Definitions /Dictionary/Glossary - nptel

Exothermic Heat: Heat given off during polymerization by chemical ingredients as they react
and the resin cures.
Extend: To add fillers or low-cost materials in an economy producing endeavor. To add inert
materials to improve void-filling characteristics and reduce crazing.
Extenders: Low-cost materials used to dilute or extend high-cost resins without extensive
lessening of properties.
Extruder: Machine that pushes molten plastic through small holes to form fibers.
Fabrication: The process of glass fiber production during which forming cakes are put into
creels and "roved" or fabricated onto doffs.
Fabricator: Manufacturer of reinforced plastic products.
Fall: Shape or pattern of chopped fibers as they drop from the chopper to the bed.
Fan or Curtain: Chopped bundles that fall or are thrown off the chopper and cot.
Fatigue: Failure or decay of mechanical properties after repeated applications of stress. Fatigue
tests indicate a material’s ability to resist cracking, which eventually causes failure due to a large
number of cycles.
Fatigue Life: How many cycles of deformation it takes before a test specimen will fail under a
given set of oscillating conditions (stresses and strains).
Fatigue Limit: It is the maximum level under which a material can be stressed cyclically for an
infinite number of times before it fails.
Fatigue Strength: The maximum cyclical stress a material can withstand for a given number of
cycles before failure occurs. It is the residual strength after being subjected to fatigue.
Fiber: The major reinforcement material component in a composite matrix. Often, fiber is used
synonymously with filament.
Fiber Content: The amount of fiber present in a composite. This is usually expressed as a
percentage volume fraction or weight fraction of the composite.
Fiber Diameter Letter Designation: Fibers are generally classified in hundred thousandths, i.e.,
a "K" fiber has a mean average diameter of 50+ to 55 heights.
Fiber Direction: The orientation or alignment of the longitudinal axis of the fiber with respect to
a stated reference axis.