Materials for Turbine Power Blades, Reinforcements, and Resins - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 60

calculation.of.the.constants.A.and.B.and.subsequent.determination.of.viscos-
ities.at.other.temperatures..The.Andrade.equation.holds.for.many.polymer.
solutions.and.polymer.melts.well.above.its.glass.transition.temperatures. 6
Viscosity.is.an.important.parameter.for.the.online.process.for.making.vinyl.
ester/carbon. iber. composites.. Vinyl. ester. resins. need. to. have. a. low. viscos-
ity.in.order.to.low.into.the.ibers.and.to.permit.good.wetting.of.the.carbon.
ibers..Styrene.is.used.as.a.diluent.to.decrease.the.viscosity.of.the.vinyl.ester.
resins..Thus,.the.styrene.concentration.is.an.important.factor.that.controls.the.
viscosity. of. vinyl. ester. resins.. Concurrently,. viscosity. is. highly. sensitive. to.
changes.in.temperature,.and.the.molecular.weight.of.the.vinyl.ester.oligomers.
also.affects.viscosity.signiicantly..All.of.these.factors.need.to.be.studied.and.
understood.so.that.the.viscosity.of.the.vinyl.ester.resins.can.be.controlled.
The. effect. of. temperature. and. the. effect. of. styrene. on. viscosity. of. vinyl.
ester.resins.have.been.reported.in.literature. 7,8
Low-viscosity. epoxy. resins,. such. as. Bisphenol. A. mPa.s. @. 25°C,. offer. a.
superior. blend. of. low. molecular. weight. epoxy. resin. and. reactive. diluents,.
designed.to.produce.an.easy-lowing,.reliable.system.with.low.drip.and.no.
blush,. as. well. as. no . volatile. organic. compounds. (VOCs).. MAS. low. viscos-
ity.epoxy.resin.is.typically.used.at.room.temperatures.using.your.choice.of.
hardeners.(fast,.medium,.or.slow).in.a.2:1.mix.ratio,.resin:hardener.
Low. viscosity. epoxy. resin. can. be. used. in. a. huge. variety. of. applications.
including.boat.hulls.and.turbine.blade.structures,.which.need.to.completely.
exclude.moisture,.as.well.as.the.laminating.and.bonding.of.nearly.all.materials.
The.viscosity.of.the.epoxy.resins.must.be.low.to.provide.eficient.low.of.
the.resin.into.the.iber.preforms.in.an.online.process..The.viscosity.of.vinyl.
ester.resins.decreases.with.increases.in.styrene.concentration,.but.styrene.
concentration. can. be. bad. for. your. health.. Vinyl. ester. resins. with. varying.
styrene. concentrations. provide. a. system. with. a. wide. range. of. viscosities,.
which.are.suitable.for.different.applications..Vinyl.ester.resins.with.higher.
styrene.concentrations.offer.improved.resistance.to.acids.and.alkalis.while.
those.with.lower.styrene.concentrations.afford.better.resistance.to.solvents. 9 .
PPG.Industries,.Shelby,.North.Carolina,.creates.iberglass.materials.Hybon ®
2002. and. Hybon ® . 2026.. Hybon. is. a. continuous. ilament,. single-end. iber-
glass.roving,.with.unique.chemistries.to.work.in.a.variety.of.resin.systems.
Hybon.2002.roving.is.the.industries.leading.product.for.wind.blade.com-
posites..With.more.than.20.years.of.wind.blade.experience,.this.product.has.
the.proven.performance.for.wind.blade.applications..Hybon.2002.is.offered.
as.a.single-end.roving.product.in.multiple.high.mechanical.properties.and.is.
fully.compatible.with.polyester,.epoxy,.and.vinyl.ester.resin.systems.
Hybon. 2026. is. PPG's. highest. performance,. single-end. roving. for. wind.
blades..Its.unique.surface.chemistry.has.an.afinity.for.resin.and.drives.its.
excellent.performance.in.wind-blade.fabrication.minimizing.dry.spots.and.
reworkings..Use.of.Hybon.2026.wind-blade.design.achieves.higher.mechani-
cal.performance,.most.notably.in.tensile.strength.and.fatigue.life,.which,.in.
turn,.allows.one.to.optimize.the.composite.structure.