1912^ The Value of Commercial Starches 141 



containing a small amount of borax and is slightly alkaline. 

 The viscosity of the alkaline N starch has been reduced by the 

 addition of a small amount of alkali. The other starches given 

 in the table have been treated to reduce the viscosity and are 

 neutral in reaction. The effect of several reagents on the vis- 

 cosity of starches has been shown in a previous paper.^ 



It will be seen from this table that the viscosities of the 

 treated starches cover quite a wide range, from a viscosity 

 slightly less than that of corn starch to a viscosity only slightly 

 higher than water. The Special Warp Sizing Starch is a pul- 

 verized corn starch. It is frequently claimed that pulverized 

 starch makes a smoother size mixture than the ordinary gran- 

 ular starch. These treated starches, on account of having lower 

 viscosities than untreated starches, are of value in sizing and 

 finishing to obtain more penetration of the starch into the yarn 

 or cloth and to increase the amount of starch which is put into 

 the goods. This may be accomplished by using the treated 

 starch in place of the untreated and increasing the amount used 

 or by mixing the treated starch with the untreated starch in 

 such proportion as to secure the desired results. For instance, 

 in sizing or finishing if the mixture contains 50 lbs. of corn 

 starch to 100 gallons of water and it is desired to increase the 

 amount of starch put into the goods nearly double this amount 

 of a thin boiling starch could be used which has a viscosity of 

 half of that of corn starch and still obtain a size mixture with 

 the same thickness or viscosity as with the 50 lbs. of corn starch. 

 In other words nearly twice as much starch would be put into 

 the yarn, thereby increasing the weight of the yarn, by using 

 the thin boiling starch than by using the untreated corn starch. 

 This is shown in the following formulae for sizing No. 26 yarns 

 which are taken from actual practice: 



100 gallons water 

 50 lbs. corn starch. 



100 gallons water 

 95 lbs. Eagle Finishing Starch. 



' Journal of Industrial and Engineering Chemistry, Vol. IV, No. 6, 1912. 



