Film Processing Advances - 7. Biaxial Oriented Film Technology

7232019 Film Processing Advances - 7 Biaxial Oriented Film Technology

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7 J Breil

983095983089 Introduction 983089983097983092

983095983090 Biaxial Oriented Film Lines 983089983097983094 983095983090983089 Sequential Film Lines 983089983097983094

983095983090983089983089 Extrusion 983089983097983096 983095983090983089983090 Casting Machine 983090983088983089 983095983090983089983091 Machine Direction Orienter (MDO) 983090983088983091 983095983090983089983092 Transverse Direction Orienter (TDO) 983090983088983093 983095983090983089983093 Pull Roll Stand 983090983088983096 983095983090983089983094 Winder 983090983088983097

983095983090983090 Simultaneous Stretching Lines 983090 983089 983089

983095983091 Process Control 983090 983089983095

983095983092 Development Environment or Biaxial Oriented Films 983090983090983090 983095983093 Market or Biaxial Oriented Films 983090983090983093

Biaxial Oriented FilmTechnology



983089983097983092 983095 Biaxial Oriented Film Technology

983095983089 Introduction

The stretching o films constitutes a finishing process in which the mechanical prop-

erties optical characteristics and barrier properties are increased significantly Theimprovements o the properties result rom the orientation o the molecular chainsdue to the stretching as well as rom the increase in the degree o crystallinity in thecase o semicrystalline plastics These effects have been known since the 1930swhere stretching processes were already used or polystyrene and PVC (polyvinylchloride) However there was not a commercial breakthrough until the mid-1950swhen ICI and DuPont developed the biaxial stretching o polyester (BOPET) Thistechnology initially had proved o value due to the achievable property profiles ortechnical applications and was spread around the world in a short time due to licens-

ing The biaxial stretching o polypropylene (BOPP) ollowed in the mid-1960swhich gained a large market share mainly in the field o packaging and substitutedor the previously dominant cellophane [1]

The stretching technologies can distinguished in terms o the orientation o thestretching and the stretching process itsel Longitudinal stretching transversestretching sequential biaxial stretching and simultaneous biaxial stretching as wellas the double-bubble process do not really represent competing technologies butrather complete each other in order to achieve specific film characteristics each o

which is suitable or certain product groups (Fig 71)

Figure 71 Outline of stretching technologies



983095983089 Introduction 983089983097983093

In the case o monoaxial stretching in the machine direction (MD) the stretching isrealized by means o rollers with increasing speeds which in turn results in anorientation o the molecules in the machine direction This leads to mechanicalproperties that are mainly enhanced in the machine direction and are thus suitable

or high-strength packaging straps and tear-off strips Furthermore this process isalso applicable to breathable films where polymers with a high content o inorganicfilling materials are employed

Tenters are used in the case o monoaxially stretched film in the transverse direc-tion (TD) with the most common application being shrink labels with high shrinkvalues in the transverse direction and low shrinkage in the machine direction

By ar the most commonly used stretching process is the biaxial sequential technol-ogy In this case the film is usually first stretched in the longitudinal direction and

then in the transverse direction This method prevails or most o the packaging andalso technical applications because it makes it possible to combine the highest pro-ductivity and very good quality Another variant is biaxial sequential stretching inwhich the film is first stretched in the transverse direction and then in the machinedirection In this case an additional annealing oven is required in order to reducethe shrink values to acceptable limits This process is restricted with respect to themaximum working width and speed with the result that the productivity o sequen-tial MD-TD machines cannot be attained For this reason this method is only usedor a ew applications in which a very high strength in the machine direction is

decisive

Another long-established process is simultaneous biaxial stretching where the filmis stretched in the longitudinal and transverse directions at the same time In thiscase the clips that hold the film move on diverging rails so that the film is stretchedin the transverse direction while the distance o the clips is increased at the sametime [2] There are different technical solutions available to control the clip distancespindle pentagraph and LISIM (linear motor simultaneous stretching technology)which will be explained in detail in Section 722

The so-called double-bubble process is another simultaneous biaxial stretchingmethod In this case first a tube is extruded and cooled down It is then heated tostretching temperature and stretched aferwards This is simultaneously done byincreasing the haul-off speed and the effect o the internal pressure which orms abubble This process usually serves to realize lower outputs with the result that theproductivity data o state-o-the-art tenter stretching machines cannot be attainedThe prevailing application or this method is shrink film on PE-basis (polyethylene-basis) as well as to a minor degree BOPA BOPP BOPET (biaxially oriented poly-ethylene terephthalate) and multilayer films




983095983090 Biaxial Oriented Film Lines

In the ollowing sequential and simultaneous film stretching machines are

explained in detail in order to illustrate the current state-o-the-art configuration othe systems and system components

983095983090983089 Sequential Film Lines

BOPP production lines represent the majority o the sequential film stretching sys-tems Thereore the typical components can be explained by taking the example ostate-o-the-art BOPP machines With net film widths up to 104 m speeds up to

525 mmin machine lengths up to 150 m and output capacities up to 75 th (met-ric tons per hour) these types o biaxial stretching machines rank among the larg-est plastic processing systems ever Dimensions and design o the individual compo-nents depend on the film types to be produced the layer structure and the outputIn general the layout o the systems or different film types with its components oraw material supply extrusion casting unit longitudinal stretching machine trans-verse stretching machine pull roll stand and winder are basically similar (Fig 72)In detail however the system components must be adapted to the specific require-ments o each raw material

Figure 72 Sequential biaxial stretching line



983095983090 Biaxial Oriented Film Lines 983089983097983095

The outline o typical state-o-the-art line data or different film types is given inTable 71

Table 71 Outline of Typical Thickness Ranges and Line Data

Line Types PP PET PA

Capacitor Packaging Capacitor Packaging IndustrialOptical Packaging

Medium Thick

Max Line

Widthm 58 104 57 87 58 58 66

Thickness

Range microm 3ndash12 4ndash60 3ndash12 8ndash125 20ndash250 50ndash400 12ndash30

