PATT-FiltrationInfopack2004

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Dear Processor,

We would like to take this opportunity to thank you for your interest in our product.

We here at PATT Filtration have made it our goal to deliver a superior quality product to meet all your polymerfiltration needs.

Through the years, our ongoing efforts toward perfection have brought about many changes, some subtle other stillmore drastic, to both our product line as well as our corporation.

From our proprietary thin film coating to our dedication to achieve ISO 9001 Standards by September 2004 PATTFiltration places emphasis on ensuring customer satisfaction and product quality.

Our experts in the fields of plastics, polymer filtration, metallurgy and engineering have made our ROTARY IIITM

Constant Pressure Drop Continuous filtration system the preferred choice among industry leaders and have madePATT Filtration a worldwide leader for customer satisfaction.

We invite you to learn more about our product line and the solutions we can offer you by reading this publication.

Please do not hesitate to contact us and it would be our pleasure to assist you in any way.

Regards,

__________________________

Hubert Patrovsky

President, PATT Technologies Inc.

PATT Filtration is a division of PATT Technologies Inc.

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PATT Filtration collaborates with metal treatment specialists atPATT Ionics and RUBIG-PATT Technologies to constantly furtherthe development of wear-resistant filter components as well aswith PATT Europe to market PATT technology in Europe.

From the outset, the company’s main objective to provide superiorquality products has been realized by applying advancedmanufacturing technology. A large part of the earnings isreinvested in R&D and latest technology machinery. We pioneered new materials and coating technologies toachieve a filtration system that simply is unmatched. Integrated microprocessor controls provide reliable operation,simplified maintenance, and computer interface.

We basically reinvented everything except the wheel.

Only by timely adaptation to economic and technological changes could we start to become the leader in the fieldof polymer filtration. Our integration of engineering skills and advanced technology puts us on the leading edge offiltration development.

While PATT Filtration prides itself on its range of screenchangers handling the broadest range of polymers, filtrationproblems often demand something more than our standard product line. Our custom engineering services offer farmore than the "Off the Shelf" screenchanger. Our flexibility as a small company enables quick response to customerproblems and service requirements.

PATT Filtration is the solution to your filtration problem.

About PATT Filtration

PATT Filtration was established in 1986 in St-Eustache, Canada. Since then, we have grownto be a major competitor in the filtration systems industry. PATT Filtration is now a division ofPATT Technologies.

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Modern polymer filtration usually calls for removing particles orcontaminants in a controllable, definable and safe manner. Theexpense of the filtration system which solves the separation problemwithout changing operational conditions, has to be weighed againstimproved productivity and lower operating costs. A generalunderstanding of the basic principles and technical terminology cangreatly simplify the process of system selection. This Technical Briefoffers an overview of the main elements of ROTARY IIITM ConstantPressure Drop Continuous filtration system.

The ROTARY IIIT M Constant Pressure Drop Continuousscreenchanger series uses a rheologically correct flow channel designand microprocessor controls to stabilize process conditions andmaintain constant pressure to improve overall production conditions.

The melt flows through a revolving disk with a fixed number of eitherintegral fixed or removable breaker plates with screen cavities,arranged in a circular shape and separated by curved ribs. Even ifthose narrow webs pass through the flow channel their kidney shapeand the optimized melt channel will insure maximized available screenarea and undisturbed melt flow.

The vent and vacuum port will automatically purge air from theoncoming screen cavity to avoid air being passed into the melt flow.The pressure relief port will automatically purge material from theexiting screen cavity to ensure operator safety. The filter disc isenclosed between two body blocks and advanced in ultra-fine angularsteps by the microprocessor control, allowing continuous rotation evenat lowest speed, while maintaining a constant pressure drop.

In general terms, the filtration process consists of passing the moltenpolymer and contamination through a porous screen pack that entrapsthe solids in its matrix or retains them on its surface. Anything largerthan the opening size cannot pass through, and will clog the screenand increase the pressure drop across the screen if no clean filtermedia is introduced.

The Practical Art of Melt Filtration

Principle

How It Works

Screen capture from the PCS-1controller Datalogger softwareshowing the constant pressuredrop our screenchangers are

known for.

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"Throughput" is the time based volume of polymer that can be filteredbefore the screens need to be changed, causing productioninterruptions. Fine screens with high retention efficiencies tend to plugfaster and need to be changed more frequently.

"Throughput", with a ROTARY IIITM means the volume of material thatcan be filtered without any interruption to production. Themicroprocessor control will always keep the same amount of openscreen area in the flow path while maintaining a constant differentialpressure, essentially offering an unlimited screen area.

