CANZ Glossary of Terms

Magnesia/alumina/silicate glass reinforcement designed to provide very high tensile strength. Commonly used in high-performance parts. Has high compressive strength.

Sag: Slumping of gel coat or resin film. Run: Running of gel coat film or laminating resin.

A laminate with two composite skins separated by, but bonded to, a structural core material. Used to create, rigid, lightweight structures.

Applied to joint in paste or liquid from that which hardens in place to form a seal.

Joining together by adhesive bonding of two or more previously cured parts, or subsequent lamination onto earlier cured laminate surface.

Ceases to burn when the source of flame is removed.

To convert resin into fixed or hardened state by chemical or physical action, such as condensation, polymerization, vulcanization or gelation.

Stress resulting from applied forces. Caused by two contiguous parts of body sliding, relative to each other, in direction parallel to their plane of contact. In cross shear, plane of contact is composed of resin and glass fibres. In interlaminar shear (ILS), plane of contact is composed of resin only. In liquids, force and movement of components or layers against each other.

Ready-to-mould, glass-fibre-reinforced, thickened polyester material primarily used in closed moulding. Similar to bulk moulding compound (BMC) but with improved mechanical properties.

Length of time uncatalyzed polyester remains workable while stored in tightly sealed container; also referenced as “storage life”.

Method of joining two panels together by means of one panel having a recessed shelf to receive the other panel on top of it leaving a flush surface.

One complete cycle on injection moulding machine. Shot weight is measured compound delivered to completely fill mould in injection or transfer moulding.

White fibre produced from leaves of agave plant. Used as reinforcing filler, in short chopped lengths, to impart moderate impact resistance.

Water-soluble solution of chemical additives used to coat filaments; additives protect filaments from water absorption and abrasion. They also lubricate filaments and reduce static electricity (see chapter on “Open moulding”).

Thin, glass laminate applied directly against gel coat to pro vide durability by eliminating entrapped air, and good cosmetic quality by isolating gel coat from subsequent laminate shrinkage due to exotherm heat.

Small, specifically sized pump driven by master gel coat or resin pump to deliver catalyst in ratio of one to three per cent.

Liquid used to dissolve and clean materials.

Specification of properties, characteristics or requirements; a particular material or part must have to be accept able to potential user of material or part.

Ratio of weight of any volume of substance to weight of equal volume of some substance taken as standard unit; usually water for solids and liquids, and air or hydrogen for gasses.

An open mould made in two or more pieces.

Process in which glass fibres, resin and catalyst are simultaneously deposited in mould. Roving is fed through chopper and ejected into resin stream directed at mould. Catalyst and accelerated resin may be sprayed from one or two guns., Glass resin mix is then rolled by hand before curing.

Additive for polymers which aids maintenance o certain properties.

Structural property that describes relationship between forces and moments applied to and stretching and bending deflections experienced by any item.

Deformation resulting from stress.

Primary bundle of continuous filaments combined into single compact unit without twist.

Preferential attack of areas under stress in corrosive environment, where such an environment alone would not have caused corrosion.

External or internal cracks in composite caused by tensile stresses; cracking may be present internally, externally or in combination.

Unsaturated aromatic hydrocarbon, used in plastics. In polyester, a reactive diluent.

Material on which adhesive-containing substance is spread for any purpose, (e.g.: bonding o coating).

Cosmetic quality of surface (see “Profile”).

Material (commonly paraffin wax) that allows surface of polyesters to cure; limits adhesion of another coat of resin if first is thoroughly cured. May be removed by sanding or rubbing with steel wool.

Used with other reinforcing mats and fabrics to enhance quality of surface finish. Designed to block out fibre patterns of underlying reinforcements; also called “surfacing mat”.

Laminate design term used with composites to indicate that laminate is symmetric about the lane, midway through its thickness.