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Capacity Increase: Wind Turbines

Causes of scrap and rework eliminated to increase output by 25% and reduce resin yield loss by >70% in 3 months


Industrial products – LM, wind turbines

Project Length

3 months - one consultant


To improve process understanding and control in the serial manufacture of large composite wind turbine blades


  • Reduced scrap blades from 1 in 20 to zero
  • Reduced rework from 20% to zero, thereby increasing moulded blades output by 25% in three months
  • Improved resin yield to >90%
  • The team went on to roll out process globally through a wider change programme
"I've used several consulting firms in the past with mixed results. I'm often presented with many short term actions and few sustainable results. With these guys, it was different: the approach quickly identified significant improvement potential, involved the teams and drive for immediate changes, and then let the teams themselves create long-lasting and sustainable results". - CEO

Why was Chartwell brought on board?

As the largest supplier of wind turbine blades in the world, LM was going through a period of very rapid global expansion and required an uplift in both quality and operational performance.  There was a need to increase output massively at the same time as making progressively longer wind turbine blades.

Key Workstreams

Scrap and Rework Reduction

  • LM had talented plant and technical leadership. There were known problems relating to wrinkles in glass layup and with the resin infusion process. 
  • The main technical challenge was to understand the optimum resin flow rate over time during the infusion cycle. Every operator followed the flow front and adjusted the controls differently.
  • Using Chartwell's Fault Tree Modelling methodology for solving technical problems, the team identified three parameters that were not being effectively controlled:
    • Injection and vacuum pressures - standardisation across all shifts was needed gave the best resin distribution for minimum waste.
    • Resin viscosity - the resin supplied had variable viscosity and gel time. It was discovered this was due to test method inaccuracies at the supplier.
    • Glass fibre permeability - variable permeability of the glass fibre was affecting resin flow rate and penetration.
  • The team devised an automatic control system to ensure the injection and vacuum pressures were optimised on every blade, and worked with both the resin and glass suppliers to eliminate variability in viscosity, gel time and permeability.

Solving the scrap and rework not only presented a large materials saving, but also enabled sales to increase by 25% as productivity increased