216 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1941 



has shown closer resemblance to wool than any other synthetic fiber 

 yet produced. This fiber was imported into this country as Lanital 

 until Italy entered the war. 



Owing to certain weaknesses in the casein fibers, particularly 

 tensile strength in dyeing, attempts have been made to mix viscose 

 and casein together. Such products as Raiian and Cisalfa are the 

 result of such experiments. Further, casein has been mixed with 

 Latex and glue with some success in fibers known as Tiolan (German) 

 and Lactofil (Dutch). 



In this country Whittier & Gould in their United States patent 

 No. 2140274, of December 13, 1938, and later No. 2204535 in June 

 1940, offered a process of making casein fiber and assigned the patents 

 for public use. 



Recently in this country a new synthetic staple fiber has been an- 

 nounced by F. C. Atw^ood, president of the Atlantic Research Asso- 

 ciates of Boston, under the trade name of Aralac. It was announced 

 at the National Farm Chemurgic Conference in March 1940, at De- 

 troit. This casein material is made in natural or opaque form, or 

 in a delustered condition; also in a softened condition to simulate 

 the softness of high-quality wool, as well as in an unsoftened con- 

 dition, possessing a scroop. It is made in less than 20 microns and 

 over 30 microns to match the thickness of every grade of wool. It 

 is now being produced commercially by the Aratex Division plant 

 of the National Dairy Products Corporntion, at Bristol, R. I. 



The present physical and chemical properties are about the same 

 as Lanital, reported on by von Bergen. It has a high afiinity for all 

 wool dyes. Its dry strength is about one-half that of wool and its 

 wet strength is about one-fifth that of wool. Compared to viscose 

 rayon it has about 10-20 percent less strength. Of course, lack of 

 strength is not always a drawback to its introduction, as was the 

 case with rayon. 



The longitudinal structure of Aralac is more or less smooth and 

 shows no pronounced indentations or .striations like rayon, but its 

 surface is peculiarly "rippled," the only word I can find to describe 

 it. Its cross section is nearly circular and highly uniform. The 

 contour shows hardly any deviation from a smooth circle. Its dif- 

 ferentiation from soybean and Lanital is not easy, because of its 

 close chemical composition. 



The price of Aralac is now fi-om 40 to 55 cents per pound. Its 

 principal use at present is in the felt-hat industry, as an admixture 

 with wool and rabbit hair. It is claimed that hats and hat bodies 

 containing up to 50 percent of Aralac are already on the market. 

 Experiments in other woolen fabrics and admixtures are now in 

 progress and all uses will consume almost a million pounds in the 

 first year of its existence. 



