Hydraulics & Pneumatics November/December 2023

www.hpmag.co.uk HYDRAULICS & PNEUMATICS November/December 2023 21 tensile strength and resilience. The precise control and etching of metal filters enable manufacturers to create filters with consistent and uniform pore sizes, ensuring that the filter material can withstand substantial pressures without compromising its structural integrity. This advantage is particularly critical in applications like the automotive sector, heavy equipment, and aerospace hydraulic systems, where filters may be exposed to extreme operating conditions and substantial fluid pressures. Thin metal filters not only offer longevity and reliability but also provide a lightweight solution, minimising overall weight in aerospace applications and improving fuel efficiency in automotive systems. Their ability to endure high pressures while maintaining filtration efficiency makes them indispensable in these industries, where safety and performance are paramount. Martinson says that the ability of micrometal’s PCE process to make filters with higher transmission rates (up to 90%) than can be achieved with woven mesh and even conventional PCE processes is advantageous because they allow for increased fluid or gas flow while maintaining effective filtration. This enhanced transmission can boost process efficiency and reduce pressure drops, ultimately leading to energy savings and improved system performance. It can also increase the filter life between changes or backflushing with obvious cost-saving results and reduced downtime. Additionally, the ability to vary hole patterns, including angled or conical through-holes, in a single filter design offers adaptability for diverse industrial needs. This versatility allows manufacturers to tailor filters to specific applications, optimising filtration performance while minimising production costs and inventory management complexities. PCE is also a highly repeatable and cost-effective process, explains Martinson. Once the photo tool is created, it can be used repeatedly to produce identical filters with consistent quality, reducing production variability. Additionally, this method is well-suited for high-volume production, making it cost-effective for industrial applications. The elimination of the need for intricate tooling or costly molds, as seen in other manufacturing processes, further enhances its cost efficiency. Martinson says that PCE also offers versatility in terms of material selection, highlighting that it can be applied to a wide range of materials, including metals like stainless steel, copper, and aluminium. This versatility allows manufacturers to select materials that suit the specific requirements of their industrial applications, whether it’s for chemical resistance, temperature tolerance, or other factors. Overall, the process proves to be a superior choice for producing high-transmission industrial filters due to its precision, repeatability, cost-effectiveness, and material flexibility, making it an ideal process for meeting the stringent demands of modern industrial high transmission filtration. Martinson emphasises his belief that micrometal’s PCE process is very different from conventional PCE processes. He explains that the company uniquely uses a special liquid resist system to obtain ultra-thin (2-8 micron) photoresist layers enabling a higher degree of precision in the chemical etching process. It allows the achievement of extremely small feature sizes of 25 microns, a minimum hole diameter 80% of the material thickness, and single digit micron tolerances repeatably. Traditional PCE uses relatively thick dry film resist which compromises ultimate part precision and the tolerances that are available, and it is only able to achieve 100-micron feature sizes and a minimum hole diameter of 100-200% material thickness. Martinson says the micrometal PCE process enables ultraprecise contours to take shape, and as such the company can produce metal parts with unique features and a level of complexity that cannot be matched. In addition, he says that whereas most PCE service suppliers use digital photo tooling created on films, micrometal uses photo tooling created on glass, which can achieve tolerances in the range of 1-2 microns, and negates issues with distortion due to environmental factors such as humidity that are a constant problem when using film tooling. Therefore, according to Martinson, micrometal’s PCE process allows the manufacture of thinner lightweight filters, and filters that promote higher transmission than traditionally made filters. The process also allows variable hole geometries with angled or conical through-holes which can be varied in a single pattern. Conclusion Traditional methods of manufacturing high-transmission filters, says micrometal, have their limitations, such as restricted precision, limited hole geometries, and material wastage. In contrast, the company believes that photochemical etching process emerges as the method of choice for creating these filters, offering superior advantages. Martinson concludes that micrometal’s next generation PCE enables the production of highly precise, lightweight filters with intricate hole patterns, capable of withstanding high pressures. This versatility and precision make photochemical etching particularly well-suited for industries like automotive, aerospace, and heavy equipment, where efficient filtration and space-saving designs are critical. Therefore, according to Martinson the use of photochemical etching for high-transmission filter production strongly stands as a reliable solution for modern industrial filtration needs. For further information please visit: www.micrometal.de