CN101228021A - Method for controlling crossing omentum thickness distribution of biaxial orientation polymer membrane - Google Patents

Abstract

The present application discloses a method of controlling a cross-web caliper profile of a biaxially oriented polymeric film by stretching the film in a length orienter (100) having an adjustable profile cross-web heat distribution system (150a, 150b, 150c), subsequently deforming the film in a tenter (200) oven having a deformation zone, measuring the cross-web caliper profile of the film at a location downstream from the deformation zone, optionally mapping the measured cross-web caliper profile of the film onto the length orienter, and adjusting the cross-web heat distribution system in response to the measured cross-web caliper profile.

Description

The method that the crossing net film thickness of control biaxially oriented polymer film distributes

Invention field

The present patent application relates to and is controlled at the variation of extruding thickness in the alignment films.

Background

Extrusion film causes usually along the variation of film length and width thickness.The method of prior art control varied in thickness comprises regulates mould bolt (US4 of Kogo etc., 409,160), regulates heating power (US3,347,960, the Fenley of fixing heater during stretching; JP52,047,070, Tsutsui), or (GB 1,437,979, Hoechst Aktiengesellschaft to have the diverse location place that is intended to whole knitmesh to produce zone thick and that approach; GB 1,437,980, HoechstAktiengesellschaft), so finished films to twist in be uniform in appearance.

Summary of the invention

The present patent application discloses the method for the crossing net film thickness distribution of control biaxial tension thin polymer film, be included in oriented film in the length orientation device with adjustable section intersection nethike embrane heat compartment system, in having the stenter of deformed area, make deformation of thin membrane subsequently, distribute at the crossing net film thickness of deformed area location downstream MEASUREMENTS OF THIN, and intersect the heat compartment system of nethike embrane in response to the crossing net film thickness profile adjustment of measuring.Above-mentioned summary is not to be intended to describe each disclosed embodiment of the present invention or each implementation process.Following drawings and detailed description more specifically illustrate illustrative embodiment.

The accompanying drawing summary

Consider following detailed description together with accompanying drawing, can understand the present invention more completely, wherein similarly reference number is indicated similar elements.It is the example of explanation that accompanying drawing is intended to, and is not that to be intended to be restrictive.

Fig. 1 is the schematic diagram that is used for the film line of biaxially oriented film.

Fig. 2 a is the schematic diagram of an embodiment of adjustable section intersection nethike embrane heat compartment system in the length orientation device.

Fig. 2 b is the schematic diagram of the other embodiment of adjustable section intersection nethike embrane heat compartment system in the length orientation device.

Fig. 2 c is the schematic diagram of the other embodiment of adjustable section intersection nethike embrane heat compartment system in the length orientation device.

Fig. 3 is the top view of signal of an embodiment of geosynclinal block assembly.

Fig. 4 is the schematic diagram of the other embodiment of adjustable intersection nethike embrane heat compartment system.

Fig. 5 is the schematic diagram of an illustrational reducible pivot heating element heater of embodiment.

Fig. 6 is the part perspective view of the assembly of a reducible pivot heating element heater of embodiment.

Fig. 7 is presented among the embodiment 1 specific geosynclinal block to the influence of optical thickness.

Fig. 8 is presented among the embodiment 2 influence of one group of geosynclinal block to optical thickness.

Fig. 9 is presented among the embodiment 3 variation along with the variation optical thickness of crossing net film location.

Figure 10 shows in embodiment 4 tables 4, and relative optical thickness is to the variation of crossing net film location that arrangement is set corresponding to heating element heater.

Figure 11 shows in embodiment 4 tables 5, and relative optical thickness is to the variation of crossing net film location that arrangement is set corresponding to heating element heater.

Figure 12 shows in embodiment 4 tables 6, and relative optical thickness is to the variation of crossing net film location that arrangement is set corresponding to heating element heater.

Figure 13 shows in embodiment 4 tables 7, and relative optical thickness is to the variation of crossing net film location that arrangement is set corresponding to heating element heater.

Describe in detail

The present patent application relates to the varied in thickness of controlling alignment films. Film production causes usually along the varied in thickness of film length and width. The invention discloses the new system and method for effectively regulating the distribution of alignment films crossing net film thickness for trickle.

The system and method for the disclosure can be used to make the film that comprises any polymer, and its performance has benefited from the stretching during thin film fabrication.Film can comprise a kind of or more than a kind of polymer.The film that has more than a kind of polymer of composition can have form or structural form arbitrarily, yet comprise and be not limited to miscible blend, wherein a kind of polymer is that continuous phase is immiscible blends of decentralized photo with one or more, be total to continuous blend, interpenetrating polymer networks and have the laminar films of many layers.The invention discloses the system and method that is particularly useful for multilayer optical film.These system and methods also are particularly useful for comprising the film of polyester.

By using the multilayer optical film that disclosed system or method make can be including, but not limited to the mirror film, polarizing coating is such as the polarizer of reflection, display film, filter, compensate film, antireflection film, or provide for example ultraviolet ray or infrared shield, the painted or window that covers with (energy control or control at sunshine) film (being used for architectural, motor vehicle, greenhouse or other purposes).

The film of the application of the invention system or method manufacturing needs not to be the optical thin film of multilayer.Other high performance membrane also can have benefited from crossing net film thickness control disclosed by the invention.The application of high performance thin film including, but not limited to: be used for sound, the magnetic medium basement membrane of the analog or digital record of image or data, plate technology film, copy film, the projection transparent membrane, photographic film, x light film, microfilm, the photo printing film, the ink jet type print film, the plain paper copier film, the galley film, the color proof film, digital printed film, the carbon ribbon film, the hectographic printing film, the photogravure film, sketch and diazo copying film, holo film, tape substrate, the grinding agent substrate, label film, the release liner film, masking film, laminated film, encapsulating film, heat-sealing film, epiphragma, two ovenable films, barrier film, marking paper tinsel, metalized film, the decoration film, archives and preservation film, be used for electric wire, cable, motor, the electrical insulation film of transformer and generator, the flexible printed circuit film, capacitor films, be used for card such as credit card, prepaid card, the film of identity card and " smart card ", be used for scratch resistance, anti-graffiti or vandal-proof window or security film (safety film), the diaphragm switch film, the touch screen film, medical energy converter and diagnostic device film, sound deadening sheet, sound equipment loud-speaker diaphragm and drum facial mask.

