CompositesWorld

MAR 2017

CompositesWorld

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NEWS 39 CompositesWorld.com Aeris Energy, Brazil rank-and-file, and puts the five founders in direct proximity to day-to-day operations of the plant. Next stop is the GE/WEG building, featuring three 56.9m GE molds and one 53.7m WEG mold. We enter the building from the middle of its long side and find the largest molds, for the wind blade shells, lined up one after the other along the left side of the facility, each fully open, surrounded by workers and in various states of being laid up with dry glass fiber fabric and core material, including balsa and foam (Figs. 2-4, pp. 37-38). Some ply and core placement is guided by overhead lasers. Each mold is a clamshell construction, comprising two halves connected by massive hinges. On our right, across from each mold, are smaller tools, used to fabricate the corresponding shear webs and spar caps, and these are also being laid up. It is obvious, looking at the molds, that the architectures and material selection for the turbine manu- facturers' blade designs vary. Where and how core and glass are applied is readily apparent. Similarly, shear web and spar cap designs also differ significantly. Once layup of each blade half is complete, spar caps are placed in each half, and then the entire mold is bagged for resin infusion. e molds are heated and full cure takes about a day, says Lolli, but the blades usually can be bonded within 4-5 hours of infusion, followed by demolding. Aeris, he says, carefully controls mold temperature and manages exotherm closely. When infusion is complete, the molds are prepared for shear web attachment. e shear web, which runs about 90% of the blade's length, is a large composite structural beam that is attached to and works with the spar cap to stiffen the blade and carry bending loads. e three primary blade components — shells, spar caps and shear web — are critical not only to blade function, but also blade longevity. Each must meet closely managed specifications to provide optimum wind turbine perfor- mance, says Lolli. Passing through the building, we see an overhead crane trans- ferring a shear web into one of the GE mold halves. Workers are carefully positioning the web onto adhesive attachment points in the mold on the spar cap to ensure precise location and fit. After we leave, workers will apply bonding paste to mating points of the mold half with the shear web. en, the mold half without the shear web attached will be closed over the half with the shear web, thus completing blade fabrication. As we leave the GE/WEG building, we notice, in the facility's midsection, between the blade molds and the spar cap/shear web molds, the blade root molds. Oriented with the blade-mating side facing the blade molds to permit easy attachment with minimum effort, each is being laid up and infused, to coincide with its blade. Adjacent to the GE/WEG building is the newest structure on the Aeris campus, where Acciona's blades are laid up — at 61.2m, the longest Aeris manufactures. During our visit, this space was being reconfigured to accommodate mold reorganization. Aeris FIG. 5 Kitting, cutting … and controlling scrap Workers in the cutting and kitting building prepare peel ply kits. In the background is the Eastman Machine cutting table used to cut glass fiber fabric. Aeris pays particular attention to development of kits for each blade type it manufactures. The goal is to make sure that the scrap rate of dry fiber and consumables is kept to an absolute minimum. Source | Wellington Fernandes SIDE STORY • Location: Caucaia, Brazil • Facility: 45,000m 2 • Employees: 2,000 • Customers: GE, WEG, Acciona, Vestas • Molds: 10 • Blades/year: 2,000 • Glass fiber: Owens Corning, SAERTEX, CPIC, Gammatensor • Epoxy: Hexion, Olin Epoxy • Certifications: ISO 9001:2008; ISO 14001; OHSAS 18001; NBR 16001 • Blade length limit: 70m • Fraction of wind blade cost assigned to transportation: 20% • Fraction of wind blade cost assigned to materials: 70% • Wind blade materials: Glass fiber, 50%; resin, 35%; core, 5%; adhesive, 3%; coatings, 2%; bolts, 5% • Fraction of Aeris wood, plastic, metal waste recycled: 27% • People per shift devoted to mold maintenance: 10 • Average mold life: 500-1,000 blades • Mold weight: 8-11 MT Aeris Energy factoids

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