Max Pro-

duction

Speed

mmin 280 525 330 500 325 150 200

Max

OutputKgh 600 7600 1100 4250 3600 3600 1350

The dimensioning o the widths o all components results rom the required net filmwidths taking into consideration the TD stretching ratio edge trim and neck-ineffects The chill roll diameter and roll number or the longitudinal stretchingmachine as well as the zone lengths o the transverse stretching machine are calcu-

lated rom the heating and cooling time as well as the required dwell time in theindividual temperature zones For this purpose suitable calculation programs areavailable that calculate both the film temperature in the machine direction and thetemperature profile along the film cross section Figure 73 depicts an example othe typical temperature profile or BOPP production The maximum temperature di-erences along the cross section can be determined rom the temperatures o thechill roll center and air-knie side which are illustrated separately In particularthe cooling process on the chill roll is decisive or the molecular structure along thecross section Here a symmetric cooling is required which is achieved by placing

the cooling roller into a water bathExact temperature control in all process steps is essential in order to attain therequired characteristics o the stretched film This must also be ensured in all sys-tem components along the complete system width




Figure 73 Calculated film temperatures for BOPP stretching process

983095983090983089983089 Extrusion

The extrusion unit of the stretching machine is usually equipped with a main extruder

and several coextruders in order to meet the requirements for a multilayer structurewith different raw materials by means of coextrusion The most common variant is

the three-layer structure with one extruder for each layer For BOPP systems however

five-layer coextrusion with five extruders is also used (Fig 74) in rare cases there

are seven or nine layers which is primarily for barrier film applications

Figure 74 Extrusion configuration for five-layer structures




Corotating twin-screw extruders have become common or the main extrusion(Fig 75) The advantages over single-screw and cascade extruders are

low specific-energy consumption

compact machine design

continuous vacuum degassing

adaptability by modular design o screw and cylinder

direct additive compounding o powder and liquid components

adjustable melt temperature

good homogenization and mixing and

availability or maximum output o up to 82 th

For coextrusion single-screw and twin-screw extruders are used In twin-screw

extruders melt pumps are installed both or the main extrusion and the coextrusionin order to realize the required pressurization or filtration and nozzle as well as tomake the output as constant as possible The filtration is done by means o large-area filters that in BOPP systems are usually equipped with plain or pleated candlefilters o up to 6 msup2 filter surace in order to achieve a service lie o greater thanour weeks For BOPET large-area filtration is also required but in this case diskfilters are used Figure 76 shows both types o filter systems

Figure 75 Corotating twin-screw extruder




Figure 76 Large area melt filtration

Afer the filtration the melt is led to the extrusion die which is designed as a multi-channel coat-hanger die in BOPP systems This has been proven or obtaining a veryuniorm thickness o the individual layers across the width in the desired thicknessand output range even or different viscosities In general the extrusion dies are

equipped with an automatic die bolt adjustment which is operated in a closed loopwith the thickness gauge in the pull roll stand in order to be able to control the filmthickness along the entire working width The automatic die bolt systems have beenoptimized in such a way that on the one hand the distance o the actuators could bediminished and on the other hand the response time could be reduced Figure 77is the schematic diagram illustrating that the individual bolts are heated by rodheaters and cooled down rom the outside The good heat contact and the low massallows or the ast response time o 20 s and the pitch o the die bolts is 10 mm

Figure 77 Automatic die bolt system




983095983090983089983090 Casting Machine

When the melt exits the extrusion die it must be cooled down rapidly even acrossthe width and a homogenous cast film must be ormed as a base or the subsequentstretching process This process significantly affects the output capacity and film

quality obtainable with the system Figure 78 depicts a typical configuration or achill roll unit or BOPP systems Typical is the arrangement o the chill roll in awater bath in order to achieve a symmetric cooling and the subsequently requiredwater removal which is realized by a high-pressure air blowing nozzle The coolingin a water bath has the advantage that a high heat transer is realized on both filmsides and that the cooling happens as ast and as symmetrically as possible in thisway Furthermore it is critical that the same cooling conditions are achieved alongthe entire working width

Figure 78 Casting unit with chill roll

This is on the one hand made possible by efficient water circulation on the otherhand the internal layout o the chill roll is o vital importance in achieving tempera-ture equality Figure 79 illustrates the principle o internal cooling in which the

demand or the preerably uniorm chill roll surace temperature is taken into con-sideration by use o a degressive design o the cooling ducts The heat transerdepends on the temperature difference between melt and chill roll surace as well ason the heat transer coefficient This in turn is defined by the speed o the water in




the cooling duct The act that the cooling medium warms up in the spiral windingis compensated here by the increased speed due to the diminishing design o theduct cross sections in the spiral which leads to a higher heat transer The resultinguniorm cooling o the film along the working width makes it possible to attain cor-

respondingly uniorm film properties along the working width

Figure 79 Chill roll with degressive cooling channel

In cast film processes the uniormity o the melt discharge and the speed o the chillroll are o vital importance or the achievable longitudinal tolerances o the film Theconstant melt discharge is defined by the extrusion with minimum pressure fluc-tuations having to be realized when the melt enters the die The uniormity o thechill roll surace speed is determined by the run-out tolerance o the chill roll as wellas the speed stability o the drive unit Direct drives are particularly suitable or thispurpose because aults by mechanical transmission units like belts or gears areavoided in this way Here a high-resolution rotary encoder is attached to the sameaxis and a corresponding control loop is implemented that is optimized in order to

achieve the best speed tolerance Another advantage is the act that this drive typeis generally maintenance-ree and low in losses Figure 710 describes the configu-ration or a direct-drive system or a chill roll using a torque motor

Another important component o the casting unit is the pinning system In the caseo BOPP lines air-knie units are preerentially used For this purpose the uniorm-ity o the air discharge is decisive as well as the airflow afer the discharge In addi-tion to the air-knie either external-edge blow nozzles are used or this unctionalityis integrated into the air-knie Furthermore an exact adjustability o the position

relative to the die and chill roll is required or all pinning devices which is eitherrealized by manually operated or automatic two-axis positioning units Pinning tech-nologies have to be variably adjusted and optimized or each raw material Whereas




the air-knie application is the standard or PP packaging film an electrostatic pin-ning device either with a high-voltage wire or blade is typically used or BOPETlines In BOPA lines an electrostatic needle pinning is the state o the art As analternative an HPA (high-pressure air-knie) was developed that serves to realize

approximately 20 higher line speed compared with the electrostatic pinning

Figure 710 Chill roll with direct drive

In considering the pinning technology it must be noted that the maximum achieva-

ble speed depends not only on the pinning device but also on the raw material usedIn particular the melt viscosity is important and in the case o electrostatic pin-ning also the electrical conductivity o the melt There is a correlation that withincreased melt conductivity higher pinning speeds can also be realized In the caseo polyester pinning speeds up to 130 mmin can be realized which lead to linespeeds afer stretching o more than 500 mmin

