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 polymer
filtration needs.
Through the years, our ongoing efforts toward perfection have brought about many changes, some subtle other still
more 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 PATT
Filtration 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 made
PATT 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 at
PATT Ionics and RUBIG-PATT Technologies to constantly further
the development of wear-resistant filter components as well as
with PATT Europe to market PATT technology in Europe.
From the outset, the company’s main objective to provide superior
quality products has been realized by applying advanced
manufacturing technology. A large part of the earnings is
reinvested in R&D and latest technology machinery. We pioneered new materials and coating technologies to
achieve 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 field
of polymer filtration. Our integration of engineering skills and advanced technology puts us on the leading edge of
filtration development.
While PATT Filtration prides itself on its range of screenchangers handling the broadest range of polymers, filtration
problems often demand something more than our standard product line. Our custom engineering services offer far
more than the "Off the Shelf" screenchanger. Our flexibility as a small company enables quick response to customer
problems 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 grown
to be a major competitor in the filtration systems industry. PATT Filtration is now a division of
PATT Technologies.

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Modern polymer filtration usually calls for removing particles or
contaminants in a controllable, definable and safe manner. The
expense of the filtration system which solves the separation problem
without changing operational conditions, has to be weighed against
improved productivity and lower operating costs. A general
understanding of the basic principles and technical terminology can
greatly simplify the process of system selection. This Technical Brief
offers an overview of the main elements of ROTARY IIITM Constant
Pressure Drop Continuous filtration system.
The ROTARY IIIT M Constant Pressure Drop Continuous
screenchanger series uses a rheologically correct flow channel design
and microprocessor controls to stabilize process conditions and
maintain constant pressure to improve overall production conditions.
The melt flows through a revolving disk with a fixed number of either
integral fixed or removable breaker plates with screen cavities,
arranged in a circular shape and separated by curved ribs. Even if
those narrow webs pass through the flow channel their kidney shape
and the optimized melt channel will insure maximized available screen
area and undisturbed melt flow.
The vent and vacuum port will automatically purge air from the
oncoming screen cavity to avoid air being passed into the melt flow.
The pressure relief port will automatically purge material from the
exiting screen cavity to ensure operator safety. The filter disc is
enclosed between two body blocks and advanced in ultra-fine angular
steps by the microprocessor control, allowing continuous rotation even
at lowest speed, while maintaining a constant pressure drop.
In general terms, the filtration process consists of passing the molten
polymer and contamination through a porous screen pack that entraps
the solids in its matrix or retains them on its surface. Anything larger
than the opening size cannot pass through, and will clog the screen
and increase the pressure drop across the screen if no clean filter
media is introduced.
The Practical Art of Melt Filtration
Principle
How It Works
Screen capture from the PCS-1
controller Datalogger software
showing the constant pressure
drop our screenchangers are
known for.

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"Throughput" is the time based volume of polymer that can be filtered
before the screens need to be changed, causing production
interruptions. Fine screens with high retention efficiencies tend to plug
faster and need to be changed more frequently.
"Throughput", with a ROTARY IIITM means the volume of material that
can be filtered without any interruption to production. The
microprocessor control will always keep the same amount of open
screen area in the flow path while maintaining a constant differential
pressure, essentially offering an unlimited screen area.
Applied in an in-house Pulse Plasma process chemical inert ultra-thin
non porous layers backed by hardened and nitrided substrate provide
the ultimate in corrosion and wear resistance.
The design of an optimum melt filtration system is a complex
issue.
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 of
uninterrupted filtration systems.

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Our technical service department has the experience to develop
a system that best meets your needs for reliable performance as
well as operating economy.
We will agree to do only that which can be accomplished while
maintaining our standard of excellence. We want to be known as the
best in what we do, and we set our standards to accomplish that
purpose.
At PATT Filtration we take existing technologies and our proven designs
and engineer them into solutions specifically for your requirements.
Whatever you need - filtration systems for fibers, film and sheet, profile
and tubing, or systems to withstand the rigors of unknown materials
and contamination in recycling - our Application Specialists will work
directly with you to devise the best solution.
Our engineers will adapt the selected system to the extruder and die in
the most suitable way. The capability to manufacture all parts in-house
insures quality and on-time delivery.
Our clients’ success is the best measure of the value of the
services we render.
than anybody else that improved quality and increased quantity are the
main profit factors for your business. Your engineered filtration solution
from PATT Filtration will improve product quality and eliminate
downtime.
PATT Filtration Business Philosophy
Custom Engineering
You know better
PATT Filtration shares its
St-Eustache building with PATT
Technologies, its mother
company.

