reading

Cover
Title Page
Preface
1 Roll‐to‐Roll Manufacturing: An Overview
1. 1.1 Introduction
2. 1.2 R2R Operation Overview
3. 1.3 Process Economics
4. 1.4 Environmental, Health, and Safety Considerations
5. 1.5 Summary
6. References
2 Coating and Solidification
1. 2.1 Coating Methods
2. 2.2 Drying and Curing
3. 2.3 Defect Management
4. References
3 Drying of Polymer Solutions: Modeling and Real‐Time Tracking of the Process
1. 3.1 Introduction
2. 3.2 Modeling of the Drying Process
3. 3.3 Real‐Time Tracking of the Drying Process of Polymer Solutions
4. 3.4 Conclusions
5. References
4 In‐Line Vacuum Deposition
1. 4.1 Introduction
2. 4.2 Substrates
3. 4.3 Managing Defects
4. 4.4 Managing Heat Load
5. 4.5 Vacuum Deposition Systems
6. 4.6 Vacuum Deposition Processes
7. 4.7 Vacuum‐Deposited Coatings for Growth Markets
8. 4.8 Conclusions
9. References
5 Web Handling and Winding
1. 5.1 Web Handling
2. 5.2 Design for Manufacturability (DFM) for Web Handling
3. 5.3 Rollers
4. 5.4 Tension Control
5. 5.5 Nip Control
6. 5.6 Temperature, Speed, and Gravity
7. 5.7 Web Path Control, Guiding, and Oscillators
8. 5.8 Slitting and Trim Removal
9. 5.9 Winding
10. 5.10 Wrinkling
11. References
6 Polymer Film Substrates for Roll‐to‐Roll Manufacturing: Process–Structure–Property Relationships
1. 6.1 Introduction
2. 6.2 Category II: Polyester Films
3. 6.3 Category I: Solvent Cast High T_g Materials
4. 6.4 Summary
5. References
7 Curl Effects in Roll‐to‐Roll Operations
1. 7.1 Introduction
2. 7.2 Core‐Set Curl
3. 7.3 Physical Aging Effects
4. 7.4 Core‐Set Curl in R2R Operations
5. 7.5 Other Curl Mechanisms and Curl Mitigation Strategies
6. References
8 Roll‐to‐Roll Processing of Glass
1. 8.1 Introduction
2. 8.2 History of Rolled Glass at Corning
3. 8.3 Key Attributes of Glass
4. 8.4 Properties of Glass That Impact R2R Processing
5. 8.5 Important Considerations for a Successful R2R Glass Process
6. 8.6 Summary
7. References
9 Novel Hybrid Composite Films by Roll‐to‐Roll Processing
1. 9.1 Introduction
2. 9.2 Process Overview
3. 9.3 Transparent Electrically Conductive Films
4. 9.4 Bendable Aerogels (Xerogel)
5. 9.5 Flexible Hydrogels
6. 9.6 Conclusion
7. References
10 Roll‐to‐Roll Manufacturing of Flexible Displays
1. 10.1 Introduction: Thin and Flexible Substrates
2. 10.2 Roll‐to‐Roll Display Technologies
3. 10.3 Conclusions
4. References
11 Flexible Solar Cells
1. 11.1 Introduction to Photovoltaic Technologies
2. 11.2 R2R Processing
3. 11.3 Organic Photovoltaics
4. 11.4 Perovskite Photovoltaics
5. 11.5 Conclusions
6. References
12 Field‐Assisted Self‐Assembly of Nanocomposite Films: A Roll‐to‐Roll Approach
1. 12.1 Introduction
2. 12.2 Process Overview
3. 12.3 Electric Field Alignment
4. 12.4 Magnetic Field Alignment
5. 12.5 Thermal Gradient
6. 12.6 Conclusions
7. References
Index
End User License Agreement

List of Tables

Chapter 02
1. Table 2.1 Attributes of some common coating techniques.
2. Table 2.2 Approximate ranges of heat transfer coefficients and drying rate for various unit operations.
Chapter 05
1. Table 5.1 Examples of waste, delay, and customer complaints associated with web handling.
2. Table 5.2 Web handling main topics.
3. Table 5.3 Slitting methods.
4. Table 5.4 Shear slitter adjustments and factors.
5. Table 5.5 Some common winding defects.
6. Table 5.6 Major wrinkling cases.
Chapter 06
1. Table 6.1 Coefficient of linear thermal expansion (CLTE) for annealed PEN.
Chapter 07
1. Table 7.1 Winding conditions for sensitivity analysis.
2. Table 7.2 Viscoelastic parameters for PET film (Eq. 7.18) at 25°C.
Chapter 10
1. Table 10.1 Customer‐desired attributes for flat panel display product categories.
Chapter 11
1. Table 11.1 Comparison of different deposition techniques used for organic semiconductor layers.

List of Illustrations

Chapter 01
1. Figure 1.1 Typical roll‐to‐roll production line.
2. Figure 1.2 Drawing of a roll‐to‐roll coating process in Reichenbach’s 1889 patent.
3. Figure 1.3 Generic roll‐to‐roll operation with five converting steps (S1–S5), one tension roller (T), and two conveyance rollers (C).