983095983090983089983091 Machine Direction Orienter (MDO)

The first stage o the sequential biaxial stretching process is uniaxial in the machinedirection and is realized by rollers with increasing speeds The typical stretchingratios are or PP 15 or PET 135ndash45 and or PA (polyamide) 13 According totheir unction the rollers can be classified into three groups (Fig 711) preheatingzone stretching zone and annealing zone

The preheating zone requires a homogenous preheating o the cast film to the targetstretching temperature which is realized by a high heat transer coefficient anduniorm heating o the rollers along the working width The stretching zone is char-acterized by rollers with a small diameter that are arranged in such a way that a niproller can be added to each roller and that the roller distance can be adjusted inorder to be able to adapt the stretching gap to the product




Figure 711 Machine direction orienter (MDO)

This arrangement makes it possible to minimize the neck-in effect which causes awidth reduction during the MD stretching process to avoid slippage at the rollersand to control the stretching speed In doing so it is advantageous to use directdrives in the entire MDO in order to control each roller separately that is to set theoptimal speed and torque It is also important or the preheating zone to ensure a

good contact o the film to the roller by means o sufficient tension thus ensuring auniorm heat transer and to compensate or the length variation that is caused bythe thermal expansion during the heating process at the same time

In the stretching system the drive concept o direct drives has the advantage thatthe stretching gaps can be individually divided by adjusting the increase in speedbetween the individual rollers which thereore leads to optimal settings or eachproduct (Fig 712)

In particular sensitive skin layers such as low-temperature sealing layers can be

shielded rom surace damage in this way By separating the total MD stretchingratio into several individual stretching gaps a higher total stretching ratio can berealized which leads to better product properties and process stability

The rollers are heated using thermal oil or pressurized water In the case o BOPETlines additional inrared heating elements are employed in the stretching gap Alsoin this case the total stretching ratio can be increased correspondingly by means omultigap stretching which has the advantage or BOPET that this also allows or ahigher total line speed because the bottleneck o the line is the limited pinningspeed at the chill roll Due to the speed increase in the MDO a production speedover 500 mmin can thereore be realized or BOPET lines




Figure 712 MDO multigap stretching

983095983090983089983092 Transverse Direction Orienter (TDO)

In the transverse direction orienting machine the MD stretched film is fixed withholding devices (clips) at the film edges and stretched along an adjustable rail in thetransverse direction This process takes place in an oven that is segmented into apreheating zone a stretching zone a thermosetting zone and a cooling zone(Fig 713) The machine component that ensures the transport and holding mecha-nism through the oven is the so-called chain-track system which has to perormwith high reliability low wear and long lietime For this purpose roller chains or

sliding chains with speeds over 550 mmin are available (Fig 714) In the slidingsystems the chain is guided on the rail with replaceable sliding elements where athin wetting o oil or lubrication has to be ensured on the sliding suraces

These systems are designed in such a way that the chain system is effectivelyshielded rom the process environment in order to avoid the contamination o thefilm suraces with oil spots In the roller chains the support and guide o the chaintrack system is realized by means o roller bearings In this case less oil is used orlubrication compared with a sliding chain The roller bearings and track are exposed

to wear which can be reduced by a special chain geometry that ensures that thebearings have permanent contact with the rail The clips must be closed at thebeginning o the transverse stretching machine in order to hold the film and must




be opened at the end in order to allow or the urther transport o the film in the pullroll stand This is realized contact-ree by magnetic opening and closing bars Dur-ing the gripping process the proper position o the closing system must ollow thefilm edge or which hydraulic systems or most advantageously linear motors are

used

Figure 713 Transverse direction orienter (TDO)

Figure 714 Roller chain- and sliding chain track systems




In the transverse stretching machine the temperature control is decisive or achiev-ing the desired film properties and their distribution along the working widthThereore it is necessary that both the temperature and the heat transer conditionsare as uniorm as possible along the working width

Also in a 10-m-wide oven a temperature accuracy o plusmn1degC must be complied withover the entire working width For this purpose a circulating air system is used(Fig 715) which is designed in such a way that a very uniorm air discharge is real-ized by means o slot or hole nozzle boxes The air sucked back flows over heaterexchangers which are optionally heated using electric oil steam or a direct gasheating The circulating air system is designed with separate ans above and belowthe film surace which are controlled by requency controllers in order to adjust thean speed individually or different products The additive content o the films and

the surace enlargement during the transverse stretching process leads to evapora-tion at the applied temperatures which results in condensate ormation in the ovenThis must be reduced to a tolerable amount by means o suitable air exchange ratesBecause high exchange quantities entail a corresponding energy loss the applica-tion o heat recovery systems is useul at this stage In doing so the resh air isheated by the exhaust air by a heat exchanger (Fig 716) and added to the individualzones by a central resh air channel

Approximately 300 kW can be recovered in this way For BOPET lines the installa-tion o catalysts and filters which are integrated into the circulating air system

have proven necessary in order to reduce the concentration o oligomers in the ovenIn optical applications large-area HEPA filters are mounted on the oven roo (pent-house design) and thus much cleaner conditions are obtained

Figure 715 Cross section of a TDO oven zone




Figure 716 TDO heat recovery system

983095983090983089983093 Pull Roll Stand

When the film exits the transverse stretching machine it must first be cooled downbeore the edges are cut the thickness is measured and the surace is treatedThese unctions are realized in the so-called ldquopull roll standrdquo which is preerably

realized in a C-rame design in order to allow or a simple and sae film eed rom theoperating side (Fig 717)

Figure 717 Pull roll stand




This requires a correspondingly robust structure or rollers o greater than 10 mworking width and diameters up to 600 mm in order to avoid vibrations even orhigh speeds o over 500 mmin