For giving specific optics of finished films and/or physical characteristic, can pass through the film die extruded polymer, mould openings is usually by a series of mould bolt controls.The film of extruding can for example be orientated by stretching with the determined ratio of desired properties subsequently.As shown in Figure 1, in length orientation device 100, can implement longitudinal stretching by carry-over pinch rolls.The length orientation device has one or more drawing zones longitudinally usually.Can in the stenter stove 200 in being shown in accompanying drawing 1, implement cross directional stretch.This stenter stove generally includes at least one preheating zone 210 and a cross directional stretch district 220.Usually as shown in Figure 1, the stenter stove also comprises a heat setting district 230.System can be designed to comprise arbitrarily or all these districts one or more.If desired, film can biaxial tension.Can in proper order or carry out biaxial stretching simultaneously.Film also can be separately by longitudinal stretching, or separately by cross directional stretch.For coaxial stretching, about 3: 1 to 10: 1 draw ratio is general.For biaxial stretching, the product of vertical and horizontal draw ratio is generally 4: 1 to 60: 1.Those of ordinary skill in the art's understanding can be used other draw ratio as one sees fit for given film.

For purpose of the present invention, term " cross directional stretch district " refers to any district of cross directional stretch purely or simultaneously biaxial stretch-formed district in the stenter baking oven.With regard to " stenter ", we are meant any equipment, are clamped in its edge by this equipment film, transmit at machine direction simultaneously.Usually, film is stretched in stenter.Usually, the draw direction in stenter is perpendicular to machine direction (horizontal or crisscross), but same expection has other draw direction, for example stretches with the angle that is different from perpendicular to the film move angle.Optional, except that being different from the first direction oriented film of machine direction, this stenter also can or approach the second direction oriented film of machine direction at machine direction.Second direction in stenter stretches and can take place simultaneously with the stretching of first direction or take place individually, or both take place together.Can finish in many steps in the stretching within the stenter, each step can have tensile product at first direction, second direction or both.Stenter also can be used for controlling the transverse relaxation amount of film, will dwindle if do not grip described amount of relaxation at its edge.In this case, relaxation takes place in the relaxation district.

The stenter that general-purpose industrial is used utilizes two groups of stenter clips to firmly grasp two edges of film.Every suit stenter clip is by chain drive, and clip moves on two tracks, thereby its position can be adjusted in some way and makes that track departs from each other in the stenter when a track moves through.This deviation causes crisscross stretching.Variation about this common scheme is known, and is that the present invention is desired.

Some stenters can be pulled at machine direction and stretch film, or are approaching oriented film on the direction of machine direction, simultaneously their oriented films on crisscross.These are commonly referred to the stenter of biaxial stretching simultaneously.One class is used pantograph or is cut shape mechanism drives clip.This can make the clip on each guide rail, in they are advanced along guide rail, departs from their the most adjacent clips on that guide rail.Certainly as in the stenter of routine, the clip on each guide rail departs from mutually owing to two tracks, thereby departs from their homologues on this relative guide rail.The stenter of biaxial stretching replaces each chain with the spiral of varying pitch in the time of outer type.In this scheme, every suit clip is driven by mobile screw thread along its guide rail, and this varying pitch provides clip departing from along this guide rail.In another type in the stenter of biaxial stretching, this clip separately by linear motor by Electromagnetic Drive, therefore allow that clip departs from along each guide rail.The stenter of biaxial stretching also can be used for only in machine direction stretch simultaneously.In this case, machine direction stretch takes place in the machine direction stretch district.In this invention, cross directional stretch, relaxation and machine direction stretch are the examples of distortion, and cross directional stretch district, relaxation district or machine direction stretch district are the examples of deformed area.Other the method for distortion is provided also is possible two-way within stenter, be that the present patent application is desired.

The processing film method can comprise the melt by extruder die head 10 extruded polymers.The available usually a series of mould bolt of die head projection profile is regulated.For plural layers, use multiple melt-flow and a plurality of extruder.This extrudate is cooling on the casting wheel 12 of rotation.Film at the moment is commonly referred to " casting nethike embrane ".During being orientated, depend on the desired properties of finished films, at machine direction, horizontal or both direction oriented film or casting nethike embrane.The film forming procedure details for example is described in United States Patent (USP) 6,830, among 713 (people such as Hebrink).For the sake of simplicity, will use term " film " to be illustrated in the film of any operation stage in the specification of the present invention, not consider the difference between " extrudate ", " casting nethike embrane " or " finished films ".Yet the film that those of ordinary skill in the art will understand difference in technology can be called other term listed above, and other terms well known in the art.

In the whole thin film fabrication technology, many key elements can cause the variation of film gauge uniformity.For example, can cause inhomogeneity fluctuation owing to the variation of many intersection nethike embrane conditions, comprise air-flow, stenter temperature heterogeneous and/or pressure and conspicuous various other factors of those of ordinary skills in die lip profile, intersection nethike embrane die head temperature, intersection nethike embrane casting wheel temperature, the surrounding air.Uniformity of film is important in the optical thin film of high-quality plural layers, particularly multilayer.For ever-increasing application scenario, wish that these films show the physics and the optical homogeneity of height within large tracts of land.Disclosed system and method can provide intersection nethike embrane initiatively to control to realize the uniformity of this film in the present patent application.

The typical method of control crossing net film thickness is included in the die head bolt of regulating during the casting nethike embrane forming technology in the die head in film production.These adjustings comprise by physics rotates the physical separation that the die head bolt changes die lip, or changes the temperature of die head bolt.Yet the result that the die head bolt is regulated film thickness is rough and slowly.Because the rigidity of die lip, what the physical separation of change die lip obtained is coarse adjustment.In most of the cases, the effect of regulating single die head bolt can change film thickness and is up to 7 die head pitchs of bolts in finished films.Therefore, by regulating the trickle variation that the die head pitch of bolts is difficult to control the crossing net film thickness.The temperature that changes the die head bolt produces thickness adjusting slowly and changes, because this die head bolt heater will be used the long duration heating and cooling.In addition, because the path in film line from the die head to the spool is very long, the response time of the varied in thickness that the adjusting of die head bolt causes is quite long usually, makes varied in thickness control become difficulty with slow.

