@article{alade_theoretical_2025,
	title = {Theoretical coatability properties of modified woods derived from contact angle, surface free energy and surface tension measurements and experimental correlation},
	volume = {19},
	issn = {2666-8459},
	url = {https://www.sciencedirect.com/science/article/pii/S2666845925001011},
	doi = {10.1016/j.rsurfi.2025.100514},
	abstract = {Synergizing coating and wood modification has the potential to achieve enhanced functionality beyond the natural ability of wood to resist dimensional instability, biodeterioration and weathering degradation. However, wood modification could impact surface thermodynamics and coatability. This study aimed at defining theoretical coatability of modified woods based on adhesion markers, namely work of adhesion, interfacial tension and spreading coefficient, derived from wetting properties and surface energetics. Eight water and solvent-based coatings with different binders that include acrylate, alkyd, natural oil and hybrid-based were explored. Acetylated, 1.3-dimethylol-4.5-dihydroxyethyleneurea-modified, furfurylated, phenol formaldehyde resin-impregnated, and sorbitol/citric acid-modified woods were investigated as substrates. A new parameter, theoretical coating delamination coefficient (CDC), was proposed as a quantitative relation between forces that support and oppose phase separation at the coating-wood interface. Practical coating-wood adhesion performance was evaluated by crosscut, scratch hardness and pull-off strength tests. Both wood modification and coating types influenced the surface energetics of wood and thermodynamic characteristics at the coating-wood interface. Based on Pearson product moment correlation, the association between CDC and actual coating-wood adhesion strength showed strong correlation for unmodified wood but mostly weak correlation for modified woods. Factoring morphological characteristics such as surface roughness could strengthen the CDC and adhesion strength correlation. Compared to traditional experimentation, this theoretical-based approach offers a more efficient method, by reducing time, material and labour inputs, in determining and/or optimizing the coatability of modified woods. This approach could potentially be applied to coatability of other substrates of different material origin or composition.},
	urldate = {2025-04-11},
	journal = {Results in Surfaces and Interfaces},
	author = {Alade, Adefemi Adebisi and Stolze, Hannes and Hoette, Christoph and Militz, Holger},
	month = may,
	year = {2025},
	keywords = {Coatings, Wood modification, Wettability, Interfaces, Surface energetics},
	pages = {100514},
	file = {ScienceDirect Snapshot:/home/maicher/Zotero/storage/IJ52V5DY/S2666845925001011.html:text/html},
}

Synergizing coating and wood modification has the potential to achieve enhanced functionality beyond the natural ability of wood to resist dimensional instability, biodeterioration and weathering degradation. However, wood modification could impact surface thermodynamics and coatability. This study aimed at defining theoretical coatability of modified woods based on adhesion markers, namely work of adhesion, interfacial tension and spreading coefficient, derived from wetting properties and surface energetics. Eight water and solvent-based coatings with different binders that include acrylate, alkyd, natural oil and hybrid-based were explored. Acetylated, 1.3-dimethylol-4.5-dihydroxyethyleneurea-modified, furfurylated, phenol formaldehyde resin-impregnated, and sorbitol/citric acid-modified woods were investigated as substrates. A new parameter, theoretical coating delamination coefficient (CDC), was proposed as a quantitative relation between forces that support and oppose phase separation at the coating-wood interface. Practical coating-wood adhesion performance was evaluated by crosscut, scratch hardness and pull-off strength tests. Both wood modification and coating types influenced the surface energetics of wood and thermodynamic characteristics at the coating-wood interface. Based on Pearson product moment correlation, the association between CDC and actual coating-wood adhesion strength showed strong correlation for unmodified wood but mostly weak correlation for modified woods. Factoring morphological characteristics such as surface roughness could strengthen the CDC and adhesion strength correlation. Compared to traditional experimentation, this theoretical-based approach offers a more efficient method, by reducing time, material and labour inputs, in determining and/or optimizing the coatability of modified woods. This approach could potentially be applied to coatability of other substrates of different material origin or composition.