The edges are trimmed off by an appliance in which a blade and an automatic cut-

ting device guarantee a sae cutting-off o the thicker edges which are continuouslysucked off on both sides These edges are shredded to film fluff and then ed to theraw material supply or the extrusion via pipes with the result that the edge trim-ming does not result in a loss o material

Afer the edge trimming the thickness is measured continuously by a thicknessgauge head that is traversing over the working width Depending on the film typedifferent measuring procedures are employed Beta-ray X-ray and inrared are themost common The accuracy requirement or the measurement is typically 005 microm

because the final film thickness and the thickness profile must be controlled on thebasis o this signal

The control is accomplished by activating the automatic die with a special algo-rithm being required that allows or the correct alignment o the die bolt position tothe corresponding film position o the biaxial stretched film Afer the thicknessmeasurement the surace treatment is realized in most cases by means o one orseveral corona stations In some cases a flame treatment is applied too Its aim is tomodiy the surace tension in such a way that the film is suitable or subsequentprocessing (printing lamination metallization) The act that the film is guided overseveral rollers with a large working width requires special ocus on the tension con-trol For this purpose each roller is driven by an individual torque motor and asuperimposed tension control ensures that in varying conditions the necessary ten-sion is applied in each section o the pull roll stand

983095983090983089983094 Winder

The winding process in film stretching lines takes place on a winder with the entireworking width where winding weights o up to 7 metric tons are reached Accord-

ing to the film type the contact winding mode or gap winding mode can be selectedThe contact rollers which are made o carbon fiber laminates are dimensioned insuch a way that a preerably low deflection along the working width as well as agood vibration damping are ensured In order to adjust the contact rollers amechatronic system has been developed (LIWIND) with which the ollowing unc-tions are realized in one unctional unit (Fig 718) contact roll position contactpressure and damping unction against vibrations Linear motors in combinationwith precision linear scales are employed here and a special control sofware is

implemented that ensures all three unctions The programmed preselection o thewinding tension and contact pressure characteristics is required or the ideal wind-ing structure




The inormation on film thickness winding length and contact roller positionserves to calculate and control the winding density The correct winding density set-ting in turn is a quality criterion or the subsequent storage process o the windingroll in which the postcrystallization takes place Only this guarantees optimal pre-

requisites or the subsequent cutting process on primary cutting machines wherethe customization to user-specific working widths and roll lengths rom the primaryroll takes place The dimensions o the film winder in a 104 m BOPP line can beseen in Fig 719

Figure 718 Full width film winder

Figure 719 Winder of a 104 m BOPP production line




983095983090983090 Simultaneous Stretching Lines

As a contrast to sequential film stretching lines in simultaneous stretching lines thefilm is not stretched in two separate steps in the MD and TD directions but simulta-

neously in both directions in one oven In this case the clips that hold the film moveon diverging rails so the film is stretched in the transverse direction while the dis-tance o the clips is increased at the same time There are different technical solu-tions or this process In the so-called ldquopentagraph methodrdquo the clip distance isadjusted by a olding pentagraph geometry o the chain whereas the distance o theclips is determined by the geometry o the guiding rails In the spindle method theclips moving along the rail lock into a spindle with a progressive notch and areseparated in this way which makes the longitudinal stretching possible A thirdvariant is the LISIM technology (linear motor simultaneous stretching) [3] With

this method the clips are driven by linear motors which allows or a ree adjustabil-ity o the clip distances along the entire machine and thus the local MD stretchingratio This technology has the ollowing advantages over the previously describedmechanical solutions which have a significant effect on both productivity and prod-uct quality

production speed up to 400 mmin

high flexibility o the stretching ratios in the longitudinal and transverse direc-tions

variable setting o the relaxation in the longitudinal and transverse directions

low maintenance costs

high uptime

suitability or clean room conditions and

applicability or all stretchable polymers in a large thickness range

This technology has been employed in production scale since 1998 and is availablein adapted versions or different plastic film types (Fig 720)




Figure 720 LISIM (linear motor simultaneous stretching) technology

The above-mentioned advantages are realized by a symmetric monorail track sys-tem (Fig 721) The clip is guided by eight roller bearings and permanent magnetsare mounted on the top and bottom o the clip opposite to the linear motor statorsthat are fixed on the track system The orce that each clip needs or moving accel-eration and film stretching is generated by the interaction o the magnetic fields othe permanent magnets and the stator ollowing the principle o the synchronouslinear motor In this case the moving magnetic wave o the linear motor stator isgenerated by the current supplied by adjustable requency drives whereas the cur-rent amplitude defines the orce and the requency defines the speed o the mag-netic wave The linear motor stators are cooled by integrated water pipes thereore

they can resist the severe conditions o a hot oven environment or a long lietimeThe system is designed or clean room conditions so a protective oil shield ismounted on the top and bottom o the system

Due to the design eature that there are no mechanical links between the clips thereis an extreme flexibility regarding the speed patterns and MD stretching ratioswhich are determined by the local distance o the clips throughout the wholemachine This flexibility in stretching patterns can be utilized to enhance the filmproperties significantly (Fig 722)




Figure 721 Cross section of a LISIM track system

Figure 722 Comparison of stretching curves for BOPP with sequential and simultaneous

stretching

An example is shown or the BOPP process comparing sequential and simultaneousstretching Whereas in sequential stretching the MD and TD stretching ratios aredetermined by process limitations in the corresponding machine (MDO and TDO)

the simultaneous stretching process allows a much wider range or the MD and TDstretching ratios The advantage in this case that in contrast to sequential stretch-ing the MD ratio can be adjusted to higher values than TD which results in higher




mechanical properties in MD as well or it is possible to adjust the stretching patternor MD and TD in exactly the same way which results in isotropic propertiesAnother advantage o this flexibility o the stretching patterns is the possibility oMD relaxation which is an effective method or adjusting the shrinkage o the film

in the MD directionFor the product-related layout o the linear motor system or a production line it isnecessary to know the required orces in each individual zone o the machine Forthat purpose a simulation using the finite element method (FEM) is used This isbased on the stress-strain relationship o the individual materials during the simul-taneous stretching process The model takes the temperature strain rate andstretching ratio under consideration and calculates the two-dimensional distribu-tion o the stress and the thickness as well as the orces in MD and TD on the clip

positions (Fig 723)

