Filtech 15: Looking After the Small Steps

By Adrian Wilson, European Correspondent

March/April 2015 | Volume 34 No. 2

“50 Breakthroughs” is a two-year study, which has been carried out by the Institute for Globally Transformative Technologies at the Lawrence Berkeley National Lab in California, with input from a wide range of specialists and support from the Bill and Melinda Gates Foundation. The idea behind it, the authors note, is that one reason major technology breakthroughs are rare may be because “too much effort is focused on incremental technologies which – despite compelling narratives, significant funding and considerable media hype – fail to reach any reasonable scale or impact.”

Number One
By identifying the next 50 major developments that would be the most vital in improving the quality of life, it’s notable that right up there at Number One is a filtration challenge – to develop a new method for desalination that is scalable, low cost and employs renewable energy.

“Water scarcity is one of the most critical problems the world is facing today, and this problem is likely to get significantly worse in the coming years,” the authors noted. “An increasing amount of the world’s freshwater is becoming brackish, and more is being dissipated into oceans and other bodies of unusable water. Reclaiming this seawater and inland brackish water through desalination will need to be a significant part of the larger solution to meet the needs of the growing global population. Current forms of desalination, such as reverse osmosis, are prohibitively expensive and energy-intensive.”

Integrated science
The report was mentioned by Dr. Karsten Keller of DuPont in his keynote speech on the opening day of the Filtech Conference and Exhibition, which took place in Cologne, Germany, from February 24-26.

Keller firmly believes in an integrated science approach to solving some of the world’s biggest challenges, including, he explained, the need to be producing 70% more food by 2050 – even though agriculture is not growing – and also to generate 40% more energy by then, without increasing global warming.

“The filtration and separation industry is worth an annual $100 billion and there is nothing that can’t now be separated scientifically by one method or another,” Keller said, “which means a linear approach to research in the service of solving such major challenges is no longer enough.”

With 10,000 scientists and engineers worldwide, along with 26,000 existing patents and a further 21,000 pending, DuPont has very much embraced the concept of integrated science across the fields of biology, chemistry, engineering, materials, design and manufacturing.

“It’s a question of pulling all of the information together because Big Data is already out there,” Keller said, going on to cite a number of examples of how the approach has already been successful for DuPont in a number of areas, including the commercial development of nanofiber nonwovens.

Portable solution
Global breakthrough technologies could hardly be expected from the 330+ individual companies at Filtech 2015, working as they do on what are certainly much smaller-scale developments, but that shouldn’t be overlooked.

Bl├╝cher, based in Erkrath, Germany, for example, introduced the new Saratech Water Purifier 400 as a portable solution for ensuring clean water in disaster relief operations or in temporary camps away from a municipal drinking water supply.

In a multi-stage process, it can treat almost any natural, untreated water (with the exception of salt water), initially with an ultrafiltration stage, which reliably removes all types of microbial contamination. This is followed by the patented adsorption stage, which enables the elimination of organic pollutants and toxic heavy metals. Optional downstream disinfection stages via ultraviolet radiation and/or chlorination can reliably prevent recontamination. All in all, this is a low weight and low energy consumption system likely to prove highly useful out in the field.

Japan’s Toray, meanwhile, remains a leader in reverse osmosis (RO) technology for water treatment and introduced its latest low-pressure BWRO elements. These have been further refined, resulting in improved ion rejection and with better pH tolerance for cleaning and day-to-day operation. The polyamide composite membranes are also characterized by enhanced oxidant tolerance and high durability.

Nanofiber media
There is always a strong presence of filter media suppliers, primarily for air filtration, at Filtech, primarily for day-to-day business and small-scale projects, and the 2015 event was no exception.

PGI, for example, introduced its new nanofiber-based Everist media, which is said to outperform traditional mechanical media in key areas including:

  • Enhanced efficiency – a higher initial efficiency and the same mechanical efficiency as glass, while providing the same initial efficiency and a higher discharge efficiency than synthetic media.
  • Half the pressure drop of glass media and a similar performance to electrostatically-charged synthetics.
  • Doubles the dirt holding capacity of synthetic composites and a similar capacity to glass.
  • The media pleats on both rotary and blade pleaters and can be sonically welded.

The launch of Everist represents the culmination of recent investments in PGI’s Waynesboro, Virginia, manufacturing facility.

“For years PGI has served as a global leader in filtration, and the launch of Everist marks a critical step in our strategy for growth both in this market and in our overall business,” said Mike Disotelle, global vice president of technical specialties at PGI.

Tech reference
The Czech Republic’s Elmarco has been perhaps the leading developer of nanofiber technology over the past decade and in Cologne introduced its HVAC reference filter. This, explained Marketing Manager Martin Kopic, has been designed to demonstrate how nanofibers can be utilized within a composite structure to achieve optimum targets for pressure drop, efficiency and capacity in gradient air filtration. The reference filter was made with commercially available materials using commonly used manufacturing processes.

