Presented By:
Ngangkham Peter Singh

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Composite materials and technology in the manufacturing of windmills
Windmill history
 200 B.C.-1st wind machines used in Persia for grinding grains
 7th century- 1st practical windmill used in Sistan pumping and grinding
 14th Century- Dutch windmills were in use to drain areas of the Rhine River delta
 1887- 1st electricity generation in Scotland by James Blyth
 1888- 1st automatically operated wind turbine was built in Cleveland by Charles F. Brush
 Types of windmill in the modern world
 Horizontal Axis Wind Turbine
 Vertical Axis Wind Turbine
 Horizontal axis
 The wind direction and the rotor are in the same direction.
 Mostly used design
Materials used
 In earlier times
 Steels
 Wood
 Poly foam and Aluminum
 Present times
 Fiber glass and Epoxy Resin, Vinyl Ester
 Carbon Fibers and Epoxy Resin, Vinyl Ester
Manufacturing of HAWT blades
 Processes used
 Hand lay up process
 VARIM process
 Materials required
 EPS foam
 Model table
 Resin
 Glass fabrics
 Heaters
 Accessories
 Vacuum pump
 Manufacturing steps
 Model table and model
 Preparation of mould
Manufacturing of windmill blades
 Model table and model
Model table preparation
 Foam cutting
 Joining of the separate blocks
 Lamination
 Finishing
 Contour checking
Preparation of the mould
 Hand lay up process
 Multiple passing
 Curing
 Thermoset and heaters embedded
 Metal frame also attached
 Lay up of the mould
 Finishing operations
Manufacturing of blades
 Steps
 Layup of moulds
 Vacuum testing
 VARIM process
VARIM Process
 Vacuum assisted resin infusion method
 Vacuum pulls the resin through the lay out
 P1=Atmospheric Pr
 P2=Applied Vacuum Pr
 Preparation
 Injection
 Vacuum reduction
 Curing
 Additional materials are removed after curing
Fill time
 Darcy’s Law:
 Flow of fluid in a porous material
 Software pack to determine the feeding point
Stages of Resin impregnation
 Assembly
 Cured parts are joined
 Parts include
 Nose insert
 Root insert
 Shear plate
 Two halves of the blade
Finishing
 Dry finishing
 Sanding
 Painting
 PU paints
Nacelle Cover and Nose Cone
 Made by hand lay up process
 Finishing operations
 Assembly
Problems
 Dry glass
 Air in laminates
 Foam burning
 Wrinkle
 Variations in paint thickness
 Corrosion
 Improper bonding
Conclusion
 VARIM process is used for the production of windmill blades.
 Advantages of VARIM are
 Unskilled labour
 Constant thickness
 Minimum thickness and shrinkage
 Faster cycle time
 No pollution from volatile organic compounds
 Better fiber to resin ratio
 Nacelle covers and Nose cone are produced by hand lay up process
 Composite materials used are combination of Vinyl Ester or Epoxy resin and Glass fabrics or Carbon Fabrics in the manufacturing of windmills