Definitions /Dictionary/Glossary - nptel

Surfactant: Chemicals used to modify or change the surface of a layer of resin or polymer. It is
usually used to form a film on a curing resin, producing a tack-free surface.
Tack: Surface stickiness.
Tack Free: Surface which is not sticky after cure.
Tangent Modulus: Slope of the line at a predefined point on a static stress-strain curve,
expressed in force per unit area per unit strain. This is the tangent modulus at that point in shear,
tension or compression, as the case may be.
Tape: A narrow fabric whose mass per unit area is less than 0.5 kg/m 2 (0.1 LB/ft2) for each
25.4 mm (1 in.) of width; used primarily for utilitarian purposes.
Tenacity: Term used in yarn manufacture and textile engineering to denote the strength of a yarn
or filament of a given size. Numerically, it is expressed as grams of breaking force per denier
unit of yarn or filament size; grams per denier, gpd. The yarn is usually pulled at the rate of 12
inches per minute. Tenacity equals breaking strength (grams) divided by denier.
Tensile Elongation: Engineering term referring to the amount of stretch a sample experiences
during tensile strain.
Tensile Load: Lo ad applied away from and to opposite ends of a given sample.
Tensile Modulus: When a bar is pulled in tension, it gets longer. Tensile modulus calculates
how much longer it will get when a certain load is applied. Units are normally millions of pounds
per square inch. (10 6 psi) - Giga Pascals (GPa). Higher numbers indicate materials that do not
elongate as much as others under equal tensile loading conditions.
Tensile Strength: The amount of nonmoving load a bar can withstand before it breaks due to
elongation. Units are normally thousands of pounds per square inch. (103 psi) - Mega Pascals
(MPa). Higher numbers indicate materials that can withstand a stronger pull before breaking.
Tensile Stress: Normal stress caused by forces directed away from the plane on which they act.
Tension Device: A mechanical or magnetic device that controls tension.
TEX: A unit for expressing linear density, equal to the mass in grams of 1 km of yarn, filament,
fiber or other textile strand.
Texturized Glass Yarn: Yarn processed from continuous filaments that have been disoriented,
adding bulk.
Thermal Coefficient of Expansion: Measures how much the length of a material will change
when it is heated or cooled. The value given is based on the inch as a unit. The number given