Bicomponent fibers can be defined as "extruding two polymers from the same spinneret with both polymers contained within the same filament. " A close relative is "co-spun fiber", which is a group of filaments of different polymers, but a single component per filament, spun from the same spinneret. The term "conjugate fibers" is often used, particularly in Asia, as synonymous with bicomponent fibers