4. Figure 1.4 Schematic definition of “process window” for a roll‐to‐roll operation.
Chapter 02
1. Figure 2.1 Definition of the contact angle.
2. Figure 2.2 Pan‐fed reverse roll coaters: (a) three roll and (b) four roll [4].
3. Figure 2.3 Reverse roll, metered film thickness on the applicator roll divided by gap, G, as a function of the ratio of the metering roll speed U_m to applicator roll speed U_a for various capillary numbers based on U_a. (—) represents theoretical values; experimental ones; and (‐ ‐ ‐) is the lubrication model. Final thickness is applicator roll thickness times the wipe ratio [4].
4. Figure 2.4 Operability diagram for reverse roll coating [4], where A, represents a stable coatings area; B, ribbing; and C, cascade; for (a) a gap G = 750 µ and (b) a gap G = 250 µ.
5. Figure 2.5 Mayer rod details.
6. Figure 2.6 Common configurations of gravure coating: (a) direct (and differential), (b) reverse, (c) offset, and (d, e) two implementations of kiss (tensioned web) gravure (the engraved roll may rotate in either direction in kiss coating).
7. Figure 2.7 Wetting options for gravure coating: (a) open pan, (b) closed head (or pressurized), (c) fountain roll, and (d) fountain die.
8. Figure 2.8 Gravure bands (vertical = MD) and doctor blade chatter (dark horizontal lines just below the midpoint of the picture) [29].
9. Figure 2.9 Doctor blade configurations.
10. Figure 2.10 Common mechanical engraving patterns for gravure coating.
11. Figure 2.11 Comparison of the Martin and Saad correlations for convective heat transfer coefficients.
12. Figure 2.12 Comparison of slot (top) and hole (bottom) impingement nozzles. Note that the flow is normal to the web on both sides.
13. Figure 2.13 Roll support for delicate and extensible webs.
14. Figure 2.14 One‐sided air floatation nozzle, also known as airfoils or Bernoulli bar.
15. Figure 2.15 Two‐sided air floatation nozzles also known as air bar or Coanda bars.
16. Figure 2.16 Hybrid IR/Coanda bar nozzle.
Chapter 03
1. Figure 3.1 Schematic representation of the one‐dimensional mass and heat diffusion during evaporation from a coating.
2. Figure 3.2 Temperature and solvent concentration profiles for evaporation‐limited and diffusion‐limited stages.
3. Figure 3.3 Schematic representation of the drying process of a polymer solution in a drying chamber.
4. Figure 3.4 Solvent weight fraction profiles during evaporation of solvent at various times (in seconds).
5. Figure 3.5 Concentration profiles of the solvent during the drying of poly(vinyl acetate)/toluene coating under low airflow. Profiles are shown in 10 s increments starting at when the concentration is uniform.
6. Figure 3.6 Concentration and temperature profiles at the onset of evaporation of the solvent. φ, θ, t*, and ξ are volume fraction of the solvent, dimensionless temperature, dimensionless time, and dimensionless length, respectively. shows the substrate and represents the evaporating surface at .
7. Figure 3.7 Schematic representation of the real‐time measurement system for studying the drying process. From right to left: (1) hot air blower, (2) connection of the blower to the tunnel, (3) vertical baffles, (4) drying sample and sensor location, and (5) open end of the tunnel.
8. Figure 3.8 Sample and sensor location: (1) cast iron base, (2) balance and plastic box, (3) small breadboard for optical components, (4) large breadboard for optical components and sensors, (5) laser displacement sensors, (6) visible range light sources, (7) UV light source, and (8) sample platform.
9. Figure 3.9 Glass substrate with cast polymer solution. L1, L2, and L3 are the points for laser displacement measurements, and circles labeled P1, P2, P3, and P4 are the locations where the pyrometers read the surface temperature.
10. Figure 3.10 Glass substrate with cast polymer solution located on the sample holder: (1) optical paths and fiber optic cables, (2) pyrometers, (3) honeycomb‐structured air diffuser, and (4) position of laser displacement sensors.
11. Figure 3.11 Drying behavior of 15 wt % polyimide/DMF cast film. Drying conditions are as follows: air blower set temperature 60°C, airflow rate 0.5 m/s. Temp (up) and temp (down) are surface temperatures at P2 and P4 points of the substrate, respectively (see Figure 3.9). Δn₁₂ and Δn₂₃ are in‐plane and out‐of‐plane birefringence, respectively.
12. Figure 3.12 Effect of airflow temperature on the drying process of 15 wt % polyimide/DMF polymer solution with the airflow velocity 0.5 m/s. (a) Temporal development of solvent content and (b) temporal development of out‐of‐plane birefringence.
13. Figure 3.13 Effect of airflow velocity on the drying process of 15 wt % polyimide/DMF polymer solution with drying temperature 80°C. (a) Temporal development of solvent content and (b) temporal development of out‐of‐plane birefringence.