The system and the method for the crossing net film thickness of disclosed control extrusion film make and can initiatively critically control varied in thickness in thin film fabrication.Between film stretching or deformation phases, distribute and control flows to the heat changes in distribution of film heat by monitoring crossing net film thickness, can realize intersecting the THICKNESS CONTROL of nethike embrane.Monitoring crossing net film thickness distributes to be included in and measures the variation that physics or optical thickness change and mapping are surveyed on the position of wherein implementing heat distribution control.Various systems and the method for control response in the intersection nethike embrane heat distribution of monitoring variation below will be discussed.The step that monitoring thickness and adjusting heat distribute can form feedback control loop, reuses this feedback control loop up to the varied in thickness that reaches last hope in film.Disclosed system and method also can be regulated the varied in thickness of using with precision control intersection nethike embrane with the die head bolt.

In some open embodiments, the particular technology that can use the crossing net film thickness that is used to control the biaxial tension thin polymer film to distribute.For example, in some cases, geosynclinal block is used to adjust the heat changes in distribution, in some cases, uses reducible pivotable heating element heater to adjust the heat changes in distribution.Variation such as longitudinal stretching, cross directional stretch, biaxial stretch-formed during or between the control relaxation period, these technology can be used singly or in combination.For example, in the length orientation device, geosynclinal block can be used, or in stenter, geosynclinal block can be used for horizontal or biaxially oriented film for the longitudinal stretching film.Similarly, reducible, pivotable heating element heater can be used in length orientation device or the stenter.Controlling the method for the crossing net film thickness distribution of bidirectional oriented thin polymer film can use with any heat compartment system disclosed by the invention and other heating systems well known in the art.

Disclosed intersection nethike embrane heat compartment system can provide the distribution control of adjustable Position Control and adjustable transfer heat with heat delivery to film in being stretched simultaneously when film.If desired, this comparable system of knowing can the finer thickness distribution that get ground control intersection nethike embrane more.Compare with the system of knowing, the system of the disclosure also can provide the response time faster usually.

The method that a kind of crossing net film thickness of control biaxially oriented film of novelty distributes is disclosed.This method depends on and is controlled at length orientation device (LO) drawing zone or distributes near the heat in this drawing zone, in stenter, make deformation of thin membrane subsequently, the crossing net film thickness that measures after this stenter deformed area distributes, and the heat that is adjusted among the LO based on the varied in thickness of measuring distributes.In one embodiment, the deformed area can be positioned at the production line end, just before spool.In other embodiment, for example as shown in Figure 1, the deformed area can be positioned between other districts.Other embodiments can have other parts, such as the second length orientation device subsequently.

As will be described in more detail, these systems and method can be used singly or in combination in the film line of any reality, to produce the film that crisscross thickness evenness strengthens.These systems and method also can be used to produce the crossing net film thickness and vertically distribute through the film of adjustment, and such as the optical thin film application scenario of the multilayer of wishing color change therein, described film thickness change has a mind to give.

Two illustrative embodiments below at length are discussed.First embodiment uses geosynclinal block in the length orientation device.Second embodiment uses reducible pivot heater in the stenter baking oven.

In some embodiments, this intersection nethike embrane heat compartment system comprises the horizontal heater block that at least one combines with a plurality of geosynclinal blocks.Three examples of this system are shown among the accompanying drawing 2a-2c.In these accompanying drawings, film stretches in the length orientation device.In accompanying drawing 2a and 2c, carry-over pinch rolls 102,104 and 106 are with the assembling of S-bellows-shaped structure.In accompanying drawing 2b, carry-over pinch rolls are with standard or the assembling of table top structure.The embodiment of describing in accompanying drawing 2a-c uses heating component 150a-c and one group of geosynclinal block 170 respectively, and being used for provides optional heat to distribute to the longitudinal stretching district 140 or the 140b of film 20.

In accompanying drawing 2a, heating component 150a comprises three horizontal infrared ray heater blocks 160.The intersection nethike embrane heat compartment system that can regulate vertical distribution comprise equally with the machine direction of film in line, be placed in one group of geosynclinal block 170 between heating component 150a and the film 20.Although this specific implementations is used one group of three heating element heater 160 and a plurality of geosynclinal block 170, depend on the problem of considering in the design of system, can with use many heating element heaters and many geosynclinal blocks.For example, the system with single heating element heater (heating component 150b) is shown among the accompanying drawing 2b, and the system with five heating element heaters (heating component 150c) is shown among the accompanying drawing 2c.Additional embodiments can comprise one group of 10 heating element heater and one group of 50 geosynclinal block.Each horizontal heater block can be heater or a plurality of small heaters of the whole width in film zone that will control of single leap, and they comprise that the film zone that will control of giving of layout provides the heat point source of institute's calorific requirement.The combination of same expection heat point source and extended source.

The crossing net film thickness of controlling film for precision vertically distributes, the intersection nethike embrane heat compartment system of accompanying drawing 2a via the drawing zone that heating component 150a is transported to film, is transferred vertical distribution control of heat with heat simultaneously by the position-adjustable that changes each geosynclinal block 170.In each of accompanying drawing 2a-c, the part heats that geosynclinal block 170 is preferably blockaded required at the crossing net film location place of hope.When heating element heater provides in the heat to film, geosynclinal block or one group of geosynclinal block are set with casting shielded area on film effectively, therefore reduce the heat that flows to film in the specific location of selecting.The position of each specific geosynclinal block is in the casting shielded area, position corresponding to the film zone of wanting trickle control.By the degree of approach of geosynclinal block and film and the size adjustment resolution of geosynclinal block.In accompanying drawing 2a, geosynclinal block 170 is horizontally disposed with usually, and is parallel with the heating element heater 160 of heating component 150a.Film among the accompanying drawing 2a is the structure of S-bellows-shaped.Therefore, the thin film planar of geosynclinal block 170 relative S-bellows-shaped structures tilts.In accompanying drawing 2b, geosynclinal block 170 is horizontally disposed with equally usually, but film is the table top structure, so geosynclinal block is parallel to the plane of film.In accompanying drawing 2c, make geosynclinal block angled to be parallel to the thin film planar of S-bellows-shaped structure.

The width of each independent geosynclinal block can be made narrowly as requested, also can adjust the distance of blockading between thing and the film.For example, it is wide that geosynclinal block can be 10mm, is arranged within the film of 50mm.Therefore, the geosynclinal block assembly as control element can be provided excellent THICKNESS CONTROL according to requiring to adjust crossing net film thickness control hierarchy by in small, broken bits.In addition, because the wherein nethike embrane that the control position is positioned at length orientation is accelerated to the platform place of line speed, the lag time from the geosynclinal block to the spool is shorter than from the die head to the spool basically.Therefore, the response time that is used to control is shorter, makes it obtain the uniformity of final thickness quickly.In addition, the length orientation platform is usually located in the open spaces and loading and unloading easily, and the system that makes is convenient to install and operation.The geosynclinal block embodiment also can be used for the stenter baking oven.In this system, the distance between spool and stenter baking oven even can be shorter, so response time even can be faster.Can be designed to controllably enter the heating component with geosynclinal block from stenter baking oven outside.