@article{martin_investigating_2025,
	title = {Investigating the {Efficacy} of {Established} {Chemical} {Wood} {Modifications} on {Large}-{Diameter} {Pine}: {Durability} {Against} {Basidiomycetes}},
	volume = {18},
	copyright = {https://creativecommons.org/licenses/by/4.0/},
	issn = {1996-1944},
	shorttitle = {Investigating the {Efficacy} of {Established} {Chemical} {Wood} {Modifications} on {Large}-{Diameter} {Pine}},
	url = {https://www.mdpi.com/1996-1944/18/13/2985},
	doi = {10.3390/ma18132985},
	abstract = {In Germany, Pinus sylvestris is a dominant tree species, and many trees with large diameters are not utilised due to difficulties with processing. However, older pines have larger volumes of sapwood, and boards with a high sapwood content can be produced. The durability of boards from large-diameter ({\textgreater}50 cm) P. sylvestris trees, treated with furfurylation, acetylation, DMDHEU (1.3-dimethylol-4.5-dihydroxyethyleneurea), and SorCA (Sorbitol/Citric Acid), was assessed. The samples were taken from different sections along the longitudinal axis and the cross-section. The durability was tested against Coniophora puteana, Rhodonia placenta, and Trametes versicolor, according to the EN 113-2 standard. All treatments had a median mass loss {\textless} 5\%, so classed as “highly durable” (Durability Class 1) against all fungi. DMDHEU had a large deviation in mass loss against Coniophora puteana and could potentially be classified as “moderately durable” (Durability Class 3), if based on the mean mass loss. The inner part of the end section had a higher mass loss, indicating that there was poorer retention of the treatment at this location. Overall, chemical modifications on large-diameter pine trees were effective at increasing durability. Utilising large-diameter pine trees can help to make use of regional resources and potentially reduce reliance on imported timber. With favourable mechanical properties and easy-to-treat sapwood, large-diameter P. sylvestris trees could be used for commercial treatments.},
	language = {en},
	number = {13},
	urldate = {2025-06-25},
	journal = {Materials},
	author = {Martin, Lucy S. and Stolze, Hannes and Hötte, Christoph and Militz, Holger},
	month = jun,
	year = {2025},
	pages = {2985},
	file = {PDF:/home/maicher/Zotero/storage/C2R3QCT9/Martin et al. - 2025 - Investigating the Efficacy of Established Chemical Wood Modifications on Large-Diameter Pine Durabi.pdf:application/pdf},
}

In Germany, Pinus sylvestris is a dominant tree species, and many trees with large diameters are not utilised due to difficulties with processing. However, older pines have larger volumes of sapwood, and boards with a high sapwood content can be produced. The durability of boards from large-diameter (\textgreater50 cm) P. sylvestris trees, treated with furfurylation, acetylation, DMDHEU (1.3-dimethylol-4.5-dihydroxyethyleneurea), and SorCA (Sorbitol/Citric Acid), was assessed. The samples were taken from different sections along the longitudinal axis and the cross-section. The durability was tested against Coniophora puteana, Rhodonia placenta, and Trametes versicolor, according to the EN 113-2 standard. All treatments had a median mass loss \textless 5%, so classed as “highly durable” (Durability Class 1) against all fungi. DMDHEU had a large deviation in mass loss against Coniophora puteana and could potentially be classified as “moderately durable” (Durability Class 3), if based on the mean mass loss. The inner part of the end section had a higher mass loss, indicating that there was poorer retention of the treatment at this location. Overall, chemical modifications on large-diameter pine trees were effective at increasing durability. Utilising large-diameter pine trees can help to make use of regional resources and potentially reduce reliance on imported timber. With favourable mechanical properties and easy-to-treat sapwood, large-diameter P. sylvestris trees could be used for commercial treatments.

@article{brischke_origin-specific_2024,
	title = {Origin-specific differences in the durability of black locust ({Robinia} pseudoacacia) wood against wood-destroying basidiomycetes},
	volume = {58},
	issn = {1432-5225},
	url = {https://doi.org/10.1007/s00226-024-01571-0},
	doi = {10.1007/s00226-024-01571-0},
	abstract = {Global climate change is accompanied by a change in tree composition in many regions. In Europe, the distribution areas of many species are expanding towards the north so that, among others, black locust (Robinia pseudoacacia), which is native to the USA and has long been established in south-eastern Europe, is also becoming increasingly important in central and northern Europe. Many other tree species are known to have different properties between their original and new locations, including the biological durability of the wood. Hence, the resistance of black locust wood against decay fungi was studied concerning origin-specific differences. Wood was sampled from seven different origins in Europe and original habitats in the United States. Fungal incubation experiments were conducted, wood extractives were analysed, and different anatomical characteristics were quantified such as ring width, vessel size distribution and the presence of tyloses. In addition to differences in durability between juvenile and mature wood, origin-specific differences within the mature heartwood were attributed to extractive contents and the percentages of earlywood vessels containing tyloses. Based on parameters that contributed at least 20\% to mass loss, susceptibility to fungal decay was modelled with multiple regressions.},
	language = {en},
	number = {4},
	urldate = {2024-10-29},
	journal = {Wood Science and Technology},
	author = {Brischke, C. and Stolze, H. and Koddenberg, T. and Vek, V. and Caesar, C. M. C. and Steffen, B. and Taylor, A. M. and Humar, M.},
	month = jul,
	year = {2024},
	keywords = {Timber},
	pages = {1427--1449},
	file = {Full Text PDF:/home/maicher/Zotero/storage/BRM4N373/Brischke et al. - 2024 - Origin-specific differences in the durability of b.pdf:application/pdf},
}