14. Figure 3.14 Effect of initial thickness of cast polymer solution on the drying process of 15 wt % polyimide/DMF polymer solution with drying temperature 80°C and the airflow velocity 0.5 m/s. (a) Temporal development of solvent content and (b) temporal development of out‐of‐plane birefringence.
15. Figure 3.15 Effect of solvent type on the drying process of 15 wt % polyimide polymer solution with drying temperature 80°C and the airflow velocity 0.5 m/s. (a) Temporal development of solvent content and (b) temporal development of out‐of‐plane birefringence.
16. Figure 3.16 Drying and imidization process. The process was divided into three regimes: (i) drying regime, (ii) transition regime, and (iii) imidization regime.
17. Figure 3.17 Effect of initial thickness of cast solution on the weight change during the drying and imidization of 15 wt % PMDA−ODA/NMP solution. In the first step the temperature was kept at 100°C at 0.5 m/s air speed, and the films were dried for 4 h. In the next 4 h, the temperature was increased to 200°C to for the imidization reaction. Increasing the initial thickness results in a reduction in the drying kinetics. (b and c) Magnified views of two parts of (a).
18. Figure 3.18 Effect of initial thickness of cast solution on the development of in‐plane and out‐of‐plane birefringence during the drying and imidization of 15 wt % PMDA−ODA/NMP solution. In the first step the temperature was kept at 100°C at 0.5 m/s air speed, and the films were dried for 4 h. In the next 4 h, the temperature was increased to 200°C to for the imidization reaction. The out‐of‐plane birefringence increases with decreasing initial casting thickness. (b and c) Magnified views of two parts of (a).
19. Figure 3.19 Effect of drying temperature on the weight change during the drying and imidization of 15 wt % PMDA−ODA/NMP solution. The first 4 h drying regime was performed at five different temperatures, 100, 120, 140, 160, and 200°C, and then the temperature was increased to 200°C for the next 4 h. Increasing the drying temperature results in a faster drying kinetics. (b and c) Magnified views of two parts of (a).
20. Figure 3.20 Effect of drying temperature on the development of in‐plane and out‐of‐plane birefringence during the drying and imidization of 15 wt % PMDA−ODA/NMP solution. The first 4 h drying regime was performed at five different temperatures, 100, 120, 140, 160, and 200°C, and then the temperature was increased to 200°C for the next 4 h. The out‐of‐plane birefringence increases with increasing the drying temperature; PI 100/200 and PI 200/200 exhibited the lowest and the highest birefringence, respectively. (b and c) Magnified views of two parts of (a).
21. Figure 3.21 (a) optical measurements using an Abbe refractometer during the drying of 10 wt % PAI/DMAc solution; (b) temporal evolution of principal refractive indices at air–liquid interface and (c) temporal evolution of principal refractive indices at substrate–liquid interface. Inset: molecular drawings depict planar low‐energy conformation state for single PAI repeating unit.
22. Figure 3.22 Solution casting and sample preparation procedure for retardation calculation using the compensation technique.
23. Figure 3.23 Cross‐polarized optical micrographs obtained using 30‐order Berek compensator inserted at 45° orientation captured during the drying of PAI/DMAc solution at different drying times. (a) air–solution interface and (s) substrate–solution interface; ΔD_ol: high orientation layer.
24. Figure 3.24 Calculated birefringence values at different drying times (minutes) from optical micrographs using the compensator method.
25. Figure 3.25 Effect of organoclay loading on real‐time thickness of 8 wt % PAI/DMAc solution. The cast polymer solutions were exposed to airflow rate of 0.5 m/s at room temperature. Arrow shows the increase in the clay loading from 0 to 5 wt %.
26. Figure 3.26 Effect of organoclay loading on the development of out‐of‐plane birefringence during the drying process of 8 wt % PAI/DMAc solution. The cast polymer solutions were exposed to airflow rate of 0.5 m/s at room temperature. Arrow shows the increase in the clay loading from 0 to 7 wt %.
27. Figure 3.27 Effect of GO loading on real‐time weight and thickness of 10 wt % PAI/DMAc solution. The cast polymer solutions were exposed to airflow rate of 0.2 m/s at room temperature. Arrow shows the increase in the GO loading from 0 to 0.10 wt %.
28. Figure 3.28 Effect of GO loading on the development of out‐of‐plane birefringence during the drying process 10 wt % PAI/DMAc solution. The cast polymer solutions were exposed to airflow rate of 0.2 m/s at room temperature. Arrow shows the increase in the GO loading from 0 to 0.10 wt %.
29. Figure 3.29 Effect of initial polymer concentration on the development of birefringence during the drying process of PEI/NMP solution at 65°C under the airflow rate of 0.5 m/s. (dashed line is the in‐plane birefringence and solid line is the out‐of‐plane birefringence). Arrow shows the increase in the initial polymer concentration.
30. Figure 3.30 The effect of drying temperature on temporal evolution of birefringence during the drying process of 17 wt % PEI/NMP solution under the airflow rate of 0.5 m/s: (a) 300 µm initial thickness and (b) 750 µm initial thickness (dashed line is the in‐plane birefringence and solid line is the out‐of‐plane birefringence). Arrows show the increase in the drying temperature.