The system of accompanying drawing 2a-c and method can make heat delivery in fast-changing specific region.As discussed further below, can use other intersection nethike embrane heat compartment system, the nethike embrane heat distribution curve that wherein intersects can change by the electrical power that change offers heater arrays.Other system has certain advantage, such as there not being movable part, but depends on that there is shortcoming equally in the heater types of use, such as lower spatial resolution and slower response time.For example, the heating of the infrared heater of some technical grades was five minutes, and cooling was 15 minutes.On the contrary, use the system of removable geosynclinal block can be designed to have reaction time and high spatial resolution relatively fast.Mobile geosynclinal block or one group of geosynclinal block casting on film go out the shielded area, thereby reduce the heat that is transported to film, and this moves faster than the response time of the infrared heater of routine.The response time of the system of use geosynclinal block can be moved by geosynclinal block only and how soon responds the time restriction that needs cost with nethike embrane.This depends on specific Machine Design and its controlling organization of geosynclinal block assembly.Those of ordinary skill in the art understands the multiple possible structure that is suitable for mechanical control flume block assembly.

Accompanying drawing 3 shows the top view of illustrational geosynclinal block assembly 300 structures.Assembly 300 has the geosynclinal block of 34 settings adjacent one another are, and this device is crossed over the whole width that will control film.If desired, the actual size of film can extend beyond the thin-film width that will control, and for example wherein the outer rim of film is cut off and abandons or reclaim, and stays available thin film center part.Comprising intersection nethike embrane heat compartment system such as a kind of geosynclinal block assembly of describing in the accompanying drawing 3 can be used among length orientation device, stenter or both.

Can be used for vertical distribution of repeated measurement physics or optical thickness for the feedback mechanism of drawing zone, the optional thickness longitudinal distribution curve of measuring of drawing, and intersect nethike embrane heat compartment system in response to vertical distribution curve adjustment of measuring or draw.Feedback mechanism is known, does not describe in detail.In brief, feedback mechanism can be the form of manually controlling by the operator, and it can be computer-controlled, or it can be computer and the manually combination of control.For example, a kind of such feedback mechanism is the computer control system with manual override device.Preferably, the drafting algorithm that this feedback mechanism uses a computer and controls, any mapping method that uses the present invention to describe.Also can make drafting algorithm by hand.

In some embodiments, intersecting nethike embrane heat compartment system comprises the heating element heater of one group of reducible lateral arrangement along finder.Illustrate in the embodiment discussed below, such intersection nethike embrane heat compartment system is used for stenter.The deformed area of this stenter can be pure cross directional stretch district, relaxation district, machine direction stretch district or biaxial stretch-formed district.This intersection nethike embrane heat compartment system of reducible heating element heater that comprises also can be used for the length orientation device.

An implementation process of accompanying drawing 4 these embodiments of usefulness schematic view illustrating.In accompanying drawing 4, film in stenter baking oven 200 (referring to Fig. 1) by cross directional stretch.In this specific implementation process, reducible heating element heater is pivotable equally.This intersection nethike embrane heat compartment system 250 comprises five reducible rod shaped heater 260a-e that are installed on a pair of fitting recess 253.Other implementation processes are possible equally, yet comprise that being not limited to one arranges the less thermal source that specific required response shape is arranged that is used for linear or any other optimization.

Although in the embodiment of accompanying drawing 4, heater is arranged in the drawing zone of finder, and their position is not limited to drawing zone.Finder can have other district or other deformed areas, wherein can use intersection nethike embrane heat compartment system.District in addition including, but not limited to the preheating zone, annealed zone and heat setting district.When being used for the length orientation device, this drawing zone is a drawing zone longitudinally.When being used for stenter, this deformed area can be cross directional stretch district, relaxation district, machine direction stretch district or biaxial stretch-formed district.This intersection nethike embrane heat compartment system can be positioned at or near any of these districts.Although most of embodiment disclosed by the invention refers to drawing zone, it means and intersects that nethike embrane heat compartment system also can be positioned at other districts or near other districts.In this application, the position that the nethike embrane heat compartment system that wherein intersects in any embodiment exists is called the heat distributed area.

In accompanying drawing 4 heat compartment systems 250, heating element heater can reset in two ways.At first, this heating element heater energy edge assembling channelling moves laterally to any position along thin-film width.The second, this heating element heater is pivotable equally.The advantage of pivot heater below is discussed.Same other implementation processes of expection and embodiment.For example, this heating element heater is reducible, thus they can be in perpendicular to the plane of thin film planar towards with move away from the film direction.

For draw when film move along film line in lateral attitude on the film any part, imagining center line 22a-e represents each Road narrows 40a-e respectively in accompanying drawing 4.Limit film Road narrows 40a-e by imaginary line.In accompanying drawing 4, the same representative of each center line 22a-e when film be stretched in the moving direction of each corresponding film Road narrows.During cross directional stretch, each increases pro rata to the amount of the distance between the imaginary line by cross directional stretch.In other words, increased by the width of each film Road narrows in the cross directional stretch when film.Desirable, if for example film stretches with 3: 1 ratio, at the point before the drawing zone 220 with just in time during the mensuration of the point after drawing zone 220, then the width of each film Road narrows will increase by three times when just in time.Yet in practice, various factors can cause the unequal of film Road narrows width.These factors for example comprise the variation of crossing net film uniformity before that stretches, the variation that the crossing net film temperature distributes in stenter, the edge effect of the variation of extrusioning mixture homogeneity and the film web of finite width.

The rod shaped heater 260a-e that intersection nethike embrane heat compartment system is installed makes heater be provided with independently of one another.Optional, except that laterally moving, each rod shaped heater also can be installed to be and make that it can be that the center rotates with the pivot.Pivotable heater has two advantages.At first, the pivot rod shaped heater can with the moving direction of the specific Road narrows of the film that described heater is set thereon in line.The second, the pivot rod shaped heater can be angled to provide wideer heat changes in distribution from any single heating rod with film Road narrows moving direction.In following embodiment, will discuss the influence of widening in more detail to the heat distribution curve.With the pivot is that the center rotates, reducible heating element heater can be controlled the heat that flows to film better, conversely with known system mutually specific energy more fine regulate the heat distribution curve.

