Vinyon is a synthetic fiber made from polyvinyl chloride.
It can bind non-woven fibers and fabrics.
In the past, Vinyon was used a substitute for plant-based filters in tea bags.
The U.S. Federal Trade Commission definition for vinyon fiber is "A manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed of at least 85 percent by weight of vinyl chloride units (—CH2—CHCl—)."
First U.S. commercial vinyon fiber production: 1939, FMC Corporation, Fiber Division (formerly American Viscose Corporation).