How industry and the environment benefit from lubrication-free plain bearings

• RWTH Aachen University and WBA Aachener Werkzeugbau Akademie conducted a study commissioned by igus on the benefits of lubrication-free polymer bearings.

• Traditional metal plain bearings are costly and environmentally harmful due to the need for relubrication.

• Lubrication-free polymer bearings from igus reduce costs and maintenance time, with savings of up to €14 million annually for companies.

• The study included nine companies from various industries, such as Lemken, Heineken, and Wacker Neuson, showcasing significant savings and efficiency improvements.

• Heineken Brasil saved 1,560 working hours and €2,815.49 annually by switching to igus polymer bearings.

• The study also highlighted the environmental benefits, with Heineken Brasil saving 180kg of CO2 equivalents annually by using polymer bearings.

Lubrication-free polymer bearings instead of metal bearings: RWTH study commissioned by igus quantifies ecological and economic benefits for the first time

Advertisement

From ploughs in agriculture to conveyor belts in breweries: traditional metal plain bearings are costly and time-consuming due to the need for relubrication. To save money, economise on human resources and preserve the environment, more and more industrial companies are therefore switching to lubrication-free polymer bearings from the Cologne-based plastics specialist igus. Together with igus, scientists from RWTH Aachen University and the WBA Aachener Werkzeugbau Akademie conducted a study that shows actual savings and the environmental benefits for the first time.

Classic plain bearings made of metal are an indispensable part of industry. The problem is that they cause considerable costs. Companies not only have to buy additional lubricants, but also plan time and corresponding personnel resources for maintenance work. In addition, many lubricants, and therefore the manufacturers of machines and systems that rely on them, are being criticised due to increasing public awareness of environmental issues. For example, some products contain environmentally harmful additives that improve the performance of the lubricants - including antioxidants, corrosion inhibitors and detergents. The Cologne-based plastics specialist igus has been supporting manufacturers for many years in replacing lubricated plain bearings with lubrication-free iglidur and igutex plain bearings - thus protecting the environment while improving productivity. These plain bearings use a self-lubricating effect. This means that microscopically small solid lubricants are integrated into the high-performance plastic, which enable low-friction dry operation - without the need for additional lubrication. "Customers tell us that the new solution is a game changer for them, as it significantly reduces purchasing and personnel costs," says Stefan Loockmann-Rittich, Head of the iglidur Plain Bearing Business Unit at igus. "However, until now there has been a lack of scientific data quantifying the benefits of polymer bearings in black and white and demonstrating their impact on the environment and the efficiency of machines and systems as a whole. We have therefore decided to commission an independent study. And, for the first time, we have achieved figures that surprise even us." The WBA Werkzeugbau was commissioned, a research company that works together with the Laboratory for Machine Tools (WZL) and the Fraunhofer Institute for Production Technology (IPT) on the RWTH Aachen Campus as part of one of Europe's largest research laboratories in the field of production technology.

Is the change worthwhile? Independent experts analyse the success of nine industrial companies

The study is based on expert interviews with nine companies from the automation technology, construction machinery, agricultural, food, packaging and bottling industries. Participants include the agricultural-machinery manufacturer Lemken, which uses igus plain bearings in cultivators, the company Rockinger, whose trailer systems for commercial vehicles contain the bearings made of high-performance plastic, the agricultural machinery manufacturer CNH Industrial with iglidur bearings in hinges of a sowing coulter and the company KettenWulf, which installs the bearings in escalators. The study also includes the Brazilian branch of beer manufacturer Heineken, which uses plain bearings made from high-performance polymers in conveyor belts, construction machinery manufacturer Huppenkothen with igus plain bearings in its excavator shovel mounts, Krones, a producer of filling systems, which incorporates the bearings in container transport systems, Wacker Neuson, which installs lubrication-free plain bearings in excavator arm systems, and GMG, which uses the polymer bearings in gripper systems. The respondents described to the independent experts of the WBA Werkzeugbau Akademie the savings they achieved by switching from lubricated plain bearings to lubrication-free iglidur bearings.

Without lubricants: save up to €14 million per year

The result: as companies and their customers, such as buyers of agricultural machinery, no longer have to buy lubricant, they save between €7,000 and €14 million a year. In addition, between 8,000 and two million hours are no longer needed for the manual relubrication of bearing points. "The figures impressively demonstrate how a supposedly small change can save enormous sums of money and resources," says Loockmann-Rittich. Another advantage: users of machines, systems and vehicles can no longer cause damage due to insufficient lubrication. This danger is omnipresent with lubricated metal bearings. For example, 45 per cent of those surveyed confirmed that insufficient lubrication can lead to product failure. And such a failure can lead to expensive downtimes of entire production lines. This is shown in the "True Cost of Downtime" study by Senseye, a manufacturer of analytics software from the UK: industrial companies worldwide lose between $39,000 and two million per hour due to plant downtime. In the 500 companies with the highest turnover in the world, failures add up to a loss of almost $1.5 trillion per year.

Heineken Brasil saves 1,560 working hours per year

The Dutch brewery Heineken shows how the cost savings are made up. At the branch in Brazil, the company has switched from classic metal bearings to lubrication-free radial bearings from igus for 600 bearing points on the conveyor belts of bottling plants. Thanks to the change, the company saves 124.8 kilogrammes of material per year, or €2,815.49, with four grammes of lubricant per bearing point and weekly maintenance. However, the savings in personnel costs are far more significant. Whereas in the past, employees had to relubricate the 600 bearing points every week, the company now saves 1,560 working hours per year thanks to the self-lubricating effect of the polymer bearings. The figures are even more impressive when extrapolated to more than 160 Heineken locations worldwide. By switching to lubrication-free bearings made of high-performance plastic, they would save around 20 tonnes of lubricant per year and therefore costs of €450,478. The personnel costs saved would amount to around €5.4 million.

Dispensing with lubricants: study calculates the environmental effect for the first time

However, the study not only reveals the cost advantages of lubrication-free polymer bearings compared to conventional metal ones, but also the positive environmental impact. "More and more manufacturers of machines, systems and vehicles are feeling the pressure to disclose the carbon footprint of their products," explains Loockman-Rittich. This is an enormous challenge, especially for products that consist of hundreds of components. "Our customers are very happy: now there is a scientifically proven assessment showing the environmental benefits that our plain bearings offer due to their self-lubricating effect." To this end, the independent experts carried out an ecological evaluation based on a life cycle assessment in accordance with the DIN EN ISO 14040/44 standard. The result using the example of Heineken Brasil: thanks to replacing metal bearings with polymer bearings at 600 bearing points, the company saves 180kg of CO2 equivalents per year - which corresponds to flying an Airbus A320 neo for 20 kilometres. In addition, there are annual savings of oil equivalents amounting to 155kg, which corresponds to a 461km journey by an average diesel lorry. The more bearings there are, the greater the environmental effect. "If all Heineken branches were to switch to polymer bearings, the company could save 28,814kg of CO2 equivalents. And that is a remarkable value for such a small adjustment," concludes Loockman-Rittich.