Smart fluid management for the factory of tomorrow

Everything at a glance: A user-friendly dashboard shows the ideal concentration, ph-value, conductivity and temperature of the cooling lubricant in real time, among other things.

In the course of Industry 4.0 and the smart factory, intelligent systems independently control their own production process. The goal is maximum operating efficiency through the most comprehensive automation possible. Fluid management should also be taken into account in automation projects in order to avoid deviations and the associated production downtimes. And this is exactly where the experts from Zeller+Gmelin and HYDAC come in: With the help of the newly developed fluid management system "ZG Fluid-Check Pro", the cooling lubricant supply of machines and systems can be automatically monitored, organised and controlled. It incorporates Zeller+Gmelin's many years of expertise in the field of fluid management. One of the first practical users of the newly developed system is the company Heron CNC-Technik from Vorarlberg, Austria.

The smart device monitors the fill level and measures the concentration, pH value, conductivity and temperature in real time - the current measured values are displayed on the dashboard every minute. In addition, up to four further values such as nitrite or, for example, the tramp oil content can be entered manually. In the event of deviations from the target concentration, readjustments are made automatically. It is also possible to store coolant profiles, whereby the top ten of the most common water-miscible coolants from Zeller+Gmelin are already stored, so that the user only has to select his preferred product on the display, without having to enter any additional parameters. Two dosing pumps can be connected for the automatic addition of additives/inhibitors. Together with a multiplexer, one system monitors up to seven CNC machines. "Our fluid management system permanently records the emulsion status so that traceability is also guaranteed," emphasises Thorsten Wechmann, Strategic Business Unit Manager at Eislingen-based lubricant manufacturer Zeller+Gmelin.

As an independent company within the family-run Heron Innovations Factory, Heron CNC-Technik GmbH specialises entirely in metal and plastic machining. As a contract manufacturer for milling and turning, Heron uses state-of-the-art CNC machining centres to produce prototypes and series parts in batch sizes from 1 to 10,000. Customers come from a wide range of industries, such as medical technology, special machine construction, automotive or semiconductor technology. "We want to meet the demands of increasing competition and a growing clientele, which is why we rely on continuous, automated processes entirely in the sense of Industry 4.0," is how Manuel Gmeiner, the business manager there, sums it up. "Our machines run largely fully automated, around the clock, 365 days a year."

Smart and compact: the ZG Fluid-Check Pro fluid management system in cooperation with Zeller+Gmelin. The system also "tracks" concentrate consumption and the required water volume.

Manufacturing processes and techniques are constantly being developed. One hurdle to 'unmanned' production, however, is cooling lubricant management. Levels have to be checked regularly and refilled manually - even on holidays or weekends. "The failure of the lubrication could not only mean the complete standstill of the machine, but also cause damage," Heron Managing Director Manuel Gmeiner points out.

Digital factory: Maintenance is often forgotten
And Thorsten Wechmann from Zeller+Gmelin poses the question in the direction of the Smart Factory: "What use is the simulation of production and the elimination of interference contours in the machining process if an employee has to intervene at the machine at the end because the filling level or other parameters of the cooling lubricant are not correct? Self-organising production always includes the ability to take timely and automated countermeasures when deviations from defined values occur. A deviation in the cooling lubricant must not become the eye of the needle." Although solutions already exist today with which current lubricant values or key figures can be transmitted to a smartphone via SMS, "If there is a deviation, someone still has to readjust manually," continues Thorsten Wechmann.

Smart monitoring for small and medium-sized enterprises
"In order to ensure the long-term competitiveness of a medium-sized company, there is often no way around a high degree of automation and the associated digitalisation of processes," emphasises Philipp Götz, Product Manager at HYDAC Filter Systems GmbH: "Our goal is to support manufacturing companies on their way to Industry 4.0. With the ZG Fuid-Check, we have developed a compact device that can not only monitor the entire cooling lubricant cycle of up to seven machines as well as central systems simultaneously, but also intervene independently and in a regulating manner in the event of deviations.“

Fluidmanagement from Eislingen
In Zeller+Gmelin, the company has also found a suitable cooperation partner. As a long-standing supplier of water-miscible cooling lubricants, which are available from Zeller+Gmelin under the brand name Zubora for machining production. With ZG Fluidmanagement GmbH, a separate subsidiary was even founded for this purpose. "Many modern companies now rely on effective fluid management, which is essentially based on the analysis and conditioning of liquid working media as well as precise consumption recording and evaluation. The aim is to increase economic efficiency by, among other things, maintaining the target concentration and preventing underconcentration.
 
