HENKEL: Polyurethane Adhesive
The adhesive has reportedly demonstrated a tensile shear strength exceeding 20 MPa at -40 to +80°C and a Tg of 65°C and higher. In addition, it has reportedly shown superior dynamic fatigue strength, which allows wind blades to handle deflection, dynamic load and stress on the adhesive bond line while reducing the risk of stress cracking.
The adhesive passed a four month test conducted by the Fraunhofer Institute for Wind Energy and Energy System Technology IWES in which a 40-m ENERCON blade was subjected for four months to stresses and strains that would normally occur over 20 years. The bonded joints reportedly passed all static and dynamic load tests specified in the IEC 61400-23 standard to determine the rated load and fatigue behavior of the blade. The test criteria specified for approval of wind energy plants were met without any problems, and ENERCON’s specifications were reportedly also satisfied in this test.
For more information, visit www.henkel.com.