Bicomponent Fiber  

Current U.S. Bicomponent Fiber Producers: BASF Corporation; DuPont Company; Fiber Innovation Technology, Inc.; KoSa; Solutia Inc.

Definition: Bicomponent fiber is comprised of two polymers of different chemical and / or physical properties extruded from the same spinneret with both polymers within the same filament.

Bicomponent Fiber Capabilities
Bicomponents can provide:
Thermal bonding 
Self bulking 
Very fine fibers 
Unique cross sections 
The functionality of special polymers or additives at reduced cost 

Common Bicomponent Configurations
Most commercially available bicomponent fibers are configured in a sheath / core, side-by-side, or eccentric sheath / core arrangement.
  

Advantages of Bicomponent Thermal Binder Fibers
Uniform distribution of adhesive 
Fiber remains a part of structure and adds integrity 
Customized sheath materials to bond various materials 
Wide range of bonding temperatures 
Cleaner, environmentally friendly (no effluent) 
Recyclable 
Lamination / molding / densification of composites. 

Common Polymer Combinations in Bicomponent Thermal Binder Fibers
Polyester Core (250C melt point) with Copolyester Sheath (melt points of 110C to 220C) 
Polyester Core (250C melt point) with Polyethylene Sheath (130C melt point) 
Polypropylene Core (175C melt point) with Polyethylene Sheath (130C melt point)

Self Bulking Bicomponent Fibers
Created most often with side-by-side or eccentric cross section 
Variation in orientation across the fiber causes crimping due to differential shrinkage or strain with applied heat or relaxation.