Global climate change is accompanied by a change in tree composition in many regions. In Europe, the distribution areas of many species are expanding towards the north so that, among others, black locust (Robinia pseudoacacia), which is native to the USA and has long been established in south-eastern Europe, is also becoming increasingly important in central and northern Europe. Many other tree species are known to have different properties between their original and new locations, including the biological durability of the wood. Hence, the resistance of black locust wood against decay fungi was studied concerning origin-specific differences. Wood was sampled from seven different origins in Europe and original habitats in the United States. Fungal incubation experiments were conducted, wood extractives were analysed, and different anatomical characteristics were quantified such as ring width, vessel size distribution and the presence of tyloses. In addition to differences in durability between juvenile and mature wood, origin-specific differences within the mature heartwood were attributed to extractive contents and the percentages of earlywood vessels containing tyloses. Based on parameters that contributed at least 20% to mass loss, susceptibility to fungal decay was modelled with multiple regressions.

@article{stolze_tensile_2024,
	title = {Tensile and {Bending} {Strength} of {Birch} and {Beech} {Lamellas} {Finger} {Jointed} with {Conventional} and {Newly} {Developed} {Finger}-{Joint} {Profiles}},
	volume = {17},
	copyright = {http://creativecommons.org/licenses/by/3.0/},
	issn = {1996-1944},
	url = {https://www.mdpi.com/1996-1944/17/20/5063},
	doi = {10.3390/ma17205063},
	abstract = {In this study, the tensile and bending strength of birch and beech lamellas finger jointed with conventional (Standard) and newly developed finger-joint profiles (New) are presented. Polyurethane (PUR), Melamine-Urea-Formaldehyde (MUF) and Phenol-Resorcinol-Formaldehyde (PRF) adhesive systems were used to bond the finger joints. The objective of the New profiles was to reduce the stress concentrations within the finger joint by cutting the cross-grooved fingers perpendicular to the main orientation of the finger-joint profile. In the first trials of the development, larger cross-grooved fingers were cut with the aim to improve the stress distribution and to reinforce the finger joint by filling gaps in the finger joint with adhesive. As the study progressed, initial optimisations of the New profile were made. Smaller cross-grooved fingers were cut as it was assumed that they are beneficial for the manufacturing and integrity of the New profile. In combination with the MUF adhesive system, the New profile achieved the highest increase in the bending and tensile strengths compared to the Standard profile. In addition to the increased strength, other advantages such as reduced cracking in the finger joint were observed when using the New profile. The high strength and stiffness of hardwoods or other high-performance materials used in timber construction can probably be better exploited in combination with the New profile. Further tests will be carried out by considering different configurations of the New profile and different materials.},
	language = {en},
	number = {20},
	urldate = {2024-10-29},
	journal = {Materials},
	author = {Stolze, Hannes and Militz, Holger},
	month = jan,
	year = {2024},
	note = {Number: 20
Publisher: Multidisciplinary Digital Publishing Institute},
	keywords = {beech, tensile strength, bending strength, adhesives, birch, finger-joint profile},
	pages = {5063},
	file = {Full Text PDF:/home/maicher/Zotero/storage/VRKJDZ7C/Stolze and Militz - 2024 - Tensile and Bending Strength of Birch and Beech La.pdf:application/pdf},
}

In this study, the tensile and bending strength of birch and beech lamellas finger jointed with conventional (Standard) and newly developed finger-joint profiles (New) are presented. Polyurethane (PUR), Melamine-Urea-Formaldehyde (MUF) and Phenol-Resorcinol-Formaldehyde (PRF) adhesive systems were used to bond the finger joints. The objective of the New profiles was to reduce the stress concentrations within the finger joint by cutting the cross-grooved fingers perpendicular to the main orientation of the finger-joint profile. In the first trials of the development, larger cross-grooved fingers were cut with the aim to improve the stress distribution and to reinforce the finger joint by filling gaps in the finger joint with adhesive. As the study progressed, initial optimisations of the New profile were made. Smaller cross-grooved fingers were cut as it was assumed that they are beneficial for the manufacturing and integrity of the New profile. In combination with the MUF adhesive system, the New profile achieved the highest increase in the bending and tensile strengths compared to the Standard profile. In addition to the increased strength, other advantages such as reduced cracking in the finger joint were observed when using the New profile. The high strength and stiffness of hardwoods or other high-performance materials used in timber construction can probably be better exploited in combination with the New profile. Further tests will be carried out by considering different configurations of the New profile and different materials.

