Toray Industries, Inc. has developed an innovative prepreg for primary structural components of aircraft that enables high-grade carbon fiber reinforced plastic (CFRP) molding with excellent mechanical characteristics without using an autoclave. The company plans to further refine this new technology to expand demand for high-performance CFRP components based on the low processing cost in various applications including aircraft, vehicles and general industrial use.
A mock tail assembly fabricated out-of-autoclave.
In general, CFRP primary structural components, used for the main wings and fuselage of an aircraft, are manufactured using an autoclave process method by laminating prepregs sheets, which are carbon fibers impregnated in epoxy resin, on a mold and heating them in an autoclave to apply high pressure during resin curing. While the autoclave method has the advantage of stable molding for high performance, high-quality CFRP components, it requires high initial capital investment, thus increasing the production cost of CFRP components.
To replace an autoclave method, Toray last year developed a vacuum pressure molding technology, in which CFRP is manufactured at one atmospheric pressure under vacuum suction, and recently developed a prepreg that is suitable for this vacuum pressure molding technology. The new prepreg, enabled by a newly developed novel matrix resin, has mechanical performance — compression strength after an impact and tensile strength — equivalent to primary structural aircraft components that employ traditional prepregs and molding using an autoclave.
A two-meter-long by 1.5-meter-wide test component simulating part of an existing aircraft tail assembly was fabricated using the new process and prepreg, and it exhibited a low porosity on a par with existing prepregs and confirmed that CFRP components of a level that can clear strict quality control standards for aircraft components are achievable.
Part of this successful development is attributable to the “Innovative Structural Materials (Cross-ministerial Strategic Innovation Promotion (SIP) program,” a strategic innovation program of the Council for Science, Technology and Innovation (managed by Japan Science and Technology Agency).
Toray has set business expansion in growth fields and creation of new demand through the development of new products as important tasks for the carbon fiber composite materials business in its medium-term management program, Project AP-G 2019.