The new iglidur A181PF plain bearing material from igus contains no PTFE or bisphenols and is suitable for use in food-processing machinery where high hygiene standards apply. (Source: igus SE & Co. KG)
Many design engineers are under pressure when sourcing plain bearings for food-processing machinery as they are increasingly required to take regulatory requirements into account. While potential restrictions on PTFE are under discussion, new regulations are already tightening the requirements for materials with food contact that contain bisphenol. To offer design engineers long-term regulatory certainty, igus is now launching the new iglidur A181PF plain bearing material, which does not contain these controversial chemicals.
Plain bearings are an essential component of food-processing machinery. They are used in pivot arms, guides, flaps and rollers. However, procurement is becoming increasingly complex for design engineers. Considering only hygiene and functionality is no longer sufficient. The focus is also shifting to controversial chemicals, the use of which could be subject to stricter regulations in future. One example is polytetrafluoroethylene (PTFE), a chemical that belongs to the so-called PFAS group. Some PFAS are suspected of being harmful to humans and the environment. The European Chemicals Agency (ECHA) is therefore currently working on a restriction proposal submitted by several member states. EU Regulation 2024/3190, which will prohibit the use of bisphenols in food-contact materials in future, is exerting further pressure. “We have therefore developed the new A181PF plain bearing for food-processing machinery, which contains no PTFE or bisphenols,” says Dr Magnus Orth, Head of the igus Materials Centre.
Materials researchers at igus find an alternative to PTFE
At igus, PTFE has always played a key role in plain bearings when it comes to low coefficient of friction and good dry operation. Finding an alternative was, accordingly, a complex task. “Developing a plain bearing that does not require PTFE meant completely rethinking its tribological specifications,” explains Orth. The task was also complicated by the fact that applications involving contact with food entail additional requirements, for example, high resistance to cleaning agents and media in addition to strong mechanical properties. “We tested many different combinations of materials until we found a solution. “The new material is based on a combination of alternative solid lubricants and an optimised polymer matrix, which together result in a robust, food-safe overall profile.”
The plain bearing is resistant to shocks, impacts and edge loads and operates reliably at temperatures from -50°C to +90°C. Depending on the application parameters, it achieves a running performance that is comparable to or even better than that of the standard PTFE-based material iglidur A181. In its in-house test laboratory, igus rotated the PTFE-free bearing on a steel shaft at a speed of 0.3m/s and under a load of 1MPa. Wear amounted to just 0.57µm/km, which is not visible to the naked eye. A human hair is more than one hundred times thicker.
Hygienic dry operation and high resistance to cleaning agents
The alternative solid lubricants are finely dispersed within the high-performance plastic iglidur A181PF. They allow for low-friction dry operation without requiring external lubricants. Consequently, plain bearings made from the new material are suitable for use in the hygiene-critical food industry, where lubricants pose a risk of contamination. The bearings comply with the requirements of EU Regulation 10/2011 and the FDA’s standards for food contact.
Furthermore, the material is free from bisphenol A as well as bisphenol derivatives and their salts, which means it also meets the requirements of EU Regulation 2024/3190 on BPA in materials with food contact. This makes the material ideal for applications in which food may come into direct contact with machine components. It is also extremely resistant to cleaning chemicals and shows low moisture absorption, so that it can be installed with minimal bearing clearance. Says Orth: “Customers can be confident that the material meets the stringent requirements of the food industry. It therefore offers greater planning security in the face of future regulatory developments.”
You can find more information about igus’s PTFE-free products here: https://www.igus.eu/company/products/ptfe-free