180 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1934 



render them taut. Whatever the future of the metal airplane, the 

 availability of cellulose and its remarkable adaptability have helped 

 markedly in the progress of aviation. 



The merchandising of packaged articles is today dependent to a 

 very large extent upon cellulose. The large container or carton is 

 made from paper board as are the smaller boxes which hold the in- 

 dividual units of merchandise. To increase the appeal to the eye, 

 the chemist in recent years has furnished transparent sheets of Cello- 

 phane and Sylphwrap. The chemistry involved in the manufacture 

 of this material is the same as that of the viscose process for manu- 

 facturing artificial silk, but instead of extruding the cellulosic solu- 

 tion through minute orifices it is forced through a long narrow slot 

 into a hardening bath. 



Another new use for a cellulose derivative is in the manufacture 

 of shoes. In this novel process all sewing or nailing of the shoe is 

 eliminated and the shoes are literally stuck together. The cement 

 used is a specially compounded cellulose nitrate cement with unusu- 

 ally rapid sticking qualities. When the process was first used in the 

 United States in 1928 the soles had to be held in contact with the 

 uppers for 30 minutes. At the present time the process has been so 

 perfected that it is now only necessary to hold the two parts together 

 for 50 seconds. The process is so rapid that a single operator in 8 

 hours and 15 minutes applied soles to 1,580 pairs of shoes. The indi- 

 cations are that over 50,000 pairs of shoes will be made by this 

 method in the United States in 1933. 



In this new age cellulose has taken its place as a great chemical 

 raw material, and with increasing knowledge its importance is bound 

 to be enhanced. Technical literature and patent indices are record- 

 ing at an increasing rate new chemical derivatives of cellulose, many 

 of which may reasonably be expected to appear in industry within 

 the next 5 or G years. Already cellulose ethers are available, some 

 of which have a very unusual resistance to both acid and alkaline 

 solutions. Reports are also being heard with increasing frequency 

 of new mixed esters with greatly improved properties. It is only the 

 complex chemical character of cellulose that has so long delayed its 

 utilization as a raw material for chemical transformation, but as the 

 nature of the cellulose molecule continues to be elucidated a material 

 of which so large a supply is potentially available Avill surely find 

 useful application in increasing quantities. 