In accompanying drawing 4, each heating element heater 260a-e utilizes and is pivotally mounted on two parallel channels 253 of crossing stenter.Utilize this method, the position of each heater of intersection nethike embrane can accurately be regulated from stenter baking oven outside.The position and orientation of each rod shaped heater 260a-e can be controlled by various methods known in the art.In the embodiment of accompanying drawing 5-6, use a pair of Acme board threaded rod 262 to position and directed control for each rod shaped heater.Also can use the method for other control positions and pivot, for example a pair of cable is connected on each rod shaped heater.

The closure (state) of single reducible heating element heater of accompanying drawing 5 expression heat compartment systems 250.Heating element heater 260 can be arranged on along any position of two assembling channelling 253L and 253R.Optional, heating element heater 260 also can shown in dotted linely rotate, and aims at line 26, thereby makes it with respect to machine direction 25 angulation θ.In one embodiment, in heating element heater 260 rotations, by realizing rotation along a fixing bolt 266 and a bolt 268 that sliding channel 270 moves.Bolt 266 that should be fixing is positioned at the center of heating element heater 260 in this embodiment as the pivoting point of heating element heater.When not required be center when rotating with the pivot, can remove 270, two kinds of bolts of sliding channel and all fix.Other structure of same expection.

The fragmentary, perspective view of accompanying drawing 6 expression accompanying drawings 4 heat compartment systems 250.Two heating element heater 260a and 260b that are installed on channelling 253L and the 253R of accompanying drawing 6 expressions.The position of heating element heater 260a is controlled by a pair of threaded rod 262a.Similarly, the position of heating element heater 260b is controlled by a pair of threaded rod 262b.Optional, by nut 264b being positioned at along on fixing (253R) side of the position of threaded rod 262b on the passage 253R, simultaneously corresponding nut 264b is positioned at along being installed in the diverse location place that passage 253L goes up the respective threads bar, realizes the rotation of heating element heater 260b.This also can be in accompanying drawing 5 as seen.The crossing net film location of each heater 260 can utilize a pair of spiral (not signal) that is connected to each double thread bar accurately to regulate from stenter baking oven outside.In addition, the angle of orientation of heater also can be from stenter baking oven outside by accurately being regulated by the pivoting point 266b of screw pair control and 268 relative position.

When film be stretched or be out of shape in, install and to make that it is removable in the horizontal and optionally can regulate the control that distributes of film heat with respect to the pivotable single rod shaped heater of machine direction.When being used in combination, the heater assembly for example heater 260a-e heat that can regulate the film portion of crossing any selection together or cross whole thin-film width distributes.

As in the geosynclinal block embodiment, this embodiment has the advantage that quick and trickle ACTIVE CONTROL heat of response time distributes equally.When the control position was the length orientation platform, nethike embrane accelerated to line speed on described platform, from intersect nethike embrane heat compartment system to lag time of spool shorter than from the die head to the spool basically.Therefore, the response time of control is very short, causes short circulation timei, makes it can obtain last required thickness evenness quickly.Once more, the loading and unloading easily in open spaces usually of length orientation platform make the arrangement of intersection nethike embrane heat compartment system become convenient.When the control position is in stenter, circulation timei and response time even shorter.

Usually, the thickness longitudinal of film distributes and can measure at any point in intersection downstream, nethike embrane heat compartment system position.For example, use in the system of any disclosed intersection nethike embrane heat compartment system in the length orientation device, vertical distribution of crossing net film thickness can be in the measured downstream of length orientation device.Use in the stenter baking oven in the system of intersection nethike embrane heat compartment system, the vertical distribution of crossing net film thickness can be in the measured downstream of stenter baking oven.Perhaps, if this intersection nethike embrane heat compartment system is present in the stenter baking oven, then the vertical distribution of this crossing net film thickness also can just in time measured in the stenter baking oven after the deformed area.Not only in the length orientation device, use to intersect nethike embrane heat compartment system but also use stenter to be used for the system of cross directional stretch subsequently, the measurement that the crossing net film thickness vertically distributes can be in length orientation device downstream but the upstream of stenter baking oven carry out.Yet the applicant finds that control intersection nethike embrane heat distributes in the length orientation device, is out of shape in stenter subsequently, and the crossing net film thickness of measuring the film in downstream, deformed area subsequently vertically distributes, and unexpected result is provided.Following examples 2 are described a kind of this system and method.

For optical thin film, can use the optical thickness measuring instrument via optical transmission or reflection spectrum detection and the total optical thickness of thin film of monitoring.For example, can assemble online spectrophotometer, therefore submit necessary information to measure the vertical distributing homogeneity of crossing net film thickness and the feedback of process control is provided to leave the spectrum transparency of MEASUREMENTS OF THIN in the production line when film.A kind of so spectrophotometric example is the U-4000 type spectrophotometer of Hitachi Ltd.Wavelength when sometimes, transmitted spectrum is reduced to specified level can be as the tolerance of its optical thickness.In other cases, can be in the transmissivity of specific wavelength as the tolerance of its optical thickness.Additive method is possible, comprises the indirect method of using above-described direct method to demarcate.

Thickness gage can MEASUREMENTS OF THIN physical thickness, other performances that optics thickness of film or aforesaid film thickness are relevant.In this application, the crossing net film thickness refers to optical thickness, physical thickness, two kinds combination or any other characteristic relevant with thickness of product particular configuration needs.The those of ordinary skill in optical thin film or high performance thin film field can be configured to the suitable thickness of specific products.For example, can use the online beta rays thickness measuring scanner that laterally passes through to carry out the measurement of physical thickness, such as from Honeywell International, Inc.Morristown, New Jersey, USA can the commercial Measurex that obtains ^TMScanner.Other thickness gages include, but are not limited to β absorption type gauge, X-light transmission formula pachometer, γ backscattering measuring instrument, contact calliper type sensor and laser card formalism sensor.Such measuring instrument is for example from NDC Infrared Engineering, Irwindale, and California, USA can commercially obtain.

