To manufacture complex, rotationally symmetric precision components with deep holes and fine internal contours, machines must be equipped with a high-pressure coolant lubricant (KSS) supply – especially if they are to run unattended.
Medical technology manufacturer TROKAMED swears by the retrofittable devices of the LubiCool® series from KNOLL Maschinenbau, which contribute to maximum process reliability with high-pressure pump and band filter.
"We supply the medical technology sector 80 percent of the time," explains Mauriz Ostendorp, junior production manager at TROKAMED GmbH in Geisingen. "We primarily develop and produce endoscopic product solutions for the fields of laparoscopy, gynecology, and urology, which we market worldwide under our own name, as well as in the context of customer-specific developments. We see ourselves as a technology leader here."
TROKAMED has particular manufacturing strengths in pipe processing. This expertise is needed, for example, for the production of trocars and similar medical instruments used to create and maintain access to the body. For this, pipes in various shapes are required, sometimes with filling holes, etc.
But this know-how is also necessary for orders from precision engineering, which accounts for the remaining 20 percent of revenue.
"For high-precision components, such as custom thermometers and measuring probes, we must process thin-walled pipes with complex geometries with the highest precision," says Mauriz Ostendorp.
Whether medical or precision engineering products, all components critical for precision and durability are produced in-house by TROKAMED. For this purpose, 13 CNC-controlled manufacturing centers, five laser marking machines, assembly and cleaning systems, as well as a clean room are available on a production area of 3000 m2.
Yasin Kaya is responsible for the CNC area and pre-assembly: "On our modern long and short turning machines, milling-turning and turning-milling centers, as well as erosion machines, we can process components with diameters from 4 mm to 63 mm with high precision. This means we maintain form, position, and dimensional tolerances of up to 4 µm during machining and can even achieve high-gloss turning."
High-pressure supply is indispensable in many cases
The CNC department head places special importance on the high-pressure KSS supply: "This ensures optimal chip removal, especially with deep holes and fine machining. Tool wear and heat generation are reduced, which positively affects the dimensional accuracy, repeatability, and surface quality of our components. This allows us to consistently guarantee high quality even with demanding geometries and small tools."
As a partner for KSS management, TROKAMED primarily relies on KNOLL Maschinenbau, Bad Saulgau. "I have personally known KNOLL for a long time as the leading supplier of high-quality chip conveyors and coolant systems," says Yasin Kaya. "At TROKAMED, we have also had very good experiences with various KNOLL systems since 2007. Our philosophy includes sourcing locally whenever possible. Made in Germany can cost a bit more if the quality is right and we have a contact person who advises us well and provides quick service when needed. With KNOLL, this is 100 percent the case."
According to Yasin Kaya, this was an important reason why TROKAMED decided in 2020 to have two new short lathes from Miyano-Citizen each supplied with a LubiCool-L high-pressure system. TROKAMED also equipped the two long lathes SP-23 and SV-20R purchased in 2023 and 2024 from Star Micronics with LubiCool devices, but in size M.
Perfectly cleaned coolant
Matthias Wachter, the KNOLL sales representative responsible for TROKAMED, explains: "Since 2019, we have been offering the mobile high-pressure station LubiCool-M for use on chip-removing machine tools, especially for short and long lathes." Such a system first takes care of the cleaning of the KSS – whether oil or emulsion – through the efficient KNOLL KF band filter. With a filter fineness of up to 25 µm, it ensures the cleanliness required for high-pressure applications and prevents a concentration of fine particles in the medium circuit due to good filter quality.
Secondly, the LubiCool-M supplies the lathe with high pressure. "For this, we use a KNOLL KTS screw spindle pump that provides up to 150 bar pressure and a flow rate of up to 30 l/min," mentions Matthias Wachter. "We produce 12,000 units of the KTS pump per year. It has proven itself many times and ensures extremely high service life and process reliability."
