SENSORY ANALYTICS
More precise inline coating thickness
measurement solutions for coated films and foils
Vivek Komaragiri
Technical Director
Sensory Analytics
Greensboro, NC USA
AIMCAL
Key features: New in-line measurement technology
Ruggedized optical interference technique
Coating thickness or Coat weight results
Lab and In-line system configurations
Measurement of single or multiple layers
Current thickness ranges:
~ 0.15 µ to 200 µ
~ 0.10 lbs/ream to 130 lbs/ream
AIMCAL Technology of the Year:
systems
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Applications: Broad industrial utilization of technology

Medical Devices

Automotive Industry

Electronics

Metal Coils and Containers

Rigid Packaging

Window Films

Thin Films & Coatings
Overview: Alternate Technology
1. Beta/Gamma Nuclear gauging:
 Non-absolute measurement method
 Differential type of measurement technique
 Extra administrative burden
 Cannot measure thin coatings below 5 microns
 Cannot measure wet coating thickness
 Cannot measure individual layer thickness
4
Overview: Alternate Optical Technologies
1. Reflectance Modeling:
 Non- Absolute measurement method
 Heavily dependent on theoretical modeling
 Will be affected by changes in coating or
substrate properties
 Not fast enough for in-process plant use
 Extensive set-up time for new coatings
 Difficult to setup for multi-layer coatings
5
Overview: Alternate Optical Technologies
2. Optical Absorption/ Transmission:
 Non- Absolute measurement method
 Depends on magnitude of absorption levels
 Limited wavelengths versus broad wavelength
range
 Different wavelengths for different coatings
 Not suitable for discrete layer measurements
 Often supplied on same overdesigned frames
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Overview: Exclusive SpecMetrix Optical Technologies
 Proprietary ‘ruggedized optical interference’
technology
 Absolute thickness measurement results
 Substrate independent
 Measures clear and opaque coatings
 Not affected by base color or printed substrate
 Scalable for off-line or In-process use for wet or
dry coating measurement use
 Current range:0.15 to 250 micron thickness
Technical advantages: SpecMetrix Optical Methods
 Discrete layer measurements
 Not a differential or total coat weight measurement method
 Discrete film weights of single or dual layers can be measured
 Absolute thickness measurements
 Highly precise and real-time measurement data.
 No necessity to calibrate on supplied thickness/ weight standards
 Takes wet or dry in-process coating/layer measurements
 Ability to monitor coatings immediately after application
 Multiple probe and scanning configurations to meet QA needs
 Non-radioactive, non-contact and non-destructive method
 Reduced administration and plant safety burdens
 Continuous readings eliminate end-of-roll weight samples
 Sample integrity maintained
 Intrinsically safe for wet-end installations
8
Lab system: View of multiple layer film stack
 Simultaneous measurement of multiple film and adhesive layers
 Reflection is generated from each interface of multi-layer surfaces
 Thickness peaks shown for individual layers and combination of layers
 Suitable for adjacent layers with dissimilar refractive index values
 Well-suited for ‘film weight forensics’ / QA review of finished film stack
9
Data Analysis: SpecMetrix technology outputs
Precise thickness and coat weight results:
nanometers
microns
mils
mg/sq. inch
gsm
lbs/ream
Simple user and operator interfaces
Requires minimal input from operator
OPC, TCP/IP, PLC integration options
Management gets more reliable results:
- Automatic data recording and storage
- No manual recording or data manipulation
- Direct porting to SPC and QA systems
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Performance: Customer Gage R&R Results


Gage R&R testing performed using NIST thickness standards
Only gauge variability is tested
Performance: Measurement stability over time
Product
Da ys
La ye r1
La ye r2
La ye r3
302398
Day1
Day5
1.630
1.610
1.630
1.650
1.630
3.250
3.310
3.220
3.180
3.270
6.750
6.750
6.770
6.800
6.880
Sta nda rd De via tion
0.014
0.049
0.054
Day1
Day5
1.590
1.570
1.560
1.610
1.570
3.240
3.250
3.240
3.280
3.250
6.850
6.800
6.840
6.800
6.800
Sta nda rd De via tion
0.020
0.016
0.025
Day1
Day5
1.590
1.470
1.530
1.550
1.590
3.280
3.360
3.230
3.300
3.280
6.190
6.220
6.310
6.200
6.160
Sta nda rd De via tion
0.050
0.047
0.057
Day1
Day5
1.560
1.540
1.540
1.500
1.510
3.200
3.220
3.210
3.100
3.220
6.110
6.150
6.160
6.000
6.170
Sta nda rd De via tion
0.024
0.051
0.070
Day2
Day3
Day4
302386
Day2
Day3
Day4
302558-2
Day2
Day3
Day4
302558-2B
Day2
Day3
Day4
 Measurements taken on same sample daily for five days
 High repeatability over a period of five days.
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Range of Use: QA and Production
Corporate Teams
QA Labs and sample testing
R&D centers
Film weight forensics/ Claim review
Manufacturing Plants
QA work stations
Incoming film roll inspection
Pilot lines
Coating/Laminating lines
Coating and material suppliers
In-process coating measurements
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Applications: Representative film & coating thickness

Scratch Resistant coatings – including UV Hard Coats

Adhesives: Solvent-based, Water-based, Pressure Sensitive

Coatings on Foils and metallized films

Solar Control and Specialty Films

TiO2 filled opaque base films

Barrier coatings including nano-barrier coatings

Optical enhancement coatings

Non-nuclear alternative for blown film measurement
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Applications: Expanding coated films opportunities
Transparent conductors
Flexible electronics
Thin film photovoltaics
Touch screen displays
Organic LEDs
Passive (nano) barrier films
Lubricious coatings & pretreatments
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In-Process Benefits: Technology Impact on Production

