ASTM D3822 covers the measurement of tensile properties of both natural and man-made single textile fibers that are of sufficient length to permit mounting into a tensile testing machine.
Individual fibers are usually very delicate and fragile. It is very important to remove the individual fibers from the laboratory sample with extreme care. Specimens can be tested dry or wet (with or without immersion). The single-fiber specimens are then broken at a constant-rate-of-extension (CRE) type of tensile testing machine. Using the force-elongation curve, the breaking force and elongation at break are determined.
The results obtained from this test, breaking tenacity and the elongation, are fundamental properties that are widely used to establish limitations of fiber process or conversation and on their end-use applications. The tangent modulus and tensile stress at specified elongation may be used to differentiate between the probable performance of fibers in processing and end-use performance. The breaking toughness is an indication of the durability of materials produced from the fiber.