Dexwet Filters introduces breakthrough filtration technology to aluminum die-casting industry boosting efficiency and sustainability
By: Clemens Sparowitz, President and Chief Operating Officer, Dexwet Filters
The die casting industry has long grappled with the inefficiencies caused by outdated steel wool pad filters in vacuum systems. These filters compromise the process’s security and stability, leading to excessive machine downtime and high cold and warm scrap ratios. Dexwet Filters, a pioneer in filtration technology, has developed a game-changing solution called Dexwet SUPER-APF (aluminum particle filters) that addresses these challenges. Leading companies in Europe and the USA are rapidly adopting this innovative technology, recognizing its potential to optimize profits and set new industry standards.
The Problem with Traditional Steel Wool Pad Filters
Over the past two decades, vacuum support systems have become critical in producing complex aluminum structural parts for the automotive industry. As these components, including power drain components, chassis parts, and battery housings, become more intricate, the need for effective evacuation of the tool form becomes increasingly vital. Dexwet Filters was first approached by a German foundry in 2017 to find a solution to the filter problem caused by outdated steel wool pad filters in vacuum suction lines.
Inefficiencies and Costs of Traditional Vacuum Filters
Traditional vacuum filters require replacement once per shift, causing an average machine downtime of up to 30 min. With 20 shifts per week, this amounted to a staggering 10 hours of lost production time per week. Furthermore, resuming the machine operation after such downtime requires three warming shots, leading to 60 “warm scrap” parts that had to be remelted, wasting time and energy. The analysis also indicated that quality-deficient parts increased in the second half of the shift, pointing to vacuum filter malfunction as the primary culprit.
The Dexwet SUPER-APF Solution: Revolutionizing the Die Casting Industry
After three R&D stages, Dexwet Filters developed the groundbreaking SUPER-APF solution, which was awarded the Original Equipment Manufacturer (OEM) Part status for the technology’s leading vacuum system supplier, Pfeiffer Vacuum. Comprising nine sophisticated and patented layers, the Dexwet SUPER-APF vacuum filters are permanent filters with a stable filter inlet. The first two versions enabled 2-3 days of continuous operation without machine downtime, whereas the third and current versions nearly doubled this effectiveness. Dexwet SUPER-APF filters typically require exchange only once per week, with a maximum of one additional filter exchange per week. Preventive filter exchanges are now dictated by the vacuum system itself, considering the specific conditions and emission behavior of each die-casting unit. This revolutionary filtration solution promises to reshape the die casting industry and help companies maintain a competitive edge.
Addressing Quality Fluctuations and Enhancing Output
Traditional steel wool pad filters have long caused fluctuations in the quality of the output part owing to extreme conditions within the vacuum suction line. When the vacuum valve is opened, the particle speed at the bottleneck reaches a staggering 671 mph. Air and gases must pass through the filter, while oily and hot liquid aluminum particles are captured to protect the vacuum valve, which is the most critical component of any vacuum system. The resulting changes in the fiber orientation and throughput behavior lead to inconsistent vacuum system effectiveness and quality discrepancies. Dexwet Filters’ groundbreaking SUPER-APF solution addresses these issues, promising a return on investment in less than a year and transforming the die-casting industry for improved sustainability as well as profitability.
Efficient Filter Exchange and Cleaning Process
The Dexwet SUPER-APF system is a one-time investment that significantly reduces waste and downtime while providing valuable insights from the analysis of filtered material or filter cake. Users can easily exchange Dexwet filter cartridges at a central cleaning station by rotating the cartridges between the three foundry locations. A set of replacement filters is provided in a transport box directly at the die casting unit, enabling swift filter exchanges with just 5-15 minutes of machine downtime, eliminating the need for warming shots, and allowing immediate resumption of high-quality part production.
The filter-cleaning station is central to maximizing the benefits of this innovative technology. Workers analyze the filter cake, a compound of aluminum particles and various oily or waxy substances, to identify any abnormalities in its composition. Early flaw detection in the tool enables adjustments to system parameters and dosing, providing valuable feedback to the machinist and improving the overall process stability and security. The true costs of outdated steel wool pad filters have been overlooked because the direct costs of these inexpensive filters were not recognized within the foundry’s overall cost structure. Pioneering companies such as Georg Fischer (GF+) adopted Dexwet technology early on and have since implemented filters in all their foundries worldwide. Dexwet Filters recently entered the US market, offering its full product suite to various industries and applications, including the aluminum die-casting industry.
Dexwet Filters partners with Pfeiffer Vacuum, a global leader in vacuum system technology. Their patented two-tank vacuum system is the only one that allows for precise pressure measurement within the form throughout the entire microsecond injection cycle. The Pfeiffer Vacuum system ensures uninterrupted vacuum capacity during the shot curve, providing accurate measurements of the advantages of using Dexwet SUPER-APF technology compared to old-tech filters. Pfeiffer Vacuum has been offering Dexwet SUPER-APF technology in conjunction with their cutting-edge systems since 2018, cementing a powerful partnership that promises to revolutionize the die-casting industry.