Elimination of labor intensive and less accurate gauging

Optimized coating utilization and film weight distribution

Real-time adjustments can be made to in process coating application

Streamlined film weight checks and 1st piece inspections

Objective measurement data helps to eliminate operator error

Traceable quality certifications for each production run or coil

Reduced product rework and coating spoilage

Reduced new coating trial times and set-up times

Reductions in waste streams, solvent, coating and oven usage
Technology Implementation – Multi Channel Fixed
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Technology Implementation – Scanning systems
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Technology Implementation – Blown Film
Available as OEM accessory or as replacement to nuclear gauging
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Technology Implementation – Multiple Coatings
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Exclusive Coating Measurement Applications
 Thickness measurement results on the following coatings
 Adhesives on films and foils
 Clear topcoats with similar coating/substrate
 Opaque TiO2 base films
 UV hardcoat on window films
 Nano Barrier coatings
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Measurement Results - Adhesive on Foil

Solvent based adhesive on foil

Typical wet coating thickness is measured around 7.5 microns.

Typical dry coating thickness around 2 microns.

Two probes used for simultaneous measurement on left and right
side of the roller.
Copyright Sensory Analytics LLC all rights
reserved
22
Measurement Results - Clear top coat layers
Meas #
Wet Thickness Estimated Dry Thickness
wet(µ)
dry(µ)
1
2.87
0.86
2
2.91
0.87
3
2.88
0.86
4
2.85
0.86
5
2.95
0.89
AVERAGE
2.89
0.87
 Coating applied to facilitate printing on film substrates.
 Thin clear coated layer makes weigh strip weigh analysis difficult
 Material properties of coating are very similar to substrate making it
difficult for other tools to measure.
 Measurements were performed in the wet state and dry coating
thickness is accurately estimated based on percentage of solids.
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Performance: Correlation of wet (inline) to dry results
Meas # Wet Thickness Dry Thickness
wet(µ)
dry(µ)
Correlation factor
1
18.20
3.75
4.85
2
21.66
4.45
4.87
3
22.20
4.52
4.91

Average of wet and dry inline measurements over a
period of time.

Strong correlation between wet and dry measurements.

Coating inspection possible in the wet state early in
the process
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Measurement Results – Acrylic on TiO2 base film


Clear acrylic coating on opaque Tio2 filled white base film.
Simultaneous measurement of two layers.
1
2
3
4
5
Acrylic
thickness(μ)
12.134
12.235
12.112
12.127
12.123
TiO2
thickness(μ)
25.434
25.365
25.389
25.408
25.429
Copyright Sensory Analytics LLC all rights
reserved
25
Measurement Results: Nano-barrier coatings
Meas #
Coating Thickness
dry(µ)
1
0.27
2
0.28
3
0.29
4
0.27
5
0.29
AVERAGE
0.28
 Protective barrier coatings applied to PET films for food applications
 Coated films useful for printing and laminating uses
 Coated layers are well below thickness range of traditional weight tools
Difficult to perform coat weight analysis without off-line layer removal
gravimetric methods
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Measurement Results: UV Hardcoats
Meas #
Coating Thickness
dry(µ)
1
1.61
2
1.61
3
1.62
4
1.60
5
1.62
AVERAGE
1.61
 Applied as a top most layer for a window film.
 Functions as a scratch resistant layer.
 Provides smooth finish to the product
 Thickness range below the measurement range of conventional tools.
 Very expensive coating.
Significant saving opportunities with tight control of applied coating.
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New Opportunity: A Move to Thickness from Weights
Simple and absolute thickness measurement data now available
 Simple and easy characterization for discrete layers
in multi-layer film applications
 Move to single global uniform measurement unit
(currently Mg/in2, g/m2 Lbs./ream are all used)
 One simple recipe used for multiple coatings
 No dependence on accuracy of supplier coating data
 Ability to accurately characterize difficult layers
 Better means to properly study coating distribution
New Technology Offering:
Next Generation of In-line Measurement
New technology advancements to meet customer needs
New ultra thin In-line coating thickness measurement module
 Minimum thickness limit for current optical configuration is ~ 150nm (0.15 microns)
 Core ruggedized technologies are being expanded to measure ultra-thin coatings
or layers ranging from 10 nanometers and above
 Strong pre-interest from film industry leaders for measurement of:

Silicone Coatings

Coatings on Stretched films

High performance optical coatings
Overview: New optical technology for thinner coatings
Step 1: Unpolarized light from a light source is converted into
polarized beam of light of know polarization state.
Overview: Principle of operation of new technology
Step 2: Linearly polarized light incident on the coated sample at an
angle is reflected resulting in change in polarization and phase.
Technology is ruggedized for both lab and in-process measurements
Overview: Principle of operation of new technology
Step 3: Change in polarization and change in phase are evaluated
from the reflected wave.
Step 4: These parameters are used to calculate thickness of the
coating with Angstrom level accuracy (1Angstrom ~ 1/10000th msi)
Questions?
For additional information:
For system demos:
SENSORY ANALYTICS®
The Sensory Building
4413 West Market Street
Greensboro, NC 27407 USA
Tel: +1-336-315-6090
www.specmetrix.com
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