US Patent 11339508 Process for forming a yarn comprising bicomponent filaments

A yarn comprising a plurality of bicomponent filaments having a first region comprising a first polymer composition and a second region comprising a second polymer composition, each of the first and second regions being distinct in the bicomponent filaments; each bicomponent filament comprising 5 to 60 weight percent of the first polymer composition and 95 to 40 weight percent of the second polymer composition; wherein the first polymer composition comprises aramid polymer containing 0.5 to 20 weight percent discrete homogeneously dispersed carbon particles and the second polymer composition comprises modacrylic polymer being free of discrete carbon particles; the yarn having a total content of 0.1 to 5 weight percent discrete carbon particles.