Chapter 04
1. Figure 4.1 The formation of pinholes or scratches by debris on a substrate surface.
2. Figure 4.2 A schematic of a gas cleaning system. Ultrasonically neutralized air is used to flutter the web enabling the release of debris from the surface that is then removed by vacuum extraction.
3. Figure 4.3 A schematic of a modern compact air cleaning head for web materials. The turbulent air disturbs the debris, which are then removed by vacuum. The air also acts as air bearing, preventing the web from making contact with the head surfaces and thus preventing surface scratching.
4. Figure 4.4 A schematic of a tacky roll cleaning process with the tacky roll transferring the debris from the web to the high adhesive accumulation roll.
5. Figure 4.5 A schematic showing the change in surface energy of a polymer substrate due to migration of low molecular weight contaminant, such as oligomer, to the surface.
6. Figure 4.6 A schematic showing how oligomer, or debris, can be transferred from the back surface to the cleaned, or freshly coated, front surface.
7. Figure 4.7 A schematic showing the marginal change in contact surface area with increasing web tension.
8. Figure 4.8 A schematic showing how gas injection can improve the heat transfer coefficient and how gas can be lost from the edges.
9. Figure 4.9 A schematic showing how gas can be fed through the drum surface to maintain a gas cushion, with gas lost from the edges being continuously replenished.
10. Figure 4.10 Left: A schematic of a system where the winding and deposition systems are combined in a single chamber with zone separation plates to allow for a pressure difference between the unwind, rewind, and deposition zones. Right: A system with load locks for unwind and rewind chambers. A sealing mechanism between the load locks and main deposition chamber allows the main chamber to remain under vacuum while the load locks are vented.
11. Figure 4.11 Top: A schematic showing a large system with a series of chambers with large pumps. Bottom: A schematic showing a much smaller system with precision machined channel plates requiring considerably less space and pumping.
12. Figure 4.12 Top: A schematic showing the sequence of slots in an ALD deposition head for depositing one layer. Bottom: A schematic showing a design where the deposition head is machined into a rotating drum that rotates in the opposite direction to the web direction in a way, allowing more layers to be deposited in a single pass [91].
13. Figure 4.13 A schematic of a serpentine web path for ALD deposition.
14. Figure 4.14 A schematic comparing ALD coating (left) with PVD coating (right) in their ability to deposit around particles present on the coating surface.
15. Figure 4.15 A schematic showing how a polymer overcoat and planarizing layer can improve the barrier performance of an inorganic vacuum deposited coating.
16. Figure 4.16 A tortuous path of diffusing moisture in a multilayer organic/inorganic film structure.
Chapter 05
1. Figure 5.1 Live shaft, dead shaft, and cantilevered roller mounting styles.
2. Figure 5.2 A dancer for controlling tension.
3. Figure 5.3 Static and dynamic nip impression techniques.
4. Figure 5.4 A displacement guide.
5. Figure 5.5 A shear slitter.
6. Figure 5.6 Cant or toe‐in angle for the shear slitter blade.
7. Figure 5.7 Winder types.
8. Figure 5.8 Winder arrangements. (a) Turret winder, (b) reel, (c) two‐drum, (d) duplex, and (e) gap winder. Not shown is the slipped core winder that is a variation of the duplex.
9. Figure 5.9 The motivation for slipped core winding.
10. Figure 5.10 Wrinkle locations.
Chapter 06
1. Figure 6.1 Typical tenter frame film stretching process. Inset shows an example category II polymer and temperature window left on the chill roll to quench the polymer to amorphous state, middle stretching window between T_g and T_cc, and right heat setting window between T_cc and T_m.
2. Figure 6.2 Polymers used in R2R substrates and their transition temperatures.
3. Figure 6.3 Chemical structure of polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).
4. Figure 6.4 Most common stretching protocols practiced in the film industry [20].
5. Figure 6.5 Stress optical behavior of PET at rubbery temperatures: effect of stretching rate [27].
6. Figure 6.6 Stress optical behavior of PET combined with offline DSC, X‐ray, and Raman spectroscopy [27].
7. Figure 6.7 Structural model for simultaneous biaxially stretched films [27].
8. Figure 6.8 WAXD patterns for the as‐stretched and the relaxed sequentially biaxially stretched samples at the rate of 0.125 s⁻¹ and different stretch ratios [26].
9. Figure 6.9 Temporal evolution studies for different sequentially biaxially stretched and annealed samples [29].
10. Figure 6.10 Types of deformation applied to PET film stretching: engineering strain versus time (global deformation history) [33].
11. Figure 6.11 Temporal evolution of mechano‐optical behavior of LPET (lower MW PET) for each type of deformation profile [33].
12. Figure 6.12 Effect of heat setting on long‐term creep behavior of unstretched and 3 × 3 stretched PET films (top) and effect of in‐plane direction on long‐term creep behavior of 3 × 1 stretched PET films (bottom).
