The patented RTM-ROBOT® process has been specially developed for the manufacture of integral and hybrid components.
Compared with other systems, the sensor-based, fully automated RTM-ROBOT® injection process offers the possibility of undertaking complex component geometries using a wide range of materials in a one-shot process, producing outstanding surfaces. This enables multiple requirements in terms of the characteristics of a component to be implemented simply and quickly. With the RTM-ROBOT® process, the complexity of the materials employed in these hybrid constructions is virtually limitless. The degree of creative freedom in terms of geometry and design is extraordinary! This process does away with the need for work steps involving laborious post-processing through joining and sticking together several individual components. In this way, the frequency of errors during the manufacturing process is drastically reduced.
And crucially: The strength at the component interfaces otherwise usually found within a single module is significantly higher.
The innovative RTM-ROBOT® manufacturing process enables complexities, geometries and designs for integral hybrid components to be tackled that were previously regarded as unfeasible using current production methods. The sensor technology integrated in the tool enables the flow of resin to be precisely regulated. The results are high-performance components with perfect surfaces, which only have to undergo minimal post-processing at their parting lines.
The advantage of the one-shot process, in which all the reinforcing materials and inserts are already in place on the preform, is that in most cases only a small amount of post-processing at the parting line of the component produced following the injection process is required. The controlled pressure injection means that the various components are completed embedded and joined to one another to create an extremely strong composite structure. The finished surface of the component is completely sealed and (subject to the corresponding tool surfaces) meets the requirements laid down for a class A surface.
The RTM-ROBOT® enables the manufacture of composite components using sensor-based process automation. The measurement of parameters (temperature, pressure, injection speed) relevant for production together with the targeted control of the flow of resin through RS valves allows the injection to be controlled and monitored in a fully automated fashion.
Using an interactive system consisting of a capacitive measuring unit for detecting the flow of resin and pneumatically operated RS valves, the software connects the individual profile of the component with the injection routine written by the user in manual operating mode. During the subsequent stages of process automation the sensor detects the flow of resin at an outlet of the moulding tool and closes the outlet using an RS valve. It is irrelevant whether the sequence of the resin flowing out of the mould outlets is the same as the sequence for the previous component in the same series. This in no way affects the quality of the component.
The RTM-ROBOT® process offers the possibility of manufacturing parts with complex geometries and integrating systems and functions in a single finished part. This means that cables, pipes etc. or inserts and connecting parts made from the widest range of materials can be embedded in the components.
The illustrations show the integration of cooling/ventilation tubes in the chassis area:
Adherence to close tolerances in the dimensions of RTM parts depends to a large extent on the tool design, on the choice of resin system and naturally on the injection process itself and the optimal filling and joining of all the reinforcing materials. The use of the RTM-ROBOT® generally enables fibre volume contents of over 50% to be attained.
The sensor-based control of the injection process means that the RTM-ROBOT® process is especially suitable for particularly large components. Together with the viscosity of the resin and the permeability of the reinforcing materials inserted, only a relatively low pressure is required to fill the cavity. This enables the manufacture of extremely large parts using low locking forces.
Each side of a component produced using the RTM-ROBOT® has a flawless surface quality defined by the characteristics of the tool and by the manufacturing process. The surface on both sides may be improved further by applying a gel coating in the tool.