CANZ Glossary of Terms

Technique in which composite material is placed in rigid mould and covered with flexible bag. Pressure is applied by vacuum, autoclave, press, or by inflating the bag.

Laminate design term used with aligned-fibre composites to indicate that each ply oriented at plus theta degrees is matched by a ply at minus theta degrees. When plus theta is zero degrees, minus theta is 90 degrees. See related Symmetric. Laminate can be balanced and not be symmetric.

A measure of surface hardness made with a Barcol Impressor instrument in accordance with ASTM D-2583. The harness value can be used as an indication of the degree of cure of a gel coat or laminate.

Instrument invented by Walter Colman during WWII to measure hardness of soft metals; manufactured by Barber-Colman Company. Two types are commonly used in the FRP industry. Model 934 is used to check ultimate cure; Model 935 is used for initial readings prior to

Identity for all material produced during one operation possessing identical characteristics throughout.

Catalyst used in conjunction with aniline accelerators or where heat is used as an accelerator.

Arrangement of reinforcing fibre strands in which half the strands are laid at right angles to the other half; a directional pattern that provides maximum product strength to those two directions.

Bonding resin applied to glass fibres to hold them in position in a broadgoods textile structure. During lamination, this resin is dissolved by the styrene in polyester resin, and, if unsaturated, can become part of the final polymer network.

Textile material consisting of short glass fibres held together with polymer fibre cross-stitch; resembles chopped strand mat without the binder. Also called Stitched Chopped Strand Mat.

Excess liquid resin appearing at the surface, primarily occurring during filament winding or from an RTM mould tube.

Layer of porous material placed in a vacuum bag to absorb excess resin and allow air and gas to escape.

Result of softening of backside of gel coat (typically by laminating resin or post applied gel coat) which causes pigments (colour) to reflow.

A void formed within a composite that may be the result of either trapping air in a laminate, or chemical action within the laminate.

Integral structural element used to stiffen or strengthen mould skin.

Separation or breakage of fibres when edges of a composite part are drilled or cut.

Condition that occurs when textile or sheet material does not conform to inside edge or radius on mould or laminate surface and does not come into contact with the laminate below.

Failure mode usually characterised by fibre deflection rather than breaking.

Premixed blend of thermosetting resin, reinforcements, catalysts and fillers for use in closed moulding process. Similar to sheet moulding compound (SMC) but mechanical qualities are not as good, and it is less expensive.