MANUFACTTJKING TESTS OF COTTON STANDARDS. 9 



Chemicking. — The yarn was bleached in a 1^-degree Twaddle 

 chlorine solution for 2 hours and washed in cold water. 



Wash. — The yarn was washed in 2 per cent bisulphite of soda for 

 one-half hour — cold. It was then washed in warm water (160° F.) 

 for 10 minutes and then in cold water and dried. 



Fair whites were obtained on two grades only, when using this 

 bleach, namely Good Middling Yellow Tinged and Low Middling. 



Double-boil chlorine bleach: - 



The time of boiling with the caustic soda was doubled over the 

 time used in first chlorine bleach to see if the length of time in the boil 

 affected the whites obtained. The yarn was boiled for 2 hours in a 

 solution of 2 per cent caustic soda and 1 per cent Turkey Red Oil, after 

 which it was drawn off and a new solution of the same strength was 

 put into the machine and the boiling continued 2 hours longer. The 

 yarn was then soured and bleached in the same manner as in the first 

 chlorine bleach. 



A good commercial white was obtained on Good Middling Yellow 

 Tinged, Low Middling, and Good Middling Yellow Stained under 

 these conditions. 



Peroxide bleach: 



Scouring. — The yarn was first washed in cold water and then boiled 

 one-half hour in a solution of 2 per cent Turkey Red Oil, then washed 

 in cold water. 



Bleaching. — The yarn was bleached in the solution shown below : 

 7| gallons of water. 

 5| ounces sulphuric acid. 

 4f ounces sodium peroxide. 

 4f ounces sodium silicate. 

 This solution was kept at 180° F. and run until exhausted. It 

 was tested every 10 minutes and found to be exhausted in \\ hours. 

 The yarn was then rinsed in cold water. 



Wash. — The yarn was washed in three different warm waters — 

 the first at 120° F., the second at 100° F., and the third at 90° F. 

 It was then washed in cold water and dried. 



Good Middling Yellow Tinged and the Low Middling were the 

 only grades that gave fair whites. 



Double peroxide bleach: 



The yarn was treated in the same manner as the first peroxide 

 bleach except that the time was doubled in the bleaching, a fresh 

 solution being made up when the first was exhausted. 



Good commercial whites were obtained on Good Middling Yellow 

 Tinged, Low Middling, and Good Middling Yellow Stained. 