Filter media manufacturer Irema is also now making its own compact fully synthetic filter systems for industrial filtration applications. The EcoTitan 3V-Cell is based on a microfiber media with a progressive 3D design for optimum dust holding capacities, with integrated nanofiber layers. All of the fibers employed by the company, which is based in Postbauer-Pavelsbach, Germany, are produced in a solvent-free, melt-based and environmentally friendly proprietary process and contain no binder. The endless fibers are highly damage resistant and totally non-shedding.

The perfect V-shaped pleat geometry can be maintained throughout handling and usage with optimum airflow assured. They are encased in a stiff, polystyrene frame, which has been optimized using the latest airflow simulation package. Designed for pleat pack heights of 34mm, the frame keeps airflow channels open to their maximum extent.

The Super Absorbent Fibre (SAF) manufactured by the UK’s Technical Absorbents has a number of interesting applications in filtration and separation, due to its ability to absorb up to 200 times its own weight in water and 60 times its weight in saline. In nonwoven filter media fabrics it can consequently remove contaminants from aviation fuel, automotive diesel and a wide range of other oils to very low levels. This helps reduce fuel and oil degradation, provides the required filter quality for efficient machine operation and offers full compliance in meeting stringent international filtration standards. SAF media also deliver cost savings over traditional cellulosic-based absorption media.

Heimbach, based in D├╝ren, Germany, introduced its new blue.PRESS polypropylene fabric for automatic filter presses – an application in which increasingly stringent demands in terms of separation efficiency, directional stability and mechanical resistance are required.

blue.PRESS has a patented fabric design with a PTFE finish, which enables it to remove even very fine particles, such as precipitated calcium carbonate or nano-structured flame retardants.

A very precisely designed edge seal prevents damage to the fabric during operation and visual assessment of cleaning requirements is enhanced by integrated blue threads, which contrast against any solids remaining in the fabric’s surface.

Haver & Boecker promoted its Minimesh woven metal filter cloth, which is characterized by an optimized pore diameter with precision pore sizing. As a result, explained Julian Zurbr├╝gen, it allows very precise cut points to be obtained and unbeatable stability.

As a fifth-generation family-owned company, Haver & Boecker can draw on know-how in metal weaving built up since its foundation in 1887. As a consequence, the majority of its products remain customer-specific, while its in-house weaving technology remains proprietary. Expertise at the company, however, extends to the production of sections and round parts and deep drawn parts in which single or multi-layered mesh is manually or automatically formed into three-dimensional shapes.

Additive manufacturing
The possibilities in working with metal have recently been taken a stage further with additive manufacturing (AM) – more widely known as 3D printing – as demonstrated by Croft Filters, based in Warrington, U.K., at Filtech 15.

“Traditional metal filters are manufactured from perforated plate and one or more layers of woven wire mesh,” explained Croft Director Neil Burns in his presentation in Cologne. “The perforated plate forms the support portion of the filter and delivers the overall strength of the filter to withstand operational pressures. The woven wire mesh forms the filter portion with the aperture size chosen to suit the required level of filtration. An ideal filter would have the maximum open area possible to minimize its resistance when in situ in the conduit. However, maximizing the open area decreases the overall strength of the filter and so open area must be compromised to deliver the required strength.”

With additive manufacturing, however, it is now possible to design novel filter media that are depth filters with x, y and z planes with an integrated support portion and a filter portion.

The filter mesh has a defined aperture size and by reducing the equivalent wire diameter, the media has a greater open area compared to the equivalent woven wire mesh. This potentially reduces the pressure drop across the filter and so reduces pumping energy requirements.

In preliminary studies carried out by Croft with Lancaster University, AM filter media have been designed using a repeating node unit to form the latticework.

“The aim is to develop the integrated support and filter design to incorporate different sizes of repeating nodes, with a larger node providing strength and the smaller node providing the filtration level,” said Burns. “It’s already been possible to develop two node structures to deliver two latticeworks, one with a 1,000 micrometer aperture and the other with 500 micrometer aperture. Filter disks comprising one, two and three layers of the individual nodes have been tested for strength by collapse pressure. Conical filters have now been designed and tested for each individual node and for combinations of the nodes. We think this is a technology development with considerable potential moving forward.”

The core business of Bl├╝cher is the development and production of high efficiency filter technologies based on spherical, high performance adsorbents similar to activated carbon, but superior in their performance.

  • PGI – The PGI Team at Filtech 15. From left to right: Sales Manager Chantal Claise, Sales Director Sean Kearsley and Catherine Fyfe, marketing communications.filtration-news-pgi
  • Elmarco – Elmarco Marketing Manager Martin Kopic and the company’s HVAC reference filter.filtration-news-el-marco


  • Irema – Anja Michen and Jessica Hiller at the Irema stand.filtration-news-irema
  • Minimesh – Julian Zurbruggen of Haver and Boeckerfiltration-news-minimesh
  • Heimbach – The Heimbach Team in Cologne: Oliver Kunze, Ingrid Dinges and Bernd Silkens at the company stand.