1912] The Value of Commercial Staeches 145 



of water, 65 lbs. starch and 8 lbs. of tallow will size about 720 

 lbs. of No. 141/^ yarn by the short chain system, w^hile by the 

 slasher system the same amount of size will be sufficient for 

 about 950 lbs. of the same yarn. 



In preparing the starch for use it is very important that the 

 size be thoroughly boiled before being used. In the reports 

 which the author has received from the cotton mills it is always 

 recommended to boil the size mixture from thirty minutes to 

 one hour before using. From this it is safe to say that the size 

 mixture should be boiled for not less than forty-five minutes 

 before being used. 



From the data which has been presented in this article it is 

 seen that the viscosity of the starch solution is the important 

 point to be considered in determining the value of a starch for 

 textile purposes. There is another property of starch which 

 is of value in the textile industry which is not shown by the 

 viscosity, that is the finish which is imparted to the goods by 

 the starch. Potato and cassava starch are said to produce a 

 smooth finish, while corn and rice starch are said to produce a 

 harsh finish. While this property may be of value in sizing 

 and finishing some grades of goods, still no matter which one 

 of the starches is used some softening agent must be used with 

 it to modify the effect of the starch and it is therefore best in 

 the majority of cases to use a cheap starch and control the finish 

 by the use of softeners than to control the finish by varying 

 the kind of starch used. 



Sufficient data has been given to show the value of the differ- 

 ent starches for textile purposes. There is a wide variation in 

 the viscosity of the different starches and in the effect of boil- 

 ing on the viscosities and as this is such an important factor 

 in sizing and finishing it must be taken into consideration in 

 selecting the starch to be used in cotton mills. As starch plays 

 such an important part in the manufacture of cotton goods 

 it is very important for the manufacturer to use the kind of 

 starch which will produce the desired results most economically. 



Feed and Microchemical Laboratory, 



N. C. Department of Agriculture, Raleigh, N. C. 



