FLEXIBLE REPEATER MANUFACTURE 109 



area and the processes are free from, and not conducive to producing, 

 particles of material which are capable of causing trouble. 



The various classifications established for the production areas include 

 specific requirements as to temperature, relative humidity, static pres- 

 sure with respect to adjacent areas, cleanliness in terms of restrictions 

 on smoking and the use of cosmetics and food, and the type and use of 

 special clothing. 



Special Clothing 



Employees' clothing was considered one of the most important sources 

 of contamination for two reasons; first, for the foreign material that 

 could be collected upon it and carried into the manufacturing areas, and 

 second, that various types of textiles in popular use are subject to con- 

 siderable raveling and fraying. 



After considerable study of many types of clothing for use in critical 

 areas, the material adopted was closely woven Orion, which has proved 

 to be acceptably lint-free. The complete uniform — supplied at no cost 

 to employees — consists of slacks and shirts for both male and female 

 employees, Orion surgeon's caps for the men and nylon-visored caps 

 for the women. In addition shoes, without toecap seams, were provided. 

 Nylon smocks were furnished to protect the uniforms while employees 

 moved from locker rooms to the entrance vestibule. Two changes of 

 clothing were provided each week, and the laundering was done by an 

 outside concern. 



Employees to whom this special clothing was issued were paired for 

 locker use. Both kept their uniforms and special shoes in one locker and 

 their own clothes and shoes in the other. This prevented the transfer 

 to the uniforms of any foreign material that might exist on the street 

 clothing. At the entrance vestibule to the A, B, and C areas (Fig. 1) 

 the employees were required to clean their shoes in the specially designed 

 facilities provided and to wash their hands in the wash basins installed 

 for this purpose. Smocks were then removed and hung on numbered 

 hooks that line the walls at the end of the vestibule. Employees were 

 then permitted to go to their work positions within the inner areas. At 

 any time that it was necessary for employees to leave the work areas 

 for any purpose, they were required to put on their smocks in the vesti- 

 bule and upon their return, to go through the cleaning procedure again. 



Employees in the other areas were provided only with smocks, mainly 

 for the protection of their clothes since the work invoh-ed could soil or 

 stain them but could not be contaminated from the clothing. 



