Elder Engineering - Plastics Engineering

Laminates

Laminates by definition
are products made by bonding together two or more layers or laminae of material.

In the reinforced plastics industry, the term refers mainly to superimposed layers of resin-impregnated or resin coated fabrics or fibrous reinforcements which have been bonded together, usually by heat and pressure, to form a single piece.

Laminate is also used to include composites of resins and fibers which are not in distinct layers, such as filament wound structures and spray-ups.

Laminated plastic compositions in which fibrous reinforcements are imbedded, have enhanced strength properties greatly superior to those of the base resin. The reinforcements are usually fibers, rovings, fabrics or mats.

Other types also include some forms of laminate and molded parts in which the reinforcements are not in laminated form.Such as composite laminates which are plastics joined to a non-plastic material such as a metal or rubber.

Other forms of laminating process include; Cross Laminating which pertains to a laminate in which the reinforcing fibers in some layers are positioned at right angles with respect to the fibers in other layers.

On from this technique spring two other similar methods of manufacture. One is a Bidirectional Laminate of a reinforced plastic laminate with the fibers oriented in two directions in the plane of the laminate. Two is a Unidirectional Laminate which is a reinforced plastic laminate in which substantially all of the fibers are oriented in the same direction.

Laminates are also formed under high pressure conditions, being moulded and cured at pressures not lower than 6900 kPa (1000 psi) and more commonly in the range of 8.3 to 13.8 × 103 kPa (1200 to 2000 psi).

High Pressure Laminating uses a matched-die technique to form thick laminates. Lamination is accomplished by employing moulding pressures of 300 psi or greater and curing temperatures up to 175°C.