Acrylic fibres, or polyacrylonitrile, PAN for short, are essentially available in 2 forms, "co-polymer acrylic" & "homopolymer acrylic". As the name suggests, co-polymer acrylic fibre is generaly used for clothing, apparel, blankets etc, whereas homopolymer acrylic fibre is, as the name suggests, is from a single polymer, (hence "homo" polymer). There are many producers of co-polymer acrylic fibre world wide, but the technology of producing acrylic fibres from a single, homo polymer is available with less than a handful companies. Homopolymer acrylic fibres exhibit far higher chemcial & thermal resistance when compared to the far cheaper co-polymer fibres, Homopolymer acrylic fibres do not hydrolysis, so they are used in applications of high moisture environments. Homopolymer acrylic also has a far better resistance to acidic environments.