String-wound Filter Cartridges

1. String-wound Filter Cartridges Superiorfiltration technology 01/2005 Revision 1

2. Sedifilt string-wound filter cartridges:New developments in filter media • No media migration • Yarn consists of continuous filaments. • No short fibers to come loose and migrate. Sedifilt media

3. Sedifilt string-wound filter cartridges:New developments in filter media • No media migration • No chemical leaching • No chemicals to leach out with new melt spinning and yarn forming process (patented). • No downstream foaming in filtrate. • 100% pure polypropylene.

4. Coarse outer layer Medium middle layer Finer inner layer Illustration: Sedifilt graded density structure Sedifilt string-wound filter cartridges:New developments in filter media • No media migration • No chemical leaching • True graded density • New winding technology. • Continuously controlled pitch, number ofcrossings and space between each strandof yarn. • Denser winding in inner layers,coarser winding in outer layers. • Consistent winding tension.high structural integrity,more consistent performance.

5. Coarse outer layer Medium middle layer Finer inner layer Illustration: Sedifilt graded density structure Sedifilt string-wound filter cartridges:New developments in filter media • No media migration • No chemical leaching • True graded density • High dirt holding capacity • Longer life as particles are trappedthroughout the cross-section of the filter.

6. High bulk media Multi-lobal cross section Sedifilt string-wound filter cartridges:New developments in filter media • No media migration • No chemical leaching • True graded density • High dirt holding capacity • High bulk mediaBetter performance • Media with high bulk, stable, three-dimensional random structure with multi-lobal cross section filaments. • Captures more particles compared to conventional filters. • Improved solid to void ratio gives higher flow rates with low pressure drop.

7. Sedifilt string-wound filter cartridges:New developments in filter media • No media migration • No chemical leaching • True graded density • High dirt holding capacity • High bulk mediaBetter performance • 100% polypropylene • 100% pure homopolymer polypropylene. • Wide chemical compatibility. • Excellent micro-organism resistance. • Environmentally safe. • Ease of disposal. • Incinerates to trace ash.

8. Sedifilt string-wound filter cartridges:New developments in filter media • No media migration • No chemical leaching • True graded density • High dirt holding capacity • High bulk mediaBetter performance • 100% polypropylene • High structural stabilityNo particle unloading • Firm, stable structure. • No shifting of media. • Improved resistance to particle unloading. • More consistent performance. • Excellent knife-edge sealing.

9. Sedifilt string-wound filter cartridges:New developments in filter media • No media migration • No chemical leaching • True graded density • High dirt holding capacity • High bulk mediaBetter performance • 100% polypropylene • High structural stabilityNo particle unloading • Environmentally friendly • Environmentally friendly disposal. • Incinerates to trace ash. • No hazardous volatiles.

10. Test Method: Efficiency and Capacityper ASTM F795-88Instrumentation: LD 400 SN 95020054 Fluid: WaterFlow Rate: 3 gpm (US)Temperature: AmbientContaminant: ISO Fine Test DustShut Off delta P: 21 PSI Test Method: Water atambient temperature (25 °C.)Flow in US gallons per minute 5 micron, 10” polypropylene cartridge:Test results Test Method: Retention Efficiency andCapacity per ASTM F795Instrumentation: LD 400 SN 95020054 Fluid: WaterFlow Rate: 3 gpm (US)Temperature: AmbientContaminant: ISO Fine Test Dust Shut Off delta P: 21 PSI Test Method: Retention Efficiency andCapacity per ASTM F795Instrumentation: LD 400 SN 95020054 Fluid: WaterFlow Rate: 3 gpm (US)Temperature: AmbientContaminant: ISO Fine Test Dust

11. Sedifilt string-wound filter cartridges:Economic benefits of Sedifilt • Increased filtration capacity • Higher dirt holding capacity • Longer lifetime • Fewer change outs • Reduced costs • Less labour requirement • Less equipment downtime • Lower inventory levels

12. Sedifilt string-wound filter cartridges:Filter cartridge range: End adapters and extended cores

13. Sedifilt string-wound filter cartridges:Filter cartridge range

14. Sedifilt string-wound filter cartridges:Applications • RO Pretreatment (SDI Reduction) • Drinking Water and Beverage Processing • Sea Water Desalination • Deep Well Injection • Gas Purification • Cooling Tower Water Filtration • Electronics and Electroplating • Industrial Process Water • Pharmaceutical & Healthcare • Chemical Industry • ED Automotive Paint • Photographic Solutions • Wastewater Disposal • And more …

15. String-wound Filter Cartridges Comparison with conventional media

16. Conventional mediacross-section Conventional media cross-section • Round cross-section • Fewer micro-voids • Lower dirt holding capacity • Higher resistance to flow

17. Sedifilt mediacross-section Sedifilt media cross-section • Multi-lobal cross-section • More micro-voids • Higher dirt holding capacity • Lower resistance to flow

18. Conventional mediacross-section Sedifilt mediacross-section Comparison with conventional media:Conventional media vs. Sedifilt media • Sedifilt media has a higher void to solid ratio, giving higher flow rates, improved dirt holding capacity, and lower pressure drop.

19. Conventional string-wound filter cartridges:Problems with conventional media • Media migration • Short fibers are not properly or fully locked into the main body. • Fibers tend to come loose and migrate into filtrate with flow of liquid and pressure surges. • Loose fiber ends protruding from the surface can be seen clearly in friction-spun yarn media. Friction-spun yarn media

20. Conventional string-wound filter cartridges:Problems with conventional media • Media migration • Chemical leaching • Spin-finish chemicals (lubricants, surfactants, antioxidants, antistatic agents, emulsifiers, bactericides, etc.) leach out. • Evident as foaming in filtrate. • Washed media is never 100% ‘clean’. Friction-spun yarn media

21. Unstable structure of conventional cartridge of friction-spun yarn allows a paper clip to be pushed through the media. Conventional string-wound filter cartridges:Problems with conventional media • Media migration • Chemical leaching • Particle unloading • Round cross-section media have unstable structure. • Under conditions of flow and pressure surges, unstable round yarns shift, giving rise to ‘tunneling’ effect and particle unloading.

22. Conventional cartridge of friction-spun media Conventional string-wound filter cartridges:Problems with conventional media • Media migration • Chemical leaching • Particle unloading • Poor knife-edge sealing • Unstable edges cause seal by-pass problems.

23. Conventional melt-blown cartridges:Melt-blown media Only Advantage: • Freedom from process chemicals Disadvantages: • Tendency to collapse under moderate pressure differential • Requires supporting core • Very poor knife- edge sealing • Particle unloading Melt-blown filter cartridge

24. Resin-bonded filter cartridges:Resin-bonded media Disadvantages: • Higher cost • Limited chemical compatibility • Bonding agent compatibility problems • Poor density grading • Lower dirt holding capacity • Prone to media migration – media crumbles easily • Poor knife-edge sealing Resin-bonded filter cartridge

25. Pleated paper cartridges:Pleated paper media Pinched pleat Only Advantage: • Absolute ratings are possible Disadvantages: • Consists of more than one material • Weak strength of thin paper media • Pleat pinch-off and pleat collapse problems Collapsed pleat Pleated paper cartridge

26. Comparison of surface and depth filtration • Direct interception • Particles larger in size than the pores deposit on surface of media • Numerous tortuous flow passages • Direct interception and dirt retention within depth of media • Complex mixture of mechanisms

27. String-wound Filter Cartridges Increased filtration capacity Higher performance Reduced costs Longer lifetime Superiorfiltration technology