CANZ Glossary of Terms

Laminated so all layers of material are oriented approximately parallel with respect to the grain or strongest direction in tension. Also called unidirectional. This pattern allows the highest loading of reinforcement but gives maximum strength in only one direction.

Process of composites fabrication in which multiple discrete parts are designed and fabricated together into a single part, thus reducing the number of fabricated parts and the need to join those parts together.

See Mould Release and PVA

General term for master model that is usually constructed from single material or material type. Pattern is generally not durable and suitable for producing only one (or small number) of moulds. Sometimes used interchangeably with Plug.

A removable non-stick fabric applied to a lay-up surface that is removed from the cured laminate prior to bonding operations in order to leave clean, resin-rich surface ready for bonding. -

Strength of adhesive bond obtained by stress that is applied “in a peeling mode”.

Category of compounds containing unstable O-O (or O-OH) Group: Oxygen to Oxygen atoms; used as initiators.

Thermosetting resin produced by condensation of aromatic alcohol with aldehyde, particularly phenol with formaldehyde.

ingredient used to impart colour, as in gel coats.

Occurs when the pigment is not thoroughly mixed into the gel coat during formulation or the gel coat is improperly mixed prior to use. It is characterised by a non-homogeneous surface colour.

Small air bubbles in gel coat film, few enough to count. Generally larger in size than porosity.

Organic chemical compounds called polymers that can be formulated to produce a wide range of properties.

General term for master model that is usually hand-crafted from a variety of materials. Plug is generally not durable; suitable for producing only one (or a small number) of moulds. Sometimes used interchangeably with “Pattern”.

A single layer within a laminate.

Layup of individual plies or layers to build laminate (FRP). Plies may be arranged (scheduled) in alternating fibre orientation to produce multi-directional strength part (see “Fibre Architecture”).

Resin formed by reaction between dibasic acids and dihydroxy alcohols, one of which must be unsaturated (typically maleic anhydride) to permit cross-linking.

Large chemical chain composed of many repeating groups such as polystyrene.

Chemical reaction of linking molecules or chains of molecules.

A parting film applied to a mould for part releasing. Water-soluble.

Small air bubbles in composite or gel coat film; too numerous to count. Generally small in size than pinholes.

Exposure of cured resin to higher temperatures than during moulding; necessary in certain resins to attain complete cure and ultimate mechanical properties.

The time during which the catalyzed resin remains liquid or “workable”. See Gel Time.

The premature release of the el coat or laminate from the mould. Pe-release causes cosmetic or dimensional problems.

Pre-shaped fibrous reinforcement formed by distribution of chopped fibres by air, water flotation, or vacuum over surface of perforated screen to approximate contour and thickness desired in finished part. Also, compact pill of compressed premixed materials.

Fibre reinforced mat shaped like mould in which it will be used. Eliminates need for overlapping corners in moulding.

Heating of compound prior to moulding or casting in order to facilitate operation, reduce moulding cycle, or remove volatiles.

Mixture of resin, pigment, filler and catalyst for moulding.

Resin-impregnated cloth, mat or filaments in flat form that can be stored for later use. Resin often partially cured to tack-free state called “B-staging”. Additives can be added to obtain specific end-use properties and improve processing, storage and handling characteristics.

A membrane that conforms to the inside of a laminate laid-up on a mould. The membrane or bag is then inflated by applying pressure that consolidates and densifies the laminate.

A distortion in the surface of a part that allows the pattern of the core or fibreglass reinforcement to be visible through the surface. Also known as print out, telegraphing or read through.

durable, robust mould used to produce hundreds or thousands of part copies. Laminated production moulds are best manufactured from laminated master moulds.

Surface contour of part viewed from edge or cross section. When describing cosmetic features, profile is the roughness of surface on a scale large enough to affect visual appearance but small enough to be insignificant with respect to dimensional functionality. Low profile corresponds to very smooth surface; high profile corresponds to a surface with greater roughness.

An additive to speed up the cure. This additive is required for room temperature resin cure. See Accelerator.

Process of creating test part not intended for commercial release that establishes design, material and fabrication parameters for new product. May require multiple iterations (repetitions) to arrive at final/commercial part design.

Automated continuous process for manufacturing composite rods, tubes and structural shapes having constant cross section. Roving and other reinforcements saturated with resin and continuously pulled through a heated die, where part is formed and cured. Cured part then automatically cut to length.

A thickened mixture of resin made by adding fillers, fumed silica (thixotropes) and reinforcing fibres.