@inproceedings{stolze_flatwise_2024,
	address = {Sopron, Hungary,},
	title = {Flatwise bending strength and stiffness of finger jointed beech lamellas ({Fagus} sylvatica, {L}.) using different adhesive systems and effect of finger joint gap size},
	volume = {11},
	booktitle = {11th {Hardwood} {Conference} {Proceedings}},
	publisher = {University of Sopron Press},
	author = {Stolze, Hannes and Alade, Adefemi Adebisi and Militz, Holger},
	month = may,
	year = {2024},
	pages = {395--401},
}

@inproceedings{alade_feasibility_2024,
	address = {Sopron, Hungary,},
	title = {Feasibility study on manufacturing finger-jointed structural timber using {Eucalyptus} grandis wood},
	volume = {11},
	booktitle = {11th {Hardwood} {Conference} {Proceedings}},
	publisher = {University of Sopron Press},
	author = {Alade, Adefemi Adebisi and Stolze, Hannes and Wessels, Coenraad Brand and Militz, Holger},
	month = may,
	year = {2024},
	pages = {481--465},
}

@article{stolze_determination_2023,
	title = {Determination of the {Bonding} {Strength} of {Finger} {Joints} {Using} a {New} {Test} {Specimen} {Geometry}},
	volume = {11},
	copyright = {http://creativecommons.org/licenses/by/3.0/},
	issn = {2227-9717},
	url = {https://www.mdpi.com/2227-9717/11/2/445},
	doi = {10.3390/pr11020445},
	abstract = {In this study, a specimen geometry for testing finger joints was developed using finite element simulation and proofed by experimental testing. Six different wood species and three adhesives were used for finger-jointing specimens. With the test specimen geometry, the bonding strength of the finger joints was determined without the usual self-locking of the joint. Under load, the test specimen geometry introduces maximum stress at the beginning of the bond line (adhesive zone). However, the test specimen geometry does not generate a symmetric stress state. The main difficulty here is the flank angle of the finger joint geometry. The wood species and adhesives significantly influenced the performance of the finger joints.},
	language = {en},
	number = {2},
	urldate = {2024-01-11},
	journal = {Processes},
	author = {Stolze, Hannes and Gurnik, Michael and Kegel, Sebastian and Bollmus, Susanne and Militz, Holger},
	month = feb,
	year = {2023},
	note = {Number: 2
Publisher: Multidisciplinary Digital Publishing Institute},
	keywords = {hardwoods, softwoods, bonding strength, adhesive joint design, finger joints, finite element simulation},
	pages = {445},
	file = {Full Text PDF:/home/maicher/Zotero/storage/Q42YXSYZ/Stolze et al. - 2023 - Determination of the Bonding Strength of Finger Jo.pdf:application/pdf},
}

In this study, a specimen geometry for testing finger joints was developed using finite element simulation and proofed by experimental testing. Six different wood species and three adhesives were used for finger-jointing specimens. With the test specimen geometry, the bonding strength of the finger joints was determined without the usual self-locking of the joint. Under load, the test specimen geometry introduces maximum stress at the beginning of the bond line (adhesive zone). However, the test specimen geometry does not generate a symmetric stress state. The main difficulty here is the flank angle of the finger joint geometry. The wood species and adhesives significantly influenced the performance of the finger joints.

@article{alade_characterizing_2023,
	title = {Characterizing surface adhesion-related chemical properties of copper azole and disodium octaborate tetrahydrate-impregnated \textit{{Eucalyptus} grandis} wood},
	volume = {37},
	issn = {0169-4243, 1568-5616},
	url = {https://www.tandfonline.com/doi/full/10.1080/01694243.2022.2125208},
	doi = {10.1080/01694243.2022.2125208},
	language = {en},
	number = {15},
	urldate = {2023-12-11},
	journal = {Journal of Adhesion Science and Technology},
	author = {Alade, Adefemi Adebisi and Naghizadeh, Zahra and Wessels, Coenraad Brand and Stolze, Hannes and Militz, Holger},
	month = aug,
	year = {2023},
	keywords = {adhesion, FTIR, Eucalyptus grandis, SEM-EDS, surface modification, Wood preservation},
	pages = {2261--2284},
}

@techreport{hermans_untersuchung_2023,
	address = {Göttingen, Germany},
	type = {Bachelor thesis},
	title = {Untersuchung ausgewählter {Eigenschaften} von {Fensterkanteln} aus {Kiefernkern}- und -splintholz},
	language = {de ger},
	institution = {Wood Biology and Wood Products, Faculty of Forest Sciences and Forest Ecology, University of Goettingen},
	author = {Hermans, Jan Paul},
	month = sep,
	year = {2023},
	note = {Prüfer: Prof. Militz, Dr. Bollmus, Stolze},
	pages = {39},
	file = {Hermans - 2023 - Untersuchung ausgewählter Eigenschaften von Fenste.pdf:/home/maicher/Zotero/storage/34532KJU/Hermans - 2023 - Untersuchung ausgewählter Eigenschaften von Fenste.pdf:application/pdf},
}

@inproceedings{stolze_finger-jointing_2023,
	address = {Ås, Norway},
	title = {Finger-jointing of recycled wood – potential technology for improved circular use of wood},
	booktitle = {Proceedings of the 19th {Meeting} of the {Northern} {European} {Network} for {Wood} {Science} and {Engineering} ({WSE})},
	author = {Stolze, Hannes and Gedde, Kristina B. and Militz, Holger},
	month = oct,
	year = {2023},
	pages = {37--39},
}