This also results in longer tool life and better surface qualities in the machining process," Thorsten Wechmann knows from numerous practical applications. But too high a concentration also has negative effects:  On the one hand, more lubricant is consumed, on the other hand, the foaming behaviour of a cooling lubricant can change. If all parameters are always optimally adjusted, the lubricant can be used for a significantly longer time and with greater process reliability.

"Of course, we are also permanently concerned with the question of how lubricant management can be further optimised." In terms of fluid management systems, the market still offers a lot of room for improvement. Many devices are not capable of flushing. This makes them inaccurate and they have to be constantly readjusted - not so the ZG Fluid-Check. The device is also very compact and fits into any production area. "The very first projects were successful and we were able to benefit from each other's experience and pass it on to the user. Our customers can now purchase the system through our Fluid Management business unit, of course in combination with our own skin- and resource-friendly high-performance Zubora cooling lubricants."

And Phillip Götz from HYDAC adds: "Medium-sized industrial customers in particular want an "all-round carefree package" from their lubricant suppliers so that they have time internally for their core business. With the distribution of our devices, Zeller+Gmelin also addresses its offer specifically to companies that want to manufacture highly automated, but do not want to provide additional resources in terms of fluid management. The machine operator then no longer has to re-measure, refill or readjust at the machine. This is an enormous time saving and thus more time for value-adding tasks.“

High-precision prototypes and series parts in machining technology
Manuel Gmeiner from Heron agrees: "The cooperation with Zeller+Gmelin and HYDAC is another important building block for us towards the complete digitalisation of our production. The ZG Fluid-Check is currently being tested on a fully automated Hermle system in which a robot system equips three 5-axis milling centres. The system is connected to an autonomous transport robot system from Servus Intralogistics, another Heron Innovations Factory company. "This allows the plant to be operated in a fully automated manner 24/7." After a successful trial phase together with Zeller+Gmelin, Heron had decided on two of the units with multiplexers, to which up to 14 machines can be connected and supplied.

Digital, intuitive and user-friendly
In addition to the fill level, the unit continuously measures the concentration, as well as the pH value and other parameters. To keep the concentration at the desired level, the dosing pump counteracts in time if necessary. This also prevents all risks that could be associated with under/over-concentration, such as foam formation or impairment of corrosion protection. "The values can be read either directly on the touch panel from the unit or also from outside - for example on a PC or via tablet. A user-friendly dashboard clearly summarises all the information so that it can be presented in a maintenance meeting, for example, or is permanently available to the staff, even without them being directly in front of the system," explains Phillip Götz.[0]

Multiplexer for up to seven machines simultaneously
Two units are currently in use at Heron. Later, the solution is to be extended to eleven more machining centres. The experts around Manuel Gmeiner then want to additionally test the multiplexer, with which up to seven machines can be monitored simultaneously.

"The multiplexer ensures continuous monitoring and readjustment of the cooling lubricant concentration and is particularly suitable when, as with Heron, several individually filled, robot-controlled systems are in use," Philipp Götz specifies. And Markus Müller from ZG Fluidmanagement adds: "Our employees are specially trained for such installations so that we can offer the most comprehensive support and service possible. The system is extremely smart and will pay for itself quickly," is already the conclusion of Heron Managing Director Manuel Gmeiner. "Lubricant is now not only automatically refilled in the correct concentration, but in addition, further measured values are provided. This allows us to permanently monitor the concentration of our lubricant, which has significantly improved the reliability. Also, we no longer have to continuously check manually, so that our colleagues can concentrate on their actual activities."

After the ZG-Fluid-Check Pro proved itself in practice right from the start, an expansion for multi-machine supply is already planned for 2023: the ZG-Fluid-Check Neo can connect several machines at the same time via a ring line and ensure efficient fluid management.