CTF3 (Cuben Fiber) is a product marketed and developed by the Cuben Fiber and Cubic Tech Corporations as a high-performance non-woven fabric for applications such as yacht sails, airship hulls, kites and many designs that require extremely strong rip resistance and light areal weight.
The name Cuben Fiber was coined by the press in reference to America³ (pronounced America Cubed), the winner of the 1992 America's Cup. During the 1992 Cup, that yacht reportedly used sails made from precursors to the currently available commercial product. In late 2007, the Cuben Fiber Corporation was acquired by North Sails. North Sails says they will continue to supply the materials to competitors on an as available basis. Cubic Tech Corporation has the exclusive rights to develop and sell "Cuben Fiber" type laminates for all non-sailing applications.
Cuben Fiber is a laminated fabric constructed from Ultra High Molecular Weight Polyethylene (UHMWPE) fiber monofilaments and polyester, PVF etc. films. Cuben fiber is sometimes confused with carbon fiber, one of the many fibers used as a reinforcement in some Cuben Fiber laminates. Cubic Tech Corporation's ultra-high performance flexible laminates were re-branded from Cuben Fiber to CTF3 (TM) in 2009. Cubic Tech Corp produces CTF3 with a wide variety of fibers such as Vectran, Carbon, Kevlar etc.
The material is used in yachting, performance sailing, windsurfing, inflatables, airship hulls, medical applications and increasingly in ultralight backpacking equipment, such as tents etc. Similar to sails made from traditional woven sail cloth, Cuben Fiber sails are constructed from panels that are bonded and sewn together, as opposed to 3DL sails that are laminated over a mold. The material is reportedly more durable than laminated sails of comparable strength while being lighter in weight. UHMWPE has excellent resistance to ultraviolet light and is less prone to disintegrate from repeated flexing than either Kevlar or Carbon Fiber.
While the UHMWPE fiber has great breaking or ultimate strength, its elongation or creep under consistently high loads causes deformation of a sail. The patented treatment of the Cuben Fiber is said to minimize this elongation.