Definitions /Dictionary/Glossary - nptel

at right angles to one another, while the term angle-ply is used for all others. In the handbook,
the two terms are used synonymously. The reservation of a separate terminology for only one of
several basic orientations is unwarranted because a laminate orientation code is used.
Cross-ply Laminate: A laminate with plies oriented at 00 and 900 only.
Crystallinity: The quality of having a molecular structure with atoms arranged in an orderly,
three-dimensional pattern.
Cure: To change the properties of a thermosetting resin irreversibly by chemical reaction, i.e.,
condensation, ring closure, or addition. Cure may be accomplished by addition of curing (crosslinking)
agents, with or without catalyst, and with or without heat. Cure may occur also by
addition, such as occurs with anhydride cures for epoxy resin systems.
Cure Cycle: The schedule of time periods at specified conditions to which a reacting
thermosetting material is subjected in order to reach a specified property level.
Cure Stress: A residual internal stress produced during the curing cycle of composite structures.
Normally, these stresses originate when different components of a lay-up have different thermal
coefficients of expansion.
Cure Time: The time required for the liquid resin to reach a cured or fully polymerized state
after the catalyst has been added.
Cure Stress: A residual internal stress produced during the curing cycle of composite structures.
Normally, these stresses originate when different components of a lay-up have different thermal
coefficients of expansion.
Curing Agent: A catalytic or reactive agent which when added to a resin causes polymerization,
synonymous with hardener. It is an agent which when added to a resin causes polymerization.
Curing Temperature: It is temperature at which a cast, molded, or extruded product, a resinimpregnated
reinforcement, an adhesive, etc., is subjected to curing.
Curing Time: It is the period of time during which a part is subjected to heat (or pressure), or
both, to cure the resin. It is an interval of time between the instant of cessation of relative
movement between the moving parts of a mold and the instant that pressure is released. (Further
cure may take place after removal of the assembly from the conditions of heat or pressure.)
Cyanate Ester Resin: Thermosetting resins that are derived from bisphenols or polyphenols and
are available as monomers, blend~ and solutions.
Cycle Time: In molding, the total time used to carry out a complete sequence of operations
making up the molding cycle.