CANZ Glossary of Terms

Reinforcing fibre known for its light weight, high strength, and high stiffness.

The process of pouring a mixture of resin, fillers and/or fibres into a mould as opposed to building up layers through lamination. This technique produces different physical properties from laminating.

In a scientific sense, the substance that promotes or controls the curing of compound without being consumed in the reaction (initiator). Within the composites industry, free radial initiators such as MEKP are often referred to as “catalysts”. Such usage is scientifically inaccurate since initiator is consumed during usage.

In FRO terms, substance added to resin or gel coat in controlled quantities to make it gel and cure. Catalyst is reduced by accelerator, creating free radicals, which in turn initiate polymerization.

Used with spray equipment to catalyse polyester at spray gun, therefore eliminating the need to clean system within gel time of polyester. Internal mix guns require a solvent flush for cleaning gun head.

Space between matched moulds (pressure moulds) in which laminate is formed. Also, a term for a female mould.

(CPS) A unit of measure used to describe the viscosity of a liquid. Viscosity is measured with a Brookfield Viscometer for most polyester resin applications. At 21 deg.C water is on cps.

A surface phenomenon indicating degradation of a cosmetic surface. Chalking is a powdery film that appears lighter than the original colour.

A fibreglass reinforcement consisting of short strands of fibre arranged in a random pattern and held together with a binder. Mat is generally used in rolls consisting of 225 – 600gm/m2 material.

Fabrication process in which composite part is produced in a mould cavity formed by the joining of two or more tool pieces.

A fibreglass reinforcement made by weaving strands of glass fibre yarns. Cloth is available in various weights measured in ounces per square yard or Kg/2.

Used as an accelerator for methyl ethyl ketone peroxide catalyzed polyesters.

Material’s fractional change in dimension for given unit change of temperature.

Tendency of single substance to adhere to itself. Also, force holding single substance together.

Failure of adhesive joint that occurs either within adhesive material or within one or both adherends.

A material made of distinct components. For example, a reinforcing fibre in a resin matrix where the combined properties are superior to the individual materials.

Mould that is open when material is introduced and that shapes material by heat and by the pressure of closing.

See “Closed moulding”.

Resistance to crushing or buckling force; maximum compressive load specimen sustains divided by its original cross-sectional area.

Processing step that compresses fibre and matrix to remove excess resin, reduce voids and achieve particular density.

Refers to the use of a single or open mould onto which resin and reinforcement materials can be applied. Contact moulding is characterised by one finished cosmetic side.

Impurity or foreign substance that affects one or more properties of composite material.

A fibre bundle composed of many glass filaments. Also, when referring to gun roving, a collection of string like glass fibre or yard, which is fed through a chopper gun in the spray up process.

A bundle of glass filaments which are fed through a chopper gun in the spray up process.

Large chemical chain composed of two or more dissimilar groups.

Loosely twisted cord made up from rovings and designed for incorporation in mouldings where edge reinforcement and high strength ribs are necessary.

A low-density material used between two FRP skins. Examples of core materials are end-grain balsa wood, urethane foam, PVC foam and various honeycomb materials.

Compression damage to core.

On honeycomb core, used to line up ribbon direction, thickness of cell depth, cell size, and transverse direction.

Geometric feature characterised as point where three edges come together, as in a box corner. Can be either inside corner or outside corner.

Capability of substance or part to maintain appearance with respect to surface smoothness, colour, gloss or other visual appearance characteristics.

Cracking of the resin due to internal stress.

Device used to hold required number of roving spools or other supply packages of reinforcement in desired position for unwinding.

Over time, dimensional change in material under physical load (beyond initial elastic deformation).

Laminated so some layers are oriented at right angles to remaining layers with respect to grain or strongest direction in tension.

The chemical bonding of molecules which in polymerisation occurs in the curing transition from a liquid to a thermoset solid.

The completion of the cross-linking process during which a composite develops its full strength.

Time between introduction of catalyst or initiator to a polymer and final cure.

An initiator or catalyst that initiates polymerisation when added to a resin. For epoxies these are known as hardeners.