@article{slabohm_evaluation_2023,
	title = {Evaluation of wet tensile shear strength and surface properties of finger-jointed acetylated beech ({Fagus} sylvatica {L}.) laminated veneer lumber},
	volume = {0},
	issn = {0018-3768, 1436-736X},
	url = {https://link.springer.com/10.1007/s00107-023-01970-3},
	doi = {10.1007/s00107-023-01970-3},
	abstract = {Abstract
            
              Experiments on finger-jointing acetylated beech (
              Fagus sylvatica
              L.) laminated veneer lumber (LVL) have been made. The specimens were examined on its wet tensile shear strength (TSS) using three adhesives, including phenol resorcinol formaldehyde (PRF), one-component polyurethane (PUR) (without primer), and melamine urea formaldehyde (MUF). Contact angles (CA) of uncured and drop-applied MUF, PRF, and PUR adhesives on freshly cut finger-joints were evaluated. Surface roughness was measured using a laser-scanning-microscope (LSM). Results showed that PRF bonded acetylated specimens had highest wet TSS, followed by specimens with PUR bonding. MUF performed poorly, which was most likely caused by its inadequate water resistance and changes in chemical reactions due to remaining acetic acid. Acetylated finger-joints had a topography similar to untreated joints. Moreover, CA were just barely lower for MUF and PRF on acetylated wood than on untreated references.},
	language = {en},
	number = {0},
	urldate = {2023-06-26},
	journal = {European Journal of Wood and Wood Products},
	author = {Slabohm, Maik and Stolze, Hannes and Militz, Holger},
	month = jun,
	year = {2023},
	pages = {9},
	file = {Slabohm et al. - 2023 - Evaluation of wet tensile shear strength and surfa.pdf:/home/maicher/Zotero/storage/BRR5ZSPB/Slabohm et al. - 2023 - Evaluation of wet tensile shear strength and surfa.pdf:application/pdf},
}

Abstract Experiments on finger-jointing acetylated beech ( Fagus sylvatica L.) laminated veneer lumber (LVL) have been made. The specimens were examined on its wet tensile shear strength (TSS) using three adhesives, including phenol resorcinol formaldehyde (PRF), one-component polyurethane (PUR) (without primer), and melamine urea formaldehyde (MUF). Contact angles (CA) of uncured and drop-applied MUF, PRF, and PUR adhesives on freshly cut finger-joints were evaluated. Surface roughness was measured using a laser-scanning-microscope (LSM). Results showed that PRF bonded acetylated specimens had highest wet TSS, followed by specimens with PUR bonding. MUF performed poorly, which was most likely caused by its inadequate water resistance and changes in chemical reactions due to remaining acetic acid. Acetylated finger-joints had a topography similar to untreated joints. Moreover, CA were just barely lower for MUF and PRF on acetylated wood than on untreated references.

@inproceedings{alade_effects_2023,
	address = {Cairns, Australia},
	title = {Effects of preservative impregnations on wettability and surface free energy properties of {Eucalyptus} grandis wood},
	doi = {IRG/WP 23-40978},
	abstract = {Wettability and surface free energy (SFE) are crucial parameters for evaluating the adhesion thermodynamics of solid surfaces. Hence, this study investigated the effects of copper azole (CA) and disodium octaborate tetrahydrate (DOT) preservative impregnations on Eucalyptus grandis wood wettability and SFE. Wettability was determined in terms of contact angles with polar (water) and non-polar (diiodomethane) probe liquids by sessile drop measurement. SFE was determined based on the Owens-Wendt-Rabel-Kaelble model. Results obtained showed that CA and DOT impregnations reduced the wettability and SFE of E. grandis wood. CA impregnation had higher effects on water wettability recording a 22\% increase in mean water contact angle, and a 90\% reduction of mean polar SFE component. On the other hand, DOT impregnation had higher effects on diiodomethane wettability recording a 28\% increase in mean diiodomethane contact angle, and a 10\% reduction of mean dispersive SFE component. Adapting adhesive application and bonding protocols would be critical to mitigating the adverse effects of CA and DOT impregnations on adhesive bonding of treated E. grandis wood. These recommendations could apply to other preservative-impregnated woods with similar surface thermodynamic modifications.},
	language = {en},
	booktitle = {Proceedings {IRG} {Annual} {Meeting}},
	author = {Alade, Adefemi Adebisi and Wessels, Coenraad Brand and Stolze, Hannes and Militz, Holger},
	month = jun,
	year = {2023},
	pages = {13},
	file = {Alade et al. - Effects of preservative impregnations on wettabili.pdf:/home/maicher/Zotero/storage/2IUV9XMP/Alade et al. - Effects of preservative impregnations on wettabili.pdf:application/pdf},
}

