Ensuring the right chemistry during grinding

Author: Daniel Schauber, trade journalist, Mannheim

Data-based monitoring of cooling lubricant ensures optimal results. In the grinding process, tiny imperfections make the difference between a good part and a reject. To achieve a perfect grind, not only do the mechanical components at the factory have to be set up correctly - the chemistry has to be just right as well. This brings an often underestimated component into focus: The cooling lubricant.

Data-based cooling lubricant monitoring is an essential part of achieving autonomous production and optimal grinding results. This monitoring forms the link between the chemistry and the mechanical components and makes the grinding process more robust, more efficient and more sustainable thanks to standardized data exchange and the use of digital twins. This is also where the umati (Universal Machine Technology Interface) connectivity initiative comes into play, ensuring smooth data transfer in the factory. As a global mechanical engineering community based on the OPC UA communication standard, umati enables machines to communicate with each other regardless of the manufacturer. This creates the necessary interoperability to seamlessly integrate data from cooling lubricant monitoring into higher-level IT systems or cloud platforms, paving the way for plug-and-play connectivity in the industrial ecosystem.

At the GrindingHub trade fair, organized by the VDW (German Machine Tool Builders' Association) in Stuttgart from May 5 to 8, 2026, visitors will learn more about optimized cooling lubricant supply for achieving the highest surface qualities.

Energy savings of up to 27 percent

Scientific research has shown that a supply of cooling lubricant that is tailored to requirements produces large gains in efficiency and productivity. "Even in our initial research, we were able to identify process windows that allowed the energy required for grinding to be reduced by up to 27 percent without sacrificing workpiece quality or increasing tool wear," says Prof. Berend Denkena, Head of the Institute of Production Engineering and Machine Tools (IFW) at Leibniz University of Hanover. "At the same time, we were able to increase the metal removal rate by up to 20 percent, resulting in a significant increase in productivity." Requirement-based cooling lubricant supply should allow this potential to be transferred to industrial applications in the future in a way that is both systematic and reproducible.

There are also positive effects in terms of sustainability in industrial production. "Requirement-based cooling lubricant supply allows the consumption of cooling lubricant to be reduced, which not only reduces the energy requirement in the grinding process, but also the costs for producing, preparing and disposing of the cooling lubricant," explains the scientist. He is a member of the WGP (German Academic Association for Production Technology), which has been researching requirement-based usage of cooling lubricants for many years. More stable process conditions also increase tool life and reduce the amount of rejects and rework. Overall, this contributes to a more efficient use of resources and more sustainable industrial production.

Keeping a close eye on grinding forces and spindle power

"Requirement-based cooling lubricant supply is made possible by continuously recording process-related status variables and using them to vary the cooling lubricant supply," explains Prof. Denkena. At the IFW, research was initially carried out on the fundamentals of cooling lubricant supply in the grinding contact zone. Based on this, sensor and control technology concepts are currently being developed in order to achieve a requirement-based and automated supply of cooling lubricant in the future. Data is the most important raw material here. "In our initial research, we recorded variables relevant to the cooling lubricant such as flow rate, temperature and pressure as well as process-related parameters such as grinding forces, spindle power and workpiece-related properties," explains the researcher. This involved analyzing how changing cooling lubricant conditions affect the grinding process. The aim is to build on this research so that sensor-based data can be used in the future to specifically influence target variables such as energy efficiency, cooling lubricant consumption, tool wear and workpiece quality.

Healthy emulsion without foam and infections

The optimal management of cooling lubricant in the factory is also a key area of focus for lubricant manufacturer Fuchs SE from Mannheim. "Efficient cooling lubricant management is essentially based on four main components," says Alexander Kaiser, Head of Global Product Line Smart Services & Digital Business Partner at Fuchs. He explains them as follows: firstly, a stable emulsion must be mixed with the finest possible droplet structure using a known and recommended level of water quality; secondly, the emulsion's "state of health" must be continuously monitored to ensure its long-term performance; thirdly, regular replenishment with fresh emulsion is required to control the concentration and compensate for volume losses; and fourthly, additives must be used selectively to prevent infections or foaming. "Parts of the process can be partially or fully automated," says Mr. Kaiser. Automation makes sense if the application is stable and not subject to strong fluctuations. Cost efficiency is also a consideration, as automation always requires investments to be made.