Applied in an in-house Pulse Plasma process chemical inert ultra-thinnon porous layers backed by hardened and nitrided substrate providethe ultimate in corrosion and wear resistance.

The design of an optimum melt filtration system is a complexissue.

The following variables must be taken into account:

� Material to be filtered.

� Corrosive or non-corrosive application.

� Size and nature of particles to be removed.

� Amount of contamination.

� Temperature.

� Viscosity.

� Size of mesh required to achieve the separation.

� Desired throughput.

� Maximum allowable line pressure and pressure drop.

Discontinuous Filtration

Continuous Filtration

Thin Film Nano Coating

PATT Filtration units are at the forefront ofuninterrupted filtration systems.

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Our technical service department has the experience to developa system that best meets your needs for reliable performance aswell as operating economy.

We will agree to do only that which can be accomplished whilemaintaining our standard of excellence. We want to be known as thebest in what we do, and we set our standards to accomplish thatpurpose.

At PATT Filtration we take existing technologies and our proven designsand engineer them into solutions specifically for your requirements.

Whatever you need - filtration systems for fibers, film and sheet, profileand tubing, or systems to withstand the rigors of unknown materialsand contamination in recycling - our Application Specialists will workdirectly with you to devise the best solution.

Our engineers will adapt the selected system to the extruder and die inthe most suitable way. The capability to manufacture all parts in-houseinsures quality and on-time delivery.

Our clients’ success is the best measure of the value of theservices we render.

than anybody else that improved quality and increased quantity are themain profit factors for your business. Your engineered filtration solutionfrom PATT Filtration will improve product quality and eliminatedowntime.

PATT Filtration Business Philosophy

Custom Engineering

You know better

PATT Filtration shares itsSt-Eustache building with PATT

Technologies, its mothercompany.

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About Polymer Filtration

PATT Filtration is a leader in polymer filtration equipment. As such, we have an excellentknowledge of our clients’ processes.

The goals of polymer filtration are to maintain the highest possible line productivity while removing particulatecontaminants and causing little or no changes to the polymer's characteristics. We define polymer filtration as theremoval of unwanted solid contaminants, above a specified diameter or width, from the flow of melted polymer. Inthis discussion we will not address the separation of liquids or gels to any great extent.

There are many techniques that can be used in polymer filtration. Unfortunately some techniques would haveserious deleterious effects on the polymer. It is simply not worth a lengthy discussion about how to filter contaminantsand cause material degradation.

However, the following technologies are worthy of note:

� Cartridge filters

� Belt filters

� Candle filters

� Bag filters

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The basic idea of polymer filtration is to force polymer to flow throughsome media whose porosity is such that particulate larger than the poresize will be retained while the polymer and contaminants smaller thenpore size will pass through freely.

We'll call this particulate retention.

Each of the devices mentioned above are capable of filtering polymersand each performs its job by particulate retention. Because thisdiscussion is limited to only the most practical solutions, only the mostpopular, the screen filtering technique used in the plastics industry willbe discussed.

Within the plastics industry, screen filters are the most commonand perhaps the best-suited type media to be used in thedecontamination process.

Screen filters are woven from strands of wire. The wire can be copper,brass, steel or, the most popular wire, stainless steel. Stainless steel ispreferred in the plastics industry because of its strength, durability andresistance to corrosion.

Manufacturing the screen filter is a technology in itself. The processinvolves weaving horizontal wires (weft wires) through alternate verticalwires (warp wires) in exactly the same way as cloth is manufactured.Looms are used in exactly the same way to weave the metal strands intoa cloth made of wire.

Clockwise from top left: cartridge,belt, candle and bag filters.

Screen Filters


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The significant difference between woven cloth and wire cloth isthat the parallel wires are precisely spaced with some distancebetween them.

This opening (pore) corresponds to the minimum particle retention ofthe screen filter. The opening, in inches, plus the diameter of the wire,in inches, divided into one inch yields the mesh of the screen filter.Although rectangular mesh is the most common geometry, the meshcan be different in horizontal and vertical directions.

Still other variations of weaving are available for added strength of flowpurposes. Warp wires can differ from weft wires in diameter. The weavecan change to have parallel pairs of wires touching each other.

These patterns are available in a seemingly endless variety ofcombinations with each pattern having some uniquecharacteristic to contribute to the filtration processes efficiency.However, as the complexity of weave increases, so does the cost.

A single layer screen filter placed in the melt flow is sufficient to trapcontaminants on its surface. The screen filter is placed between theextruder and the die, typically on the upstream side of the breakerplate. The plastic, under pressure, is forced through the screen filterand contaminants too large to pass through the openings of the screenfilter get trapped.

