Fibre is chopped in a hand-held gun
and fed into a spray of catalysed resin directed at the
mould. The deposited materials are left to cure under standard
atmospheric conditions. Materials Options: Resins: Primarily polyester.
Fibres: Glass roving only.
Cores: None. These have to be incorporated separately.
Main
Advantages Widely used for many years.
Low cost way of quickly depositing fibre and resin.
Low cost tooling. Main Disadvantages Laminates tend to be very resin-rich
and therefore excessively heavy.
Only short fibres are incorporated which severely
limits the mechanical properties of the laminate.
Resins need to be low in viscosity to be sprayable.
This generally compromises their mechanical/thermal
properties.
The high styrene contents of spray lay-up resins generally
means that they have the potential to be more harmful
and their lower viscosity means that they have an
increased tendency to penetrate clothing etc.
Limiting airborne styrene concentrations to legislated
levels is becoming increasingly difficult.
Typical Applications: Simple enclosures, lightly loaded structural
panels, e.g. caravan bodies, truck fairings, bathtubs, shower
trays, some small dinghies.
