Light-Induced Colour Changes in Wood Surfaces in Indoor Conditions Determined by an Artificial Accelerated Test: Influence of Wood Species and Coating Materials
Abstract
1. Introduction
2. Materials and Methods
2.1. Wooden Material
2.2. Coating Materials
2.3. Test Sample Preparation
2.4. Colour Measurements
2.5. Accelerated UV–VIS Light-Induced Ageing Procedure
2.6. Data Processing and Statistical Analysis
3. Results and Discussion
3.1. Light-Induced Colour Changes in the Uncoated Wood Surfaces
3.2. Light-Induced Colour Changes in the Coated Wood Surfaces
3.3. Light-Induced Colour Changes in the Wood Substrate under the Coating Film, Simulated by V1/Z1 Zones—Contribution of the Underlying Wood Substrate to Overall Colour Changes
3.4. Light-Induced Colour Changes in the Coating Films—Contribution of Finishing Film to the Overall Colour Changes
3.5. Influence of Wood Species and Coating Materials on the Light-Induced Colour Changes in Wood Surfaces
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Lb. Code | Commercial Code | Film-Forming Resin | Solids Content, Csu, % | Density, g/cm3 | Formulation | Gardner Gloss Index |
---|---|---|---|---|---|---|
F1 | YO 20-M702 | Acrylic-polyurethane (non-yellowing) | 25 ± 1 | 1.02 | 1k | 20 |
F2 | YO 15-M864 | Acrylic (non-yellowing) | 34 ± 1 | 1.03 | 1k | 15 |
F3 | YO 20-M838 | Polyurethane | 30 ± 1 | 1.03 | 1k | 20 |
Wood Species Substrate | Experimental/Calculated Value | Type of Coating | ||
---|---|---|---|---|
F1 | F2 | F3 | ||
Maple | Application rate [g/m2] | 191.1 ± 16.2 | 196.3 ± 19.7 | 203.5 ± 20.2 |
Film thickness [μm] | 47.8 | 57.9 | 55.6 | |
Ash | Application rate [g/m2] | 180.5 ± 25.8 | 203.3 ± 17.4 | 168.3 ± 4.0 |
Film thickness [μm] | 45.1 | 59.9 | 46.0 | |
Walnut | Application rate [g/m2] | 161.6 ± 16.2 | 184.9 ± 28.6 | 189.4 ± 17.4 |
Film thickness [μm] | 40.4 | 54.5 | 51.8 | |
Glass lamella | Film thickness [mm] | 0.034 ± 0.004 | 0.043 ± 0.008 | 0.046 ± 0.007 |
Coating material | Solids content [%] | 25.0 | 29.5 | 27.3 |
Flow time, ϕ 6 mm, 20 °C [s] | 12 | 49 | 6 |
Wood Species | Colour Changes after 72 h Light /UV Exposure | ||||||
---|---|---|---|---|---|---|---|
V1/Z2 Uncoated Wood under Clear Glass (Reference Values) | V1/Z1 Uncoated Wood under Coated Glass | ||||||
(F1) | (F2) | (F3) | F1 | F2 | F3 | ||
Maple | ∆E | 4.90 (1.39) | 5.80 (1.13) | 5.20 (1.86) | 4.44 (1.36) | 6.02 (1.55) | 5.17 (1.73) |
∆L* | −3.56 (1.42) | −4.29 (0.62) | −3.43 (1.46) | −3.51 (1.11) | −4.37 (1.16) | −3.36 (1.85) | |
∆a* | 0.99 (0.52) | 1.74 (0.51) | 0.70 (0.68) | 1.00 (0.32) | 1.26 (0.71) | 0.45 (0.71) | |
∆b* | 2.95 (1.23) | 3.40 (1.16) | 3.69 (1.47) | 2.33 (1.24) | 3.82 (1.28) | 3.64 (1.15) | |
Ash | ∆E | 4.84 (0.76) | 4.23 (0.82) | 4.23 (1.34) | 4.32 (1.15) | 4.20 (0.77) | 4.03 (0.96) |
∆L* | −3.25 (0.55) | −2.94 (0.76) | −3.23 (1.30) | −3.07 (1.11) | −3.16 (0.59) | −2.98 (1.39) | |
∆a* | 0.80 (0.32) | 0.67 (0.58) | 0.92 (0.65) | 0.79 (0.54) | 0.76 (0.27) | 0.50 (0.82) | |
∆b* | 3.45 (0.73) | 2.70 (1.18) | 2.22 (1.25) | 2.79 (0.88) | 2.62 (0.64) | 2.18 (0.94) | |
Walnut | ∆E | 4.77 (1.38) | 4.51 (1.13) | 5.52 (1.52) | 4.51 (1.54) | 4.83 (1.35) | 5.93 (1.20) |
∆L* | −3.37 (1.88) | −2.07 (0.74) | −2.13 (1.43) | −3.18 (1.60) | −2.32 (0.79) | −2.22 (1.38) | |