Metal wire mesh.


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As the contaminants build up, less surface area is available, the screenfilter becomes blocked and a number of problems occur.

� The melt flow is restricted.

� Pressure rises between the extruder and the screen filter.

� Shear increases.

� Temperature increases

When any one or a combination of these problems reach a limit oftoleration, the line is shut down and the breaker plate along with thescreen filter is removed. A fresh screen filter is then replaced along withthe breaker plate and the line is eventually restarted. This exercise is theoldest and most frequently used method of polymer filtration and filtermedia renewal in the industry.

It is also the most costly and least efficient in terms of production.

In the example above, a single layer screen filter was discussed. Whenparticulate blocks an opening, polymer stops flowing. The blockedpart of the screen is lost for filtration and the overall polymer flow isrestricted. Particles blocking more than one aperture lead to evenfaster blocking of the screen filter. To lengthen the interval betweenscreen filter changes additional screens with a mesh larger than thesingle layer filter are added to the upstream side of the assembly.

Various screen meshes.


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Another consideration to enhance efficiency is to add a layer or layersof screen downstream of the final filter layer. This addition allowsfiltered polymer to drain away from the final layer and find its waythrough the holes in the breaker plate and continue on its journey. Ifthe wires in the mesh were to contact the lands in the breaker plate,then flow paths would be severely restricted.

The more thought and technology that goes into the selection,composition and construction of a screen pack, the better andmore efficient the filtration process.

Regardless of the method chosen to replace or renew the screen pack,it, the screen pack, is the very heart of the polymer filtration process.When the screen pack is properly designed and installed, it willprobably do an excellent job of removing particulate.

Filters are supposed to get clogged. It's their job.

Unfortunately, this is where the real problems begin. Alreadymentioned above are some of the problems associated with blockingand clogging filters. If the problems cause the process to go out ofcontrol then the solution is to renew the screen pack, or filtrationmedia, before control is lost. Some schools of thought believe thatincreasing the area of filtration is the answer.

The thought that increased area will decrease the renewalfrequency sounded logical.

Clogged screen filter.


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However, increasing filtration area means changing polymer flowcharacteristics within the flow channel and, in some heat sensitivepolymers, causing degradation.

Degradation could generate carbon specks whose diameter is lessthan the screen pack's final filtration layer and the result could be amore highly contaminated product, albeit with smaller particulate.

Experience taught processors when to change the screen packs toavoid problems with melt flow restrictions and polymer degradation.Head pressure, Delta P, time or physical observations could be used ascriteria to renew or replace screen packs.

Each time the screen pack is replaced, the line shuts down. Forthose processors operating intermittently, one or two shifts per day ofthree or four days per week, this was not a significant problem. Forthose processors operating continuously, 24 hours per day 7 days aweek, week in and week out, changing screen packs createsproduction shutdowns.

Those shutdowns mean lost money.

Mounting the screen pack outside the extruder but still between thescrew and the die managed to reduce the time lost in renewing thescreen pack but the basic problems of flow restriction increased shear,

Four-layered screen pack.


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temperature rises and polymer degradation persisted. The line neededto be stopped or at least slowed considerably to renew a cloggedscreen pack.

One solution to reducing down time was to machine multiple breakerplates into an assembly mounted outside the extruder and precede thebreaker plates with a screen pack.

This solution was a logical one in terms of reducing downtime. The linepressure could be reduced and the assembly shifted so that the cloggedscreen pack could be shifted out of the melt stream and replaced withclean media.

One of the problems with this arrangement was sealing againstpolymer leakage.

If the integrity of the seals was high enough to stop leaks then the slidingassembly could not be shifted without undoing clamping bolts; if theclamping bolts were undone then the assembly leaked.

This device was the original screen shifter or screenchanger.

Modified slide platescreenchanger.


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The screen pack is the accepted filtration media for a very largesegment of the plastics industry. For the most part, prices of the screenpacks are acceptable and price considerations can be had by volumepurchasing and other creative techniques. New media and newtechnologies are being developed. Among these new products aresintered metal media, non woven wire cloth and metal felt. Theseproducts show promise and are making an impact in the 20-50micron particulate retention range. Combinations of metal felt andwoven screens are getting popular in the fibers industry.

While the filtration media part of the goal is seemingly well undercontrol, the problems of maintaining production are only beginning tobe resolved.

In production the 'sameness' of the process leads to success.

The same polymer, the same operating conditions, the samemachinery, the same everything leads to a predictable operation.Whenthe day begins, you know how much production you'll have at the endof the day. When a production line must be randomly shut down tochange filtration media, predictability is lost. Of course, one could'allow' for some number of filter renewals per shift and factor the losttime into production figures. Experience tells us that this would workbut on some days contamination levels would be higher or lower thanother days and shutdowns would vary accordingly; that shoots downpredictability.

