A term used to describe fibres composed of synthetic linear macromolecules having in the chain more than 50% (by mass) of chloroethene (vinyl chloride) or 1,1-dichloroethene (vinylidene chloride) groups. If the rest of the chain is made up of cyanoethene (acylonitrile) groups then the chloroethene content must be greater than 65%, thus excluding modacrylic fibres from this definition
Textile Resource (http://www.textile.org.uk)
