CFM International is not the first company to use 3-D woven technology. Both Boeing and Airbus have implemented 3-D woven parts in their new fuel-efficient aircraft models to help reduce weight. The importance of the 3-D wovens in the LEAP project is that the company used an advanced textile in a major structural engine component. This unique application has attracted attention to the advantages of designing with advanced textiles to enhance composite parts.
For example, CFM International weighed the LEAP engine series against its similar CFM56 engines, which employ heavier metal parts, and found the LEAP engine was lighter by more than 1,000 pounds. Compared to another composite engine, the GE90 produced by CFAN, the 3-D woven composite engine is smaller by 50 inches in diameter but strong enough to pass the same birdstrike test, according to the company.
Another advantage of 3-D woven RTM fan blades is that the prepreg is designed with different thicknesses. The blade is thinner at the top and thicker at the bottom. This reduces the delamination that typically occurs on similar 2-D fan blade parts. For markets like aerospace, the ability to seamlessly integrate smart sensors into the part without compromising part durability is critical for aerospace composite maintenance and repair.
Stepping into the New Dimension
Since the LEAP engine was launched at the 2012 Farnborough International Airshow in July, the company has sold more than $12.6 billion in orders and is expected to produce 32,000 composite fan blades per year by 2019 – or one every 30 minutes, according to CFM International. It will continue to develop the patented 3-D woven RTM process to work efficiently on a commercial scale.
AEC and its partners are enthusiastic about the level of response they have received from the industry. “The LEAP RTM fan is one of the revolutionary technologies that will change the face of commercial aviation,” says Jamie Jewell, director of strategic communications at CFM International. “Our biggest challenge ahead is to finish refinement and industrialize the technology.” Snecma and AEC will open two new facilities with 200 employees operating each in order to meet the demand.
McIlhagger agrees with Jewell that the major challenge for 3-D wovens is introducing the new technology to the industry and producing these composites for high-volume applications. He believes that 3-D woven composites are a key tool for using composites more intelligently to fit the specific property or fiber direction of material. But to benefit from this technology, the industry needs to understand the weaving, preform and manufacturing process.