Wettability and surface free energy (SFE) are crucial parameters for evaluating the adhesion thermodynamics of solid surfaces. Hence, this study investigated the effects of copper azole (CA) and disodium octaborate tetrahydrate (DOT) preservative impregnations on Eucalyptus grandis wood wettability and SFE. Wettability was determined in terms of contact angles with polar (water) and non-polar (diiodomethane) probe liquids by sessile drop measurement. SFE was determined based on the Owens-Wendt-Rabel-Kaelble model. Results obtained showed that CA and DOT impregnations reduced the wettability and SFE of E. grandis wood. CA impregnation had higher effects on water wettability recording a 22% increase in mean water contact angle, and a 90% reduction of mean polar SFE component. On the other hand, DOT impregnation had higher effects on diiodomethane wettability recording a 28% increase in mean diiodomethane contact angle, and a 10% reduction of mean dispersive SFE component. Adapting adhesive application and bonding protocols would be critical to mitigating the adverse effects of CA and DOT impregnations on adhesive bonding of treated E. grandis wood. These recommendations could apply to other preservative-impregnated woods with similar surface thermodynamic modifications.

@article{stolze_determination_2023-1,
	title = {Determination of the {Bonding} {Strength} of {Finger} {Joints} {Using} a {New} {Test} {Specimen} {Geometry}},
	volume = {11},
	issn = {2227-9717},
	url = {https://www.mdpi.com/2227-9717/11/2/445},
	doi = {10.3390/pr11020445},
	abstract = {In this study, a specimen geometry for testing finger joints was developed using finite element simulation and proofed by experimental testing. Six different wood species and three adhesives were used for finger-jointing specimens. With the test specimen geometry, the bonding strength of the finger joints was determined without the usual self-locking of the joint. Under load, the test specimen geometry introduces maximum stress at the beginning of the bond line (adhesive zone). However, the test specimen geometry does not generate a symmetric stress state. The main difficulty here is the flank angle of the finger joint geometry. The wood species and adhesives significantly influenced the performance of the finger joints.},
	language = {en},
	number = {2},
	urldate = {2023-02-03},
	journal = {Processes},
	author = {Stolze, Hannes and Gurnik, Michael and Kegel, Sebastian and Bollmus, Susanne and Militz, Holger},
	month = feb,
	year = {2023},
	pages = {445},
	file = {Stolze et al. - 2023 - Determination of the Bonding Strength of Finger Jo.pdf:/home/maicher/Zotero/storage/HISDKZQN/Stolze et al. - 2023 - Determination of the Bonding Strength of Finger Jo.pdf:application/pdf},
}

In this study, a specimen geometry for testing finger joints was developed using finite element simulation and proofed by experimental testing. Six different wood species and three adhesives were used for finger-jointing specimens. With the test specimen geometry, the bonding strength of the finger joints was determined without the usual self-locking of the joint. Under load, the test specimen geometry introduces maximum stress at the beginning of the bond line (adhesive zone). However, the test specimen geometry does not generate a symmetric stress state. The main difficulty here is the flank angle of the finger joint geometry. The wood species and adhesives significantly influenced the performance of the finger joints.

@article{stolze_non-destructive_2022,
	title = {Non-{Destructive} {Evaluation} of the {Cutting} {Surface} of {Hardwood} {Finger} {Joints}},
	volume = {22},
	copyright = {http://creativecommons.org/licenses/by/3.0/},
	issn = {1424-8220},
	url = {https://www.mdpi.com/1424-8220/22/10/3855},
	doi = {10.3390/s22103855},
	abstract = {In this study, the surface parameters wettability, roughness, and adhesive penetration, which are important for wood bonding, were investigated and evaluated utilizing non-destructive methods after different mechanical processing. For this purpose, beech and birch finger joints were prepared with different cutting combinations (three cutters with different sharpness levels and two feed rates) in an industrial process. Effects and interactions on the surface parameters resulting from the different cutting combinations were evaluated using three Full Factorial Designs. The various cutting parameters had a predominantly significant influence on the surface parameters. The effects and identified interactions highlight the complexity of the cutting surface and the importance of wood bonding. In this respect, a new finding is that with sharper cutters, higher contact angles of the adhesives occur. The methods (contact angle measurement, laser scanning microscopy, and brightfield microscopy) used were well suited to make effects visible and quantifiable, which can be of interest for the quality control of the wood processing industry. The results can help to better understand and evaluate the design of wood surfaces via machining and the bonding of hardwoods. Possibly the results can contribute to further standardizing the production of load-bearing hardwood finger joints and making them more efficient.},
	language = {en},
	number = {10},
	urldate = {2022-05-19},
	journal = {Sensors},
	author = {Stolze, Hannes and Gurnik, Michael and Koddenberg, Tim and Kröger, Jonas and Köhler, Robert and Viöl, Wolfgang and Militz, Holger},
	month = jan,
	year = {2022},
	note = {Number: 10
Publisher: Multidisciplinary Digital Publishing Institute},
	keywords = {hardwood, wettability, roughness, non-destructive evaluation, adhesive penetration, cutting surface, finger-jointing, wood characterization},
	pages = {3855},
	file = {Full Text PDF:/home/maicher/Zotero/storage/H4WWF56G/Stolze et al. - 2022 - Non-Destructive Evaluation of the Cutting Surface .pdf:application/pdf;sensors-22-03855.pdf:/home/maicher/Zotero/storage/J6S2BUM3/sensors-22-03855.pdf:application/pdf},
}

