Introduction

Wind turbine blades are manufactured and repaired using fiber-reinforced composites (glass fiber + epoxy resin). The curing of epoxy is a critical process that defines the blade's structural strength, durability, and fatigue resistance. 

Due to the large size of blades and on-site repair requirements, conventional ovens or kilns are not practical. Hence, heating blankets are used to provide localized and uniform heating for curing. 

  • Epoxy requires controlled heat for proper curing  
  • Low temperature → incomplete curing  
  • Excess heat → defects like bubbles and deformation  

Heating blankets ensure even heat distribution, enabling proper curing even in outdoor or cold environments.  

Challenges

  • Non-Uniform Heating 

    • Blade geometry varies across length and thickness  
    • Causes uneven curing and weak bonding  

  • Risk of Overheating (Exothermic Reaction)

    • Epoxy generates heat during curing
    • Overheating leads to bubbles, discoloration, and defects

  • Thermal Gradients in Thick Sections 

    • Different laminate thickness leads to uneven curing  
    • Causes internal stress and structural weakness  

Solution

The GIC TCS4T300 temperature controller integrated with heating blankets provides a precise, stable, and reliable curing solution.

  • Accurate PID Temperature Control 

    • Maintains exact curing temperature  
    • Ensures uniform heating across the blade surface  
    • Eliminates under-curing and overheating  

  • High Control Stability 

    • Minimizes temperature fluctuations  
    • Ensures consistent curing quality across entire blade  

  • Sensor Compatibility (Thermocouple Input) 

    • Works with multiple sensing points  

  • Alarm & Timer Features 

    • High/Low temperature alarms  
    • Prevents damage due to overheating or process deviation  
    • Timer for heating process  

Conclusion

The combination of heating blankets and GIC TCS4T300 temperature controller ensures: 

  • Uniform and controlled curing. 
  • Improved bonding strength and durability. 
  • Reduced defects and rework.