The manufacture of fiber glass yarn starts with the mixing of batch ingredients in precise proportions. This mixture, or batch, is then melted in a high-temperature furnace. While in a molten state, the viscous glass is drawn through bushings in continuous filament form by high-speed precision winders.
  
   A chemical treatment, usually referred to as "sizing" or "binder," is applied to the filaments during the winding process to coat the filaments and reduce filament breakage during subsequent processing steps. The binder is engineered to meet customer mechanical and chemical processing needs.
  
   These basic fiber glass strands (each strand is composed of filaments) are then twisted to achieve a product which meets the processing requirements of the customer. The amount of twist per unit of length is identified as "turns per inch" or "turns per meter." The direction of the twist is identified by an "S" or "Z" designation.
  
   When required, twisted yarn is the input to the warping operation for fabricating a beam of many parallel ends for use in customer weaving operations. The number of ends, along with beam width and length are defined by customer weaving needs, which determine the number of yarn bobbins that have to be used to feed a single beam.
  
   Texturized yarn is made by passing yarn through high-pressure air stream. When appropriate for customer applications, a special binder is applied to the texturized product to set the texture.