Work performed during the project:
Following a global approach, from the raw material, the automatization and control of the manufacturing process to the modelling of the final part, the Consortium has achieved promising results during the execution of the activity. The project progress through the main 3 axes (tapes manufacturing, part manufacturing and modelling of process/part) is explained below.
Tape manufacturing process:
There are 2 relevant research lines for the tape manufacturing process, attending the final application:
- For the automotive sector, the main goal is to develop a highly efficient process able to produce a large volume of ready-to-use tapes, minimising their cost. Polypropylene and glass fibre were used attending to their good balance between price and performances. Different impregnation methods were tested in a monotape line, selecting the melting polymer technology as the best choice for this kind of polymer. Currently, a multitape system is under construction, to increase exponentially the production ratio, improve the efficiency and optimise the cost.
- For the aeronautical sector, the main goal is to reach a high quality tape, based in a fireproof polyamide with carbon fibres, processable by in-situ consolidation. Due the viscose nature of this type of polymer, different impregnation methods were tested to reduce the voids and increase the performances of the tape. The super critical CO2 process and the fluidized bed technologies were selected as the most promising process for the aeronautical sector.
Parts manufacturing:
As for the tape manufacturing process, different approach were developed depending on the final application:
- In the case of the automotive sector, the overmoulding of UD tapes guarantee a high production ratio using a conventional injection moulding machine. During these first months, first trials were carried out using simplified geometries, in order to optimise the injection moulding parameters to reduce the warpage and to measure the effect of the UD tapes in the mechanical properties. The preliminary results showed a significant improvement in the flexural performances. The strategy for the automation of the tapes lay-out was developed, and during last months complex geometries were developed obtaining promising results.
- The process for the aeronautical application (the in-situ consolidation) was tested using the first manufactured tapes. The parameters had to be adapted to work with PA instead of PEEK, and some trials were carried out. The imperfections of the samples (voids, delamination, etc.) were analysed and the best kind of tape was selected in consequence, to continue with the research. High quality UD tapes were obtained during last months and a prototype part (window frame) was obtained as demonstrator.
The main results obtained in the Project (Key Exploitable Results) are:
- Innovative manufacturing methods of UD tapes. These methods include the newly developed "multitape technology" using different impregnation methods. The main advantage of these UD tapes is the fact of having an inline calibration at 1/4" or 1/2" withouth slitting, post consolidation or splicing steps.
- Development of models for the prediction of crash behaviour of UD-tapes used within injection molded parts. This is the first model that predicts the local reinforcement due to the overmolding of UD tapes.
- Development of integrated and cost-effective manufacturing processes for automotive and aeornautical parts using UD tapes.
