Definitions /Dictionary/Glossary - nptel

Carrier: A mechanism for carrying a package of yarn through the braid weaving motion. A
typical carrier consists of a bobbin, a track follower and a tensioning device.
Casting: The process of pouring a mixture of resin, fillers and/or fibers into a mold as opposed
to building up layers through lamination. This technique produces different physical properties
from laminating.
Cast Polymer: Non-reinforced composite (resin used without reinforcing fibers). It
includes/combines polymers, fillers and additives as composites to meet specific applications
requirements.
Catalyst: A substance which changes the rate of a chemical reaction without itself undergoing
permanent change in its composition; a substance which markedly speeds up the cure of a
compound when added in minor quantity as compared to the amounts of primary reactants.
Catalyst Injection: Used with spray equipment to catalyze the polyester at the spray gun,
therefore eliminating the need to clean the system within the gel time of the polyester. Internal
mix guns do require a solvent flush for cleaning the head. Injector: Atomizing air atomizes the
catalyst at the injector unit itself. Pot: Catalyst is supplied to the spray gun, then air is introduced
to atomize the catalyst.
Catastrophic Failures: Failures of a mechanical or unpredictable nature.
Catenary: A measure of the difference in length of the strands in a specified length of roving as
a result of unequal tension; the tendency of some strands in a taut horizontal roving to sag lower
than the others.
Carrier: A mechanism for carrying a package of yarn through the braid weaving motion. A
typical carrier consists of a bobbin spindle, a track follower, and a tensioning device.
Caul Plates: Smooth metal plates, free of surface defects, the same size and shape as a
composite lay-up, used immediately in contact with the lay-up during the curing process to
transmit normal pressure and to provide a smooth surface on the finished laminate.
Caul Sheet: Plate or sheet the same size and shape used in contact with a composite layup to
transmit normal pressure and temperature during cure.
Caulk: An elastic material used to protect joints or connections from external elements,
particularly moisture.
Cavity: Depression in mold; the space inside a mold wherein a resin is poured; the molded
article; which forms the outer surface of the molded article (often referred to as the die); also, the
space between matched molds. (Depending on number of such depressions, molds are designated
as Single-Cavity or Multiple-Cavity).
Cell: It is a single honeycomb unit, usually a hexagon.