1. Seal-Scan™ Non-Destructive Inspection Technology for Retort Pouches
Tony Stauffer
Packaging Technologies & Inspection
Tuckahoe, New York
PTI Inspection Systems:

2. Seal-Scan™
Only Seal Inspection system that is:
Non-destructive
Non-invasive
Non-contact

3. Applications of Seal-Scan™ Ultrasound Inspection
Analyzes seal quality of pouches and flexible packages
Characterizes bonded materials
Works with all materials: film, alu, paper, or composite
Process control
Quality control
Research and development

4. Produces a single linear scan in less than 1 second
Seal-Scan™
Produces a single linear scan in less than 1 second
Digital pouch seal image in less than one minute
Images and characterizes bonded materials
Helps in process optimization

5. Seal-Scan™ Principle of Through Transmission
Ultrasonic Signal
SEAL
Transmitter
Receiver
Pouch seal or package material is placed between ultrasonic transmitter and receiver

6. Ultrasonic Signal
Ultrasonic waves propagate through single or multiple layers of well bonded materials.
Transition through different mediums causes reflection of sound waves and reduces/eliminates signal strength.

7. Seal-Scan™ Technology
Ultrasonic signal is transmitted along the X-axis through seal and signal is recorded.
Signal measurement correlates to color gauge, creating high resolution image of seal structure and quality.

8. Seal-Scan™ Signal Scale Opto Acoustic Image
The colored gauge represents the scan signal measurement.
Pink is low signal, green is normal signal (good seal), purple is high signal.
Total 6000 grades of color are used.

9. Scanning Modes L-Scan produces a graph of the signal and summary data.
C-Scan produces an ‘Opto-Acoustic’ image
and summary data

10. Pass – Fail Criteria and Data Integrity
Pass – Fail limits are set for the average, minimum, maximum, and standard deviation of the signal measurements,
All results are recorded using the system’s data log.

11. Seal-Scan™ 525 Offline Analytical Equipment

12. C-Scan window statistics
C-Scan Analytical Tools
10 mm
135 mm
128 mm
6 mm
3.5 mm
C-Scan window statistics
Modified L-Scan

13. C-Scan statistics of moving window
C-Scan Analytical Tools
10 mm
135 mm
16 mm
6 mm
3.5 mm
C-Scan statistics of moving window

14. Optimizing the Sealing Process
Seal-Scan™ serves as an analytical tool to determine optimal sealing conditions; e.g. temperature, dwell time, etc.
Variation decreases with increasing temperature.
Optimal Sealing Temperature

15. Material Analysis
HDPE exhibits better sealing uniformity and quality at higher temperatures.
TYVEK® exhibited weaker bonding at higher temperatures.
105 C HDPE C HDPE C HDPE C HDPE C HDPE
128 C HDPE C HDPE C HDPE C HDPE C HDPE
108 C TYVEK C TYVEK C TYVEK C TYVEK C TYVEK
134 C TYVEK C TYVEK C TYVEK C TYVEK C TYVEK

16. Seal-Scan™ and Peel Strength Testing
Background
Pouches with peelable seals were tested.
Peel strength test was performed on specific area of seal sample, approximately one-inch.
Seal-Scan™ C-Scan mode analysis of entire length of seal was performed.
Results confirm direct correlation of both methods.

17. Seal-Scan™ and Peel Strength Testing
The Standard Deviation of the ultrasound signal correlates to the peel strength of a peelable seal. Seals with more variation in the quality of a sealed area will be easier to peel than a seal area that is uniform. If a seal has strong points of bonding but exhibits high variation, the peel strength of the seal will be less.

18. Good Seal Profile(Film-Pouch)
C-Scan
Seal Quality Histogram
Seal width profile
Seal Width Data, mm
Avg
Min
StD
8.2
7.0
0.7
L-Scan
L-Scan Statistics, % Signal Value
Avg
Min
Max
StD
33.1
27.7
41.2
1.9
Test results to be compared against Pass-Fail reference values.

19. Defective Seal Profile (Alu-Pouch Channel Leak)
C-Scan
Seal Quality Histogram
Seal width profile
Seal Width Data, mm
L-Scan
Avg
Min
StD
9.4
3.5
1.0
L-Scan Statistics, % Signal Value
Avg
Min
Max
StD
1.7
-80.5
10.0
8.0
Low average and minimum, with high standard deviation.