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About Polymer Filtration
PATT Filtration is a leader in polymer filtration equipment. As such, we have an excellent
knowledge of our clients’ processes.
The goals of polymer filtration are to maintain the highest possible line productivity while removing particulate
contaminants and causing little or no changes to the polymer's characteristics. We define polymer filtration as the
removal of unwanted solid contaminants, above a specified diameter or width, from the flow of melted polymer. In
this 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 have
serious deleterious effects on the polymer. It is simply not worth a lengthy discussion about how to filter contaminants
and 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 through
some media whose porosity is such that particulate larger than the pore
size will be retained while the polymer and contaminants smaller then
pore size will pass through freely.
We'll call this particulate retention.
Each of the devices mentioned above are capable of filtering polymers
and each performs its job by particulate retention. Because this
discussion is limited to only the most practical solutions, only the most
popular, the screen filtering technique used in the plastics industry will
be discussed.
Within the plastics industry, screen filters are the most common
and perhaps the best-suited type media to be used in the
decontamination 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 is
preferred in the plastics industry because of its strength, durability and
resistance to corrosion.
Manufacturing the screen filter is a technology in itself. The process
involves weaving horizontal wires (weft wires) through alternate vertical
wires (warp wires) in exactly the same way as cloth is manufactured.
Looms are used in exactly the same way to weave the metal strands into
a 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 is
that the parallel wires are precisely spaced with some distance
between them.
This opening (pore) corresponds to the minimum particle retention of
the 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 mesh
can be different in horizontal and vertical directions.
Still other variations of weaving are available for added strength of flow
purposes. Warp wires can differ from weft wires in diameter. The weave
can change to have parallel pairs of wires touching each other.
These patterns are available in a seemingly endless variety of
combinations with each pattern having some unique
characteristic 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 trap
contaminants on its surface. The screen filter is placed between the
extruder and the die, typically on the upstream side of the breaker
plate. The plastic, under pressure, is forced through the screen filter
and contaminants too large to pass through the openings of the screen
filter get trapped.
Metal wire mesh.

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As the contaminants build up, less surface area is available, the screen
filter 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 of
toleration, the line is shut down and the breaker plate along with the
screen filter is removed. A fresh screen filter is then replaced along with
the breaker plate and the line is eventually restarted. This exercise is the
oldest and most frequently used method of polymer filtration and filter
media 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. When
particulate blocks an opening, polymer stops flowing. The blocked
part of the screen is lost for filtration and the overall polymer flow is
restricted. Particles blocking more than one aperture lead to even
faster blocking of the screen filter. To lengthen the interval between
screen filter changes additional screens with a mesh larger than the
single 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 layers
of screen downstream of the final filter layer. This addition allows
filtered polymer to drain away from the final layer and find its way
through the holes in the breaker plate and continue on its journey. If
the 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 and
more 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 will
probably 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. Already
mentioned above are some of the problems associated with blocking
and clogging filters. If the problems cause the process to go out of
control then the solution is to renew the screen pack, or filtration
media, before control is lost. Some schools of thought believe that
increasing the area of filtration is the answer.
The thought that increased area will decrease the renewal
frequency sounded logical.
Clogged screen filter.

