DREF friction spinning

Friction spinning: air is used to propel the sliver of fibres (1) to a carding drum (2) where they drop (3) between two perforated drums (5) that integrate and twist the yarn

Friction spinning or DREF spinning is a textile technology that is suitable for spinning coarse counts of yarns and technical core-wrapped yarns. DREF yarns are bulky with low tensile strength, making them suitable for blankets and mop yarns. They can be spun from asbestos, carbon fibres and are capable of being made into filters for water systems.[clarification needed] Yarns such as Rayon and Kevlar can be spun using this method. The technology was developed around 1975 by Dr. Ernst Fehrer.