Flow International Corp. (Kent, Wash.) on March 25 announced that Mitsubishi Heavy Industries (MHI, Tokyo, Japan) has awarded the Flow a second multi-million dollar contract to supply MHI with Flow's Composite Machining Center (CMC) waterjet machine tools to cut the carbon fiber wing skins for a major commercial jet aircraft program.
Flow's CMC waterjet machining system for carbon fiber composite wings will measure 118 feet long and 21 feet wide. The CMC will be used to cut the composite wing skins which are part of the composite wing structure. The CMC system will be built and tested in Jeffersonville, Ind., one of Flow’s four worldwide manufacturing plants. The UHP pumps that provide the ultrahigh-pressure water will be made at the Kent, Wash. headquarters.
“The award of Flow’s second CMC commercial wing machining system proves the effectiveness of Flow's waterjet technology and its ability to create 'state of the art' aircraft parts in a cost-effective manner,” said Charley Brown, CEO of Flow International.
Traditionally, conventional cutting tools – handheld diamond or carbide-tipped routers, bandsaws, cutoff saws and abrasive wheels â€“ were used to cut composites. However, due to the composition and fiber orientation of advanced composites, these traditional cutting tools can damage the composites either by over-heating or by leaving frayed or delaminated edges. Frequent delamination and fraying requires costly rework. In addition, these slow processes allowed parts to be cut only one at a time.
Waterjets eliminate cutting problems associated with advanced aerospace composites, because abrasive waterjets cut by erosive action rather than friction and shearing. To cut carbon composite aircraft parts, a thin stream of water moving at three times the speed of sound is emitted from a tiny, jeweled orifice in the tool head of Flow’s machine. The 1-gal/min water flow draws in a separate stream of fine garnet particles that slice into the surface being cut.