To maintain production predictability shut downs must beeliminated.

Of course, if planned shutdowns exist for other reasons such as colorchanges or housekeeping, and filtration media renewal is done duringthis time, then the production predictability goal becomes academic.For those processors who need to maintain predictable production,several solutions are offered.

Each solution involves the concept of 'Continuous Filtration'. In theindustry, Continuous Filtration is achieved by changing screens withoutslowing or stopping the extrusion line to effect the change.


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Continuous Filtration is not necessarily constant flow or constantpressure filtration.

One solution used to provide continuous filtration is a modified slideplate screenchanger. The slide plates are hydraulically driven and areset up in a one way track. Three slide plates, or blocks, are in the trackas the screen change begins: one active block, one heated standbyblock and one recently cleaned block.

Upon signal from an alarm or observation of pressure sensors, anoperator initiates the change cycle. An hydraulic cylinder pushes onthe recently cleaned block which in turn pushes the standby and activeblock a distance down the track. The distance these blocks travel is justenough for the heated standby block to enter the melt stream. Theactive block is still mostly in the melt stream and remains there until theheated standby block is filled with polymer. There usually is a portventing the heated standby block to atmosphere.

Opening and closing the port is under operator's manualcontrol.

When the operator is certain the standby block is filled and up tooperating temperature, he initiates the second part of the hydrauliccycle and the heated standby block is pushed, very slowly, into theactive block position. The former active block is then removed from thetrack and cleaned. The track is reset to its original position and theformer active block, or a spare, is placed in the recently cleaned blockposition.

While this solution offers a method of continuously replacing cloggedscreen packs and qualifies as a continuous filtration device, it depletesthe volume of material flowing to the die at each prefill and may causethe line to tear. Entrapped air is removed under operator's control.

Overall this solution is a good one.

However, the blocks needed for high throughputs get to be quite largeand heavy. Handling them is a problem.

Continuous Filtration


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Variations of the prefill idea can be found on some disc type filtrationunits which use a bifurcated melt flow channel to partly introduce afresh screen pack into the melt flow while retaining a correspondingpart of the active screen pack in the melt flow. Bifurcating the melt flowchannel is an idea used by a few manufacturers. Splitting the melt flowallows for a continuous flow of polymer while screen packs are shiftedfrom one flow path to the other.

The polymer is never completely shut off while the screenchange is made.

Depending on the machine's design, the restriction can be severe andcause the line to tear due to material depletion. Thermal degradationcan take its toll on sensitive polymers because of material stagnationwhen the inactive flow path is blocked off. If the degradation is severeenough, contaminant storms can occur when the flow path becomesactive.

Conveying screenchangers are those types of screenchangers thatbring screen packs or screen belts into through and out of the melt flow.These types of screenchangers are continuous because they allowpolymer to flow while screen media is replaced.

This type of screenchanger uses various sealing methods.

Some models use a polymer seal which is alternately melted and thensolidified so as to allow the screens to traverse the melt flow channel.The pressure of the melted polymer against the softened polymercombined with the shape of the exit channel of the screen belt cause thepolymer to push screen belts our of the melt flow channel. When a

Bifurcated melt flow disks.


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sufficient amount of screen is removed, the polymer seal is cooleddown and solidifies once again. Other models of this type use sealingtabs or bars welded to the screen belt. These tabs act as moving sealsagainst the sides of the melt flow channel and prevent polymer fromleaking.

This variety of belt type screenchanger uses a positive tow ratherthan polymer pressure to move the screen belt.

While these type screenchangers are continuous because they changescreens without shutting off the polymer flow, they respond to pressureincreases in order to effect screen changes.

Another variety of conveying screenchangers is the rotating disc model.

These screenchangers employ a disc as a conveying device.

The disc is sandwiched between body blocks. Specially shaped breakerplates with through holes are machined onto the upstream side of thedisc. Each breaker plate is recessed so it can accept a screen pack.Depending on the application, some discs have fixed breaker plateswhile others have removable breaker plate inserts. The periphery of thedisc is machined to be a large gear. Between the disc's cavities, thelands, or webs, form a seal against leakage.

Rotary Screenchangers

Left to right: a belt and a rotaryscreenchanger .


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Although the webs are an obstruction within the melt flow channel, theobstruction is constant. As one web partially enters the melt flowchannel, a corresponding area of another web exits. Both the disc'sbreaker plates and the body block's melt flow channel are speciallymachined to enhance polymer flow. Additionally, the polymer flow isconstant. No polymer depletion occurs as screen packs shift.

