Helix: Development of a system for automated laminating
Propellers are used throughout the aviation industry to generate thrust and propulsion for flight. Since the first few short flights propellers have been used, which are still working according to the same principle.
Around 1.4 million aircrafts fly around the world with one or more propellers providing propulsion. Helix has developed an extensive range of different propeller types for this purpose, which are extremely resilient and have outstanding efficiency ratings. These propellers are manufactured in the so-called manual lamination process (wet in wet). Layer by layer, carbon fibre fabric, several carbon fibre belts and unidirectional belts are joined together with a glass fibre-reinforced expanding epoxy resin in a mould developed for the respective propeller type. The propellers can only be released from the moulds after curing.
Following this operation, Helix generally does not carry out any further machining of the propeller surface. The clean application of the first resin layer into the mould plays a decisive role for the later quality of the propeller, as customers can only judge it on the basis of optical aspects. Faults in production can therefore only be detected at the end of the manufacturing process, i. e. at the almost finished propeller.
Due to the importance of the quality of the propeller surface, the aim of the development is to automate the process of applying resin into the mould. Only with this measure can the error frequency of the finished propeller blades be reduced. This requirement is to be achieved by developing a system that automatically and uniformly sprays a resin layer into the mould. In doing so, certain spray parameters are to be controlled in such a way that the quality of the later resulting propeller surface is improved and the occurrence of errors is minimized.
In general, the following requirements are placed on the system to be developed:
- Compact overall system, which can be moved to the respective workstation
- Automatic recognition of the existing form by the system based on certain parameters
- Automated and uniform spraying of a resin over the moulding area
- Significant reduction of the defective propeller surfaces (currently approx. 20 %), i. e. reduction of the costly rework as well as the rejects.
The project is thus divided into the following development units:
- Spraying process or spraying device:
Development of a spraying device that enables the uniform application of a resin (Helix)
- Handling unit:
Development, design, manufacture and assembly of a handling unit that enables uniform and complete spraying of the mould (IGMR)
- Shape recognition:
Integration of a recognition system that recognizes the propeller shape based on predefined parametric properties (IGMR)
- Overall concept:
Combination of selected spraying device, developed handling unit and recognition software (Helix & IGMR)
This project is funded by the German Federal Ministry of Economics and Technology as part of the Central Innovation Programme for Small and Medium-Sized Businesses (ZIM).