1. Pressure Sensitive Adhesive – Release Liner Interactions in the Label Industry
Ingrid Brase and Melanie Lack
AWA Global Release Liner Conference, 31 March – 1 Apr 2011

2. Agenda Introduction Experimental Design Results
Summary and Conclusions

3. Introduction
Multiple factors influence the choice of both adhesive and release liner
End user requirements
Converting, die cutting
Printing, dispensing, application
Adhesive characteristics
Liner characteristics
Components are impacted by one another
Overall objective is to deliver a label that end user can dispense efficiently

4. Objectives of the study: Study the interaction of various release liners with different adhesives
5 different commonly used rubber based
PSA’s for labels
General purpose
Freezer grade
No –Label look (clear)
Alkali wash-off
Removable
Release liners:
Paper and film with various release profiles
Easy release, glassine
Medium Release, glassine
Tight Release, glassine
Easy, label standard, glassine
PET, 50 μm, easy release

5. The Adhesives: Performance data
All values in N/25mm

6. Liners: Performance Data
All silicones were thermally cured, Pt catalyzed

7. Sample Preparation Adhesive Coatweight, 20 gsm Samples prepared
All adhesives to all paper liners
PET liner: alkali wash-off
PET liner: no-label look
Samples aged for 2 weeks in controlled climate chamber
Release force evaluated
Low speed, 300 mm/min
High speed, 80 m/ min

8. Observations: low speed release
Low speed release simulates manual dispensing
Increased force needed for tighter release
Clear distinction of release forces based on liner type for GP, freezer and no-label look
Release force for alkali wash-off and removable somewhat independent of liner type
Highest force needed for GP from tight release

9. Observations : high speed
High speed release simulates machine dispensing
See expected patterns for release values: low for easy, medium= medium and high for tight
Highest release force needed for removable, all liner types
More release differentiation for liners
Alkali wash-off shows least force needed for removal

10. Summary of the data

11. Conclusions Release behavior varies by speed
In general need less release force at higher speed
Supports necessity of understanding end user requirements
How label will be dispensed is critical
Changes in adhesive design have dramatic effects on release forces
Alkali wash-off designed for automated lines (high speed)
Cannot always conclude release at high speed will take less force
Removable needs higher force at high speed (softer?)

12. SUMMARY AND FUTURE WORK
When designing a new label, composition of liner and adhesive both need to be considered based on dispensing and end use
Future work:
Evaluate impact of adhesive rheology versus release
Evaluate different types of silicones, i.e UV cure

13. Thank you! Acknowledgements: Markus Moeller Monika Veit
Mondi – release liners