Figure 723 FEM simulation of the simultaneous stretching process

The reliability o the model and the results could be proven by comparison with

measured data rom a real process using a clip with load cells or the stretchingorce (Fig 724) This comparison is shown with data o a pilot line and the produc-tion o 188 microm BOPET film The orce calculation in the TD direction shows a stead-ily increasing orce until the end o the stretching zone whereas the orce in the raildirection which corresponds to the necessary motor orce shows positive and nega-tive components during the path through the machine Positive means the clip hasto pull a negative orce means the clip has to hold back the maximum orces reachedafer the stretching zone which is the basis or the layout o the linear motor drivingsystem The orces can be influenced in a wide range by adjusting the MD and TD

stretching patterns as well as the temperature patterns o the individual zones




Figure 724 Comparison of simulated and measured forces during simultaneous stretching

The advantages o a high flexible simultaneous stretching technology are differentand individually decisive or the different products due to the requirements andenhancement characteristics

For BOPP some products require high shrinkage in the MD direction and low in theTD direction which can be adjusted by the individual stretching patterns in MD andTD Such film is produced or MD shrink labels based on BOPP Another example isthe act that different materials can be coextruded and stretched together in anappropriate process window (stretching ratio temperature strain rate) This effectcan be used or example by stretching EVOH (ethylene vinyl alcohol) grades withlow ethylene content with polypropylene in order to combine the good barrier char-acteristics o both materials or enhancing barrier values regarding OTR (oxygen

transmission rate) and WVTR (water vapor transmission rate)For BOPA simultaneous stretching in combination with simultaneous relaxationallows very low and isotropic shrinkage characteristics which is significant or theBOPA converting processes that is lamination with PE film In this case the simul-taneously oriented film has much ewer distortion characteristics when the lami-nates are under the temperature influence that is required during hot fill and steri-lization processes

For BOPET two different cases have been proven in production scale ultrathin film

with high mechanical properties and isotropic film characteristics has been pro-duced down to 05 micron which is the lowest end or capacitor applications Forthick film or optical applications the advantages are summarized in Fig 725




Figure 725 Advantages of LISIM technology for BOPET optical film

In flat-screen displays the angle o the molecular orientation low and isotropicshrink values a scratch-ree surace and a very high transparency are crucial orhigh-quality optical films All o these properties can be set using the simultaneoustechnique by means o adapted stretching profiles Such high-tech films are by nowproduced with a thickness up to 400 microm The profitability is essentially determinedby the high output capacity high A-quality yield and high availability that can beachieved with this technology

Another economic advantage results i subsequent processing steps are not neces-sary due to the integration o all required unctionalities into the simultaneousstretching process Among them are off-line tempering processes in order to mini-mize the shrinkage values as or some BOPET thick film with very low shrinkagerequirements in the MD and TD directions In this case the eature o MD relaxationat the end o the annealing zone is used to lower the MD shrinkage significantly

(Fig 726)A relaxation rate o minimum 6 is needed in order to bring the shrinkage valuesclose to zero which is a requirement or some applications (or example substratesor organic electronics)

Some optical films also require a special characteristic regarding the molecularorientation angle which can be influenced in a wide range by the stretching pat-terns as well



983095983091 Process Control 983090983089983095

Figure 726 Influence of MD-Relaxation on MD-Shrink values

983095983091 Process Control

The proper unction and synchronization o all components o a biaxial film orient-ing line as well as continuous quality control have to be secured by an integratedprocess control (IPC) system which has a modular design as illustrated in Fig 727

Figure 727 Integrated process control (IPC) for a biaxial stretching line




The control of the drives temperatures and the control logic is realized by dedicated

bus systems With a drive bus system a very accurate synchronization of all line com-

ponents has to be secured not only in steady-state operation but also during ramping

functions which is necessary for starting up the line or changing products without

process interruptions The temperature control and the control logic are implemented via PLC with realization of fast reaction times For the operation of the line several

PCs along the production line are connected with a workstation via an Ethernet net-

work The user interface allows changing of set points observation of trends of all

major data points organization of product data and recipe management and depic-

tion of transparent information from the alarm management system The user inter-

face allows natural language support Because machine and process are very complex

and the huge amount of data has to be controlled it is necessary to give the operator

a guide in order to avoid failures during operation This is realized by a simple push-

button operation which brings the production line from one preconfigured parameter

setting to the next in order to allow product changes or ramping functions without

process interruptions As a result the uptime of the line can be maximized which is

an important factor for the overall production costs If there are troubles at the line in

addition to the immediate messages from the alarm management system there is also

a remote service available which provides fast support from specialists who have

access to all parameters of the line by using the internet connection

The thickness control is ully integrated into the IPC system and is based on the

signal o the thickness gauge in the pull roll stand in order to control the automaticdie (Fig 728)

Figure 728 Thickness control system



983095983091 Process Control 983090983089983097

The goal or the thickness-control system is to achieve a constant thickness over theull working width in the range o plusmn1 which is only possible by a combination o avery precise measurement o the final film and a sophisticated control loop In orderto achieve this a cascaded control loop is realized where the signal o the final film

thickness gauge is based or the calculation o the set points or the die bolt tem-peratures in the extrusion die The internal control loop controls the actual tempera-tures o the individual die bolts according to the corresponding set points For thatpurpose also a correct allocation o the individual die bolts to the correspondingsegments o the final film is necessary This is realized by an automatic sel-learn-ing bolt-mapping unction that incorporates the nonlinear assignment during cast-ing MD stretching and TD stretching

A precondition or the control is the precise and reliable measurement o the final

film thickness which can range between 1 micron and 500 micron depending onthe line type and product range There are different methods available that fit ingeneral or the requirements o the biaxial oriented film lines Table 72 gives anoverview o the advantages and disadvantages o the individual systems

Table 72 Comparison of Thickness Gauges

Beta X-ray Infrared

Pro Pro Pro

+ easy to operate + easy to operate + very accurate+ only one value to calibrate

(density)

+ only one value to calibrate

(density)

