Definitions /Dictionary/Glossary - nptel

Gel Coat: A quick-setting resin used in molding processes to provide an improved surface for
the composite; it is the first resin applied to the mold after the mold-release agent.
Gel Permeation Chromatography (GPC): A form of liquid chromatography in which the
polymer molecules are separated by their ability or inability to penetrate the material in the
separation column.
Gel Point: The stage at which a liquid begins to exhibit pseudo-elastic properties. (This can be
seen from the inflection point on a viscosity-time plot.)
Gelation Time: The time under application of load for a resin to reach a solid state.
Gelation: The formation of a gel.
Gel Time: The period of time from a pre-determined starting point to the onset of gelation (gel
point) as defined by a specific test method.
GFRP: Glass fiber-reinforced plastic, polymer or polyester.
Gelation Time: That interval of time, in connection with the use of synthetic thermosetting
resins, extending from the introduction of a catalyst into a liquid adhesive system until the
interval of gel formation
Glass: An inorganic product of fusion which has cooled to a rigid condition without
crystallizing. In the handbook, all reference to glass will be to the fibrous form as used in
filaments, woven fabric, yarns, mats, chopped fibers, etc.
Glass Cloth: Conventionally-woven glass fiber material (see Scrim).
Glass Fibers: A fiber spun from an inorganic product of fusion which has cooled to a rigid
condition without crystallizing.
Glass Filament: A form of glass that has been drawn to a small diameter and I extreme length.
Most filaments are less than 0.15 mm in diameter.
Glass Finish: A material applied to the surface of a glass reinforcement to improve the bond
between the glass and the plastic resin matrix.
Glass, Percent by Volume: The product of the specific gravity of a laminate and the percent
glass by weight, divided by the specific gravity of the glass.
Glass (/Resin) Ratio: The amount of glass by weight compared to the amount of resin by weight
in a finished laminate or molding.
Glass Rich: An area of molded part that has an overabundance of glass reinforcement. The
reinforcement may appear dry and unwet with the resin.