In this process the dry fiber blanket is placed on an impregnation table, where a mixing head with a dedicated diffuser pours the resin directly on the reinforcement. The impregnated part is then automatically transferred into a press, where the permeation of the matrix is carried through the thickness of the part. The result is an eased matrix permeation (with lower clamping force) and the possibility to impregnate in hidden time (one part gets impregnated while another is curing).
Features and advantages
LLD was born as an alternative to HP-RTM and is chosen in cases where the resin transfer is not convenient due to part dimension and type of reinforcement (e.g. in case of low cost reinforcement and recycled carbon fiber). Furthermore, this process allows to obtain parts with relatively low in mould pressure and extremely low cycle time. For these reasons, LLD is today acknowledged as one of the most convenient mass production technologies.