13. Figure 6.13 Effect of stretched ratios on the creep behavior of unstretched and 2 × 2 and 3 × 3 stretched PET films (top) and effect of temperature on long‐term creep behavior of 2 × 2 stretched PET films (bottom).
14. Figure 6.14 Breadth of T_g range, T_g, T_cc, and T_cc–T_g for PET/PEI films as a function of PEI composition (top). True stress, degree of crystallinity, and WAXS of PET/PEI films as a function of stretch ratio: (a) 100/0, (b) 90/10, and (c) 70/30 (bottom) [28].
15. Figure 6.15 Birefringence of PET/PEI 100/0, 90/10, and 70/30 blends, stretched by 3× (top) and 5× (bottom) at the rubbery state temperatures. Heat setting temperature is 180°C [28].
16. Figure 6.16 True stress versus stretch ratio of PET/PEI films, stretched by 5× and heat‐set for (a) 1 s, (b) 5 s, and (c) 4000 s. (d) Area under the curves. Stretch rate: 300%/min. Stretch temp.: room temp [35].
17. Figure 6.17 Mechano‐optical behavior of Low MW PEN during stretching and relaxation processes with corresponding WAXD pattern. Samples were stretched at 140°C and 0.01 s⁻¹ and relaxed for 10 min. The values indicated in the pictures are referring to the true strain and engineering strain (in parentheses) at relaxation time zero [36].
18. Figure 6.18 Detailed mechano‐optical behavior and WAXD patterns of LPEN strained at 70% (early stages of regime 2) and relaxed for 2 h [36].
19. Figure 6.19 Localized cooperative orientation of the naphthalene planes parallel to the surface of the film [37].
20. Figure 6.20 Uneven thickness distribution [37] in PEN film.
21. Figure 6.21 Thermal properties of PEN/PEI blend films before drawing [37].
22. Figure 6.22 Stress–strain curves of PEN/PEI films and film photographs stretched to draw ratio of 2. Draw temperature: T_g + 20°C. Draw rate: 1200%/min [37].
23. Figure 6.23 Model structure development in the neck region of PEN/PEI blend film.
24. Figure 6.24 Ternary blend (PEN/PEI/PEEK) compositions investigated [39].
25. Figure 6.25 Effect of temperature on the uniaxial deformation behavior of PEN/PEI/PEEK (80/0/10), (60/30/10) films (top) and (50/40/10), (30/40/30) films (bottom) stretched at 250 mm/min. The arrows indicate the onset of stress hardening [39].
26. Figure 6.26 Nanoplatelets and naphthalene moiety prealignment during casting (left) and engineering stress–strain curves of PEN with addition of 0, 0.5, 1, and 2% nanoplatelets (right) [24].
27. Figure 6.27 True stress–true strain (top) and % crystallinity as a function of true strain for PEN with 0, 0.5, 1, and 2% nanoplatelets [24].
28. Figure 6.28 Dynamic phase diagram for PEN with 2 wt % nanoparticle concentration [24].
29. Figure 6.29 Wholly aromatic polyimide industrial film production.
30. Figure 6.30 Real‐time molecular transformation during thermal imidization through combined mechanical, optical, and spectroscopic data [30].
31. Figure 6.31 Thermal mechanical analysis of 125 µm thick non‐heat‐stabilized and heat‐stabilized PEN films.
32. Figure 6.32 Shrinkage of sequential biaxially stretched and heat‐stabilized 3 mil PET (Melinex®) and 5 mil PEN (Teonex®).
33. Figure 6.33 Water permeability requirements for various opto‐electronic applications (oxygen permeability requirements are close to water permeability numbers).
34. Figure 6.34 Typical oxygen and water vapor transmission properties of various polymers.
35. Figure 6.35 Simplified schematics of R2R PVD or CVD process.
36. Figure 6.36 UV‐cured planarization film requirements.
Chapter 07
1. Figure 7.1 Strain distribution across a bent (curled) film. H is the film thickness and M is the applied bending moment.
2. Figure 7.2 Typical strain and stress histories during the core‐set test.
3. Figure 7.3 Tensile relaxation moduli for several film types at 21°C: cellulose acetate (CA) (), polyethylene terephthalate (PET) (*), nylon (MXD) (Δ), and polypropylene (PP) (×) [2].
4. Figure 7.4 Instantaneous core‐set curl versus winding time for CA at 21°C. Data compared with analytical predictions for recovery times of 0 (solid) and 10s (dotted) after unwinding [2].
5. Figure 7.5 Instantaneous core‐set curl versus winding time for PET at 21°C. Data compared with analytical predictions for recovery times of 0 (solid) and 10s (dotted) after unwinding [2].
6. Figure 7.6 Core‐set recovery of CA film at 21°C for three winding times: (a) 24 h, (b) 120 h, and (c) 220 h. Curves are model predictions for a_c = 13,000 (solid) and a_c = ∞ (dotted) [2].
