Textile applications: A picking stick is a lever which drives the shuttle back and forth in a fly shuttle weaving loom operating at 100 cycles per minute, accelerating a 0.5 kg shuttle to 13 m/s over a 0.3m distance. Initially, picking sticks were made of densified laminated wood and had poor fatigue resistance, with a life of some 3-6 months and the heavy stick restricted the maximum loom operating speed. Picking sticks fabricated from pultruded carbon fiber epoxy composite were 6% less in weight, operated with 3 dB less noise and had a life of up to 3 years, permitting a 10% speed increase.
Other textile components fabricated from carbon fiber including heald (heddle) frames (these position the warp to allow a shuttle with weft to pass through), lay bars, flyer arms, needles, sinkers, guide bars and faller bars. Due to the controlled expansion, the components do not change overnight when the shed temperature drops. Lucas describes the application of carbon fibers to modern high speed loom sley developments.
Chemical and nuclear applications: A full scale plant for the enrichment of U using gas centrifuges would require many thousands of rotors and cfrp is ideal to enhance the performance by enabling the longest length rotors and highest practical operational speeds to be used.
Medical and prosthetic applications: Carbon fiber has found many uses in biomedical applications.
Roland Christensen established Applied Composite Technology, a company that makes artificial feet, marketed as Flex-foot, that uses carbon fiber epoxy prepreg, which was so effective that a sports event participant with an artificial foot ran the 100m in 11.3 s in the 1996 Atlanta Paralympic Games. These artificial feet are sold throughout the world and production has exceeded some 20,000.
Braided carbon fiber is used by Ossur, an Icelandic company, to manufacture a custom fitted socket for an artificial limb, enabling the sock to conform to the changing contour of the socket. The braid is pre-impregnated with a water-activated polyurethane resin and sealed in a watertight package. When required, the prosthetist places a silicone sleeve over the limb, activates the resin with water, positions the wet braid over the silicone sleeve and the resin sets in about 4 min, achieving a 90% cure in 45 min.
A Blatchford & Sons in the UK, market a wide range of prosthetic devices and in the late 1970s, introduced carbon fiber into their prosthetic devices. The cfrp used in their Endolite equipment possessed superior strength, light weight and was easily formed to difficult shapes. They prepared a preform from woven carbon fiber or unidirectional prepreg comprising many overlapping individual patterns, molded carefully in a controlled process to avoid fiber buckling. The finished molding is then CNC machined using an in-house CAD system. The cfrp possesses excellent fatigue resistance, easily surpassing metallic limb systems. Blatchford is the largest UK consumer of CF prepreg outside the aerospace industry, with an output as high as 45,000 components per annum.