Optional at wherein intersecting the film position of the correspondence that nethike embrane heat compartment system exists, draw the vertical distribution curve of measuring of film thickness.For some embodiments,, be plotted in the vertical distribution curve of measuring after the cross directional stretch district of film thickness at the film in the length orientation device longitudinal stretching district.For other embodiments, the film thickness of measuring heat compartment system downstream vertically distributes, and draws the vertical distribution curve of film thickness at the heat distributed area.Can many methods draw.Simple method for drafting comprises thin-film width is divided into one group of imaginary film Road narrows, for example shown in the imaginary line in accompanying drawing 3 and accompanying drawing 4.In accompanying drawing 3, film is divided into 34 film Road narrows, and each Road narrows is corresponding to a geosynclinal block.In specific implementations, geosynclinal block 301 and 334 wideer than all the other geosynclinal block 302-333.Therefore, corresponding Road narrows 1 and 34 are wideer than Road narrows 2-33.In accompanying drawing 4,5 film Road narrows 40a-e are represented by imaginary line.The center of each of 5 Road narrows 40a-e is represented by center line 22a-e respectively.

Measure and wherein to intersect vertical distribution of crossing net film thickness in the downstream, heat distributed area that nethike embrane heat compartment system exists.At measuring position place, film may not have with heat compartment system wherein implements the identical width of thin-film width that the control position is located.Therefore, drafting algorithm is used at a position another position mapping.Drafting algorithm makes each crossing net film location of a position film be converted to corresponding crossing net film location on the film of other position in fact.Drafting algorithm can be considered any or all the how inconsistent factor of thin-film width that influences between two positions, comprise but do not limit stretching, deflation, bending, no matter whether the film edge a position is cut off, comprising and intersecting the inhomogeneity variation of nethike embrane before stretching, the variation that the crossing net film temperature distributes in the stenter or the variation of extrusioning mixture homogeneity.

Other method for drafting is used designator physical markings film before can comprising stretching, and measures the position of designator afterwards that stretches.For example, first method can comprise the line of drawing two 50mm from each limit of film, measures the position of those lines after stretching then, and the thin-film width between two lines is divided into many Road narrows with equal width again.This method is supposed each Road narrows stretching or is out of shape identical amount.Second method can be included in and draw 50 designator lines on the film, the position of each designator line after oriented film and measurement stretch then.Third party's method can include and selectively move one or more geosynclinal blocks or reducible heater, and measures the influence to oriented film.This method is called initiatively draws the collision drafting.Cubic method can service property (quality) conservation principle, wherein vertical distribution of the crossing net film thickness of measurement stretching front and back film.Because quality conservation during stretching, the film volume is same to keep the same, can be calculated the width to determined number film Road narrows by the change value of thickness of two measurements.Any method for drafting can be used for constructing suitable drafting algorithm.

For example, in accompanying drawing 4a, be arranged on cross directional stretch film in the system of intersection nethike embrane heat compartment system 250 at lengthwise position 60 places in use.In some embodiments, measure the crossing net film thickness in lengthwise position 70 and vertically distribute, wherein film is wideer than the film at 60 places, position.Heat distribution for 60 places, control position at the position of heat compartment system 60, is plotted in vertical distribution curve that 70 places, position are measured.Regulate the heat compartment system then to eliminate the irregular place in any thick or thin spot or the vertical distribution of film.In other example, 50 places also can have the second intersection nethike embrane heat compartment system to such system in the position.Under the sort of situation, also can be plotted in the vertical distribution curve of this crossing net film thickness that 70 places, position are measured at the position 50 that wherein has the second heat compartment system.

Available intersection nethike embrane heat compartment system can be any in the above open system, for example uses the system of reducible heating element heater, has the system of heating element heater of geosynclinal block or two kinds combination.Also can use any other vertically to distribute heat delivery to the known of nethike embrane or the intersection nethike embrane heat compartment system of exploitation afterwards according to adjustable intersection nethike embrane.The nethike embrane heat compartment system that intersects can be used in length orientation device or the stenter.When being used for stenter, selectable heat distribution is provided to the deformed area of film.When being used for the length orientation device, selectable heat distribution is provided to the longitudinal stretching district of film.

Described as following examples 1, if the film section of measuring has the thick or high spot that relative Road narrows 08 are drawn, can regulate corresponding geosynclinal block 308 so and make more heat flow to Road narrows 08.This can make the film aggravation that stretches in those Road narrows, therefore reduce or remove thick spot in the finished films.Similarly, as shown in accompanying drawing 3,, so can mobile geosynclinal block 322 arrive film in that position with block heat if the film section of measuring shows that low spot is arranged on the film corresponding to Road narrows 22 positions.In one embodiment, regulate the degree that stops or open by passage being advanced via threaded rod with axle 180 rotations.So obviously adjusting can be done atomic carefully, realizes excellent heat distribution control.

Similarly, shown in embodiment 3 and 4, in length orientation device or stenter, use reducible heating element heater also can regulate thick spot.If it is that the center rotates that reducible heating element heater allows equally with the pivot, can even more fine regulate this influence.As in the geosynclinal block embodiment, can use reducible heater effectively the crossing net film thickness of film is controlled to last required vertical distribution.

In some embodiments, the length orientation film can be out of shape in stenter subsequently.In the case, opposite intuition is to regulate intersection nethike embrane heat to distribute at length orientation platform place, rather than in stenter, this corrects the vertical distribution of crossing net film thickness in the finished films in stenter downstream will be effective.Following examples 2 show astoundingly: the heat that the crossing net film thickness can be during longitudinal stretching flows to film by stop portions selectively carries out fine adjustments, and therefore more uniform biaxially oriented film is provided.Although embodiment 2 uses geosynclinal block heat compartment systems, this method also can be intersected nethike embrane heat compartment system with any other and used together, such as reducible heating element heater disclosed by the invention, or other intersection nethike embrane heat compartment systems known in the art.Can realize the uniform crossing net film thickness of film in the approach of controlling heat location mode uniqueness during the longitudinal stretching in the length orientation device, this film is out of shape in stenter subsequently, thereby good especially result can be provided.

