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Superiorfiltration technology

String-wound Filter Cartridges

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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

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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.

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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 of

crossings 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.

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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.

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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 media

Better 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.

Multi-lobal cross section

High bulk media

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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 media

Better performance• 100% polypropylene

– 100% pure homopolymer polypropylene.– Wide chemical compatibility.– Excellent micro-organism resistance.– Environmentally safe.– Ease of disposal.– Incinerates to trace ash.

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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 media

Better performance• 100% polypropylene• High structural stability

No particle unloading– Firm, stable structure.– No shifting of media.– Improved resistance to particle unloading.– More consistent performance.– Excellent knife-edge sealing.

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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 media

Better performance• 100% polypropylene• High structural stability

No particle unloading• Environmentally friendly

– Environmentally friendly disposal.– Incinerates to trace ash.– No hazardous volatiles.

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5 micron, 10” polypropylene cartridge:Test results

Test Method: Water atambient temperature (25 °C.)Flow in US gallons per minute

Test Method: Efficiency and Capacityper ASTM F795-88Instrumentation: LD 400 SN 95020054Fluid: WaterFlow Rate: 3 gpm (US)Temperature: AmbientContaminant: ISO Fine Test DustShut Off delta P: 21 PSI

Test Method: Retention Efficiency andCapacity per ASTM F795Instrumentation: LD 400 SN 95020054Fluid: WaterFlow Rate: 3 gpm (US)Temperature: AmbientContaminant: ISO Fine Test Dust

Test Method: Retention Efficiency andCapacity per ASTM F795Instrumentation: LD 400 SN 95020054Fluid: WaterFlow Rate: 3 gpm (US)Temperature: AmbientContaminant: ISO Fine Test DustShut Off delta P: 21 PSI

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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

5 micron 10" Dirt holding capacity

Ordinary string-wound 30-55 gm

Sedifilt string-wound 108 gm

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

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Sedifilt string-wound filter cartridges:Filter cartridge range

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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 …

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Comparison with conventional media

String-wound Filter Cartridges

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Conventional media cross-section

• Round cross-section• Fewer micro-voids• Lower dirt holding capacity• Higher resistance to flow

Conventional mediacross-section

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Sedifilt mediacross-section

Sedifilt media cross-section

• Multi-lobal cross-section• More micro-voids• Higher dirt holding capacity• Lower resistance to flow

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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.

Sedifilt mediacross-section

Conventional mediacross-section

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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

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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

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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.

Unstable structure of conventional cartridge of friction-spun yarn allows a paper clip to be pushed through the media.

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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.

Conventional cartridge of friction-spun media

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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

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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

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Pleated paper cartridges:Pleated paper media

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

Pleated paper cartridge

Pinched pleat

Collapsed pleat

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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

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Reduced costsIncreased

filtration capacityHigher performance

Superiorfiltration technology

Longer lifetimeString-wound Filter Cartridges