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However, increasing filtration area means changing polymer flow
characteristics within the flow channel and, in some heat sensitive
polymers, causing degradation.
Degradation could generate carbon specks whose diameter is less
than the screen pack's final filtration layer and the result could be a
more highly contaminated product, albeit with smaller particulate.
Experience taught processors when to change the screen packs to
avoid problems with melt flow restrictions and polymer degradation.
Head pressure, Delta P, time or physical observations could be used as
criteria to renew or replace screen packs.
Each time the screen pack is replaced, the line shuts down. For
those processors operating intermittently, one or two shifts per day of
three or four days per week, this was not a significant problem. For
those processors operating continuously, 24 hours per day 7 days a
week, week in and week out, changing screen packs creates
production shutdowns.
Those shutdowns mean lost money.
Mounting the screen pack outside the extruder but still between the
screw and the die managed to reduce the time lost in renewing the
screen 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 needed
to be stopped or at least slowed considerably to renew a clogged
screen pack.
One solution to reducing down time was to machine multiple breaker
plates into an assembly mounted outside the extruder and precede the
breaker plates with a screen pack.
This solution was a logical one in terms of reducing downtime. The line
pressure could be reduced and the assembly shifted so that the clogged
screen pack could be shifted out of the melt stream and replaced with
clean media.
One of the problems with this arrangement was sealing against
polymer leakage.
If the integrity of the seals was high enough to stop leaks then the sliding
assembly could not be shifted without undoing clamping bolts; if the
clamping bolts were undone then the assembly leaked.
This device was the original screen shifter or screenchanger.
Modified slide plate
screenchanger.

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The screen pack is the accepted filtration media for a very large
segment of the plastics industry. For the most part, prices of the screen
packs are acceptable and price considerations can be had by volume
purchasing and other creative techniques. New media and new
technologies are being developed. Among these new products are
sintered metal media, non woven wire cloth and metal felt. These
products show promise and are making an impact in the 20-50
micron particulate retention range. Combinations of metal felt and
woven screens are getting popular in the fibers industry.
While the filtration media part of the goal is seemingly well under
control, the problems of maintaining production are only beginning to
be resolved.
In production the 'sameness' of the process leads to success.
The same polymer, the same operating conditions, the same
machinery, the same everything leads to a predictable operation.When
the day begins, you know how much production you'll have at the end
of the day. When a production line must be randomly shut down to
change filtration media, predictability is lost. Of course, one could
'allow' for some number of filter renewals per shift and factor the lost
time into production figures. Experience tells us that this would work
but on some days contamination levels would be higher or lower than
other days and shutdowns would vary accordingly; that shoots down
predictability.
To maintain production predictability shut downs must be
eliminated.
Of course, if planned shutdowns exist for other reasons such as color
changes or housekeeping, and filtration media renewal is done during
this 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 the
industry, Continuous Filtration is achieved by changing screens without
slowing or stopping the extrusion line to effect the change.

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Continuous Filtration is not necessarily constant flow or constant
pressure filtration.
One solution used to provide continuous filtration is a modified slide
plate screenchanger. The slide plates are hydraulically driven and are
set up in a one way track. Three slide plates, or blocks, are in the track
as the screen change begins: one active block, one heated standby
block and one recently cleaned block.
Upon signal from an alarm or observation of pressure sensors, an
operator initiates the change cycle. An hydraulic cylinder pushes on
the recently cleaned block which in turn pushes the standby and active
block a distance down the track. The distance these blocks travel is just
enough for the heated standby block to enter the melt stream. The
active block is still mostly in the melt stream and remains there until the
heated standby block is filled with polymer. There usually is a port
venting the heated standby block to atmosphere.
Opening and closing the port is under operator's manual
control.
When the operator is certain the standby block is filled and up to
operating temperature, he initiates the second part of the hydraulic
cycle and the heated standby block is pushed, very slowly, into the
active block position. The former active block is then removed from the
track and cleaned. The track is reset to its original position and the
former active block, or a spare, is placed in the recently cleaned block
position.
While this solution offers a method of continuously replacing clogged
screen packs and qualifies as a continuous filtration device, it depletes
the volume of material flowing to the die at each prefill and may cause
the 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 large
and heavy. Handling them is a problem.
Continuous Filtration

