Eckerle Industrie GmbH trialed a new vector kinematics method from Turbex partner MAFAC, designed to meet the high cleanliness requirements of the medical technology industry. Here’s how they got on…
For more than 50 years, Eckerle has been manufacturing system components that are used in a range of industries. For the medical technology company Maquet, the CNC specialist manufactures three assembly groups for the electrical operation of operating tables.
What is important for these high-quality components? Production Manager Reiner Schäfer explains: “Modern operating tables are high-performance medical devices that use many sophisticated technical features to ensure safe and easy patient positioning. To ensure that they can be used reliably for a long time, all components must meet the highest quality standards in terms of materials, technology and workmanship.
“For our assembly group it is important that the surfaces do not show any contamination from machining and leave the cleaning process absolutely dry. This enables us to guarantee not only corrosion-free storage and shipping, but also trouble-free further processing at our customer’s site.”
Up to now, the components have been washed in a simple cleaning system, then dried manually, stored, and cleaned and dried again shortly before shipping. “This procedure had since become uneconomical and would not have been able to meet the increasing demands of our customers for much longer,” adds Ferdinand Ernst, team leader at Eckerle.
How MAFAC’s multifaceted cleaning solution improved efficiency
Gunmetal components must pass through a multi-stage production chain – where they are deburred and polished after the turn-milling process – before they reach the final cleaning stage. This results in machining residues, such as cooling emulsion, polishing dust and chips, that must be carefully cleaned off since even the smallest contamination can prevent the smooth running of the engines installed in them. The boreholes and undercuts in the component parts, as well as the small particle sizes of the contaminants, pose a challenge for effective cleaning. Furthermore, gunmetal creates further requirements because it is a rather soft material and, due to its high copper content, tends to stain and develop verdigris.
Therefore, the cleaning process must be effective and gentle, and involve a drying system that releases components with stain- and moisture-free surfaces at reduced temperatures. For this reason, the Eckerle technicians decided to use the MAFAC JAVA spray-flood machine with two-tank technology. In combination with the technology options of vector kinematics and vacuum drying, it achieves high cleanliness values on the surfaces within a short time while being gentle on the material and reliable for all component regions.
Let’s look, in more detail, how MAFAC’s new technology was able to achieve optimum cleaning for Eckerle technicians.
Greater movement through vector kinematics
The new principle achieves a greater and more consistent impact on the component parts during cleaning and drying with strong turbulence. For this extra movement, the nozzle tube performs both a rotating and a rocking movement. The rocking movement is performed around its own axis by 35° to both sides. The basket receptacle system rotates synchronously at an optimally adjusted speed. This results in an optimally coordinated interplay of nozzle tube and basket movement, with both synchronous and counter-rotating operation being possible. As a result, workpieces are impacted more evenly and hard-to-reach regions such as blind holes are reached even better. Due to the higher mechanical part, vector kinematics leads to the desired cleaning result in a shorter time.
This improved flow effect, both during the cleaning and the drying phase, convinced Eckerle to invest in the new MAFAC vector kinematics: “With this method, we do not only gain effectiveness. In future, we will also be able to respond more flexibly to changes in the range of parts or to growing cleanliness requirements”, explains Reiner Schäfer.
Two-stage cleaning process with bypass filtration
Small batches of the parts, which measure approximately 500 (length) x 200 (width) x 200mm (height), are fed into the cleaning chamber as sensitive components, where they undergo an approximately 11-minute treatment process with a cleaning/rinsing/vacuum drying sequence. During the cleaning phase from tank one, to which 2.5 percent of a mild cleaning medium is added, a spraying and flooding process alternate.
Flooding is carried out cyclically. Two-thirds of the water from the cleaning chamber is drained and then re-flooded. This process is repeated several times. Parallel to this, the nozzle and basket receptacle system carry out a counter-rotating movement, using a 35° rocking movement of the basket to protect the parts. The temperature of the entire wet phase is 60° C.
Before the process switches to the rinsing phase, a so-called lifting process (which consists of blowing off the component parts) prevents the carry-over of particles. Afterwards, the parts are rinsed with demineralised water from tank two. This is particularly important because of the high copper content in gunmetal and the associated risk of oxidation. This means that the conductivity in the water must remain low, which is why the rinsing bath is also equipped with a rinse care module. This contains an activated carbon unit and two ion exchange units. In addition, it is permanently filtered with a resin cartridge in the bypass. “That such an additional component is recommendable and ultimately proves its worth was already apparent during the test cleanings in the MAFAC technical centre,” explains Ferdinand Ernst. The cleaning agent must be matched to the cooling lubricant so that the component parts leave the cleaning chamber without a grey haze. Kluthe’s mildly alkaline cleaning agent HAKAPUR 56-170, which, in combination with the water-miscible cooling emulsion of the HAKUFORM range, also from Kluthe, produces high cleanliness values and was therefore chosen to achieve this.
The drying phase is an important stage of the treatment to achieve surface quality. To make sure that the components leave the machine without residual moisture, the MAFAC JAVA is equipped with a warm air impulse blowing system and a vacuum drying system. Warm air at 40°C is supplied to the treatment chamber via the impulse blowing system. Based on the basket-nozzle rotation, the rotational movement and the impulse-like impact ensure an efficient heat and mass transfer, achieving homogeneous heat distribution. In addition, the water droplets are broken up into many small units by the compressed air pulses. The resulting increased surface area means that the water can dry faster.
With the subsequent vacuum drying process, which is particularly suitable for heat-sensitive materials such as gunmetal, the material to be dried is subjected to negative pressure. This leads to evaporation of the water at lower temperatures, as the boiling point of the water is reduced. Under this effect, the drying time is considerably reduced while the surfaces of the components are still absolutely dry and free of residues.
What’s next for Eckerle and MAFAC?
MAFAC JAVA has now been in use for more than five months, and the first positive effects in terms of economy and cleaning quality are being established. For Reiner Schäfer this is an important aspect in view of the increasing cost and time pressure in the future. “The demands of our customers in the medical sector are very high and will increase in the future. As the parts produced are always custom-made products with high quality standards, we want to raise our standards in special purpose machinery manufacture and set them up safely for the growing demands. The acquisition of the MAFAC JAVA with the new vector kinematics was a significant step in this direction and is expected to increase our USP value in the industry and create a competitive advantage.”
To discover the value MAFAC’s spray flooding cleaning can bring to your business, get in touch with Turbex today.