The root section is a critical area of the blade. Due to its thickness, the risk of exotherm is high and the drilling speed when integrating the T-bolts has to be moderate otherwise, the thermoplastic matrix could be damaged. Many manufacturers make the root as a separate component and bond it into the structure. The bonding of this joint is a key factor and concentration of stress in this area must be avoided.
Special Root Concept Product Package
Hexcel supports a special root concept combining high resin prepregs with HiMax™ dry NCF. HexPly® M79 is a low exotherm prepreg with a high TG that allows faster drilling compared to infusion systems. It also provides excellent adhesion to the T-bolts.
Advantages in Handling
Tackified fabrics, like HiMax™ DPA (dot pattern adhesive), assist preform preparation and/or infusion reduce lay-up times by enhanced handling.