∆a* | 2.26 (0.66) | 2.55 (1.10) | 2.51 (0.74) | 2.19 (0.61) | 2.08 (1.12) | 2.41 (0.72) | |
∆b* | 2.99 (1.03) | 2.99 (1.34) | 4.15 (1.55) | 1.83 (1.33) | 2.94 (2.35) | 4.56 (1.77) |
Anova: Two-Factor with Replication (α = 0.05) | ||||||
---|---|---|---|---|---|---|
Source of Variation | SS | df | MS | F | p-Value | F Crit |
Wood species (1) | 44.95563 | 2 | 22.47781 | 12.13096 | 2.88142 × 10−5 | 3.123907 |
Type of coating (2) | 13.78771 | 2 | 6.893853 | 3.720516 | 0.028997068 | 3.123907 |
Interaction (1)x(2) | 18.01943 | 4 | 4.504858 | 2.431209 | 0.055229542 | 2.498919 |
Within | 133.4109 | 72 | 1.852929 | |||
Total | 210.1737 | 80 |
Wood Species | Colour Changes after 72 h Light /UV Exposure | ||||
---|---|---|---|---|---|
Uncoated V1/Z3 | F1 V2/Z1 | F2 V2/Z1 | F3 V2/Z1 | ||
Maple | ∆E | 9.36 A (1.71) | 5.71 B (1.20) | 5.35 B (2.11) | 4.92 B (1.64) |
∆L* | −5.07 C (1.61) | −3.83 B (0.84) | −0.11 A (1.18) | −3.56 B (1.76) | |
∆a* | 1.48 B (0.79) | 1.09 B (0.58) | −0.14 C (0.66) | 2.60 A (1.45) | |
∆b* | 7.58 A (1.38) | 4.03 B (1.49) | 5.11 B (2.30) | −0.52 C (1.48) | |
Ash | ∆E | 8.39 A (1.28) | 3.37 B (1.37) | 3.94 B (1.24) | 2.25 C (1.02) |
∆L* | −4.13 B (1.13) | −0.52 A (1.74) | −0.48 A (1.50) | −0.51 A (1.57) | |
∆a* | 1.43 A (0.46) | −0.06 B (0.93) | 0.06 B (0.86) | 0.49 B (0.97) | |
∆b* | 7.05 A (1.38) | 2.65 B (1.49) | 3.45 B (1.45) | 0.24 C (1.55) | |
Walnut | ∆E | 6.20 B (1.34) | 7.70 A (1.91) | 6.31 AB (2.04) | 4.74 C (1.40) |
∆L* | −3.25 C (1.62) | 3.40 A (1.36) | 0.96 B (2.60) | 2.14 AB (1.15) | |
∆a* | 2.23 A (0.85) | 1.14 B (0.63) | 2.16 A (0.71) | 1.61 AB (1.02) | |
∆b* | 4.42 B (1.38) | 6.69 A (1.76) | 4.96 AB (2.67) | 3.24 B (2.16) |
Anova: Two-Factor with Replication (α = 0.05) | ||||||
---|---|---|---|---|---|---|
Source of Variation | SS | df | MS | F | p-Value | F Crit |
Wood species (1) | 266.8111 | 2 | 133.4055 | 52.71715 | 3.83802 × 10−18 | 3.055162 |
Type of coating (2) | 77.40668 | 2 | 38.70334 | 15.29419 | 8.80515 × 10−7 | 3.055162 |
Interaction (1)x(2) | 33.53909 | 4 | 8.384773 | 3.313366 | 0.012333886 | 2.430772 |
Within | 387.1804 | 153 | 2.530591 | |||
Total | 764.9372 | 161 |
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Torcătoru, M.-J.; Timar, M.C. Light-Induced Colour Changes in Wood Surfaces in Indoor Conditions Determined by an Artificial Accelerated Test: Influence of Wood Species and Coating Materials. Appl. Sci. 2024, 14, 1226. https://doi.org/10.3390/app14031226
Torcătoru M-J, Timar MC. Light-Induced Colour Changes in Wood Surfaces in Indoor Conditions Determined by an Artificial Accelerated Test: Influence of Wood Species and Coating Materials. Applied Sciences. 2024; 14(3):1226. https://doi.org/10.3390/app14031226
Chicago/Turabian StyleTorcătoru, Mihai-Junior, and Maria Cristina Timar. 2024. "Light-Induced Colour Changes in Wood Surfaces in Indoor Conditions Determined by an Artificial Accelerated Test: Influence of Wood Species and Coating Materials" Applied Sciences 14, no. 3: 1226. https://doi.org/10.3390/app14031226
APA StyleTorcătoru, M.-J., & Timar, M. C. (2024). Light-Induced Colour Changes in Wood Surfaces in Indoor Conditions Determined by an Artificial Accelerated Test: Influence of Wood Species and Coating Materials. Applied Sciences, 14(3), 1226. https://doi.org/10.3390/app14031226