Digital twins in the cloud

When the process is automated, a minimum requirement is that the current concentration must be measured by in-line refractometers. The current fill level of the cooling lubricant tank is also recorded. The automation system then uses the target concentration for the application to determine the necessary replenishment quantity and its concentration in order to keep the emulsion at a constant concentration level. "All production equipment – such as machines – and their lubrication points are mapped as digital twins in our cloud-based service management platform called LubeLink FluidsConnect," says the Fuchs manager. The current status, replenishment quantities and the entire maintenance process are recorded, planned and continuously managed using this system. "This ensures that the Smart-Services-Team knows the status of production at all times and can take measures at an early stage to avoid unplanned downtime," explains Mr. Kaiser.

Smell, see, measure

The concentration of cooling lubricants is typically determined at short intervals – either by refractometer (automated or manually), by titration on site or by means of detailed laboratory analyses. In addition, pH and nitrite levels are measured regularly. Swabs are used to detect possible bacterial infections. In some cases, odor and visual condition are also documented. This information is used to plan replenishment cycles and tank cleaning intervals. "LubeLink supports the efficient coordination of experts on site with deployment plans and notifications," says Mr. Kaiser. The functionality and reliability of the equipment is also regularly checked when fully automatic replenishing is implemented. All data – regardless of whether it was recorded automatically or manually – is stored and made available centrally in FluidsConnect.

Whether all this effort is worthwhile for the industrial user ultimately boils down to a commercial calculation. This is because the level of efficiency and productivity gains achieved through automated cooling lubricant management in the grinding process varies depending on the application. According to Mr. Kaiser, savings are possible both in the areas of personnel costs and fluid costs, mainly due to the extended service life of the fluids. However, these savings must be offset against the investment in automation. "The investment may not pay for itself quickly in all markets, for all customers and applications," admits the Fuchs manager. In all cases, however, professional cooling lubricant management increases productivity by reducing downtimes to a minimum and ensuring that parts are produced to the desired quality standard.

Less water, additives and energy

In addition to the economic benefits, there are also environmental benefits. Extending the service life of the cooling lubricant reduces both the amount of concentrate required and the amount of fresh water used. At the same time, the quantity of emulsion that needs to be disposed of is also reduced. "In addition, when the health of the emulsion remains consistently good, the use of additives can be reduced or even completely eliminated. It should also be mentioned that extended tool life and perfect lubrication can lead to noticeable energy savings," says Mr. Kaiser.

Data processing in the cloud offers additional advantages: "Always up-to-date, available everywhere, with a central database and high reliability," explains Mr. Kaiser, summarizing the benefits. New functions, security updates and improvements are available immediately thanks to the cloud. The data can be accessed from any location, any device and at any time, which is perfect for global production networks. Data from machines, sensors, laboratories and service deployments is available in one system – without data silos, version conflicts and media discontinuity. And redundant systems combine with professional monitoring to ensure operational stability.

Data remains in Germany

An important concern for users is that the data needs to be stored securely in the cloud. "We are aware of the key importance of IT security," emphasizes Mr. Kaiser. LubeLink is a cloud-based platform based on the latest web technologies. The application is hosted in Germany. "As LubeLink is constantly evolving, we regularly have both the application and the hosting environment tested and certified by an independent external partner," says the Fuchs manager. "So far, no vulnerabilities or security problems have been identified – a result we are proud of. This allows us to offer our customers a modern, powerful and extremely secure system for managing their lubrication processes," explains Mr. Kaiser.

AI promises even more efficiency

Machine learning promises further efficiency gains in data-based cooling lubricant management in the future. "We use a variety of modern technologies to create real added value for our customers from the available data. Artificial intelligence methods are also used where appropriate," says the expert in cooling lubricant. "Thanks to our many years of experience and the database we have built up over time, we can detect anomalies in lubrication applications at an early stage – and in many cases even predict them." However, discussions with customers do not focus on which algorithms or technologies should be used, but rather on how production can be made more productive, efficient and sustainable, says Alexander Kaiser.