Because the disc increments in small steps, pressure is constant.

Contaminant storms are handled easily because of the rapid responseof the disc to pressure changes. As the disc rotates, contaminatedscreen packs are conveyed out of the machines' body where they areremoved and replaced. This technique is sufficient for stable polymers.When degradable polymers are filtered, then the disc's breaker platesmust be removed and thoroughly cleaned before they are replaced inthe disc.

Leakage is a problem with most screenchangers. In use they areusually torqued up to prevent leaks and then backed off when a screenchange is needed. Rotary screenchangers have a huge sealing surfaceand leakage is not a common problem. The body blocks and the facesof the disc are superbly machined and polished to mirror like finishes.Using very precise torquing techniques, manufacturers squeeze thedisc to unbelievable values.

Because of the fine finishing, the disc rotates freely between theblocks.

This type of screenchanger iscontinuous because it does not shutoff polymer flow while screen packs

are changed.


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Torque values and the whole idea of clamping force differ amongmanufacturers. Some manufacturers prefer to clamp the disc to valueswhich assure leak free performance over an entire range of operatingpressures while others prefer to torque to a value somewhat more thanthe disc's free turning force and then allow internal line pressure releaseon the disc so that it may turn freely.

Special system enhancements such as pre-flooding vacuumevacuation of cavities pressure releases are easy to achieve because ofthe body block design. In some cases the melt flow channel can beextended to accept four or more breaker plates at the same time.

Electronic controls are used to operate rotary screenchangers.

The controls range from simple proprietary PLCs to dedicatedmicroprocessors performing multi functional operations. The logicused to control rotary filters is to interrogate pressure transducers andcompare pressure readings to setpoints. The readings can be upstreamof the screenchanger, downstream of the screenchanger or Delta P.

Rotary screenchanger.


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When the pressure readings approach or exceed setpoint, thecontroller signals the pneumatic drive system to initiate a stroke. Thestroke is converted into rotary motion via a one way clutch and linkage.

The interrogation is repeated at programmed intervals and suitableaction is taken as required. This type of interrogation leads to extremelyrapid response to contaminant storms and changing contaminantconditions. Pressures are kept relatively constant because of the rapidreaction to changes. One manufacturer uses a computer control tovary the length of the pneumatic stroke to maintain even finer pressurecontrol.

Rotary screenchanging systems fulfill the needs of polymerfiltration better than other systems available today.

They provide filtration of the polymer by using screen packs to retainparticulate, they are continuous in operation, they maintain a constantthroughput, constant temperature and cause no productioninterruptions just to change screen packs.


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About the ROTARY IIITM

PATT Filtration’s constant pressure continuous screenchangers, the ROTARY IIITM are the most

versatile and dependable screenchangers available today.

Our units are found in hundreds of installations with models suited for any application operating on a broad rangeof polymers.

Our numerous successes in:

� pipe

� profile

� pelletizing

� film

� sheet and

� fiber extrusion

provide our customers with the following benefits:

� Save 3-7% In Raw Material

� Save 12-50% In Screen Costs

� Maintain Uniform Product Quality

� No Downtime During Screen Change

� Industry Reported Payback Times of 20-60

Days

� Substantial Increase in Usage of Recycled

Materials

If you are presently using a filtration method such as a breaker plate, slide plate or ribbon type, the following reportshould convince you that our continuous rotary screenchangers will not only provide you with uninterrupted filtrationbut will in fact considerably improve your bottom line.

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The three alternative filtration systems mentioned previously are widelyused in your industry and they all suffer from similar problems. Theseproblems are even more acute when using a high percentage ofrecycled materials due to more frequent screen changes or high screencost.

The basic version of this system requires a complete shutdown of theextruder to physically remove and then replace the contaminatedscreen. Some units have two breaker plates that swing on an arc andcan be moved in and out of the melt flow by means of a lever. Due tothe high pressures encountered in extruders, the operator has to shutdown or at least slow down the extruder before making the change.

Both of these lead to downtime and in the case of the basicversion, production is lost for a considerable period of timebefore the line is back to full operation.

The graph shown below will give you an idea of what occurs during thisprocess.

In addition to down time as the screen gets clogged up, the meltpressure on the extruder starts to rise which increases the shear on yourmaterial and brings up the melt temperature. The final effect is changesin melt flow at the die that lead to product rejection and/or throughputreductions.

Manual Breaker Plate

Breaker plate system analysis.