7. Figure 7.7 Core‐set recovery of PET film at 21°C for three winding times: (a) 24 h, (b) 96 h, and (c) 196 h. Curves are model predictions for a_c = 13,000 (solid) and a_c = ∞ (dotted) [2].
8. Figure 7.8 Effect of winding time on core‐set recovery for CA film at 21°C: (a) 0.5 h, (b) 4 h, (c) 24 h, (d) 1 week, and (e) 4 weeks [2].
9. Figure 7.9 Effect of temperature during the winding interval on core‐set recovery of CA film at 21°C for t_w = 24 h: (a) 38°C, (b) 29°C, and (c) 21°C [2].
10. Figure 7.10 Effect of temperature during the recovery interval on core‐set recovery of CA film. Winding temperature = 21°C, t_w = 24 h: (a) 47°C, (b) 38°C, (c) 29°C, and (d) 21°C [2].
11. Figure 7.11 Instantaneous core‐set curl for PET film versus winding time for various pre‐aging times. Data (points) are compared with predictions of the LVE core‐set model modified to account for physical aging effects [9].
12. Figure 7.12 Instantaneous core‐set curl for PET film versus pre‐aging time for various winding times [9].
13. Figure 7.13 Instantaneous core‐set curl versus pre‐aging time for various pre‐aging temperatures. Data for PET film, with winding temperature of 21°C and winding time of 1 week [9].
14. Figure 7.14 Localized schematic strain history for a film element along a production roll undergoing a multistep winding process.
15. Figure 7.15 Rewinding modes: normal (N) and reverse (R).
16. Figure 7.16 A schematic multistep R2R process flow with three winding events.
17. Figure 7.17 Normalized relaxation modulus of unaged PET film. Curve is best fit of Maxwell function (Eq. 7.18).
18. Figure 7.18 Effect of winding time for the first winding event (t_w1) on the curl profile for the nominal production flow: (a) 7, (b) 14, (c) 21, and (d) 28 days.
19. Figure 7.19 Effect of winding time for the second winding event (t_w2) on the curl profile for the nominal production flow: (a) 7, (b) 14, (c) 21, and (d) 28 days.
20. Figure 7.20 Effect of winding time for the third winding event (t_w3) on the curl profile for the nominal production flow: (a) 2, (b) 4, (c) 8, (d) 16, and (e) 24 h.
21. Figure 7.21 Effect of recovery time after the third winding event (t_r) on the curl profile for the nominal production flow: (a) 1, (b) 3, (c) 6, (d) 12, and (e) 24 h.
22. Figure 7.22 Effect of core diameter on the curl profile for the nominal production flow: (a) 6, (b) 12, (c) 18, and (d) 24 in.
23. Figure 7.23 Effect of winding mode and sequence on the curl profile for the nominal production flow: (a) NN, (b) RN, and (c) RR.
24. Figure 7.24 Effect of storage temperature during the second winding event (T_W2) on the curl profile for the nominal production flow: (a) 25, (b) 21, and (c) 17°C.
Chapter 08
1. Figure 8.1 Stress‐strain curves for glass and two high‐performance polymer films at two temperatures.
2. Figure 8.2 Transmission spectra of glass versus polymer films.
3. Figure 8.3 Comparison of surface roughness characteristics of glass and high‐performance polymers.
4. Figure 8.4 Effect of bend stress and edge quality on failure probability and (top) image of crack induced by surface damage.
5. Figure 8.5 Effect of bend radius on bend stress for glass films of different thicknesses.
6. Figure 8.6 Effect of bend radius on failure probability for glass films of two thicknesses.
7. Figure 8.7 Typical spooling configuration for a glass R2R process.
8. Figure 8.8 A typical glass R2R windup station.
9. Figure 8.9 Examples of typical R2R glass film converting steps.
Chapter 09
1. Figure 9.1 Schematic of the electrospinning/solution casting hybrid machine [10].
2. Figure 9.2 Two operation modes of electrospinning/solution casting R2R machine. (a) Electrospun nanofibers directly into cast solution. (b) Cast solution over electrospun nanofiber mat [11].
3. Figure 9.3 Change in resistance during the stretching of ITO coated PET film [13].
4. Figure 9.4 Structure of the transparent conductive films with embedded nanofiber [11].
5. Figure 9.5 (a) UV–Vis spectra of PMMA conductive films, (b) stretchability comparison of ITO‐coated PET film and fiber embedded PMMA film, (c) crack development in 16.5 nm ITO coating layer while being bent around 6 mm mandrel with ITO coating in compression, and (d) flexing tests of transparent conductive flexible PI films around 2 mm mandrel with the conductive side in tension [11].
6. Figure 9.6 (a) Hybrid functional films of PC and electrospun conductive fibers as heaters and (b) on and off states of the bent PDLC display from PI films [11].
7. Figure 9.7 (a) 80 mil thick aerogel–nanofiber hybrid sheet flexing during the bending test, (b) 0.46 mm thick aerogel–nanofiber hybrid film bent almost by 180°, (c) SEM micrograph of a silica aerogel film reinforced with fibers, and (d) SEM micrograph of a fractured silica aerogel film reinforced with fibers [36].