+ wide gap

+ good accuracy + good accuracy + insensitive to ambient

conditions

+ wide measurement range + mechanically tolerant

+ high TD resolution + multilayer film measurement

+ no license needed + no license needed

+ low maintenace costs

Con Con Con ndash sensitive to ambient tempera-

ture air pressure

ndash sensitive to ambient tempera-

ture air pressure

ndash calibration with two factors

ndash sensitive to vertical variation

of gap

ndash big passline error ndash sensitive to changes of mate-

rial

ndash big passline error ndash small gap ndash no black film (dark colors)

ndash small gap ndash medium maintenance costs

ndash contaminated zone

ndash radiation license required

ndash

high maintenance costs




In the past radiometric thickness-measuring devices using beta radiation weremostly used with sources PM 147 or KR 85 depending on the required thicknessrange The advantage is the stability o the measurement which is based on theabsorption characteristics o the materials or the beta radiation Because radio-

metric sources require special licenses or operation and saety training and have alimited lietime the beta-gauge system has been more and more replaced by otheralternatives One option is to use X-ray radiation with low beam energy because lessthan 5 kV does not require a license in most countries X-ray is also more sensitiveto changes in recipe additives in film and ambient air temperature Another optionis the inrared (IR) absorption method where the absorption o the inrared light iseither measured in specific requency bands or in an analysis o the completeabsorption spectrum The different absorption characteristics o individual poly-mers also allow measurement o coextruded multilayer films where the individuallayers can be distinguished i the IR spectra show a sufficient difference

For continuous quality control it is most attractive to measure as much as possiblequality data in line Measurement devices that allow a spot measurement can beattached to the traversing head o the thickness measurement in order to also getdata or the ull width o the film This method is possible especially or optical datalike haze gloss and bireringence Figure 729 shows as an example a method tomeasure the molecular orientation angle (MOA) o the final film over the workingwidth by using a bireringence sensor with ast data processing [4] With the inor-

mation o the molecular orientation angle uneven properties over the workingwidth such as caused by the bowing effect can be optimized which is important orspecific optical films or flat-panel displays For these applications it is necessary tokeep the MOA below a specific limit value

Figure 729 Inline measurement of the MOA (molecular orientation angle)



983095983091 Process Control 983090983090983089

Another example o in-line quality control are web inspection systems which areused to detect deects in the film or on the surace By means o high-resolution linescanners in combination with ast data processing a classification o the deects(gels scratches inclusions dust and others) can be recorded and documented dur-

ing productionIn addition to the control o the line and the in-line measurement o the qualitythere is also another possibility or optimizing the production efficiency that oadapted sofware tools As with the integrated process control system there is accessto all necessary process and quality data an intelligent line management system(ILS) can utilize the data to optimize the production yield (Fig 730) A roll data his-tory module (RDH) collects all production data including the raw material recipesand process data or each produced roll and stores it or later data processing With

a quality data management system (QDM) the data that are measured in the labora-tory (mechanical optical shrinkage surace characteristics and others) are alsostored in an appropriate database A production planning system (PPS) helps theproduction manager to minimize losses due to product changes A slitting optimiza-tion system (CUT) is dedicated to increase the slitting yield A computerized mainte-nance system (CMS) is used to maximize the line availability In this case time- orevent-triggered maintenance stops secure maximum uptime by avoiding longerunplanned line stops In order to get anytime access to the perormance o each pro-duction line a mobile solution (MOS) is available that brings the key perormance

indicators to smart phones or tablets Thus the production or top management isalways inormed about the uptime capacity and yield o each production line

Figure 730 Intelligent line management (ILM) system




983095983092 Development Environment for BiaxialOriented Films

In view o the diversity o biaxial oriented films and the dynamic shif o marketscontinuing research and development is required not only or the film producersbut also or raw material suppliers and machine manuacturers Most film produc-ers o biaxial oriented films do not have their own inrastructure or pilot line withtesting acilities so the question is how can tests be perormed that are necessaryor the development o new film types In some cases existing production lines areused to test recipe variations or a modified process setting The disadvantage in thiscase is a loss o valuable production time and a high raw material consumption orsuch tests This situation can be improved with a smaller more flexible pilot lineThe extrusion and orientation process is perormed on a much smaller scale andnew developments are done with a minimum amount o raw material and withoutintererence to the running production In order to meet the demands o the ori-ented film industry Bruumlckner Maschinenbau GmbH amp Co KG Germany operates atechnology center that is available or the use o customers on a rental basis Athree-step method o research and development action is perormed in order toderive result data and to obtain inormation required or the design layout o pro-duction lines or newly developed films (Fig 731)

Figure 731 Methodology for research and development and upscaling

The first step comprises a batch-process stretching procedure on a laboratorystretching rame that is designed to simulate the continuous production processThe eatures o lab stretching equipment (Fig 732) are

up to 10 times 10 stretching ratio back-drawing capability (lt 1)



983095983092 Development Environment for Biaxial Oriented Films 983090983090983091

MD retardation or optical films(MDX lt 1 while TDX gt 1)

three flexible heating modules and

400degC high temperature

The cast film or this batch stretching process is produced on a laboratory extruderwith a multilayer die The oriented samples rom the lab stretcher are characterizedby representative film properties and can be analyzed in the laboratory or chemi-cal physical electrical shrink and barrier properties Process data such as tem-perature stretching ratio and speed can be transerred to the continuous process oa film stretching line

Figure 732 Labstretching equipment Karo IV

The pilot line is designed to be multiunctional and very flexible so that all relevantstructures and film types can be produced on a pilot scale Any important inorma-tion like production stability thickness tolerances and product perormance can bederived rom such continuous tests The pilot line is designed to operate MD TDsequential and simultaneous stretching processes (Fig 733) In combination with

a flexible extrusion system or nearly all extrudable polymers in combination withmultilayer structures by coextrusion it is possible to realize a lot o structures [5]Furthermore an in-line coater is available in order to apply thin-film coatings orprimer antiblock release protection barrier or optical enhancements and otherunctions The film orienting is realized by a multigap stretching MDO ollowed by aTDO or by using the simultaneous LISIM technology This technology allows adjust-ment o the stretching ratios stretching curves relaxation curves and process tem-peratures in the most flexible way in order to meet the required film properties onewly developed films