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The slide plate unit typically includes two identical screens mounted in aplate. The plate is moved across the melt flow at certain periodsdepending on pressure or time intervals. This system may not require ashutdown since the slide plate is moved by means of a hydrauliccylinder.

Production interruptions are reduced compared to a manual breakerplate but as the screen gets clogged the same thing happens as in amanual breaker plate: increase in back pressure, shear rates go up,melt temperature varies, melt flow is altered at the die, and throughput

reduced.

The common way to deal with these problems is to run on a heavierspec to compensate for any dimension variances between screenchanges. Imagine the savings you could realize by running at the lowend of your specification requirement. Our rotary screenchanger willgive you that capability.

Some of our customers report up to 7% material savings afterswitching from a slide-plate system to our rotary screenchanger.

In addition, both the manual breaker plate and slide-plate systems usecircular screens which can only utilize about 65% of the surface areafor filtration. These screens will typically clog up in the middle and bythat time the back pressure has increased to a point that a change isrequired. The rotary, on the other hand, can utilize about 95% of thescreen area since the screen changes only on demand and in smallincrements. The filtration area in the melt flow channel is constant at alltimes. Follow the graph above and you will see exactly what ishappening to your melt when using a slide-plate.

Slide Plate Systems

Slide plate system analysis.

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Ribbon Type Systems

These units use a long strip of screen for filtration. This screen movesthrough the flow channel and is gradually pulled as it exits thescreenchanger body. Some systems use a hydraulic clamp to pull theribbon while others rely on melt pressure to force the screen out of thebody.

The big question on these units is how to prevent leakage.

You have to cool the area where the screen enters and exits in order toform a polymer seal. What happens when the cooling system fails orlarge chunks of contamination are pulled by the screen?

A ribbon type screenchanger also requires a specific screenwhich costs double or even triple that of the rotary screens. Thesavings on screen costs with a rotary system are substantialespecially when using a high percentage of regrind or recycledmaterial.

The end result is an enormous pile of molten polymer on your floor anda possible shutdown to correct the problem. These units also sufferfrom system upsets if large shots of random contamination comethrough the line. It is difficult to move the screen fast enough andremove the impurities which lead to blown polymer seals. During ascreen movement the pressure fluctuations are not as drastic as on thebreaker plate units but we can still see a variance as shown on thegraph below:

Ribbon type system analysis.

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In conclusion, we know that we can enhance the quality of your productand considerably improve your bottom line.

We have included an application questionnaire which you should fillout and fax back to our attention. Once your questionnaire is reviewed,we will send you detailed information and a quotation for your specificprocess.

Isometric view of the ROTARY IIITM

screenchanger unit.

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ROTARY IIITM System Description

PATT Filtration’s constant pressure continuous screenchangers, the ROTARY IIITM are the most

versatile and dependable screenchangers available today.

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The body blocks for all unit sizes are:

� Constructed of custom chrome-molybdenum vanadium alloy

� In-house, deep case Pulse Plasma nitrided

� Hardness 64 Rockwell or 800 Brinell

� Near-mirror finish, optional thin film coating offers ultimate

corrosion resistance

� Vent and vacuum port provided for venting air from flooded cavity

to ambient

If needed, a vacuum pump can be connected for evacuation of cavity,prior to being flooded.

PATT Filtration units use a unique leak-free metal to metal compressionseal method which employs:

� 450-1250 tons of force generated by the custom-made body

block screws, depending on ROTARY IIITM size: this force is

directed towards compression of spacer plate and bearing ring to

form a zero interference fit between the body blocks and the Filter

disk

� No soft sealing rings which could easily be nicked, causing

subsequent leaking

The advantage of this compressive closure is that forces many timesgreater than the adversary forces, caused by the melt pressure, areused to ensure a leak-free metal to metal sealing without the problemsof interference fits which cause seizing.

Body Blocks

Compression Seal

Assembly drawing showing the metal tometal seal of body blocks with spacer

plate, disk and bearing.

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All ROTARY IIITM filter disks are:

� Manufactured of high chrome/molybdenum steel

� Hardened and in-house Pulse Plasma nitrided

� Hardness 67 Rockwell or 880 Brinell

� Near-mirror finish and standard multi layer nano coated for

extensively improved wear and corrosion resistance

� On PATT Fixed ROTARY IIITM - breaker plates are an integral

part of the disk

� On PATT Removable ROTARY IIITM - breaker plates are

removable and retained by means of a tapered seat

� The teeth are an integral part of the disk thus providing added

strength

� The kidney-shaped tapered cavities securely hold commercially

available wire mesh screen packs

Filter Disk


D-size disk, fixed, 18cavities. Details showthe cavity and themachined teeth on thedisk.

