Manufacturing Technologies for Turbine Power Blades - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 90

Fiber rovings

Steel bush

Principal of a hutter flange, illustrating
how the fiber rovings are wound around
steel bushes to form the flange

FIGURE 4.1
Photo. of. a. Hutter. lange. illustrating. how. the. iber. rovings. are. wound. around. steel. bushes.
to. form. the. lange.. (From. P.. Brondsted,. H.. Lilholt,. and. A.. Lystrup.. 2005.. Composite material
for wind power turbine blades. .Roskilde,.Denmark:.Annual.Reviews,.A.nonproit.scientiic.pub-
lisher..With.permission.)

back.into.the.blade..The.steel.bushes.formed.the.holes.in.what.became.the.
lange.of.the.blade.to.be.mounted.to.the.hub..This.principal.is.illustrated.in.
Figure 4.1.and.is.known.as.a.Hutter.lange.after.its.inventor,.who.used.this.
technique.for.a.wind.turbine.blade.as.early.as.the.1950s. 1 .In.the.mid.1970s,.
at.Tvind.in.Denmark,.a.group.of.pioneers.build.a.three-bladed.wind.turbine.
with.blade.length.of.27.m..The.blades.were.manufactured.from.glass.iber.
and.epoxy.in.a.one-sided.open.mold..The.lower.side.of.the.airfoil.was.laid.up.
in.a.mold.using.a.combination.of.CSMs.and.rovings.
A.double.Hutter.lange.with.both.an.external.and.an.internal.lange.with.
bolt.holes.was.constructed.at.the.same.time.
After.curing.of.the.lower.airfoil.laminate,.many.transverse.foam.spars,.with.
an. airfoil. proile,. were. placed. along. the. entire. length. of. the. blade. at. equal.
distances.and.laminated.onto.the.lower.airfoil..Longitudinal.webs.were.inte-
grated.as.well..The.skin.laminates.of.the.webs.also.formed.a.lange.toward.the.
upper.airfoil,.which.was.built.as.the.last.part.of.the.blade..The.Twind.turbine.
is.still.in.operation,.but.the.blades.were.replaced.in.1993. 2

4.3 FilamentWinding

Large.wind.turbine.construction.started.in.the.mid.1970s,.but.then.involved.
companies. began. looking. for. more. rational. manufacturing. techniques.
that. were. less. labor. intensive. compared. with. the. wet. hand. lay-up. pro-
cess.. Filament. winding. was. a. process. that. was. investigated. by. the. several.
countries.