8. Figure 9.8 Morphology of reinforced PVA films by larger nanofibers with different fiber contents before stretching: (a) neat, (b) 2%, (c) 3.7%, and (d) 5.4%. (e) Cross‐sectional morphology. The scale bar is 5 µm [63].
9. Figure 9.9 Morphology of reinforced PVA films by smaller size nanofibers with different fiber contents before stretching: (a) neat, (b) 2%, (c) 3.7%, and (d) 5.4%. (e) Cross‐sectional morphology. The scale bar is 5 µm [63].
10. Figure 9.10 (a) Schematic of the experimental procedure and (b) apparatus for measuring biaxial mechanical properties [63].
11. Figure 9.11 Fiber effect on mechanical properties of 6 µm PVA films with 40% water content: (a) reinforced by 330 nm nanofibers and (b) reinforced by 190 nm nanofibers [63].
12. Figure 9.12 Surface morphology of PVA films reinforced by the larger nanofibers with different fiber contents after stretching: (a) neat, (b) 2%, (c) 3.7%, and (d) 5.4%. The scale bar is 5 µm [63].
13. Figure 9.13 Surface morphology of PVA films reinforced by the smaller nanofibers with different fiber contents after stretching: (a) neat, (b) 2%, (c) 3.7%, and (d) 5.4%. The scale bar is 5 µm [63].
Chapter 10
1. Figure 10.1 Generic flowchart for LCD/semiconductor photolithography patterning process.
2. Figure 10.2 LCD Fab Production Rate (up to Gen10) compared with roll‐to‐roll (0.3 and 1.5 m wide) [6].
3. Figure 10.3 ITRI’s 3‐meter long prototype FPD made using roll‐to‐roll processes [13].
4. Figure 10.4 Left: A photograph of a flexible eWriter liquid crystal film. Right: A photograph of a Boogie Board product that allows electronic erasing of handwritten notes.
5. Figure 10.5 Top: Reflection spectra for a typical Boogie Board eWriter liquid crystal film. The written planar texture has a peak wavelength in the yellow green, approximately 570 nm. The focal conic texture appears as the color of the backcoat, in this case the backcoat is black. Bottom: A schematic showing the texture transitions for the Boogie Board eWriter liquid crystal film.
6. Figure 10.6 Cross‐sectional view of the Boogie Board eWriter liquid crystal film. The polymer forms pillars that support the substrates but do not encapsulate the ChLC.
7. Figure 10.7 SEM micrographs of the polymer structure formed within the Boogie Board eWriter liquid crystal film. The spacers show up as solid white circles in the low magnification image on the left. In the higher magnification image on the right, a channel structure for the liquid crystal is evident (the black regions).
8. Figure 10.8 Boogie Board switching waveform to focal conic texture. Initial pulse at V_P, 3.3 Hz with a 50 ms pause switches the display to the planar texture (V_P can be anywhere from 20 to 36 V, depending on the product). The following two pulses at V_FC, 3.3 Hz with a 50 ms pause fully erases the display to a focal conic texture (V_FC can have an amplitude of 9.5–18 V).
9. Figure 10.9 Boogie Board eWriter liquid crystal film pressure sensitivity for different displays at the same pressure and speed. This measurement is made with a written line speed of 75 mm/s and a 150 gF applied to the stylus.
10. Figure 10.10 Photograph of a roll‐to‐roll production line for eWriter liquid crystal films. The line is located in a clean room.
11. Figure 10.11 Photograph of eWriter display with a non‐conventional shape.
12. Figure 10.12 Boogie Boards with semitransparent eWriter liquid crystal films. Both devices include a semitransparent display that allows for use in either the reflective mode or the transparent mode.
13. Figure 10.13 The reflection spectra of the Play n’ Trace eWriter, as measured on a white and black background.
14. Figure 10.14 Boogie Board with multicolor eWriter liquid crystal film. Bottom: The reflection spectra of multicolor eWriter liquid crystal film.
15. Figure 10.15 Comparison of direct and indirect view AMOLEDs [36].
16. Figure 10.16 Konica Minolta’s roll‐to‐roll OLED manufacturing line [53].
17. Figure 10.17 LG’s flexible OLED flat panel display (left) featured in the G Flex smartphone (right) [57].
18. Figure 10.18 Cross section (a) and process flowchart (b) for 18‐inch flexible AMOLED display on a flexible substrate [58].
19. Figure 10.19 Flexibility of 18″ AMOLED FPD showing that it can be rolled [58].
20. Figure 10.20 Cross section of encapsulated electrophoretic display [58].
21. Figure 10.21 Cross section of microcup‐type electrophoretic display [60].
22. Figure 10.22 Cross section of various colored configurations for full‐color electrophoretic display [61].
23. Figure 10.23 Flowchart of Microcup® imaging film manufacturing [60].
24. Figure 10.24 Cross‐sectional views of microfluidic display (a) with exploded view of spacer design and pores, (b) voltages and charge flow, and (c) ink and oil locations in white and black states [62].
