Definitions /Dictionary/Glossary - nptel

Dwell: A pause in the application of pressure or temperature to a mold, made just before it is
completely closed, allowing gas to escape from the molding material.
E Glass: A family of calcia-alumina-silicate glasses with a certified chemical composition used
for general purpose and most electrical applications (ASTM D578-90).
Elasticity: A material’s ability to recover its original size and shape after the force deforming it
has been removed.
Ejection (De-molding): Removing a molded part from the mold by hand, mechanical means or
use of compressed air.
Ejection Plate: A metal plate used to operate ejector pins; designed to apply a uniform pressure
to them in the process of ejection.
Elastic Limit: The greatest stress a material can sustain without permanent strain after the stress
has been completely released. A material is said to have passed its elastic limit when the load is
sufficient to initiate plastic, or non-recoverable, deformation.
Elastomer: A material that substantially recovers its original shape and size at room temperature
after a deforming force is removed.
Elongation: As mentioned under tensile modulus, when a bar is pulled it gets longer. The
elongation tells how much longer it gets before it breaks.
Encapsulating: Completely surrounding an object with resin or a fiber resin composite.
Sometimes used specifically in reference to the enclosure of capacitors or circuit board modules.
End: A single bundle of filaments.
End count: An exact number of ends supplied on a ball of roving.
Environment: The aggregate of all conditions (such as contamination, temperature, humidity,
radiation, magnetic and electric fields, shock, and vibration) that externally influence the
performance of an item.
Epoxy: A polymerizable thermoset polymer containing one or more epoxide groups cured by its
reaction with amines, alcohols, phenols, carboxylic acids, acid anhydrides, and mercaptans. It is
an important matrix resin in composites and structural adhesive. Epoxies generally have higher
physical properties than polyester resins. They are also more costly and difficult to process, and
less able to withstand sunlight.
Even Tension: Applying the same amount of tension to each end of roving in a ball.
Exotherm: The liberation or evolution of heat during the curing of a plastic product.