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Exploded view of a filter assembly, complete with heaters on both the disk and body blocks.

PATT Constant Pressure Drop Continuous screenchangers are leak-freeand easily rotatable at any combination of temperature and pressureup to 12000 psi and 650 °F.

The melt enters the inlet port of the extruder side body block and isfiltered by the screens in the melt flow path.

The PCS-1 controller monitors pressure drops and elapsed time todetermine rotation speed of the disk by variable ultra fine steps utilizing95% of the screen area. It offers alarm contacts to alert the operatorwhen to change a predetermined number of screens - the only humanintervention required.

The PATT ROTARY IIITM provides continuous polymer flow, a constantpressure drop, and eliminates pressure fluctuations which, in turnreduce process variability and improve product uniformity.


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ROTARY IIITM PCS-1 Controller

PATT Filtration’s ROTARY IIITM units are fully monitored by the PCS-1 controller which

combined with the Datalogger software provides you with full monitoring capacities of theoperation of your unit.

Close-up view of the PCS-1 Controller panel.

The PCS-1 interfaces with the PATT Filtration system viaseveral sensors:

� 3 temperature sensors

� 1 melt temperature sensor

� 2 melt pressure transducers

� 1 proximity switch reading pneumatic cylinder

position

� 1 proximity switch reading disk position

� 1 air pressure sensor monitoring line air pressure

As an essential component to any PATT unit, the PCS-1 controller:

� Offers 3 built-in temperature control zones with readout selectable in Fahrenheit or Celcius.

� Rotation pick-up confirms rotation.

� Auto-tuning for finding differential pressure setpoint

� Warning alarms for back differential pressure, melt temperature, blocked filter and screen change

� Error alarms for back and differential pressure, melt temperature and maximum temperature for each zone

� 3 analog outputs including upstream pressure, downstream pressure and differential pressure

� PCS-1 is also available in an optional pre-wired plug and play cabinet

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ROTARY IIITM PCS-1 Controller

The PCS-1 controller display shows operating mode, screenconsumption, upstream pressure, differential pressure stroke %, strokeinterval time and differential pressure setpoint.

It can be toggled to show operating mode, melt temperature, actualtemperatures for all 3 zones and temperature setpoints for all 3 zones

Auto-tuning interval time betweek strokes, regulated from 1-999sdepending on proximity to differential pressure setpoints

Monitors and controls PATT Filtration system by comparing upstreamand downstream pressure readings to differential pressure setpoints,and offers serial interface RS-485 for host communication

Auto-tuning cylinder strokes, regulated infinitely from 10-100% of thefull stroke, depending on proximity to differential pressure setpoint

Both the PCS-1 controller and the Datalogger software can providedisplays in psi or bar for pressure readings and Celcius or Fahrenheitdegrees for temperature readings.

Datalogger software permits toeffectively control and archive filter

operating conditions.

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At PATT Filtration we understand the important concept ofcompatibility and can provide you with a custom-designedsolution to make our unit part of your production line.Although the following information is primarily about ourcustom adapters, we can build and install an entire line fromdie to filter to your existing extruder. Our strength lies in thecooperation with each client to build the best suited system fora particular situation.

Custom Adapters for the ROTARY IIITM Screenchangers

Our engineering department custom-fits each PATT Filtration ROTARY IIITM unit into our

client’s production line through the use of in-house machined adapters.

Twin screw adapter, extruder side.

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Custom Adapters for ROTARY IIITM Screenchangers

Sample custom-engineered extruder to die line including several adapters.

All PATT Filtration adapters are machined in-house which gives us theflexibility to meet even the most demanding situation needs. Althoughthe adapter may seem as a mere extension of the filter, the same degreeof accuracy and care goes into its engineering and making as that ofthe unit itself. There is no such thing as a ‘standard adapter’: each isdesigned keeping in mind your existing infrastructure, die and extruderconfiguration and make as well as the type of polymer processing doneon the line. All our adapters are black oxide nitrided which makes themas cost-efficient as the unit itself. Moreover, an optional proprietarycoating further minimizes wear and maximizes rust protection.

Because we custom-design each adapter to fit your process, thequantity of mica-insulated neck or flange band heaters can vary fromproject to project.

Band heaters for adapter neckand flange [biggest diameter].

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ROTARY IIITM Disk Components: Screens

PATT Filtration’s ROTARY IIITM units are fully monitored by the PCS-1 controller which

combined with the Datalogger software provides you with full monitoring capacities of theoperation of your unit.

