Takeoff and Landing

1. Though metals are strong, they have issues, including weight, corrosion, and requirements for external lubrication.
2. Orkot® materials are advanced composites that provide a reliable, lightweight alternative.
3. A new material, Orkot®C620 reduces weight in aircraft and has the highest load capability, ideal for landing gear and other aerospace applications.

have their fair share of issues. Some of the key difficulties lie in the intrinsic properties of the material: they are heavy, vulnerable to corrosion, and require external lubrication to reduce friction. Though engineers and manufacturers have worked around these problems for many years, newer solutions are more viable, more cost-effective to produce, and frequently bring advantages that metals can never provide.

"More and more specifications are now moving away from metallic components, taking advantage of the benefits of modern materials," says Shaun Walker, Development
and Process Manager at Trelleborg Sealing Solutions. For example, in hydroelectric power plants, greased bronze bearings have already been replaced with self-lubricating,
fiber-reinforced composites, such as Orkot®. "These support dry-running, increasing lifetime and reducing maintenance while preventing damage to the environment," explains
Shaun. Similarly, in the enormous container ships that ferry goods around the world, reliability and resilience are critical. In addition to the strength required to resist the high forces within the application, they counter the corrosive effects of seawater on the bearing itself, which could then spread to the housing, requiring costly downtime.

Above and beyond

High above the land and sea though, thermoplastics find one of their key applications in the skies. Trelleborg's latest material innovation, Orkot® C620, was designed with the
aerospace industry in mind. It's an engineered glass-fiber composite with a low-friction Orkot® lining, strong enough to withstand the high loads of landing gear - and it's light too.

"Reducing weight is a priority for improving the efficiency and fuel consumption of aircraft," says Shaun. Fuel is a significant cost for an airline, and consumption is closely correlated to weight. A study by MIT in 2014 estimated that Southwest Airlines spent an extra $1.2 million per year to allow passengers to each carry a cellphone. To take magazines costs $5.7 million extra and to carry one laptop per person - $21.6 million. These figures show that every gram counts. An urban legend in the aviation industry says that an airline CEO ordered the removal of a single olive from each of the complementary salads, saving $100,000 on both olives and fuel. "Aluminum, steel, and titanium were
the materials of choice, making up the majority of an aircraft. By switching over to aerospace-grade thermoplastics, weight can be reduced by 20%," says Shaun.

In 2017, the Australian airline, Qantas, challenged Airbus and Boeing to fly a loaded plane non-stop for 20 hours. It was clear that reducing weight would be one of the only
ways of achieving this. In 2019, Qantas flew from London to Sydney non-stop with 52 passengers on board. The flight took 19 hours and 19 minutes on the QF 7879 Boeing
787 Dreamliner, with passengers seeing two sunrises on the journey. Thermoplastics composed most of the aircraft structure, replacing what previously would have been aluminum.

But weight reduction is not the only factor driving the replacement. Flame retardancy, friction-free operation, and greater design latitude are making manufacturers consider the switch for many different purposes. "When the physical properties are all considered, frequently composites are outperforming metal in applications all across the plane," says Shaun. “A lot of development focus has been on structural elements like the wings and fuselage, but even landing gear bearings are good candidates to switch over to Orkot® C620.”