10 



BULLETIN &90, U. S. DEPARTMENT OF AGRICULTURE. 



Dyeing: i 



Tests were made on the eight grades by dyeing the yarns with vat 

 colors — pink and blue. 



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

 2 per cent penetrol, 2| per cent caustic soda, 2f per cent hydrosul- 

 phite, and 4 per cent indanthrene Red B. N. It was dyed at 120° F., 

 and run for 45 minutes, then washed in hot water and dried. The 

 best pinks were obtained on the grades giving the best bleach. The 

 best pink was obtained on Good Middling Yellow Tinged, followed 

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

 Yellow Stained, Middling Yellow Tinged, Low Middling Yellow 

 Tinged, Good Middling Blue Stained, and Middling Blue Stained. 



Blue. — The bleached yarn was dyed with the following formula : 2 

 per cent penetrol, 8 \ per cent caustic soda, 8-| per cent hydrosulphite 

 and 12 per cent indanthrene G. C. D. blue. The yarn was dyed at 120° 

 F. for 45 minutes, then washed for 10 minutes in hot water (160° F.), 

 then in cold water and dried. Good blues were obtained on all the 

 grades, there being very little difference in depth of color. 



Breaking strength of bleached and dyed yarns: 



Single-strand strength tests were made of the gray, bleached, and 

 dyed yarns to determine the effect of the bleaching and dyeing proc- 

 esses. The results of these tests are shown in Table 8. In order 

 to put the results on a commercial basis, different skeins were used 

 on the gray, bleached, and dyed tests. 



Table 8. — Breaking ■strength in ounces of single strands from gray, bleached, 

 and dyed yarn spun from the different grades of cotton. {Mill test.) 



Yarn. 



L.M. 



G.M. 

 Y.T. 



M.Y.T. 



L.M. 

 Y.T. 



G.M. 



Y.S. 



M.Y.S. 



G.M. 

 B.S. 



M.B.S. 



Aver- 



Double boil chlorine. 



Double peroxide. 



4.25 -v/22: 



Gray 



Bleached 



Pink 



Blue.... 



4.50 ^22: 



Gray 



Bleached 



Pink 



Blue .... 



4.75 y/22: 



Gray 



Bleached 



Pink 



Blue 



Ounces. 



Ounces. 



Ounces. 



10.4 



11.0 



11.2 



10.4 



11.5 



12.1 



10.4 



11.1 



11.1 



10.4 



11.9 



11.1 



Ounces. 

 11.1 



10.7 

 11.0 

 10.8 



Ounces. 



Ounces. 



Ounces. 



Ounces. 



11.8 



11.0 



10.0 



10.2 



13.0 



12.6 



11.0 



11.4 



12.4 



11.7 



11.1 



10.9 



11.3 



12.0 



10.0 



9.8 



Ounces. 

 10.84 

 11.59 

 11.21 

 10.91 



Single peroxide. 



10.4 



11.1 



11.9 



11.0 



11.1 



10.4 



10.5 



10.9 



9.7 



. 12.4 



11.8 



10.7 



13.3 



12.4 



10.0 



9.7 



10.0 



12.9 



11.5 



11.2 



11.1 



12.4 



10.8 



10.9 



10.2 



11.6 



12.0 



11.7 



11.4 



11.8 



9.9 



11.0 



10.91 

 11.25 

 11.35 

 11.20 



Single chlorine. 



10.6 



11.4 



11.2 



10.7 



11. S 



10.5 



9.9 



10.7 



11.6 



11.8 



12.6 



11.9 



11.4 



11.4 



10.0 



11.0 



10.7 



11.4 



10.9 



10.6 



11.9 



10.5 



10.5 



10.5 



10.9 



11.7 



11.4 



10.3 



10.1 



10.8 



9.5 



10.2 



10.85 

 11.46 

 10. 8S 

 10.62 



