Innovation
Thanks to its innovative approach, ATV was one of the first
manufacturers to introduce wind turbine blades in carbon-epoxy to the
market at a competitive price. The One
Shot process has been the key point of this success for small blades
(up to 13m).
Later, the material cost reduction by the integration of an impregnation
bench, and the lowering of the production time due to the process
optimization, allowed the company to offer also large hybrid blades made of
glass and carbon fibers and epoxy resin, while the majority of the
competitors were still producing blades of glass-polyester.
Manufacturing Processes
Various manufacturing processes are used at ATV :
- Polymerisation under pressure of polystyrene foam : the One Shot process,
- Wet hand lay-up and polymerisation under vacuum,
- Prepreg and polymerisation under vacuum
polymerisation under vacuum of a 25m
blade
A process resembling infusion, or RTM light, is currently being
developped in order to make a series of less technical products at a lower
price.
The moulding to contact, and the use of polyester resin, are rarely used
at ATV, apart from the small tools making, because of the limited
mechanical characteristics that this process brings.
The One-shot Process
This manufacturing method is inspired by the technique used for the
windsurf boards production. A polystyrene foam shaped to the piece geometry
is used as a core of the piece. A composite skin covers this core, and
stiffening spar webs are included in the piece, all in one unique
operation.
The aim of the process is to manufacture the pieces in only one
operation, in contrast with the traditional method (making of 2 half pieces
and 1 shear web bonded together).
In addition to the time saving, produced pieces are also lighter and
cheaper because they are glue-free.
This kind of technique requires the production of adapted moulds,
resistant to being put under pressure (about 2 bars). The production in
series also requires an automatic cutting machine of polystyrene cores,
that ATV developed in 1992.
Associated with the use of carbon fibre and epoxy resin, the One Shot
technique lets ATV make technical parts lighter and stiffer, at a
competitive price.
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