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Variations of the prefill idea can be found on some disc type filtration
units which use a bifurcated melt flow channel to partly introduce a
fresh screen pack into the melt flow while retaining a corresponding
part of the active screen pack in the melt flow. Bifurcating the melt flow
channel is an idea used by a few manufacturers. Splitting the melt flow
allows for a continuous flow of polymer while screen packs are shifted
from one flow path to the other.
The polymer is never completely shut off while the screen
change is made.
Depending on the machine's design, the restriction can be severe and
cause the line to tear due to material depletion. Thermal degradation
can take its toll on sensitive polymers because of material stagnation
when the inactive flow path is blocked off. If the degradation is severe
enough, contaminant storms can occur when the flow path becomes
active.
Conveying screenchangers are those types of screenchangers that
bring screen packs or screen belts into through and out of the melt flow.
These types of screenchangers are continuous because they allow
polymer 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 then
solidified so as to allow the screens to traverse the melt flow channel.
The pressure of the melted polymer against the softened polymer
combined with the shape of the exit channel of the screen belt cause the
polymer 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 cooled
down and solidifies once again. Other models of this type use sealing
tabs or bars welded to the screen belt. These tabs act as moving seals
against the sides of the melt flow channel and prevent polymer from
leaking.
This variety of belt type screenchanger uses a positive tow rather
than polymer pressure to move the screen belt.
While these type screenchangers are continuous because they change
screens without shutting off the polymer flow, they respond to pressure
increases 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 breaker
plates with through holes are machined onto the upstream side of the
disc. Each breaker plate is recessed so it can accept a screen pack.
Depending on the application, some discs have fixed breaker plates
while others have removable breaker plate inserts. The periphery of the
disc is machined to be a large gear. Between the disc's cavities, the
lands, or webs, form a seal against leakage.
Rotary Screenchangers
Left to right: a belt and a rotary
screenchanger .

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Although the webs are an obstruction within the melt flow channel, the
obstruction is constant. As one web partially enters the melt flow
channel, a corresponding area of another web exits. Both the disc's
breaker plates and the body block's melt flow channel are specially
machined to enhance polymer flow. Additionally, the polymer flow is
constant. 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 response
of the disc to pressure changes. As the disc rotates, contaminated
screen packs are conveyed out of the machines' body where they are
removed and replaced. This technique is sufficient for stable polymers.
When degradable polymers are filtered, then the disc's breaker plates
must be removed and thoroughly cleaned before they are replaced in
the disc.
Leakage is a problem with most screenchangers. In use they are
usually torqued up to prevent leaks and then backed off when a screen
change is needed. Rotary screenchangers have a huge sealing surface
and leakage is not a common problem. The body blocks and the faces
of the disc are superbly machined and polished to mirror like finishes.
Using very precise torquing techniques, manufacturers squeeze the
disc to unbelievable values.
Because of the fine finishing, the disc rotates freely between the
blocks.
This type of screenchanger is
continuous because it does not shut
off polymer flow while screen packs
are changed.

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Torque values and the whole idea of clamping force differ among
manufacturers. Some manufacturers prefer to clamp the disc to values
which assure leak free performance over an entire range of operating
pressures while others prefer to torque to a value somewhat more than
the disc's free turning force and then allow internal line pressure release
on the disc so that it may turn freely.
Special system enhancements such as pre-flooding vacuum
evacuation of cavities pressure releases are easy to achieve because of
the body block design. In some cases the melt flow channel can be
extended 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 dedicated
microprocessors performing multi functional operations. The logic
used to control rotary filters is to interrogate pressure transducers and
compare pressure readings to setpoints. The readings can be upstream
of the screenchanger, downstream of the screenchanger or Delta P.
Rotary screenchanger.

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When the pressure readings approach or exceed setpoint, the
controller signals the pneumatic drive system to initiate a stroke. The
stroke is converted into rotary motion via a one way clutch and linkage.
The interrogation is repeated at programmed intervals and suitable
action is taken as required. This type of interrogation leads to extremely
rapid response to contaminant storms and changing contaminant
conditions. Pressures are kept relatively constant because of the rapid
reaction to changes. One manufacturer uses a computer control to
vary the length of the pneumatic stroke to maintain even finer pressure
control.
Rotary screenchanging systems fulfill the needs of polymer
filtration better than other systems available today.
They provide filtration of the polymer by using screen packs to retain
particulate, they are continuous in operation, they maintain a constant
throughput, constant temperature and cause no production
interruptions 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 range
of 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 report
should convince you that our continuous rotary screenchangers will not only provide you with uninterrupted filtration
but will in fact considerably improve your bottom line.

