Manufacturing Technologies for Turbine Power Blades - Hybrid Anisotropic Materials for Wind Power Turbine Blades - page 96

large.parts.using.EB.curing.at.a.low.temperature..However,.additional.devel-
opment.of.EB-cured.materials.is.required.to.meet.RLV.and.SOV.mechanical.
and.thermal.design.speciications..Science.Research.Laboratory.(Somerville,.
Massachusetts). and. the. University. of. Dayton. Research. Institute. (Dayton,.
Ohio). have. formulated. new. EB-cured. resins. and. composites. and. tested.
these. materials. at. ambient. temperature. and. in. liquid. nitrogen.. The. results.
show. that. the. EB-cured. materials. developed. and. the. RB-curing. process.
are. promising. for. space. structures. and. for. cryogenic. applications.. EB. pro-
cessing.can.reduce.costs.by.10.to.40.percent.for.production.of.wind.turbine.
blades.. Additional. mechanical. testing. is. required. to. establish. a. complete.
set.of.mechanical.properties.in.liquid.nitrogen.and.in.liquid.hydrogen..The.
ultimate.goal.is.to.meet.or.exceed.the.properties.of.Cytec.Fiberite.977-2,.the.
baseline. used. by. Lockheed. Martin. in. the. NASA. X-33. Half-Scale. Reusable.
Launch.Vehicle.program. 15
The. new. GKN. Aerospace. (Redditch,. Worcs,. United. Kingdom). process. is.
called.resin.ilm.infusion.(RFI).and.is.now.being.used.in.conjunction.with.
self.heated.tooling.on.the.A380.wing.trailing.edge.manufacture..RFI.has.been.
shown.to.offer.a.10.percent.reduction.in.manufacturing.costs,.reduced.tool-
ing.requirements,.lower.capital.investment.costs,.lower.risk.in.manufacture,.
potential.weight.savings.as.well.as.a.consistently.high.quality.result. 16 .Kubota.
Research.Associates,.Inc..(Hockessin,.Delaware).has.developed.a.new.Green.
process.for.manufacturing.iber-reinforced.thermoplastic.prepregs.(PTIR TM ).
out-of-autoclave. 17 .The.infrared.(IR).emitter.is.dispersed.in.a.thermoplastic.
matrix..The.matrix.resin.is.impregnated.onto.a.reinforcement.fabric,.such.as.
carbon. iber. and. polyarilate. LCP. iber.. PTIR . prepreg. is. made. using. carbon.
iber,.and.organic.iber.in.woven.fabric.and.unidirectional.forms.
Last.year,.Boeing.Company.developed.some.fast-curing.prepreg.systems.
that.use.a.pressure.of.101.kPa.(14.7.psi).from.the.vacuum.applied.to.the.rub-
ber.bag.for.composite.consolidation. 18
Workable. material. has. a. low. viscosity. when. curing. at. elevated. tempera-
tures.. Volatile. and. moisture. becomes. more. critical. compared. to. the. auto-
clave.process..Voids.created.by.the.entrapment.of.volatiles.are.detrimental.to.
the.mechanical.properties.of.composite.materials..Researchers.from.NASA.
and. Lockheed. Martin. Engineering. together. with. BG. Smith. Associate. and.
Old.Dominion.University.Norfolk.developed.prepreg.packaging.IM7/MTM.
45-1.and.T40-800B/5320 19 .using.out-of-autoclave.(OOA).processing..The.tech-
nique.created.a.vacuum.pressure.of.101.kPa.(14.7.psi).

4.6.3 Select Technological Parameters and Cure Conditions

Laminate. layer. consolidation. depends. on. the. cure. speciic. pressure,. tem-
perature,.and.time.of.curing. 20
Previous.research.established.that.low.speciic.pressure.of.20.kg/cm 2 .did.
not.reduce.physical.and.mechanical.properties.. However,.future.reduction.