Industry Glossary - I

The difference in weight before and after burning. As with glass, the burning off of the binder or size.

A moving load is one that is moving when it strikes a bar. The effect of such a load which is denoted by the work “impact”. The impact strength of a material is a measure of how much energy is absorbed by the bar when it is broken by a moving weight. There are many different test methods for measuring impact. Izod is but one of these methods. Units – foot pounds per inch of width. This is sometimes given as foot pounds per inch of notch. Joules/Meter (J/M). Higher numbers mean that the material will absorb more energy before it is broken by a moving weight.

Measure of the energy necessary to fracture a standard sample by an impulse load.

In reinforced plastics, to saturate a reinforcement, especially fiberglass, with a resin.

In place. In the position which it will finally occupy, e.g. molding or forming foam.

A substance that retards polymerization, thus extending shelf life of a monomer. Also used to influence gel time and exotherm.

Peroxides used as sources of free radicals. They are used in free-radical polymerization, for curing thermosetting resins, as cross-linking agents for elastomers and polyethylene, and for polymer modification.

Method of forming a plastic to the desired shape by forcing the heat-softened thermoplastic polymer into a relatively cool cavity under pressure or thermosetting polymer into a heated mold.

Natural or synthetic metallic oxides, sulfides, and other salts that impart heat and light stability, weathering resistance, color, or migration resistance to plastics.

An integral part of plastic molding consisting of metal or other material that may be molded into the part or pressed into position after the molding is completed.

A surface that lies between two different materials.

Descriptive term pertaining to an object (for example, voids), event (for example, fracture), or potential field (for example, shear stress) referenced as existing or occurring between two or more adjacent laminae.

Shearing force tending to produce a relative displacement between two laminae in a laminate along the plane of the interface.

Fire-retardant technology which causes an otherwise flammable material to foam, forming an insulating barrier when exposed to heat.

Not capable of re-dissolving or re-melting. Chemical reactions that proceed in a single direction and are not capable of reversal (as applied to thermosetting resins).

Plastics based on resins made by the reaction or organic isocyanates with other compounds.

Polyester resin based on isophthalic acid, generally higher in properties than a general purpose or orthothatic polyester resin.

Having uniform properties in all directions.

A test for shock loading in which a notched specimen bar is held at one end and broken by striking, and the energy absorbed is measured.