JEC COMPOSITES MAGAZINE - Issue #51 - September 2009 - 20

BUSINESS Trends Innovation: carbon composite tools CNIM has decided to strengthen its activity in the field of carbon composite tooling for large-sized parts. development applications, particularly inasmuch as the master moulds can be partially recycled if required. JCM: CNIM presented a first mould made from Hextool-based carbon composite at Sampe France’s technical seminar in November 2008. What optimisations (substructure, airtightness, surface condition, etc.) have you made since then? Who have been your partners? H. B.: The product presented at Sampe 2008 has undergone quite a few changes. What we had back then was a first trial for a development application. The two tools that were manufactured, the largest of which measured seven metres by five, were meant to produce up to 5 mouldings at the most. With a view to mass production, we have had to work on the industrialisation and reliability of the product. First of all, the substructure has been optimised. It can now be appropriately and reliably adjusted, so as to minimize the release stresses involved in the moulding and machining phases. This enhancement to the way the substructure is held in place, enabling adjustment or even recycling, has been accepted by Airbus, and it also opens the door to the possibility of using other materials. What is more, curing cycles that are compatible with the different components have been defined. This makes it possible to optimally exploit their advantages, especially in terms of extended life cycle. I am thinking in particular of the resins used. The manufacturing of the epoxy skin that serves as a substrate has been optimised, particularly in terms of airtightness, but skinless solutions are now also proposed, depending on the situation. As far as machining and finishing are concerned, a machining process has been certified with our partner, Oratech. It allows finishings with roughness average (Ra) values close to 2. A suitable surface treatment has been defined for the moulding surfaces and technical surfaces. Lastly, an industrial setup has been developed in order to enable manufacturing cycles of less than five months and customer support. These developments have all been made in the framework of a collaborative project supported by OSEO with the following partners: - Hexcel for the Hextool material, - Oratech for developing the machining, - Mines de Douai engineering school for the thermal analyses and simulations, - Airbus for defining the operational conditions. AN INTERVIEW WITH HUBERT BERENGER, HEAD OF DEVELOPMENT, AEROSTRUCTURES CNIM JEC Composites Magazine: The carbon composite parts used in the fields of aerospace (Airbus A350WB, Boeing 787, etc.), wind turbines (blades) and boatbuilding (hulls, masts) are getting bigger all the time. What are the advantages of moulds made of carbon composites compared to traditional metal solutions? HUBERT BERENGER: CNIM proposes largesized composite tools made of a composite substructure and a machined Hextool skin (a patented product). For large-sized tooling (over 10m²), this product offers a genuine alternative to Invar or epoxy composite tools. The use of a thermally overdesigned BMI resin in association with machining provides remarkable dimensional tolerance (3/10 over 7m). The product offers the following advantages: - 4 to 5 times lighter than Invar, a factor which directly impacts non-recurrent and recurrent costs, particularly in terms of investment in handling and curing facilities; - curing cycles reduced by some 20% thanks to more appropriate thermal inertia; - the possibility of tool duplication and its concomitant economic benefits; - lastly, it is possible to repair or adapt the manufactured tool; with production cycles of less than five months, the product is also ideally placed for Carbon tool / 4,5m*2m. JCM: A CNIM mould will soon be commissioned at Airbus Nantes and evaluated by comparison with other moulds (Invar, etc.). Can you tell us more about this, particularly with regard to the dimensions of this mould 20 jec composites magazine / No51 September 2009

JEC COMPOSITES MAGAZINE - Issue #51 - September 2009

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #51 - September 2009