Leacril ^®is a fiber composed of linear macromolecules that have at least 85% in weight of acrylonitrile units in the chain. It is composed by an atactic polymer, through a radical polymerization mechanism. Produced with high chain orientation obtained by stretching, it has excellent mechanical characteristics thanks to the high-polarity CN groups along the molecule chain. Its highly compact, rigid structure is due to the high degree of interaction between the CN groups. Its density is 1.18 g/cc. Because of the polymer decomposition before melting, the fiber, according to traditionally used know-how, is not produced by melting but only by solution methods, according to a wet spinning (the most diffused worldwide). Thanks to the presence of chromophore groups along the molecule chains, acrylic fibers can be easily dyed either with pigments or with basic dyestuffs. With the latter the fiber can be dyed directly in the production phase (gel-dyed) or in staple, tow or yarn form (batch dying). Gel-dying, though presenting some processing difficulties, also offers many advantages such as:

• good degree of color repeatability
  
• characteristics more constant than with raw white tow
  
• lower costs than batch dying
  
• more eco-friendly, since the dyestuffs are not discharged with the water.
  

By virtue of its mechanical characteristics and the crimping imparted in the production phase, acrylic fiber can be used pure or in blends with other synthetic or natural fibers, in both worsted and cotton systems, either ring-spun and open-end, providing a soft touch, good resistance and elasticity of the yarns, which retain their characteristics even in the subsequent phases of the processing and use, thanks to the stability of their crimp and properties. The fiber is offered as:

• raw white (bright or semidull)
  
• bleached (optical white)
  
• dope-dyed, before spinning
  
• gel-dyed, in a vast range of solid colors for: knitwear, decorator fabrics, pile fabrics, outdoor uses (awnings,marine, garden furniture, beach umbrellas, car convertible tops, etc.)

The LEACRIL^® fiber is produced in a large variety of types with different dimensional stability to withstand exposure to boiling water, hot air or steam. This means that there are products with varying degrees of "shrinkability" for blending with natural or synthetic fibers, resulting in a bulking of the fibers after shrinkage, particularly appreciated in knitwear, pile fabrics, blankets, rugs, etc.