Our screenchangers use custom-fit wire mesh screen packs. Made froma variety of square mesh and dutch weaves, they can be customized to fityour needs, whether you run LLDPE, PVC, ABS, HDPE, PP, rubber or aspecial blend proper to your production. The pack combinations cancome in stainless or plain steel and are designed for all of our PATTFiltration screenchanger sizes. Mesh sizes from 20 to 400 guaranteevarious level of filtration precision. Packs are custom tailored meshcombinations specific to your production needs. Clockwise from theright: E-size, D-size, C-size, B-size and A-size screens, various meshes.

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Hole spacing and layout in aremovable breaker plate.

Fixed or Removable breaker plates are the two options available to youfor all sizes of PATT Filtration’s screenchangers.

Fixed breaker plates are an integral and structural part of the disk. Asresult, they can not be independently cleaned. Removable breakerplates on the other hand can be easily removed to clean out the diskcavities. Combined with a breaker plate remover tool, they ensurequick and efficient cleaning therefore reducing cavity contamination.

ROTARY IIITM Disk Components: Breaker Plates

A-size removable breaker plate.(Shown actual size)

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Breaker plates, both fixed and removable, can also be the standard flator a wave-like design. The most advantageous of our breaker platedesigns for the PATT ROTARY IIITM is the wave-like CORR-EX!

breaker plate.

PATT Filtration’s wave shaped breaker plate is for use in the PATTROTARY IIITM Constant Pressure Drop Continuous flow filtrationsystems.

Utilizing corrugated, or wave shape breaker plates it allows higherconcentrations of recycled materials to be used at finer levels offiltration without sacrificing throughput at lower differential pressures.And because the active filtration area is extended, screen changefrequency is also reduced.

ROTARY IIITM Disk Components: CORR-EX!

CORR-EX! Wave-like breaker plate

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Breaker plates, both fixed and removable, can also be the standard flator a wave-like design. The most advantageous of our breaker platedesigns for the PATT ROTARY IIITM is the wave-like CORR-EX!

breaker plate.

PATT Filtration’s wave shaped breaker plate is for use in the PATTROTARY IIITM constant pressure drop continuous-flow filtrationsystems.

Utilizing corrugated, or wave, shape breaker plates it allows higherconcentrations of recycled materials to be used at finer levels offiltration without sacrificing throughput at lower differential pressures.And because the active filtration area is extended, screen changefrequency is also reduced.

ROTARY IIITM Disk Components: Breakerplates

FIXED Model Filtration Area (cm2) Screen Area (cm2) Cavities Throughput (lbs/hr) Wattage (240V-kW) Weight (lbs)

A 10-30 4.6-19.0 16-38 50-1000 3.2 230

B 45-60 24.4-33.7 16-20 150-1800 4.8 350

C 90-130 53.4-70.5 15-18 350-3500 9.8 800

D 190-220 88.6-98.0 16-18 N/A 13.0 2200

E* 400 N/A 18 N/A N/A N/A

REMOVABLE Model Filtration Area (cm2) Screen Area (cm2) Cavities Throughput (lbs/hr) Wattage (240V-kW) Weight (lbs)

A 10-30 4.6-19.0 16-38 80-1000 3.2 230

B 45-65 24.4-33.7 16-20 250-2400 4.8 350

C 90-130 53.4 18** 500-3500 9.8 800

D 190-220 88.6 18** N/A 13.0 2200

* Information given for a specific filter. The E-size is made on special order only.** Information given for a specific filter. Other combinations are available depending on your production needs.

CORR-EX!

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ROTARY IIITM Tools: Breaker Plate Remover

If your process requires the PATT Filtration’s ROTARY IIITM disks to come with removable

breaker plates, a special remover tool is available for a mechanized, safe and effectivebreaker plate removing from your unit’s disk.

Close-up of the remover tool. Clearly evident hereis the remover tool mechanism: it is a precision

instrument geared towards efficiency.

The optional hydraulic breaker plate removertool makes the removal of breaker plates easierand safer for the operator and prevents damageto the disk and breaker plates which could occurif tools like steel hammers are used to removethe breaker plates.

All the operator needs to do is align the tool withthe breaker plate to be removed and step on thefoot pedal. The hydraulic pump will then pushout the breaker plate in one fluid motion and thecavity is ready to receive a clean new breakerplate.

With a remover tool you can:

� Ensure zero damage to the breaker plate and disk cavities, compared to a manual hammer method

� Easily remove breaker plates

� Maintain operator safety during breaker plate removal

� Save operator time and money in damaged breaker plates

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ROTARY IIITM Tools: Breaker Plate Remover

Hydraulic breaker plate remover tool mounted on a C-size unit.

Exploded assembly of the hydraulic breaker plate remover tool.

PATT-FiltrationInfopack2004

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