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The three alternative filtration systems mentioned previously are widely
used in your industry and they all suffer from similar problems. These
problems are even more acute when using a high percentage of
recycled materials due to more frequent screen changes or high screen
cost.
The basic version of this system requires a complete shutdown of the
extruder to physically remove and then replace the contaminated
screen. Some units have two breaker plates that swing on an arc and
can be moved in and out of the melt flow by means of a lever. Due to
the high pressures encountered in extruders, the operator has to shut
down or at least slow down the extruder before making the change.
Both of these lead to downtime and in the case of the basic
version, production is lost for a considerable period of time
before the line is back to full operation.
The graph shown below will give you an idea of what occurs during this
process.
In addition to down time as the screen gets clogged up, the melt
pressure on the extruder starts to rise which increases the shear on your
material and brings up the melt temperature. The final effect is changes
in melt flow at the die that lead to product rejection and/or throughput
reductions.
Manual Breaker Plate
Breaker plate system analysis.

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The slide plate unit typically includes two identical screens mounted in a
plate. The plate is moved across the melt flow at certain periods
depending on pressure or time intervals. This system may not require a
shutdown since the slide plate is moved by means of a hydraulic
cylinder.
Production interruptions are reduced compared to a manual breaker
plate but as the screen gets clogged the same thing happens as in a
manual 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 heavier
spec to compensate for any dimension variances between screen
changes. Imagine the savings you could realize by running at the low
end of your specification requirement. Our rotary screenchanger will
give you that capability.
Some of our customers report up to 7% material savings after
switching from a slide-plate system to our rotary screenchanger.
In addition, both the manual breaker plate and slide-plate systems use
circular screens which can only utilize about 65% of the surface area
for filtration. These screens will typically clog up in the middle and by
that time the back pressure has increased to a point that a change is
required. The rotary, on the other hand, can utilize about 95% of the
screen area since the screen changes only on demand and in small
increments. The filtration area in the melt flow channel is constant at all
times. Follow the graph above and you will see exactly what is
happening 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 moves
through the flow channel and is gradually pulled as it exits the
screenchanger body. Some systems use a hydraulic clamp to pull the
ribbon while others rely on melt pressure to force the screen out of the
body.
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 to
form a polymer seal. What happens when the cooling system fails or
large chunks of contamination are pulled by the screen?
A ribbon type screenchanger also requires a specific screen
which costs double or even triple that of the rotary screens. The
savings on screen costs with a rotary system are substantial
especially when using a high percentage of regrind or recycled
material.
The end result is an enormous pile of molten polymer on your floor and
a possible shutdown to correct the problem. These units also suffer
from system upsets if large shots of random contamination come
through the line. It is difficult to move the screen fast enough and
remove the impurities which lead to blown polymer seals. During a
screen movement the pressure fluctuations are not as drastic as on the
breaker plate units but we can still see a variance as shown on the
graph below:
Ribbon type system analysis.

27
In conclusion, we know that we can enhance the quality of your product
and considerably improve your bottom line.
We have included an application questionnaire which you should fill
out and fax back to our attention. Once your questionnaire is reviewed,
we will send you detailed information and a quotation for your specific
process.
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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ROTARY IIITM
System Description
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 compression
seal 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 times
greater than the adversary forces, caused by the melt pressure, are
used to ensure a leak-free metal to metal sealing without the problems
of interference fits which cause seizing.
Body Blocks
Compression Seal
Assembly drawing showing the metal to
metal 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
ROTARY IIITM
System Description
D-size disk, fixed, 18
cavities. Details show
the cavity and the
machined teeth on the
disk.

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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-free
and easily rotatable at any combination of temperature and pressure
up to 12000 psi and 650 °F.
The melt enters the inlet port of the extruder side body block and is
filtered by the screens in the melt flow path.
The PCS-1 controller monitors pressure drops and elapsed time to
determine rotation speed of the disk by variable ultra fine steps utilizing
95% of the screen area. It offers alarm contacts to alert the operator
when to change a predetermined number of screens - the only human
intervention required.
The PATT ROTARY IIITM provides continuous polymer flow, a constant
pressure drop, and eliminates pressure fluctuations which, in turn
reduce process variability and improve product uniformity.
ROTARY IIITM
System Description

33
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 the
operation of your unit.
Close-up view of the PCS-1 Controller panel.
The PCS-1 interfaces with the PATT Filtration system via
several 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

34
ROTARY IIITM
PCS-1 Controller
The PCS-1 controller display shows operating mode, screen
consumption, upstream pressure, differential pressure stroke %, stroke
interval time and differential pressure setpoint.
It can be toggled to show operating mode, melt temperature, actual
temperatures for all 3 zones and temperature setpoints for all 3 zones
Auto-tuning interval time betweek strokes, regulated from 1-999s
depending on proximity to differential pressure setpoints
Monitors and controls PATT Filtration system by comparing upstream
and 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 the
full stroke, depending on proximity to differential pressure setpoint
Both the PCS-1 controller and the Datalogger software can provide
displays in psi or bar for pressure readings and Celcius or Fahrenheit
degrees for temperature readings.
Datalogger software permits to
effectively control and archive filter
operating conditions.