In this study, the surface parameters wettability, roughness, and adhesive penetration, which are important for wood bonding, were investigated and evaluated utilizing non-destructive methods after different mechanical processing. For this purpose, beech and birch finger joints were prepared with different cutting combinations (three cutters with different sharpness levels and two feed rates) in an industrial process. Effects and interactions on the surface parameters resulting from the different cutting combinations were evaluated using three Full Factorial Designs. The various cutting parameters had a predominantly significant influence on the surface parameters. The effects and identified interactions highlight the complexity of the cutting surface and the importance of wood bonding. In this respect, a new finding is that with sharper cutters, higher contact angles of the adhesives occur. The methods (contact angle measurement, laser scanning microscopy, and brightfield microscopy) used were well suited to make effects visible and quantifiable, which can be of interest for the quality control of the wood processing industry. The results can help to better understand and evaluate the design of wood surfaces via machining and the bonding of hardwoods. Possibly the results can contribute to further standardizing the production of load-bearing hardwood finger joints and making them more efficient.

@article{alade_improved_2022,
	title = {Improved adhesive-bond performance in copper azole and disodium octaborate tetrahydrate-treated {Eucalyptus} grandis laminates},
	volume = {0},
	issn = {2042-6445},
	url = {https://doi.org/10.1080/20426445.2022.2058277},
	doi = {10.1080/20426445.2022.2058277},
	abstract = {The prospect of manufacturing durable structural laminated wood with copper and boron-based preservative-impregnated Eucalyptus grandis wood was previously investigated but revealed adhesive-bond performance below standard requirements. In this study, bonding process factors, viz. mechanical pretreatment (surface planing) and bonding pressure in conjunction with wood preservative and adhesive compatibility for improved bond performance in preservative-treated E. grandis laminates were investigated. The results obtained showed significant and satisfactory improvement in shear strength and delamination resistance of E. grandis laminates based on EN 14080:2013 [Timber structures — Glued laminated timber and glued solid timber — Requirements, BSI Stand. Publ. (2014) 1–110] requirements. The suitability of polyurethane, melamine-urea-formaldehyde, and phenol-resorcinol-formaldehyde adhesives for bonding copper azole (CA) and disodium octaborate tetrahydrate (DOT)-impregnated E. grandis wood was established. Satisfactory pathways, including greener process routes for manufacturing CA and DOT-impregnated E. grandis laminates for structural applications in tropical and subtropical climes were achieved. The established processes could be readily adopted industrially to enhance the global implementation of solid wood composites and promote hardwood bonding.},
	number = {0},
	urldate = {2022-04-11},
	journal = {International Wood Products Journal},
	author = {Alade, Adefemi Adebisi and Wessels, Coenraad Brand and Stolze, Hannes and Militz, Holger},
	month = apr,
	year = {2022},
	note = {Publisher: Taylor \& Francis
\_eprint: https://doi.org/10.1080/20426445.2022.2058277},
	keywords = {adhesion, Wood preservation, bond durability, bond quality, E. grandis, hardwood bonding, solid wood composites, water-borne preservatives},
	pages = {1--9},
}

The prospect of manufacturing durable structural laminated wood with copper and boron-based preservative-impregnated Eucalyptus grandis wood was previously investigated but revealed adhesive-bond performance below standard requirements. In this study, bonding process factors, viz. mechanical pretreatment (surface planing) and bonding pressure in conjunction with wood preservative and adhesive compatibility for improved bond performance in preservative-treated E. grandis laminates were investigated. The results obtained showed significant and satisfactory improvement in shear strength and delamination resistance of E. grandis laminates based on EN 14080:2013 [Timber structures — Glued laminated timber and glued solid timber — Requirements, BSI Stand. Publ. (2014) 1–110] requirements. The suitability of polyurethane, melamine-urea-formaldehyde, and phenol-resorcinol-formaldehyde adhesives for bonding copper azole (CA) and disodium octaborate tetrahydrate (DOT)-impregnated E. grandis wood was established. Satisfactory pathways, including greener process routes for manufacturing CA and DOT-impregnated E. grandis laminates for structural applications in tropical and subtropical climes were achieved. The established processes could be readily adopted industrially to enhance the global implementation of solid wood composites and promote hardwood bonding.

