Toray Industries, Inc., has developed a technology that thermally welds carbon fiber reinforced plastic (CFRP) at high speed. This technology will enable high-rate production and weight savings of CFRP airframes. The company will push ahead with demonstrations with a view to commercializing airframes after 2030 while further expanding CFRP applications.

Global aircraft demand should recover through 2025 after stagnating amid the COVID-19 pandemic. Demand for next-generation aircraft with 120 to 240 seats should be heavy from 2030. Thermosetting CFRP is the primary structural material for aircraft main frames because of its long use and high reliability.

The downside is that complicated adhesive bonding and bolt fastening processes of CFRP have become assembly bottlenecks. CFRP production times greatly lag those for aluminum alloy airframes. High-rate production and weight savings that help enhance fuel efficiency to will be important to capture prospectively large demand.

The thermal welding technology developed by Toray can swiftly and robustly join thermosetting CFRP components for aircraft like conventional welding would do.

Thermally welded assembly of aircraft structural demonstrator applying Toray's new technology.

This simple bonding approach employs the company's technology to form a thermally weldable layer on the surface of thermosetting CFRP, instantaneously heating part surfaces to bond them. This technology enables high-speed assembly of thermosetting CFRP parts or thermosetting and thermoplastic CFRP parts without the need for adhesive bonding and bolt fastening.

Using this technology to thermosetting CFRP with thermally weldable layers offers the same mechanical properties as CFRP for current aircraft models. Toray demonstrated that the joint strength of thermally welded structures is equivalent to that of co-cured CFRP structures for current aircraft models, ensuring the reliability of bonding technology for practical application studies.

The company assembled a demonstrator simulating the elemental structure of an aircraft at high-speed using thermally weldable thermosetting CFRP parts. Thereby, its elemental technology concept was confirmed. Toray believes that its technology should achieve a high-rate production that matches or surpasses that for aluminum alloy airframes.

A CFRP airframe using Toray’s technology will also reduce carbon dioxide emissions across the life cycle compared with those for an aluminum alloy airframe. Cutting the weight of bolt fasteners should lighten airframes, and further reducing these emissions.

Furthermore, the company has partnered with Boeing to promote a number of technological development projects in the fields of aircraft manufacturing and materials technology.