Industry Glossary - G

Where the molten thermoplastic enters the cavity in the injection molding tool.

The initial jelly-like solid phase that develops during the formation of a resin from a liquid. A semisolid system consisting of a network of solid aggregates in which liquid is held.

Surface coat of a specialized, quick-setting polyester resin, either colored or clear, providing a cosmetic enhancement and weather ability to a fiberglass laminate. The gel coat becomes an integral part of the finished laminate.

The stage at which a liquid begins to exhibit pseudo-elastic properties. This stage may be conveniently observed from the inflection point on a viscosity time plot.

Time required to change a flowable liquid resin into a non-flowing gel.

The point in a resin cure when the resin viscosity has increased to a point such that it barely moves when probed with a sharp instrument.

Glass fiber-reinforced plastic, polymer or polyester.

When several different fiber types, i.e. different lengths and diameters, are blended in the fiber slurry.

Percentage of glass in the compound.

Process of forming a glass mat on modified papermaking equipment.

Reversible change in the amorphous polymer or in amorphous regions of a partially crystalline polymer from, or to, a viscous or rubbery condition to, or from, a hard and relatively brittle one.

The appropriate midpoint of the temperature range over which glass transition takes place.

Side of a molding in contact with a mold surface.

A fiber made from a precursor by oxidation, carbonization, and graphitization process (which provides a graphitic structure).

Resin, which has not completely cured and is still rather soft and rubbery.

That ability of the material, while not completely cured, to undergo removal from the mold and handling without tearing or permanent distortion.

Glass-reinforced plastic, polymer or polyester. This derivation is commonly used in Europe.