The root section is a critical area of the blade. Due to its thickness, the risk of exotherm is high. Also the drilling speed when integrating the T-bolts has to be moderate. Otherwise the thermoplastic matrix could be damaged. Many manufacturers therefore 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 for preform preparation and/or infusion reduce lay-up times by enhanced handling.