The challenge of the PFAS ban Calcium sulphonate lubricating greases without PFAS: Efficient solutions with maximum safety for demanding applications in linear guides

The EU tightens its stance on PFAS

Recently, however, PTFE has come under increasing criticism as this substance is classified as a PFAS, the use of which is to be strictly regulated or even banned by the EU in future. PFAS stands for "per- and polyfluorinated alkyl substances" and comprises a group of chemical compounds that are used in numerous everyday products such as Teflon pans, water-repellent textiles, packaging and cleaning agents due to their water, grease and dirt-repellent properties. In addition, PFAS and PTFE lubricants are often compatible with the strict hygiene regulations of the food industry, which are made necessary by the unavoidable direct contact with food.

However, because natural degradation is slowed down, incomplete or not possible at all, PFAS are considered problematic substances. They are therefore also known as perpetual chemi-cals. The considerations of the European Chemicals Agency (ECHA) to include PFAS in the list of substances of very high concern (SVHC substances) are based on the potential risks to hu-man and animal health as well as negative ecological effects, particularly due to their persistence and bioaccumulation. The restriction proposal currently under discussion envisages an almost complete ban on PFAS-containing substances. Effective, PFAS-free lubricant alterna-tives are therefore required.

It is also possible without PFAS

However, there are currently no standard solutions for PFAS-free lubricants. The applications are too diverse, and the development of technologies is time-consuming and cost-intensive.

However, as a leading manufacturer of specialty lubricants, TUNAP was quick to develop high-performance lubricants that do not require PTFE additives and have proven themselves in practice many times over. These include high-performance greases based on calcium sulphonate complex soap. These greases are characterized particular by a long-lasting lubricating effect in linear guides, one of the key properties of lubricating greases for cost and resource-efficient production.

Linear guides - high demands on lubricants

Linear movements play a decisive role in drive technology. Key features are high precision, exact positioning and smooth running. They ensure precise, low-friction movements under high loads and often in adverse environmental conditions. They can be found in machine tools, automation, electrically controlled linear movements, transport and relocation of goods ("pick and place"), packaging, assembly and disassembly and numerous other industrial processes. They therefore cover a wide range of applications in all production, packaging and transport sectors. They are particularly susceptible to wear and corrosion, which is why the lubricant used plays a key role.

The versatile application of linear guides in combination with the high demands on service life and precision make the use of specially matched high-performance lubricants essential.

These must fulfil several requirements at the same time:

• High mechanical load capacity
• Good corrosion protection, even with moisture or aggressive media
• Sufficient thermal stability
• Long-lasting lubricating effect to extend maintenance intervals
• Compatibility with seals and materials

Calcium sulphonate complex soaps: High-performance alternative with added value

Calcium sulphonate lubricating greases are a promising alternative to lubricating greases con-taining PTFE. They offer a convincing combination of physical stability, chemical resistance and outstanding load-bearing capacity. In contrast to conventional soap thickeners such as lithium complex or aluminium complex, calcium sulphonate complex soaps are able to withstand both mechanical and chemical loads thanks to their crystalline structure and a base reserve.

They offer numerous advantages:

• Excellent corrosion protection: In combination with their alkaline pH value and dense structure, they provide effective protection, especially in environments exposed to moisture and water.

• Good water resistance: The lubricating effect is maintained even in splash water or extremely humid environments.

• Very good high pressure and wear protection properties: The soap structure acts as a physical buffer and reduces metallic contact.

• High mechanical stability: They retain their consistency even under heavy mechanical loads, which extends the service life of the lubricated components.

• In addition, these greases can be applied very easily via automated dosing systems, an important point for modern production systems.

The use of PFAS-free greases based on calcium sulphonate complex soap thickeners reduces risks and complies with current environmental and health standards. This is particularly im-portant in the lubrication of linear guides, especially in the food industry, where safety and hygiene standards are of paramount importance. Considered more environmentally friendly than some traditional alternatives, they are readily biodegradable and have a longer life, re-sulting in lower consumption and environmental impact.

PTFE additives vs. calcium sulphonate technology - a comparison

PTFE as a solid lubricant additive is known for its exceptionally low coefficient of friction. In linear guides, it improves the breakaway torque and emergency running properties in particu-lar. However, these advantages are also associated with disadvantages, particularly in the context of the PFAS ban. A tabular comparison between typical PTFE-containing greases and calcium sulphonate complex soap greases is shown below.

The data show that calcium sulphonate complex greases are more than just a substitute; in many applications they even represent a technically superior solution.

Praxisbeispiele und typische Einsatzbereiche

TUNAP's calcium sulphonate complex greases are already being used successfully in a wide variety of applications, especially where high loads, moisture or temperature fluctuations pre-vail.

Examples of this are:

• TUNGREASE CP-2/50: is suitable as a reliable all-round grease for packaging machines with a high cycle rate and high-capacity utilization – ideal for reducing the number of types in operation.
• TUNGREASE CP-2/200: is the optimum choice for food processing systems where, in addition to NSF-H1 registration, a particularly effective lubricating effect and a high level of protection against cleaning media are required.
• TUNGREASE CK-2: impresses with its high resistance to process media such as cooling lubricants – ideal for machine tools with precise and highly loaded linear guides.
• TUNGREASE CM-2/460: offers particularly good adhesion, excellent corrosion protec-tion and high wear protection – predestined for mobile machinery such as cranes or lifting systems that are exposed to changing weather conditions

TUNAP modular principle for maximum flexibility

The choice of the right viscosity grade should not be ignored, as this is crucial for the efficiency and service life of machines and systems. Consideration of the operating temperature, load, pressure and speed is of central importance. An optimum viscosity grade provides adequate lubrication and protection, improving equipment performance and extending its service life. In order to make the right choice for all common speed-load collectives, TUNAP has devel-oped calcium sulphonate complex greases according to a modular principle and offers base oil viscosities of 25 mm²/s, 46 mm²/s, 180 mm²/s, 220 mm²/s and 460 mm²/s. This variety enables TUNAP to offer customized solutions for different applications and ensure that customers receive the optimum lubricants for their specific requirements.

In practice, these high-performance lubricants offer reduced relubrication intervals, extended component life and higher overall equipment efficiency.

Conclusion and recommendation

The discussion surrounding PFAS and the impending ban on PTFE additives poses challenges for many industrial users. However, it also offers opportunities to put existing solutions to the test. Calcium sulphonate complex greases have established themselves as an efficient, environmentally friendly and economically attractive alternative.

For operators of systems with linear guides who want to rely on future-proof and high-performance lubrication, these greases offer a reliable solution, completely without PFAS, and with significant added value for safety, sustainability and operating costs.

With the increasing demand for high-performance and environmentally friendly lubricants, TUNAP is continuously investing in research and development. Our calcium sulphonate complex greases help to reduce environmental impact and improve operational efficiency. We set standards through quality and sustainability and offer products that are both technically and ecologically convincing.

More information at: : https://www.tunap.com/tunap/branches/industry/industry.php