Download - Precision Scan-Imaging
Mittuniversitetet
Precision Scan-Imaging
For Paperboard Quality Inspection utilizing X-ray Fluorescence
Industry – University project
Calcium content in paperboard
Tommy Nordin Salim Reza Christer Fröjdh Börje Norlin
MID SWEDEN UNIVERSITY
Mittuniversitetet
Paper coating quality
• Outline
• Motivation
• Description of Industrial interest and State of the Art measurements
• XRF Measurements, MIUN & MoRe
• Transmission measurements
• Conclusions and visions
• Challenge
• To understand internal “state of the art” quality measurements
• Every company has different views on quality.
• Show that an X-ray method is consistent with existing methods
• Gain for companies
• MoRe Research offers analysis service, including XRF
• Future vision
• An online system (i.e. Timepix 3 of Medipix 4) could be used to control and optimize the whole production line
2017-07-03
Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 3
Mittuniversitetet
“The outside counts”
The paperboard printing quality
depends on the coating homogenity
Packaging must exude luxury and live up
to the brand (Martin Sutnar, Läderach)
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 4
Mittuniversitetet
Quality measurements
• Paperboard
• Cellulose fibers [C6H10O5]
• Coating [CaCO3]
• Coating on one or both sides
• The coating gives a smooth surface suitable for high quality printing
• State of the art quality measurement –
The Burnout method
• Acid and heat ”burns” the cellulose
• Thin coating will appear as dark areas on the burnt sample.
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 5
Mittuniversitetet
Paper s
am
ple
XRF measurement setup
source
Slit
Spectrometer
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 6
Mittuniversitetet
XRF Spectrum
Ca Ka
3.69 kev
Ca Kb
Fe Ka
2.96
&
3.19
?
Pb La
Pb Lb
• Source voltage
30 keV
• 20 min exposure
• Shield removes
Fe and Pb peaks
• Argon in air
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 7
Mittuniversitetet
XRF measurement setup • MOXTEK MAGPRO, 60kV, 12W, Ag-anode
• 0.5 mm focal point
• Aluminum profile shielding removes Fe- &
Pb-signal
• JJ-XRAY ESRF-type slits
• Thorlabs translation stages
• Amptek X-123 SDD Spectrometer
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 8
Mittuniversitetet
XRF image from Ca-line
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 9
Mittuniversitetet
XRF image and reference burnout image
• Photo of
burnout
sample
• XRF image
Ca-line
0,5 mm
• Interpolated
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 10
Mittuniversitetet
Exposure time and spot size limitation
• Practical slit and spectrometer mounting considerations
• The distance from the source to the slit limits the intensity
• 0.5 mm and 20 min exposure
• The distance from the slit to the
sample limits the spot size
• Alternative geometry 1 min exposure but ~2 mm spot size
• MoRe Research mounts a pinhole
close to the sensor
• 0.1 mm and “reasonable” exposure
Focal point Spot size Slit
Source
Slit
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 11
Mittuniversitetet
Resolution comparison
• XRF images
• Sample 1: 0.1 mm resolution
• Calcium intensity (colormap jet)
• Sample 2: 0.5 mm resolution
• Sample 2 is previously compared to Burnout image
• Structure visibility limit <0.5 mm
• ”my opinion”
MoRe Sample
MIUN Sample
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 12
Copper fluorescence
Transmission measurement
Mittuniversitetet
Calcium surface measurement
Paper s
am
ple
source
Slit
Spectrometer
Copper p
late
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 14
Mittuniversitetet
Spectrum with copper plate behind paper sample
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 15
Mittuniversitetet
Transmission image from Cu-line
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 16
Mittuniversitetet
Comparison: XRF and Cu transmission image
The coating smooths the total thickness
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 17
Online applications
Visions
Mittuniversitetet
Setup proposal for online measurement
Object
Incident beam
Detector
Scan
Collimator
• Columns transverse to the paper line
• Slit collimated line beam
• Stepper methodology
• Scanning summation along rows
• The movement gives image information
• 2D collimator needed
• to retrieve “enough” resolution XRF image
• Paperboard movement
~ 10 m/s
• Realistic source can be
• Liquid jet 500 W source
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 19
Mittuniversitetet
Timepix 3 energy resolution
0
50
100
150
200
250
300
350
400
0 20 40 60 80 100 120 140
Ti Cu
• Energy resolution for Timepix3 with
a silicon sensor.
• No calibration applied. The spectrum
shows the resolution of Ti (4,5 keV)
and Cu (8,0 keV).
• The needed separation of Ca & Cu
is bigger than this separation.
• Provided by David Krapohl
2017-07-03 Precision Scan-Imaging for Paperboard
Quality Inspection utilizing X-ray Fluorescence 20
Mittuniversitetet
Thank you for listening
Welcome to Sundsvall and IWORID 18 next year!