Materials for Turbine Power Blades, Reinforcements, and Resins - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 61

TABLE 3.3
Tensile.Properties.of.Roving.Materials

Nameof
Roving
Materials

StrengthMPa(Kpsi)
600TEX—2400TEX StrengthLevel

Hybon ® .2002 Average.Standard.

dev..N

2290(332)—2230(323).
210(30)—145(21).
37—33.

Hybon ® .2026 Average..Standard.

dev..N

2790(405)—2660(386).
130(19)—135(20).
13—13

Both. materials. can. be. used. as. reinforced. dry. laminates. in. wind. turbine.
blades. 10
Tensile.properties.of.roving.materials.are.listed.in.Table 3.3.
An.improvement.of.20.percent.in.tensile.strength.for.Hybon.2026.has.been.
very. useful. in. reducing. thickness. and. weight.. Van. Wazer. et. al. 8 . demon-
strated.signiicant.reduction.of.over.50.percent.in.the.level.of.voids.in.vinyl.
ester.resin.
Carbon. ibers. usually. are. used. in. root. section. edges. of. power. turbine.
blades.and.inner.shear.web.spars.in.root.sections.

3.3 ResinsAdvantages:LowViscosityandLowCuringTime

Epoxies. cure. best. at. normal. room. temperatures,. but. will. cure. faster. if.
warmed. (30-40°C).. Cure. times. will. lengthen. as. the. temperature. drops.
and. some. epoxies. do. have. a. minimum. cure. temperature,. as. shown. in.
Table 3.4. 12
Araldite ® . 2005. has. a. minimum. curing. time. and. gap. illing. as. well. as. a.
simple.mixing.ratio.(2:1.by.volume)..The.curing.range.is.between.20.to.100°C..
This.provides.negligible.shrinkage,.high.shear.and.peel.strength,.and.heat.
resistant.to.80°C..Araldite.2005.is.resistant.to.water.and.to.a.wide.range.of.
chemicals. 13,14 . Carbon/cyanate. ester. composites. were. proposed. as. replace-
ments.for.the.carbon/epoxy.composites.with.improved.out-gassing,.micro-
cracking,.and.moisture.absorption.characteristics. 15
To.improve.service.and.reduce.lead.times,.Amber.Composites.(Nottingham,.
United. Kingdom). has. increased. its. unidirectional. (UD). prepreg. manufac-
turing.capabilities.with.the.addition.of.a.dedicated.UD.manufacturing.line..
Amber's. resin. formulations. are. now. available. in. a. wide. range. of. woven,.
multiaxial,.and.unidirectional.formats..The.new.unidirectional.systems.are.
designed.to.complement.Amber's.range.of.woven.systems,.and.are.available.
in.a.wide.range.of.ibers.and.resin.systems. 16