A new industry standard

Yannick Willemin, 9T Labs’ director, business development reveals how the company’s novel Additive Fusion Technology design & manufacturing standard is being used to make lighter, stronger, and cost competitive aircraft interior parts that produce zero waste.

Every single piece and part of an aircraft represents an opportunity to increase performance and function, reduce weight and environmental impact, and to save money. Weight, cost, performance, and more recently sustainability are key metrics that drive research, design, and innovation in the aerospace manufacturing space.

Often, there is a trade-off when balancing and applying these metrics and it can be difficult to improve one area without sacrificing another – lower cost could mean lower quality, more sustainable could mean more expensive. There is a reason the idiom “You get what you pay for” persists. However, recent advances in composites and additive manufacturing (AM) are challenging that notion; a new standard in the design and manufacture of current and future aerospace parts is on the horizon and within reach. 

A key player and innovator in this sector is Switzerland-based 9T Labs, who have defined Additive Fusion Technology (AFT), a new and emerging standard in hybrid manufacturing that opens new possibilities for continuous fibre performance when dealing with very intricate and structurally loaded components. Innovative developments in software and hardware allow AFT to deliver composite products that compete with traditional subtractive manufacturing and machined metal components on cost, weight, performance and sustainability.

An incredible potential

In practical terms, this means lighter, stronger and cost competitive parts that produce zero waste and even allow the use of composite waste as one feedstock source. For these reasons, AFT has incredible potential across multiple industries, including aerospace.

The novel and automated multi-step process that is AFT uses integrated software in concert with precision AM processes and advanced post-processing that leverage a Build Module and a Fusion Module that work seamlessly together.

The software can easily import CAD files for templates and optimise structural calculations to make sure the right amount of material is placed exactly where it is needed. The Build Module, an open material platform, takes the optimised part design from the software and implements an AM process that uses two material deposition guides to place thermoplastic filaments alongside unidirectional (UD) continuous fibre-reinforced tapes. In the final step of AFT, the Fusion Module applies heat and pressure to fuse the preform parts with a fibre volume ratio of up to 60% in a mould. This process allows for a low void content (<1%), maximum interlaminar strength, metal parts integration, and reshaping.

Automating the process of composite manufacturing the way AFT does allows for the quick and efficient production (volumes between 1,000 and 100,000 parts per year) of relatively small, strong parts that are cost competitive, lighter and more sustainable when compared to traditional metal parts. Specifically, AFT solves the problem of scrap waste that persists in most subtractive manufacturing processes, including those used to create metal parts. Using a hybrid manufacturing approach like AFT not only enables a zero-waste starting point, but it also offers an end-of-life recycling opportunity that keeps the raw materials viable through multiple lifecycles.

When compared to aluminium, the AFT process decreases part weight by about half, yet maintains mechanical performance, including dimensional stability. Parts made with AFT also offer a low buy-to-fly ratio along with excellent corrosion resistance.

Proof of concept

The overhead bin pin bracket is small, but numerous pieces are found throughout the cabin of an aircraft and are traditionally made of aluminium. Because this part has already been benchmarked with composite materials and the geometry of the small bracket is complex, 9T Labs chose this piece as a proof-of-concept to test and showcase AFT’s advanced capabilities. 

The results speak for themselves. The AFT-produced bin pin bracket costs 50% less and weighs nearly half of the machined aluminium counterpart. The thermoplastic discontinuous fibre bulk moulding compound (BMC) platelets and continuous fibre preforms used in the AFT process for the bracket represent a more sustainable material approach compared to aluminium. The BMC platelets, representing 80% of the final part volume, can be sourced from waste. Furthermore, the AFT-produced parts show higher strength, lower variation, and longer lifetime than aluminium.

Data presented at the 2023 Society for the Advancement of Material and Process Engineering (SAMPE) Conference in Seattle detailed the real, demonstrable benefits of AFT to produce the bracket, which was originally made from a platelet-based material system. When using a hybrid material system with AFT to reinforce the brackets with about 20% by weight of continuous fibre printed preforms and platelets, measurable improvements were evident in mechanical performance of approximately 99.6% in the load at the onset of damage. In addition, the load at ultimate failure increased by 25.2%, and the coefficient of variance of the load at the onset of failure and at ultimate failure decreased by 46% and 14.8%, respectively. Reinforcing the pin bracket with continuous fibre preforms not only enhanced the strength characteristics but also decreased the variability in strength characteristic.

Conclusion and outlook

The overhead bin pin bracket is one small piece on a very large aircraft, but all together, small pieces add up and have a measurable impact on critical metrics like cost, weight and performance. Numerous reports have noted that even minor reductions in weight can have large impacts. For example, The Los Angeles Times reported that when United Airlines switched to a lighter paper for their in-flight magazine in 2018, it made the aircraft 11lbs lighter which meant 170,000 fewer gallons of fuel annually, resulting in savings of nearly $300,000.

9T Labs’ AFT platform is a game-changer in the aerospace manufacturing industry by offering the opportunity to create strong, light and less expensive parts that both deliver on performance and offer a more sustainable path forward vs. traditional materials. This is particularly true as it relates to the many geometrically complex and small parts that are critical to an aircraft’s overall performance, and it also holds true for larger parts, such as seat structures, as well. This is a versatile technology whose applications have only just begun to scratch the surface of what is possible. The company’s approach has been validated by life-cycle assessment (LCA); not only can it improve the environmental footprint by avoiding scrap and embracing recycling, but it has the potential to replace heavy metal parts on aircraft, which makes aircraft lighter, thereby requiring less fuel to fly.

Traditional methods of manufacturing small size composite aerospace mechanical components have been hamstrung by high fabrication costs, which is why 80% of those parts are still made with metal. Additive Fusion Technology is future-oriented and solves the issue of higher fabrication cost while delivering highly effective and more sustainable solutions that stand to greatly benefit aerospace parts manufacturing.

www.9tlabs.com