Figure 733 Pilot line for biaxial oriented films

In particular the eatures o multilayer biaxially oriented films with three five oreven seven layers offer a significant added value to the products with low impact onproduction cost A wide range o film types has been developed and tested in thepast on this pilot line which is summarized in Fig 734

Figure 734 Experiences on pilot line scale

Based on these experiences this environment offers the best conditions or uture

development o oriented films Some o these have been transerred to productionscale using the basic stretching data rom the pilot line or a dedicated line layout othe production line



983095983093 Market for Biaxial Oriented Films 983090983090983093

983095983093 Market for Biaxial Oriented Films

With the enhancement o properties in combination with very economic production

biaxial oriented films were widely propagated in packaging as well as in technicalapplications The breakdown o raw materials used or oriented films is shown inFig 735 according to the worldwide installed line capacity [6]

Figure 735 Worldwide production capacity for biaxial oriented films (tpa = metric tons per

annum)

BOPP represents the dominant raction o about 60 o all oriented films with aninstalled worldwide capacity o nine million metric tons per year The biggest por-tion o BOPP is used or packaging applications just a small raction is used orcapacitor and other technical applications The reason or this is that BOPP is a verysuitable material because it combines good overall properties in combination withan attractive cost situation and a good yield due to the low density o 0905 g cmsup3The applications in packaging are very diverse and include single-layer and multi-layer film structures Single-layer structures are used or instance as flower wrap-ping directly but are more ofen laminated with other films or processed such as oradhesive tapes Typical applications or laminates are noodle packaging whereBOPP and cast PP are laminated together in order to combine the positive propertieso both film types (mechanical strength and puncture resistance) Multilayer BOPPfilms are produced by coextrusion where in most cases or each individual layer oneextruder is used in order to allow maximum flexibility or covering a wide range oproducts The most common three-layer coextruded BOPP films contain in the corelayer a PP homopolymer whereas in the skin layers PP copolymers with low meltingtemperatures are used so that the sealing procedure that is used or most packaging

applications can be applied in the temperature range where the skin layer sealswithout deorming the core layer This five-layer coextrusion technology offers addi-tional enhancements like improved optics and opacity but also cost advantages byemploying expensive additives in thinner intermediate layers instead o in the core




layer Besides the transparent applications white opaque film types are also usedwhich are applied in packaging or conectionary and labels

The market or BOPP has been growing with a stable rate o more than 6 per yearor many years (Fig 736) [6]

The strongest growth rates have been observed in the ar eastern area especially inChina where 44 o all BOPP production takes place This trend is caused by theongoing urbanization effect where a growing portion o the population achieves ahigher living standard causing a corresponding influence on consumer behaviorand more use o packaging materials

With biaxial oriented polyester films (BOPET) over time different market trendshave occurred The turndown o magnetic storage media such as audio- video- andcomputer tapes and floppy disks which are all based on BOPET film as a carrier has

been counterbalanced by a disproportionate growth in packaging applications

Figure 736 Market trend for BOPP

Besides the use in the packaging industry there is also a large field o technicalapplications like capacitor films electrical insulation thermal-transer film opticalfilm or flat-panel displays solar back sheets and substrates or organic electronicsBoth market segments together the technical and the packaging show a stablegrowth rate o 68 per year which is also likely in the near uture As or BOPP thecore areas move more and more into the Asian region especially to China wherealready 42 o the worldwide BOPET capacity is installed (Fig 737) [6]

Other markets or biaxial oriented films are substantially smaller So is the installedcapacity or BOPA (biaxially oriented polyamide) at 267000 metric tons per yearwhere the most common applications are in the packaging area Due to its excellentpuncture resistance in combination with being a good oxygen and aroma barrierBOPA is preerred or flexible packaging o meat sausages cheese fish and liquids

The thickness range is typically 12ndash25 micron BOPA film is produced by sequentialstretching as well as simultaneous and double-bubble processes




Figure 737 Market trend for BOPET

BOPS (biaxially oriented polystyrene) film is used in two segments The thinnerrange o 30ndash150 micron is used as window film or envelopes and separating film inphoto albums whereas the thicker range (150ndash800 micron) is mostly applied asthermoorming sheet or highly transparent packaging containers A specialty isBOPLA (biaxially oriented polylactide) which is a representative o plastics romrenewable sources The optical and mechanical properties are excellent afer theorientation process but widespread use is limited by the water-vapor barrier thethermal stability and the higher price or the raw material For applications wherea certain transmission o water vapor is required like or bread and vegetables the

properties o BOPLA can be an advantageAnother segment or oriented films is BOPE (biaxially oriented polyethylene) whichis mostly used as shrinkage film where or each application a specific property pro-file with shrinkage values shrink orces mechanical properties and barriers arespecifically adapted BOPE shrink films are mostly produced with a double-bubbleprocess

The outlook or biaxial oriented films and the development o markets in the indi-vidual fields o application is very promising The entire packaging sector is charac-

terized by strong growth in regions with high population growth rates and continu-ing urbanization which cause changes within the distribution chains or oodstuffsand other consumer goods leading to increased consumption o packaging materials

Another trend can be observed in the ever stronger discussion about CO2 emissionsinto the atmosphere and the political guidelines on the matter resulting in specificand binding measures to reduce CO2 emissions In the uture these actors will havean increased influence on the entire packaging industry and thereore also on bi-axial stretched films In some countries or example France there will be a legalobligation to print inormation about the CO

2 ootprint on consumer packaging

Because the CO2 ootprint o packaging films is mainly dependent on the appliedraw material (resin carries 85 o the CO2 balance in BOPP) it is logical to reduce




the CO2 ootprint by down-gauging films In principle down-gauging avors biaxialoriented film which allows or a maximum packaging effect with the minimum rawmaterial use Further potential to improve the CO2 ootprint can be ound in the sub-stitution o individual layers within packaging laminates (or example aluminum

oil) by coextruded or metallized high-barrier films based on biaxial oriented filmsApart rom the constant growth in conventional packaging applications or biaxialstretched films there are a number o newer technical applications represented inuture markets with strong growth rates