Embodiment

Embodiment 1

In the embodiment that is shown in accompanying drawing 7, the alternation of bed of the copolymer (co-PEN) by extruding polymethyl methacrylate (PMMA) and PEN is made the multilayer optical film of infrared external reflection.Film at first carries out length orientation with draw ratio at 3.3: 1, carries out the width orientation at 3.3: 1 with draw ratio subsequently in stenter then.Use the optical thickness of optics thickness gage MEASUREMENTS OF THIN after stenter.Characteristic curve 7A represents vertical distribution of the optical thickness of thin film of initial drawing.Be vertical distribution of control thickness, use heating component in the length orientation device with three infrared ray rod shaped heater and one group of 34 geosynclinal block.The infrared ray rod shaped heater of using is Research, Inc.Minneapolis, Minnesota, the Parabolic Strip Heaters of the 5305 type series that USA makes.Geosynclinal block 303-331 is illustrated in the bottom of curve map.Channel width is 12.7 millimeters.For being reduced in the peak value that is shown in the thick spot of expression among the characteristic curve 7A corresponding to passage 308 positions, make geosynclinal block 308 move down 25.4mm 10.2 millimeters to the final position from the 35.6mm of start position.Moving down geosynclinal block can make more heat reach the film at that crossing net film location place.More heat delivery have reduced peak value to this position by that part of film is stretched more.Thickness longitudinal distribution table in the drafting that obtains corresponding to geosynclinal block 308 positions is shown among the characteristic curve 7B.Characteristic curve 7C represents vertically to be distributed to from the initial thickness of characteristic curve 7A the vertically percentage variation of distribution of final thickness of characteristic curve 7B.In position corresponding to geosynclinal block 308, characteristic curve 7C represent geosynclinal block 308 move-25.4mm makes thickness longitudinal changes in distribution approximately-3%.Similarly, be shown among the characteristic curve 7A-C in conduit blocking effect corresponding to geosynclinal block 322 positions.Shown in characteristic curve 7A, vertical distribution of initial thickness has one and is illustrated in the decline that there is thin spot this position.By making geosynclinal block 322 25.4mm that moves up arrive the 61mm of final position, thereby more heat is blockaded and can not be arrived that part of film and make this film stretch still less than adjacent part.Shown in characteristic curve 7B, this causes increasing in that position thickness longitudinal distribution.Variation such as characteristic curve 7C at this position percentage are depicted as about 3%.

Embodiment 2

In the embodiment that is shown in accompanying drawing 8, the alternation of bed of the copolymer (co-PEN) by extruding polymethyl methacrylate (PMMA) and PEN is made the multilayer optical film of infrared external reflection.Film carries out length orientation with draw ratio at 3.3: 1.Film stretches with draw ratio crisscross in stenter subsequently at 3.3: 1.Use the optical thickness of optics thickness gage MEASUREMENTS OF THIN after stenter.Characteristic curve 8A is illustrated in the initial vertical distribution curve of drawing on the length orientation platform of intersection nethike embrane optical thickness of film.Be vertical distribution of control thickness, use heating component in the length orientation device with three infrared ray rod shaped heater and one group of 34 geosynclinal block.The infrared ray rod shaped heater of using is Research, Inc.Minneapolis, Minnesota, the Parabolic Strip Heaters of the 5305 type series that USA makes.Geosynclinal block 303-331 is illustrated in the bottom of curve map.The conduit width is 12.7 millimeters.

The film that is shown among the characteristic curve 8A vertically distributes by moving some as regulating at the last represented geosynclinal block of each geosynclinal block that is provided with in place, accompanying drawing 8 bottoms.Initial and the last setting of table 1 expression geosynclinal block 303-331.The vertical distribution table of the optical thickness that obtains is shown among the characteristic curve 8B.Characteristic curve 8C represents last and the vertically variation of the percentage between the distribution of original depth.Characteristic curve 8B shows that the initial film that can use the intersection nethike embrane heat compartment system reconciliation statement with one group of infrared heater and one group of geosynclinal block to be shown among the characteristic curve 8A vertically distributes to become more even.

Table 1

The conduit numbering	The plug setting (mm) of initial conduit	The plug setting (mm) of last conduit
			303	36	36
304	36	36
			305	36	36
306	36	66
			307	36	36
308	36	36
			309	36	36
310	36	38
			311	36	39
312	36	39
			313	36	38
314	36	38
			315	36	37
316	36	41
			317	36	41
318	36	51
			319	36	33
320	36	36
			321	36	36
322	36	36
			323	36	36
324	36	36
			325	36	36
326	36	48
			327	36	14
328	36	0
			329	36	36
330	36	36
			331	36	36

Embodiment 3

In the embodiment that is shown in accompanying drawing 9, the alternation of bed of the copolymer by extruding PETG (PET) and PMMA is made multilayer optical film.Film carries out length orientation with draw ratio at 3.35: 1.Film laterally in stenter is being orientated with draw ratio subsequently at 3.3: 1.Stenter in the cross directional stretch district of stenter, be equipped with one group reducible be the heating element heater that the center rotates with the pivot.Each heating element heater 325mm is long, and 10mm is wide, has the wide paraboloid of 80mm.The heating element heater that uses is from Watlow Electric, St.Louis, Missouri, the Raymax Model 1525 that USA obtains.The center of heating element heater is as pivoting point and position location in this embodiment.Use the optical thickness of optics thickness gage MEASUREMENTS OF THIN after stenter. Characteristic curve 9A, 9B and 9C represent for heteroid intersection nethike embrane heat compartment system, as the optical thickness change of crossing net film location function, shows reducible influence that with the pivot is the infrared heater that rotates of center to finished films.Heater element power and orientation angles are listed in table 2 and 3.

The setting of table 2 heater 962

Curve	9A		9B		9C
						Power (%)	15	15	15
Angle (°)	0	0	0

Table 3: the setting of heater 964

Curve	9A		9B		9C
						Power (%)	20	20	20
Angle (°)	0	12.5	25

When single heating element heater kept firm power with the identical angle of orientation, for three characteristic curve 9A, 9B and 9C each, the variation that the nethike embrane optical thickness that intersects vertically distributes kept identical.This influence is as observed decline in corresponding to characteristic curve 9A, the 9B of the intersection nethike embrane 460mm position of first heating element heater 962 and 9C.When single heating element heater keeps firm power, but the angle of orientation is observed the broadening effect when changing. Characteristic curve 9A, 9B and the decline among the 9C at the 950mm place show that this broadening effect is owing to single rod shaped heater causes.In this embodiment, the secondary heater 964 that is arranged in the 950mm place is spent 12.5 degree that rotate to characteristic curve B from 0 of characteristic curve 9A, 25 degree of characteristic curve C.

