A precursor fibre bundle for production of a carbon fibre bundle, a carbon fibre bundle, and a process for producing thereof

摘要

This invention relates to a precursor fiber bundle for production of a carbon fiber bundle, a process for producing the precursor fiber bundle, a carbon fiber bundle produced with the precursor fiber bundle, and a process for producing the carbon fiber bundle. A percursor fiber bundle according to the invention has a fineness being in the range of from 300,000 denier to 1,500,000 denier and has a potential dividability to sub-tows each of which has a fineness being in the range of from 50,000 denier to 250,000 denier. The precursor fiber bundle is obtained by dividing a multifilament made of an acrylic copolymer spun from a spinnerette into a plurality of sub-tows, drawing the sub-tows in this state, and after that converging the sub-tows into one tow with overlapping adjacent sub-tows at a side edge portion thereof. The converging is practiced typically by passing the overlapped sub-tows through a crimping apparatus. A carbon fiber bundle according to the invention is produced by dividing the precursor fiber bundle into the sub-tows and after that treating the sub-tows by passing thereof through stabilizing and carbonizing processes.