Good Middling Yellow 

 Tinged, followed in order by Good Middling Yellow Stained, Low 

 Middling, Middling Yellow Stained, Middling Yellow Tinged, Low 



