[1] Fibers placed in the thickness direction are called z-yarn, warp weaver, or binder yarn for 3D woven fabrics.3D woven composites, finished with resin transfer molding have been produced larger than 26 feet long."[13] Developed in the late 1960s, in an effort to circumvent the problems related to 2D composite laminates yet at the same time retain the benefits of the braiding process.[14] Braided structures, used as composite preforms, have a number of advantages over other competing processes, such as filament winding and weaving."This technology consists of embedding previously cured reinforcement fibers into a thermoplastic foam that is then placed on top of a prepreg, or dry fabric, lay-up and vacuum bagged."12 The foam will collapse as temperature and pressure are increased, which allows the fibers to be slowly pushed into the lay-up.The mold is closed and then the resin of the matrix material is injected under particular temperature and pressure, then allowed to cure.
