Euler Feinmechanik GmbH produces top quality aluminium products for their customers, who are mostly in the optical industry. One of RUF’s briquetting systems is adding to the contract manufacturer’s cost effectiveness in chip processing. The system, which works automatically, transforms bulky and wet aluminium chips into compact and practically dry briquettes, which can be sold as valuable secondary raw material.
Even the Corona crisis was only able to slightly impact the growth of Euler Feinmechanik GmbH, which is situated at the gates of Wetzlar, the City of Optics. In 2020, the contract manufacturer managed to keep turnover constant despite the restrictions and even invested around 1.5 million euros in new technology. In 2021, they have targeted a further increase in turnover of between 5 and 10 percent, to between 9 and 9.5 million euros. And after the first three and a half months of this year, they report that new machines had already been procured for the plant in Schöffengrund for a further 1.5 million euros.
Their success is no accident. The managing directors Hans and Leonard Euler, son and grandson of the company founder, consistently focus on quality and reliability, orientation to customer needs, and on cost-effectiveness in their contract manufacturing. "When it is important to increase efficiency through automation and digitalization, however, we should not only look at the core processes of turning and milling," states Leonard Euler. "The periphery is also of major importance, for example the chip handling with our briquetting plant from RUF", emphasizes the 36-year-old graduate industrial engineer. It is a simple calculation. The less time consumed by a machine operator for chip handling, the more time specialists can dedicate to productive activities and keeping the roughly 45 turning and milling centres running, around the clock. The company processes about 38 tons of aluminium per month, resulting in around 25 tons of aluminium chips, on these machines.
Leonard Euler, grandson of the company founder and managing director
"THE PERIPHERY IS ALSO OF MAJOR IMPORTANCE, FOR EXAMPLE THE CHIP HANDLING WITH OUR BRIQUETTING PLANT FROM RUF."
Dealing with chips takes a lot of time and resources. They have an extremely high bulk volume, so they take up a lot of space. Bringing these quantities to collection containers and filling them manually takes a lot of time. When contaminated with cooling lubricants, they often pollute the production areas during transport and storage. In addition, only limited revenues can be achieved with wet chips, because the logistics are complex and the chip preparation before melting causes additional costs, among other things for the separation of the cooling lubricants, which then have to be disposed of.
But Euler have chosen another path, because pressing into easy-to-handle briquettes solves all of these problems. Depending on the type of chip, the volume can be reduced to between a third and one tenth of the original. The cooling lubricants are almost completely pressed out during the process. Storage and transport of the briquettes is simple and clean; in addition, they have a permanently low and defined residual moisture, meaning discussions on moisture discount when selling scrap are avoided. As a rule, this means a medium to high double-digit figure of additional sales revenue is possible, and in many cases a three-digit amount is realizable. These are all comparisons to selling loose chips. And keep in mind that the recovered cooling lubricants are reusable in many cases. This results, in general, in amortization periods of 1.5 to 3.5 years.
When Euler purchased a 11/4000/70 RUF press in 2019, it was clear that an increase in efficiency was the priority. Complemented by an upstream lifting-tipping device, shredder and chip conveyor as well as a downstream filter system for the cooling lubricants, the system is designed for unmanned 24/7 operation.
The roller-mounted chip collection containers at each milling and turning center are pushed by a machine operator to the chip preparation plant when they are full. There is already an empty container waiting, which he takes from the lifting device and then pushes the full container into it (the lifting device). Pushing a button is all it takes to start the process, and he can immediately return to his workstation with the empty 400-litre container, without having to worry about the briquetting process. Because the container is automatically lifted three meters into the air and emptied into the shredder. This shreds flow chips and chip accumulations as well as ejecting any foreign objects via a coarse parts discharge. Slat band chains are used to convey the shredded chips to the press hopper, which is equipped with a level sensor. The system starts automatically when the hopper is full and stops when the chips are briquetted.
The RUF 11/4000/70 compresses the chips with its 11-kW motor and boasts a pressing power of up to 4000 kg/cm2. It produces round briquettes with a diameter of 70 mm and a length of also about 70 mm. The density of the briquettes is a good 2.3 kg/l and is therefore not far from the raw density of solid aluminium at 2.7 kg/l. At the same time, the clinging cooling lubricant is practically completely pressed out and collected separately. The finished aluminium briquettes fall into a collection container which can hold about one cubic meter.
Leonard Euler is totally satisfied with the success. He stresses: "The chip press has made a major contribution to the automation of our processes and the increase of efficiency. In evaluating the investment, the benefits were so clear that we did not have to carry out any complex analyses or elaborate amortization calculations down to the last detail." After the system went into operation, it was actually found that the manual effort saved by automation was roughly equivalent to three-quarters of a staff position, and that can now be used for productive activities. This effect alone was a contribution to the quick amortization period. And keep in mind, this benefit is seen although Euler had previously briquetted chips, but with a less automated system.
Further to the efficiency gains, the contract manufacturer has also been able to increase revenues from briquettes as opposed to loose chips. In addition, the reuse of the cooling lubricants results in considerable savings, as Ralf Lorbach, technical consultant at RUF calculates: "At an annual consumption of 40,000 liters of cooling lubricants, which are produced from 3,200 liters of concentrate, the potential savings lie between 12,000 and 15,000 euros per year." Euler is also equipped already for further growth with this briquetting system. To date, it is processing an average of 40 kg of chips per hour; up to 120 kg per hour is possible.
The management were also pleasantly surprised by the smooth commissioning of the complete system. The fact is, it consists of machines and components from several manufacturers: the press from RUF, the lifting/tipping device and the crusher from Erdwich as well as the filter system from Polo. "We practically didn't notice that we were dealing with different suppliers," is the praise from Leonard Euler for the good coordination and cooperation between the companies. "From day one, the cooperation with Mr. Lorbach worked very well; he coordinated everything and we did not have to worry about the coordination between the companies involved," the CEO emphasizes. Ralf Lorbach goes on: "We coordinate with each other, make proposals to the customer, for example, for the networking of the control system, and finally, fitters from the participating companies construct the system together at the customer's premises."
As Leonard Euler reports, this brings clear benefits to the users: "The entire system is linked to each other free of potential, i.e., when, for example, the coolant container of the filter system is full, a sensor on the coolant container reports this. This signal stops the filter system and passes the information on to the press, the shredder and the lifting device, so that the entire system stops and switches to a standby mode. Once the coolant container has been emptied, a push of a button is enough to restart the entire process. This gives us a coherent network."
The RUF press itself is just as reliable as the network. "Very low maintenance requirements, no unplanned downtime; we are absolutely satisfied with the machine," concludes Leonard Euler.