OptiMal – Optimized production chain and methods of integral stiffening for high-profile rims
In this project, TUM is developing a process for hybrid matrix injection, which is use to produce CFRP components with ribs made out of short-fiber-reinforced thermoset resin to increase stiffness.
Project Partners
Munich Composites GmbH, Hufschmied Zerspanungssysteme GmbH, DEKUMED Kunststoff- und Maschinenvertrieb GmbH & Co. KG
Duration
01.03.2019 – 31.12.2021
Funding authority
Bavarian Ministry of Economic Affairs, Regional Development and Energy
Motivation
The aim of this research project is the development of several technologies that greatly improve the manufacturing process for MCs bicycle rims. At TUM, the project focuses on the development of a new method for stiffening high-profile rims by means of ribbing via a hybrid matrix process. The technology can also be transferred to other components. Especially flat components from the automotive sector, but also aerospace interior components and many other components could be manufactured with this technology. Instead of ribs, it is also conceivable to use this technology to implement other types of functional integration (e.g. with the help of elastomers or electrically conductive resins). If you compare it to multi-component injection molding, it becomes clear which options in terms of design, lightweight construction potential and functional integration result from the hybrid matrix injection.
Method
At TUM, a novel method for stiffening high-profile rims using ribbing in a hybrid matrix process is being developed. Grooves are placed in the (lost) core material to later form the ribs. However, the preform does not cover these ribs. Instead, they are filled with a second resin only. This second resin is injected in parallel (with a small time advantage) to the actual RTM injection in the same tool. By specifically modifying the rheological properties of this resin, it only fills the ribs, but not the preform. In addition, its mechanical properties are modified. Together with the partner Dekumed, a dosing system is to be developed that enables hybrid matrix injection in a process-safe manner in an industrial environment. In hybrid matrix injection, two liquid reactive systems with different properties have to be processed simultaneously. It is important that the resins only get into the areas intended for them. This requires precise process control that cannot be done manually in an industrial environment. A system is therefore designed which can regulate the simultaneous metering of two resin systems based on sensor data. This system ensures the industrial applicability of the hybrid matrix injection process. At the same time, the developed control technology is also to be used in other future dosing / mixing systems.