20. Case Study Heinz Douarnenex, Fr
Defect Profile - 30,000 pouches were visually inspected 100%
Defect type
Comment
Number detected
Reject Rate
Leak
Critical 3
.01%
Corner channel
Major or critical 4
Wrinkle
Depends on height 8
.03%
Inclusion
Air bubbles
Depends on size 19
.06%
Waves
Usually minor 12
.04%
Blister
Minor 86
.29%
Fold 11
Total defects
147
.49%

21. Case Study Heinz Douarnenex, Fr Typical Defects
Leak
Critical
Corner Channel
Critical
Critical
(may vary)
Wrinkle
Minor
Inclusion
Critical

22. Case Study Heinz Douarnenex, Fr Typical Defects
Air Bubbles
Critical
Critical
Minor
Waves
Critical

23. PTI-550 Online Pouch Inspection
Pouches go onto Seal-Scan from pouch machine at 60-70/Minute

24. PTI-550 Online Pouch Inspection
1. Pouches are dropped into a special conveyor
2. Pass through PTI Seal-Scan Ultrasonic-head
3. Accepted or rejected

25. PTI-550 Online Pouch Inspection
Pouch Seal is guided through the Seal-Scan™ Head

26. PTI-550 Online Pouch Inspection
Seal-Scan Head with Operator interface

27. PTI-550 Online Pouch Inspection

28. Packaging Technologies & Inspection
Seal-Scan™ 525
Defect Gallery

29. Channel Description Cause
An area of non-bonding across the seal that will generally leak
Cause
Sealing bar settings were not correctly set (temperature, pressure and/or
dwell time.)
Contaminants may be present during seal formation.

30. Compressed Seal Description Cause
Any separation of laminates in seal area. Material bond strength is
questionable in defect area. Visual evidence of overheating such as
bubbles.
Cause
Sealing bars were too hot during seal formation.
Material bond strength is inadequate.

31. Contamination Description Cause
Foreign material is trapped in seal. Retort pouches will have noticeable
raised areas in seal where sealing bar sealed over contamination.
Cause
Seal area was contaminated during filling stage.

32. Crooked Seal Description Cause
A seal that is not parallel to the cut edge of the pouch
Cause
Pouch was misaligned in the sealing jaws.

33. Cut
Description
A breach of all layers of the laminate, where the hermetic integrity of the
package was compromised.
Cause
Equipment damage or “scrap” between laminate plies during formation.
Pouch contacted sharp edges of other pouches or equipment.
Pouches were abused during online or post-process handling.

34. Delamination Description Cause
Separation of laminated materials – can occur before or after retort
process. Delaminations ultimately affect seal strength through life
cycle/distribution process.
Cause
If occurring at the seal, bars were too hot during seal formation.
If during retort process, residual air in the pouch was not controlled to
eliminate pouch expansion during retorting.

35. Incomplete Seal Description Cause
Seal area does not extend completely across the width of pouch.
Cause
Pouch was not positioned correctly in sealer and sealing bar.

36. Narrow Seal Description Cause
Container seal area has no margin of safety to accommodate seal creep
or wrinkles.
Cause
Defective sealing bars reduced seal width.
Defects that cross seal, seal creep or mechanical separation reduce seal
width.

37. Non-Bonding Seal Description Cause
Sealing films fail to weld during sealing process. Defect appears as faint
sealing bar impression on retort seals. Application of slight pressure to
seal will cause failure.
Cause
Seal area was contaminated.
Sealing bar settings were not correct (pressure/temperature/dwell time).

38. Wrinkle Description Cause
Material fold on one seal surface, caused when one seal surface is longer
than the other. Can also be a severe fold over both seal surfaces at
sealing time.
Cause
Sealing surfaces were not flat and parallel or were not tensioned.
Various other irregularities in sealing bar or surfaces.

39. Pouch Inspection Economics
One technology useable for all materials
Non-Destructive, Non-Invasive
No sample preparation,
No special Inks, no added variable costs
Replaces costly, low efficiency manual Inspection
Reduces/eliminates Incubation
Saves product & packages
Long term quality tracking
Integrates into most pouch sealing machines
Real Time Process Control - allows immediate corrective action
Increases line efficiency
Good return on investment
You sleep better at night

40. Thank You