Definitions /Dictionary/Glossary - nptel

Soft Tool: A tool made of composites or a similar "soft" material which is vulnerable to damage
during use, storage, or transportation.
Solvent Resistance: The non-swelling of a material and, of course, the impossibility for it to be
dissolved by the solvent in question.
Solid: The amount of sizing on the glass expressed as a percentage of the total weight.
Solute: The dissolved material.
Solvent: A liquid used to dissolve and clean materials.
SPEC: Specifications of the properties, characteristics, or requirements a particular material or
part must have in order to be acceptable to a potential user of the material or part.
Specific Gravity: The ratio of the weight of any volume of a substance to the weight of an equal
volume of another substance taken as standard at a constant or stated temperature. Solids and
liquids are usually compared with water at 39°F (4°C).
Specific Heat: The quantity of heat required to raise the temperature of a unit mass of a
substance one degree under specified conditions. Units = BTUs per pound per degree Fahrenheit
(BTA/lb/ (F); = Joules/Kilogram Kelvin (J/Kg-K). Higher numbers means that it takes more
input heat energy to raise the temperature of a material.
Specimen: A piece or portion of a sample or other material taken to be tested. Specimens
normally are prepared to conform to the applicable test method.
Spindle: A slender upright rotation rod on a spinning frame, roving frame, twister or similar
machine.
Splice: The joining of two ends of glass fiber yarn or strand, usually by means of an air drying
glue.
Split Mold: A mold in which the cavity is formed of two or more components held together by
an outer chase. The components are known as splits.
Spray-Up: Techniques in which a spray gun is used as the processing tool. In reinforced
plastics, for example, fibrous glass and resin can be simultaneously deposited in a mold. In
essence, roving is fed through a chopper and ejected into a resin stream which is directed at the
mold by either of two spray systems. In foamed plastics, very fast-reacting urethane foams or
epoxy foams are fed in liquid streams to the gun and sprayed on the surface. On contact, the
liquid starts to foam.
Stabilizer: And additive for polyesters to maintain liquid characteristics such as; gel time,
viscosity and liquidity.