MFG produces blades as long as 40 m as well as other wind components at plants in five locations. The company expects to start producing 50 m blades in 2012, according to Gary Kanaby, MFG Director of Sales for Wind Energy.

“Some manufacturers use carbon fibre composites in the long blades, which require higher strength and reduced weight,” he relates, noting that MFG is not currently using carbon fibre in wind blades but may in the future. “I think the trend is to have more carbon composites in the longer blades to match the increased loads.”

The company produces wind blades using glass reinforcements, foam core and epoxy resins, both infusion and standard grades. A kitting plant near its blade facility in Gainesville, Texas, pre-cuts the reinforcements and packs them into kits by the order in which they will be placed into the mould, Kanaby relates.

Blade manufacturing takes four days, starting with a 24-hour moulding cycle to produce the blade shell halves and bond them together. On the second day, secondary bonding, trimming and drilling is accomplished. The assembled blades are primed and painted on the third day and finished for shipping on the fourth. Automated equipment is used to cut and drill the root end. Painting is done with automated spraying equipment, notes Kanaby.

MFG also supplies spare and replacement composite parts for wind turbines, conducts inspections and offers repair and maintenance service by WES, its service company. Most of the work is done up-tower on platforms, to avoid the high cost of removal of blades and other components from the wind turbine for servicing, he adds.