Embodiment 4

Among the embodiment in being shown in accompanying drawing 10-13, the optical thin film of multilayer is by extruding the alternation of bed manufacturing of PET and PMMA copolymer.Film carries out length orientation with draw ratio at 3.35: 1.Film is subsequently with 3.3: 1 draw ratio horizontal orientation.In the cross directional stretch district stenter be equipped with one group four reducible be the heating element heater that the center rotates with the pivot.Each heating element heater 325mm is long, and 10mm is wide, has the wide paraboloid of 80mm.The heating element heater that uses is from Watlow Electric, St.Louis, Missouri, the Raymax Model1525 that USA obtains.The center of each heating element heater is as pivoting point.The normal indication at each heating element heater center be " position, the right " in this embodiment in table 4-7, is that the normal indication of the bolt of center and rotary moveable is " position, left side inclination " with the pivot.Use the optics thickness gage in stenter measured downstream optics thickness of film.Represent that at the characteristic curve A of accompanying drawing 10-13 in each initial optical crossover nethike embrane thickness longitudinal distributes.Accompanying drawing 10-13 represents that subsequent iteration changes the heater setting.Originally, the intersection nethike embrane optical thickness of MEASUREMENTS OF THIN vertically distributes.Measurement data points is plotted as the characteristic curve A of accompanying drawing 10.Then, the intersection nethike embrane optical thickness of the film that drafting is measured in the cross directional stretch district vertically distributes.In response to vertical distribution curve of drawing, heater 1-4 is arranged on according to being shown in first iteration of parameter in the table 4.The intersection nethike embrane optical thickness that measures vertically distributes, and is expressed as the characteristic curve B in the accompanying drawing 10.The optical thickness of first iteration that obtains (the characteristic curve B of accompanying drawing 10) thereby become the initial thickness longitudinal of secondary iteration (the characteristic curve A of accompanying drawing 11) and distribute.Measuring the optics thickness longitudinal distributes, drawing the optical thickness of measuring on drawing zone vertically distributes, and regulate in response to vertical distribution curve of drawing and to intersect the step of nethike embrane heat compartment system and form feedback control loop, repeat this feedback control loop and distribute up to reaching last required thickness longitudinal.In secondary iteration, heater 1-4 is according to the parameter setting of listing in the table 5.The vertical distribution of the optical thickness that obtains is plotted as the characteristic curve B in the accompanying drawing 11.Repeat this process by the other two kinds of iteration shown in heater setting in table 6 and 7, thickness longitudinal distributes and is plotted in accompanying drawing 12 and 13.By the characteristic curve B in the accompanying drawing 13 one group four reducible cooperative effects that to be the infrared heater that rotates of center with the pivot distribute to the optical crossover nethike embrane thickness longitudinal of finished films are described.Representing to use one group four reducible heating element heaters that are positioned at institute's limit of consideration to obtain last planar thickness at the characteristic curve B of about 1300-1850mm scope built-in Figure 13 vertically distributes.Attention can otherwise be regulated such as the die head bolt at " recess " that surpass 1850mm crossing net film location place and solve.

Heater setting in table 4. accompanying drawing 10

Heater	1	2	3	4
					Power (%)	0	80	80	0
Angle (°)	0	+36	+36	0
					The position, (m) is tilted to the left	1.156	1.365	1.797	2.159
Position, (m) to the right	1.156	1.397	1.829	2.159

Heater setting in table 5. accompanying drawing 11

Heater	1	2	3	4
					Power (%)	0	100	100	0
Angle (°)	0	+36	+36	0
					The position, (m) is tilted to the left	1.156	1.365	1.734	2.159
Position, (m) to the right	1.156	1.397	1.765	2.159

Heater setting in table 6. accompanying drawing 12

Heater	1	2	3	4
					Power (%)	50	100	100	50
Angle (°)	+36	+36	+36	+36
					The position, (m) is tilted to the left	1.238	1.365	1.645	1.772
Position, (m) to the right	1.270	1.397	1.676	1.803

Heater setting in table 7. accompanying drawing 13

Heater	1	2	3	4
					Power (%)	50	100	80	50
Angle (°)	+36	+36	+36	+36
					The position, (m) is tilted to the left	1.238	1.365	1.594	1.772
Position, (m) to the right	1.270	1.397	1.626	1.803

Although the present invention can adapt to various changes and alternative form, its concrete situation has been carried out for instance in drawings and detailed description.Yet, should be appreciated that its purpose is not the specific embodiment that limits the invention to description.Its objective is that protection falls into as improvement, equivalent and replacement scheme in the defined spirit and scope of the invention of accessory claim antithesis.

Claims (16)

1. control the method that biaxially oriented polymer foil crossing net film thickness vertically distributes for one kind, comprise the steps:

A) oriented film in length orientation device with the intersection nethike embrane heat compartment system that can regulate distribution;

B) in having the stenter of deformed area, make deformation of thin membrane subsequently;

C) the crossing net film thickness in deformed area downstream position MEASUREMENTS OF THIN vertically distributes; With

D) in response to the vertical profile adjustment intersection of the crossing net film thickness of measuring nethike embrane heat compartment system.

2. the process of claim 1 wherein that the deformed area is the cross directional stretch district.

3. the process of claim 1 wherein that the deformed area is the relaxation district.

4. the process of claim 1 wherein that the deformed area is the machine direction stretch district.

5. the process of claim 1 wherein that regulating step is included in the vertical distribution curve of film crossing net film thickness that drafting records on the length orientation device.

6. the process of claim 1 wherein that regulating step includes selectively locatees at least one geosynclinal block and distributes with the control heat.

7. the process of claim 1 wherein that regulating step includes the power of selectively controlling at least one heating element heater.

8. the process of claim 1 wherein that regulating step includes selectively locatees at least one reducible heating element heater and distributes with the control heat.

9. the method for claim 8, wherein regulating step includes and selectively locatees at least one pivotable heating element heater.

10. claim 1 or 5 method further comprise iteration repeating step c and d.

11. the method for claim 1 further is included in the stenter after the deformation of thin membrane step step of oriented film in other length orientation device.

12. the method for claim 1 further comprises the step of regulating at least one die head bolt.

13. the method for claim 1 further comprises the step of coiled film.

14. the process of claim 1 wherein that thin polymer film comprises plural layers.

15. the process of claim 1 wherein that the vertical thickness longitudinal that comprises physics that distributes of crossing net film thickness in measuring process distributes.

16. the process of claim 1 wherein that vertical distribution of crossing net film thickness in measuring process comprises vertical distribution of optical thickness.

Images