Manufacturing Technologies for Turbine Power Blades - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 102

Infusion molding process
FIGURE 4.8
Seeman's.composite.resin.infusion.molding.(SCRIM).process.
comprehensive.three-dimensional.process.simulation.model.for.fabrication.
of.varying.stiffened.structures.are.described.in.references.22,23.
The. carbon/glass. epoxy. ilm. process. gives. an. equal. resin. distribution.
and. has. the. automation. control. for. the. solid-dip. prepreg. impregnation. 23 .
Prepreging.and.stitching.a.fabric.to.ensure.iber.alignment.adds.a.cost.mak-
ing.the.economics.less.palatable..The.high.strength-to-weight.ratio.of.carbon.
allows. for. smaller-diameter. blade. root. connections. similar. to. a. glass-only.
design..In.SCRIM,.a.strong.vacuum.is.used.to.saturate,.or.infuse,.a.dry.lay-
up. with. resin. at. a. single-sided. (male. or. female). mold.. SCRIM. built. wind.
blades. with. ratios. of. 70:30. iber-to-resin. with. 1. percent. void. content. and. a.
low.VOC.emission,.along.with.mechanical.properties.that.rival.those.associ-
ated.with.prepregs.or.wet.lay-up.and.autoclave.cure.(Figure 4.8).
Several.new.forms.of.vacuum-molding.may.save.FRP.(styrene.regulation).
boat. builders. from. the. regulators.. (The. new. fabricated. SCRIM. process. is.
partly.owned.by.production.sailboat.builder.TPI.Composites,.Inc.).A.strong.
vacuum.draws.catalyzed.resin.into.a.dry.laminate.stack.to.saturate.the.iber.
reinforcement..Because.the.part.also.cures.under.the.bag,.this.system.virtu-
ally.eliminates.styrene.emission. 25,26
Prepreg.impregnation.is.an.alternative.and.more.automated.process,.but.
it. is. not. used. for. wind. turbine. blade. fabrication. today.. This. process. was.
investigated.in.works.by.Ahn.and.Seferis 27,28. and.Lee,.Seferis,.and.Bonner. 29 .
Consistency. evaluation. of. a. qualiied. iber. prepreg. system. was. studied. by.
Buehler,.Seferis,.and.Zeng. 30 .Hayes.and.Seferis 31 .researched.the.self-adhesive.
honeycomb.prepreg.systems.for.secondary.structural.applications..Braiding.
and.RTM.succeed.in.aircraft.primary.structures.is.shown.as.alternative.tech-
nology. 32 .However,.Virginia.Tech.College.of.Engineering.demonstrated.resin.