Some changes in the markets result rom technological developments or even inno-vation leaps Within a ew years products that did not exist beore incorporatingbiaxial stretched films can be on the market A typical example is optical films orflat screens which created a substantial market not only or thick BOPET films in

the range o 188 microm to 400 microm but also or other films such as COC (cyclo olefine)PC (polycarbonate) PMMA (polymethylmethacrylate) TAC (triacetate) and othersDue to the global substitution o cathode-ray tube screens by flat screens (LCDplasma OLED) this trend will continue in the years to come and will result in respec-tive demand or the aorementioned film types Another progressive development isexpected to happen in the field o flexible electronic devices here large potentialshave been identified in electronic applications that can be produced in roll-to-rollprocesses These include flexible photovoltaic panels e-paper flexible displays flex-ible printed circuits and flat-surace illumination devices

Another trend that came up in the recent past is the requirement or ecologicallyriendly mobility hybrid and electrical power are playing an important role in theautomotive industry Forecasts show a continued substitution o combustion enginesby electrical motors in the next 20 years

Globally the development in this field is driven by the act that battery technology iskey to the ratio o cost versus range Lithium-ion batteries show the best potentialor a large market share because the required perormance data can be obtainedwith existing technology All lithium-ion batteries include a separator film in which

the major part o these films consists o biaxial stretched membranes Thereore astrong growth or this kind o specialized membrane can be expected Representing20 o the material cost the separator to date carries a significant share o the over-all cost and because the battery technology as a whole must become substantiallycheaper (the midterm goal is to cut overall costs by hal) highly productive andefficient processes or the production o battery separator films are required Fur-ther potential or lithium-ion batteries is seen in existing and urther growing mar-kets (notebooks portable phones) as well as in new applications such as stationaryenergy storage which gain momentum through renewable energy sources such aswind and solar energy



References 983090983090983097

References

1 Jabarin S A ldquoOrientation and Properties o Polypropylenerdquo presented at The Society of

Plastic Engineers Annual Technical Conference May (1992)

2 Briston J H Katan L L Plastic Films (1989) 3 rd ed Longman Scientific amp Technical

Harlow

3 Breil J ldquoAdded Value Speciality Films Produced with Sequential and Simultaneous

Stretching Linesrdquo Special Plastics Film Conference 18 th Annual World Congress Zuumlrich

Switzerland October 29ndash30 (2002)

4 Koerber A Lund R Langowski H-C ldquoGeometrical Bowing and Molecular Orientation

Angle in Biaxially Stretched Poly(ethylene terephthalate) Filmsrdquo J Appl Polym Sci

(2013) 127 pp 2928ndash2937

5 Breil J ldquoOriented Film Technologyrdquo Multilayer Oriented Films Wagner John R (Ed)

(2010) Elsevier Amsterdam6 Brueckner Sales Data Base



7 J Breil

983095983089 Introduction 983089983097983092

983095983090 Biaxial Oriented Film Lines 983089983097983094 983095983090983089 Sequential Film Lines 983089983097983094

983095983090983089983089 Extrusion 983089983097983096 983095983090983089983090 Casting Machine 983090983088983089 983095983090983089983091 Machine Direction Orienter (MDO) 983090983088983091 983095983090983089983092 Transverse Direction Orienter (TDO) 983090983088983093 983095983090983089983093 Pull Roll Stand 983090983088983096 983095983090983089983094 Winder 983090983088983097

983095983090983090 Simultaneous Stretching Lines 983090 983089 983089

983095983091 Process Control 983090 983089983095

983095983092 Development Environment or Biaxial Oriented Films 983090983090983090 983095983093 Market or Biaxial Oriented Films 983090983090983093

Biaxial Oriented FilmTechnology













983095983089 Introduction 983089983097983093






decisive




















Medium Thick

Max Line

Widthm 58 104 57 87 58 58 66

Thickness


Max Pro-

duction

Speed

mmin 280 525 330 500 325 150 200

Max

OutputKgh 600 7600 1100 4250 3600 3600 1350








983095983090983089983089 Extrusion
































983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937















983095983089 Introduction 983089983097983093






decisive




















Medium Thick

Max Line

Widthm 58 104 57 87 58 58 66

Thickness


Max Pro-

duction

Speed

mmin 280 525 330 500 325 150 200

Max

OutputKgh 600 7600 1100 4250 3600 3600 1350








983095983090983089983089 Extrusion
































983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937





983095983089 Introduction 983089983097983093






decisive




















Medium Thick

Max Line

Widthm 58 104 57 87 58 58 66

Thickness


Max Pro-

duction

Speed

mmin 280 525 330 500 325 150 200

Max

OutputKgh 600 7600 1100 4250 3600 3600 1350








983095983090983089983089 Extrusion
































983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937




















Medium Thick

Max Line

Widthm 58 104 57 87 58 58 66

Thickness


Max Pro-

duction

Speed

mmin 280 525 330 500 325 150 200

Max

OutputKgh 600 7600 1100 4250 3600 3600 1350








983095983090983089983089 Extrusion
































983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937










Medium Thick

Max Line

Widthm 58 104 57 87 58 58 66

Thickness


Max Pro-

duction

Speed

mmin 280 525 330 500 325 150 200

Max

OutputKgh 600 7600 1100 4250 3600 3600 1350








983095983090983089983089 Extrusion
































983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937







983095983090983089983089 Extrusion
































983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937




























983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937













983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937






983095983090983089983090 Casting Machine


















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937















































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937





































used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937


























used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937
















used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937







used
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937
















983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937







983095983090983089983093 Pull Roll Stand













983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937












983095983090983089983094 Winder






















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937





















high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937














high uptime
















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937















stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937








stretching








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937








positions (Fig 723)
























983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937






















983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937













983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937





983095983091 Process Control 983090983089983095
































983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937






























983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937





983095983091 Process Control 983090983089983097






Beta X-ray Infrared

Pro Pro Pro


(density)


(density)

+ wide gap


conditions






ture air pressure


ture air pressure



of gap


rial





ndash












983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937













983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937





983095983091 Process Control 983090983090983089







































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937




































annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937




























annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937


















annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937










annum)






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937






































References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937


























References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937















References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937





References 983090983090983097

References




Harlow






(2013) 127 pp 2928ndash2937



Documents

Film Processing Advances - 7. Biaxial Oriented Film Technology