35
At PATT Filtration we understand the important concept of
compatibility and can provide you with a custom-designed
solution to make our unit part of your production line.
Although the following information is primarily about our
custom adapters, we can build and install an entire line from
die to filter to your existing extruder. Our strength lies in the
cooperation with each client to build the best suited system for
a 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.

36
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 the
flexibility to meet even the most demanding situation needs. Although
the adapter may seem as a mere extension of the filter, the same degree
of accuracy and care goes into its engineering and making as that of
the unit itself. There is no such thing as a ‘standard adapter’: each is
designed keeping in mind your existing infrastructure, die and extruder
configuration and make as well as the type of polymer processing done
on the line. All our adapters are black oxide nitrided which makes them
as cost-efficient as the unit itself. Moreover, an optional proprietary
coating further minimizes wear and maximizes rust protection.
Because we custom-design each adapter to fit your process, the
quantity of mica-insulated neck or flange band heaters can vary from
project to project.
Band heaters for adapter neck
and flange [biggest diameter].

37
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 the
operation of your unit.
Our screenchangers use custom-fit wire mesh screen packs. Made from
a variety of square mesh and dutch weaves, they can be customized to fit
your needs, whether you run LLDPE, PVC, ABS, HDPE, PP, rubber or a
special blend proper to your production. The pack combinations can
come in stainless or plain steel and are designed for all of our PATT
Filtration screenchanger sizes. Mesh sizes from 20 to 400 guarantee
various level of filtration precision. Packs are custom tailored mesh
combinations specific to your production needs. Clockwise from the
right: E-size, D-size, C-size, B-size and A-size screens, various meshes.

38
Hole spacing and layout in a
removable breaker plate.
Fixed or Removable breaker plates are the two options available to you
for all sizes of PATT Filtration’s screenchangers.
Fixed breaker plates are an integral and structural part of the disk. As
result, they can not be independently cleaned. Removable breaker
plates on the other hand can be easily removed to clean out the disk
cavities. Combined with a breaker plate remover tool, they ensure
quick and efficient cleaning therefore reducing cavity contamination.
ROTARY IIITM
Disk Components: Breaker Plates
A-size removable breaker plate.
(Shown actual size)

39
Breaker plates, both fixed and removable, can also be the standard flat
or a wave-like design. The most advantageous of our breaker plate
designs 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 PATT
ROTARY IIITM Constant Pressure Drop Continuous flow filtration
systems.
Utilizing corrugated, or wave shape breaker plates it allows higher
concentrations of recycled materials to be used at finer levels of
filtration without sacrificing throughput at lower differential pressures.
And because the active filtration area is extended, screen change
frequency is also reduced.
ROTARY IIITM
Disk Components: CORR-EX!
CORR-EX! Wave-like breaker plate

40
Breaker plates, both fixed and removable, can also be the standard flat
or a wave-like design. The most advantageous of our breaker plate
designs 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 PATT
ROTARY IIITM constant pressure drop continuous-flow filtration
systems.
Utilizing corrugated, or wave, shape breaker plates it allows higher
concentrations of recycled materials to be used at finer levels of
filtration without sacrificing throughput at lower differential pressures.
And because the active filtration area is extended, screen change
frequency 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!

41
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 effective
breaker plate removing from your unit’s disk.
Close-up of the remover tool. Clearly evident here
is the remover tool mechanism: it is a precision
instrument geared towards efficiency.
The optional hydraulic breaker plate remover
tool makes the removal of breaker plates easier
and safer for the operator and prevents damage
to the disk and breaker plates which could occur
if tools like steel hammers are used to remove
the breaker plates.
All the operator needs to do is align the tool with
the breaker plate to be removed and step on the
foot pedal. The hydraulic pump will then push
out the breaker plate in one fluid motion and the
cavity is ready to receive a clean new breaker
plate.
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

42
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.

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