As a reminder the proposal is addressing the topic JTI-CS2-2016-CFP03-LPA01-14 â€œ Automated injection RTM system process based on innovative sensor technologies in a low cost smart manufacturing tooling prototype and any tooling involved in the manufacture or the validation...
As a reminder the proposal is addressing the topic JTI-CS2-2016-CFP03-LPA01-14 â€œ Automated injection RTM system process based on innovative sensor technologies in a low cost smart manufacturing tooling prototype and any tooling involved in the manufacture or the validation of the structure â€œ.
The tendency of aeronautical industry speeds up toward laminar-flow technology or active Hybrid Laminar Flow Control (HLFC), where suction of small amount of air throughout aircraft extrados surfaces. The technique has the potential of considerable drag reduction and consequently saving fuel consumption. It is expected that HLFC technique can reduce the fuel consumed by 30 per cent of the current consumption for transport aircraft. HFLE project will contribute through its results to the expected impacts set out in the work plan, under the topic JTI-CS2-2016-CFP03-LPA01-14 while improving innovation capacity and the integration of new knowledge.
The final objective is to produce the needed tooling to manufacture the HTP Leading edge structure (modified to include a HLFC system) using liquid resin injection processes, in particular RTM composite process to produce the mentioned part. A â€œquickâ€ specimen was manufactured prior to project submission to show the RTM process is suitable for the project. The resulting structure shall comply with the actual regulation of the aerospace sector, in particular regarding geometrical tolerances and defects.
In addition to Coexpair experience on RTM process and mold design, the consortium is well-balanced gathering experience in complex part mold machining (PÃ©gard Productis), but also a strong expertize in robotic development (ULG) and preforming automation (Tecnalia).
In order to produce the needed tooling to manufacture the HTP Leading edge structure, five (5) elementary technology blocs were defined as contributing sub-objectives :
1) low cost/ natural materials employed in the tooling manufactured,
2) eco-design for of the tooling manufactured,
3) energy savings during the manufacture processes of the future parts,
4) manufacturing processes simplification in order to improve the repetitiveness of the process,
5) production time savings to reduce the cost and production lead times.
Moreover the project is focusing on the automation of manufacturing steps of RTM process, including ply cutting and mold cleaning. Elementary tests of a few key points of the automation will be performed in industrial environment (Coexpair shop). In order to optimize floor shop organization, work flow simulation will be performed.
Please refer to Technical Report (Part B) enclosed to this report
Improving innovation capacity & integration of new knowledge
For Coexpair, the initial expected impact was to develop thinner mold insert technologies and develop titanium-CFRP combination. At this stage of the project, the potential and limitations of thinner inserts were listed. The technology was successfully tested even if some improvements can still be provided. In term of limitation, it must be noted that the length of the mandrel is the main issue, not only for machining and control but also for mold assembly and demolding regarding with the mold configuration. It can be reasonably expected that with other mold concepts, thinner inserts technology could be used, allowing to manufacture more advanced RTM parts.
The combination of titanium-CFRP was tested on the sub-element geometry. The high curvature of the part associated to the high complexity of the mold led to difficulties to correctly cocure the skin without debonding of the metal or leakage in the elastomer, for the first sub-element. However, prior to inject the sub-element, Coexpair tested the cocuring with metal surface sealing on panels with lower mold complexity. The sealing with elastomer worked and no resin came in contact with the metal and no resin filled the holes drilled for this test. For this test, steel was used instead of titanium. It can be also said reasonably expected that with other mold concepts, cocuring with sealing technology could be used, allowing to manufacture more advanced RTM parts.
For Coexpair, the second initial expected impact was to increase the TRL of pick-and-place concepts, to design robust sensorised RTM tool and injection equipment and to integrate tool cleaning technologies for decreasing process cycle times.
At this stage of the project, the work is still on-going on pick-and-place and on tool cleaning technologies, but promising results seems achievable in the timeframe of the second half of the project (see achievements of Tecnalia and ULg).
Up to now, Coexpair successfully tested automation of several steps of the RTM injection cycle for the first sub-element. This would help to reduce scrap rate of parts near to zero and so, decrease production costs in serial production for European RTM manufacturers.
For Coexpair, the expected environmental impact was to show that low cost/natural materials can be employed, to take environmental aspects in the design of the mold, to show energy saving to manufacture future parts, to simplify part manufacturing process and to show production time savings.
Coexpair showed that using aluminium instead of steel for the mold of the fixed leading edge was possible, allowing to decrease material and machining cost. For usage, it also allows to decrease energy consumption to heat the mold while decreasing heating time in curing cycle.
Coexpair also showed that the use of alternative Necuron for lighter preforming tools also reduced energy consumption for tool machining. And in use, this material is more eco-friendly with less energy consumption.
At this stage, the automation of several steps already allowed to simplify the manufacturing process for the operators leading to decrease of scrap rate in case of serial production, and so decrease of material waste. Work is still on-going to demonstrate automation of other steps. This demonstration is expected in the second half of the project.