PART TWO 

 THE COLLOID-CHEMISTRY OF SOAP MANUFACTURE 



PRINCIPLES OF HOT AND COLD PROCESS SOAP 

 MANUFACTURE 



1. Introduction 



IT will be the purpose of this chapter to review certain tech- 

 nical procedures followed in soap manufacture in order to see 

 where the concepts developed in the preceding pages may be 

 used as conscious substitutes for various empiric practices. In 

 doing so we will be struck by an interesting fact. Faced on the 

 one side by the myriad problems incident to the handling of a 

 widely varying crude material and on the other by the demands 

 on the part of the public for a product possessed of certain washing 

 characteristics, the practical soap manufacturer has in nearly 

 every instance hit upon both a satisfactory process and a satis- 

 factory product. 



The raw materials used by the soap chemist and, consequently, 

 the soaps which he produces are so many and so various that a 

 complete review of the situation is not possible. What is said 

 in the following pages represents little more than a broad "inline. 



We should have an ideal starting point did we know, as a 

 first foundation for our discussion, the qualitative and quantita- 

 tive composition of the fats ;m<l oils which enter the soap kettle. 

 win -i i we ignore the presence, in the crude fats and oils 

 employed, of unsaponifiable material, of alcohols other than 

 glycerin, of admixed sul^tam-es hearing no relationship to the 

 esters which make up the mass of the fat or oil, etc., we are still 

 handicapped by an inadequate knowledge of the complete com- 



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