This document compares the weathering resistance of standard polyurethane powder coating to a new superdurable polyurethane powder coating, both used in a sublimation process to produce decorative wood grain finishes on metal. Accelerated and natural weathering tests found the superdurable powder coating maintained over 80% gloss and a color variation under 2 after 3000 hours of testing, compared to 50% gloss and the same color variation for standard powder only after 1000 hours. The superdurable coating also showed over 90% gloss and under 2 color variation after 12 months of natural exposure. The results demonstrate improved weathering resistance through a new polyurethane powder

1. METAL DECORATION BY DECORAL® TECHNOLOGY
SUPERDURABLE WOOD GRAIN
Alessandro Canevarolo
Bologna, 19 maggio 2011

2. Wood Grain - Comparative test
Wood Effect
Sublimation Process (Heat transfer)
on coated metal surface

3. Sublimation Process (Heat Transfer)
Phisical process by which some substances at given temperature move directly from
solid to gas status.
Sublimatic ink support
Sublimatic ink (dyes)
Powder coating layer 200°C
Aluminum
Sublimatic ink substrate
Printed Sublimatic ink (dyes)
Powder coating layer
Aluminium

4. Used Raw Materials
- Polyurethane Powder Coating
- Heat Transfer Film
(printed with sublimatic Ink)

5. Sublimation Process Advantage
High print definition

6. Sublimation Process Advantage
Suitable to be applied to different shapes

7. Wood Grain Comparative tests
Wood Grain on Superdurable PUR Powder
vs
Wood Grain on Standard PUR Powder

8. Superdurable Polyurethane Powder
Series DS 04XX S & Series DS 07XX S
New formulation of powder coating including:
- special resins
- special combination of UV inibhitors

9. Samples Preparation
Powder Coating + Decoral Process
- Powder coating, carried out in compliance with TDS
temperature and time (20'@ 200°C)
- Decoration according to sublimatic film TDS
(peak temperature 200°C)

10. Obtained Samples
Two series of samples
- A1, B1, …, N1 serie made by Superdurable powder
coating (green line)
- A2, B2, …, N2 serie made by Standard powder
coating (red line)

11. Tests
Accelerated Weathering Test – AWT
- Decoral Laboratory
- Controlled and repeatable
- simulation of some natural exposure factor
- 3000 hours duration
Natural Exposure Test – NET
- South Florida (AWSG)
- Real enviroment
- Unpredictable test
- 12 months exposure

12. Accelerated Weathering Test
Decoral Laboratory
ISO 11304
- irradiation, 550 ± 20 W / m 2 (290-800 nm)
- black panel temperature, 65 ± 5 ° C
- wet cycle 18 minutes
- dry cycle 102 minutes.

13. Accelerated Weathering Test
Evaluated Parameter
every 100 hours until 3000 hours
- Residual gloss % (60° angle, ISO 2813)
- Colour Variation (ΔE CIELAB, ISO 7724/3)

14. AWT – Residual Gloss%
Remarks: 3000 hours are 3 times minimum required by international specification

15. AWT – Residual Gloss%
Superdurable serie (DS 07XX S)
- Residual gloss % of Superdurable wood grain > 80% @ 3000 Hours
- Residual gloss % of Standard wood grain > 50% @ 1000 Hours
Remarks: 3000 hours are 3 times minimum required by international specification

16. AWT – Colour Variation
Remarks: 3000 hours are 3 times minimum required by international specification

17. AWT – Colour Variation
Superdurable series (DS 07XX S)
- ΔE of Superdurable wood grain < 2 @ 3000 Hours (all pattern!)
- ΔE of Standard wood grain < 2 @ 1000 Hours
Remarks: 3000 hours are 3 times minimum required by international specification

18. AWT – Tested Samples – 3000 h
Tested
Samples
D1 D2
(superdurable wood grain) (standard wood grain)
Remarks: 3000 hours are 3 times minimum required by international specification

19. AWT – Tested Samples – 3000 h
Tested
Samples
I1 I2
(superdurable wood grain) (standard wood grain)
Remarks: 3000 hours are 3 times minimum required by international specification

20. Natural Exposure Test
ATLAS
Weathering Service Site
ISO 2813
- - south Florida site
- - 12 months exposure
 - facing south
 - tilt angle 5°
 - open backing

21. Natural Exposure Test – 12 months
Evaluated Parameters
(after 12 months exposure & cleaning process)
- Residual gloss % (60° angle, ISO 2813)
- Colour Variation (ΔE CIELAB, ISO 7724/3)

22. NET – Residual Gloss%

23. NET – Residual Gloss%
- Residual gloss % of Superdurable wood grain > 90% after 12 months
exposure
- Residual gloss % of Standard wood grain > 50% after 12 months
exposure

24. NET – Colour Variation

25. NET – Colour Variation
- ΔE of Superdurable wood grain < 2 after 12 months exposure (all
pattern!)

26. NET – Exposed Samples – 12 months
Unexposed
part
D1 D2
(superdurable wood grain) (standard wood grain)

27. NET – Exposed Samples – 12 months
Unexposed
part
I1 I2
(superdurable wood grain) (standard wood grain)

28. Conclusions
- Excellent results are linked to a new
formulation experience
- Superdurable series (DS 04XX S & DS 07XX S)
levels up the weathering resistance
- Performance improvement for a wide range
of finishing (different wood grain)

29. Future
- Expand the exisiting market for heat-
transfer technology
- Open new fields of application
- Complying with more strict requirements

30. More information at:
www.decoral-system.com