Gripping Technology in use during the RTM Process
In the RTM (resin transfer molding) manufacturing process, the required shapes (1) are cut from the dry FRP textiles on CNC cutting tables. A gripper picks the sensitive workpieces from the cutter and sets them on a table or in a magazine. In some cases, the cut textiles are stored temporarily before further processing and doing the “lay-up”. In doing so, different layers are placed on top of each other in a defined order to create a specific layer structure (2). Depending on the process, the cut pieces are then heated and manually or automatically draped to create a preform whose shape resembles the final product (3-5).
After preforming, the still porous, unstable, three-dimensional preform is taken out of the mold (6). Then, the preform is inserted into the RTM press. A mixture of resin and hardener is injected into the tool, and pressure and heat are applied to cure the workpiece (7). Once the workpiece is removed from the press (8), a finishing process (9) gives it its final shape. This usually takes place in a CNC milling machine or through water jet cutting.
As well as the RTM process, there are other similar manufacturing processes, such as wet pressing. Unlike the RTM procedure, the resin is applied before the actual pressing process, which means that the stack is pressed and cured in a wet state.