The KNOLL LubiCool family also includes smaller devices of size S and the larger L variants, which are installed at TROKAMED on the Miyano short lathes. The latter are built according to the same scheme as the LubiCool-M but offer a larger tank capacity and a flow rate of up to 100 l/min when machining with oil.
A thoroughly clean solution
Mauriz Ostendorp, responsible for production, has been convinced by the LubiCool® devices used: "It's not just the fundamental advantages of high-pressure supply that we appreciate; the compact design is also important to us, as space in production is limited." He also positively mentions the appealing housing of the devices and their tightly closing lid, which only needs to be opened for service and maintenance purposes: "This ensures cleanliness in the hall."
Another strength the industrial engineer sees in the compact filter with filter fleece, which is suitable for all materials. "We process stainless steel, titanium, brass, aluminum, and plastics. Especially lightweight materials are problematic when using filter cartridges or bag filters, as these then need to be changed very frequently, often after just a few weeks. This is not the case with filter fleece."
Yasin Kaya agrees and reports from practice: "Our long lathe SP23 has been running around the clock for nine months. With brass and stainless steel parts. Only 25 m of the 80 m filter roll have been used. But even with the other LubiCool® devices, we may only need to change the fleece once a year, which only means about five minutes of machine downtime."
Worthwhile retrofitting
All KNOLL LubiCool devices are suitable not only for the initial equipment of machines but also for retrofitting. "We have an older turning-milling center from Nakamura, a Super NTJX, which was previously equipped with three different, unregulated high-pressure pumps and a flatbed filter," reports Yasin Kaya. "This system was no longer state-of-the-art, so we wanted to replace it with a LubiCool® system. Upon our inquiry to KNOLL, we were offered the opportunity to serve as a test customer for the new LubiCool-L."
Matthias Wachter explains the background: "Last year, we further functionally improved the LubiCool-L to better serve larger machines – such as a turning-milling center. This means it is equipped with a larger compact filter that provides more filter area. We also increased the tank capacity by 40 liters to now 430 liters. Additionally, there is the possibility to use a second high-pressure pump."
TROKAMED gladly opted for the test operation of the new LubiCool-L variant, as it fits the requirement profile optimally and integrates seamlessly into the existing processes, according to Yasin Kaya.
For the optional equipment, the responsible parties decided on an additional low-pressure pump for flushing alongside a high-pressure pump. "Furthermore, we have integrated cooling via a plate heat exchanger," mentions machining expert Kaya. "This is essential for us. Since our staff works in a single-shift operation and our machines run unmanned overnight, a stable temperature of the cooling lubricant is crucial for process safety and dimensional accuracy."
Mauriz Ostendorp points out another aspect: "The integrated solution with a plate heat exchanger not only ensures constant cooling but also additionally supports our combined heat and power plant by recoupling the waste heat – which is both ecologically and economically sensible."
Worthwhile retrofitting
The integration of the new LubiCool®-L into the Nakamura Super NTJX went smoothly, almost plug & play. "Our goal was to increase process safety, optimize tool life, and further improve the quality of the components," explains Yasin Kaya. "We have definitely achieved that. Additionally, we have saved a lot of space compared to the previous solution. Our oil is now much cleaner, and there is no oil sludge detectable in the tank."
Matthias Wachter adds: "We were able to demonstrate the improvement in our laboratory in Bad Saulgau. The residual dirt in the dirty tank decreased from 123 mg/l to 37 mg/l and in the clean tank from 46 mg/l to 23 mg/l."
As particularly advantageous, machining expert Kaya highlights the seven pressure levels freely selectable in the NC program:
"This allows us to select the optimal pressure from 10 to 80 bar for each machining operation and each tool, leading to improved cutting values and energy savings." A prerequisite for this is the optional frequency control of the pump offered by KNOLL. An investment that is definitely worth it, according to Yasin Kaya. He explicitly praises the overall package – the quality of the components used, user-friendliness, low maintenance effort, and the exemplary service offering. From the initial consultation to ongoing support, we feel excellently supported by KNOLL at all times."
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