Chapter 11
1. Figure 11.1 Schematic of slot die coating (a) and knife over roll coating (b).
2. Figure 11.2 Schematics of the flexographic printing process (a) and the gravure printing process (b).
3. Figure 11.3 Schematics of the flatbed screen printing (a) and the rotary screen printing (b) processes.
4. Figure 11.4 Schematics of the drop‐on‐demand inkjet printing (a) and spray coating (b) processes.
5. Figure 11.5 Schematic illustration of conventional (a) and inverted (b) organic solar cells.
6. Figure 11.6 Slot die coating of photoactive layer on plastic substrate.
7. Figure 11.7 Large area ITO‐free OPV module. Transparent ITO electrode is substituted by a combination of printed current collecting grids and PEDOT:PSS semiconducting polymer.
8. Figure 11.8 OPV modules made using stripe coating technique and a module made via laser patterning.
9. Figure 11.9 R2R‐produced OPV module, which combines laser patterning of slot die‐coated layers and very precise printing of the top electrodes.
10. Figure 11.10 Inkjet printing of free‐form organic solar cells.
11. Figure 11.11 Schematic illustration of mesoporous (a) and planar “n‐i‐p” (b) and “p‐i‐n” (c) architectures of perovskite solar cells.
Chapter 12
1. Figure 12.1 Schematic of R2R electromagnetic processing line [21].
2. Figure 12.2 Actual image of the electromagnetic processing line [21].
3. Figure 12.3 (a) Schematic and (b) picture of roll‐to‐roll processing equipment developed to create indefinitely long oriented films using electric field alignment. (c) WAXS patterns at different locations for a roll of film with 6 wt % clay loading aligned at 724 V/mm [32].
4. Figure 12.4 (a) Orientation of clay was observed by TEM of microtomed samples microtomed through surface showing in‐plane and three fractured cross‐sectional SEM images showing out‐of‐plane orientation. (b) Chaining of clay platelets observed through cross‐sectional SEM with visible clay edges marked with dotted lines and schematic of the dielectrophoretic chaining [32].
5. Figure 12.5 Enhancement of dielectric properties electric field‐oriented clay‐filled nanocomposites (a) relative dielectric constant and (b) dielectric loses (EF, aligned nanocomposite film) [32].
6. Figure 12.6 Formation of skin layer or the BaTiO3‐rich layer at different DC voltages: (a) 300 V/mm, (b) 800 V/mm, and (c) 1400 V/mm, the concentration of particles was kept constant at 10 wt % [37].
7. Figure 12.7 Concentration effect on alignment of BaTiO₃ nanoparticles at 1400 V/mm and 100 Hz: (a) 10 wt %, (b) 20 wt %, (c) 30 wt %, (d) 40 wt %, (e) 50 wt % [37].
8. Figure 12.8 Change in orientation factor (S), chain length and distance between chains as a function of concentration [37].
9. Figure 12.9 Change in (a) dielectric constant and (b) dielectric loss for oriented and unoriented nanocomposite films of BaTiO₃ (EF, electric field oriented films) [37].
10. Figure 12.10 Difference between (a) dielectric constant and (b) dielectric loss for oriented samples using dielectrophoresis and skin layer formation in electrophoresis [37].
11. Figure 12.11 Increase in (a) dielectric constant and (b) dielectric loss for oriented nanocomposite films of BaTiO₃[37].
12. Figure 12.12 Depiction of the magnetic field zone on the processing line [21].
13. Figure 12.13 Preferred orientation in Ni powder/PS as a function of Ni loading (scale bar: 50 µm) [41].
14. Figure 12.14 Microcomputed tomography of the preferential orientation of 10 wt % Ni powder/PS [41].
15. Figure 12.15 A schematic model for showing the roll‐to‐roll magnetic alignment process [41].
16. Figure 12.16 Resistivity of Ni/PS composite film [41].
17. Figure 12.17 Anisotropic optical transmittance of Ni/PS film (wavelength: 547 nm) [41].
18. Figure 12.18 Anisotropic structure of Ni/PS processed by roll‐to‐roll manufacturing line (scale bar: 20 µm) [41].
19. Figure 12.19 (a) Schematic and pictures of (b) radiation‐ and (c) conduction‐based thermal alignment zones [46].
20. Figure 12.20 Examples showing (a) programmed temperature gradient and (b) constant temperature gradient on the thermal alignment zone [21].
21. Figure 12.21 Temperature gradient observed on top of the substrate [21].
22. Figure 12.22 Mosaic image of uniaxial crystallization of PEO crystals through directional solidification observed under cross‐polarizers with lambda plate (scale bar: 2 mm) [21].
23. Figure 12.23 Large‐scale R2R fabrication of vertically oriented BCP thin films. (a–c) AFM morphologies of the R2R CZA‐S annealed PS‐PMMA thin films at the velocity of 25 µm/s and (d–f) AFM images of oven annealed samples, (g) Temperature gradient curve is shown, T_max and ∇T_max are 210 and 27°C/mm, respectively. Size of scale bar is 200 nm [46].

Process Elements and Recent Advances