@inproceedings{stolze_self-locking_2022,
	address = {Sopron, Hungary},
	title = {Self-locking of finger joints - {Influence} of density and moisture content},
	isbn = {978-963-334-446-0},
	language = {EN},
	booktitle = {Hardwood {Conference} {Proceedings}},
	publisher = {University of Sopron Press},
	author = {Stolze, Hannes and Trautwein, Jan-Frederik and Mayer, Aaron Kilan and Theis, Viorica and Bollmus, Susanne and Militz, Holger},
	year = {2022},
	pages = {317--323},
}

@article{stolze_monitoring_2021,
	title = {Monitoring of {Beech} {Glued} {Laminated} {Timber} and {Delamination} {Resistance} of {Beech} {Finger}-{Joints} in {Varying} {Ambient} {Climates}},
	volume = {12},
	copyright = {http://creativecommons.org/licenses/by/3.0/},
	url = {https://www.mdpi.com/1999-4907/12/12/1672},
	doi = {10.3390/f12121672},
	abstract = {In this study, varying ambient climates were simulated in a test building by changing temperature and relative humidity. Beech glued laminated timber (glulam, Fagus sylvatica, L.) was freshly installed in the test building and monitoring of the change in wood moisture content of the glulam resulting from the variations in climate was carried out. Subsequently, finger-jointed beech specimens were exposed to the variations in relative humidity measured in the course of the monitoring experiment on a laboratory scale, and thus an alternating climate regime was derived from the conditions in the test building. Its influence on the delamination of the finger-joints was evaluated. In addition, it was examined whether beech finger-joints using commercial adhesive systems fulfil the normative requirements for delamination resistance according to EN 301 (2018) and whether different bonding-wood moisture levels have an effect on the delamination of the finger-joints. In the context of the monitoring experiment, there was a clear moisture gradient in the beech glulam between the inner and near-surface wood. The applied adhesive systems showed almost the same delamination resistance after variation of relative humidity. The normative requirements were met by all PRF-bonded and by most PUR-bonded beech finger-joints with higher bonding wood moisture content.},
	language = {en},
	number = {12},
	urldate = {2022-01-17},
	journal = {Forests},
	author = {Stolze, Hannes and Schuh, Mathias and Kegel, Sebastian and Fürkötter-Ziegenbein, Connor and Brischke, Christian and Militz, Holger},
	month = dec,
	year = {2021},
	note = {Number: 12
Publisher: Multidisciplinary Digital Publishing Institute},
	keywords = {adhesives, delamination, beech glulam, finger-joint bonding, monitoring experiment},
	pages = {1672},
	file = {Full Text PDF:/home/maicher/Zotero/storage/PTR39CZS/Stolze et al. - 2021 - Monitoring of Beech Glued Laminated Timber and Del.pdf:application/pdf;Snapshot:/home/maicher/Zotero/storage/8BNTBW9V/1672.html:text/html},
}

In this study, varying ambient climates were simulated in a test building by changing temperature and relative humidity. Beech glued laminated timber (glulam, Fagus sylvatica, L.) was freshly installed in the test building and monitoring of the change in wood moisture content of the glulam resulting from the variations in climate was carried out. Subsequently, finger-jointed beech specimens were exposed to the variations in relative humidity measured in the course of the monitoring experiment on a laboratory scale, and thus an alternating climate regime was derived from the conditions in the test building. Its influence on the delamination of the finger-joints was evaluated. In addition, it was examined whether beech finger-joints using commercial adhesive systems fulfil the normative requirements for delamination resistance according to EN 301 (2018) and whether different bonding-wood moisture levels have an effect on the delamination of the finger-joints. In the context of the monitoring experiment, there was a clear moisture gradient in the beech glulam between the inner and near-surface wood. The applied adhesive systems showed almost the same delamination resistance after variation of relative humidity. The normative requirements were met by all PRF-bonded and by most PUR-bonded beech finger-joints with higher bonding wood moisture content.

@article{alade_compatibility_2021,
	title = {Compatibility of preservative with adhesive in {Eucalyptus} grandis laminates},
	volume = {13},
	issn = {2042-6445},
	url = {https://doi.org/10.1080/20426445.2021.2018101},
	doi = {10.1080/20426445.2021.2018101},
	abstract = {The fundamental factors responsible for the complexities in adhesive bonding of preservative-treated wood are predominantly wood species, preservative composition, and adhesive system. It is post-effect of these factors that process variables such as assembly times and bonding pressure exert secondary influences on adhesive-bond development in preservative-treated laminates. Hence, this study investigated the effect of copper azole (CA) and disodium octaborate tetrahydrate (DOT) impregnations on E. grandis heartwood (HW) and sapwood (SW) bonding with melamine–urea–formaldehyde and polyurethane adhesives. Based on the adhesives and bonding conditions investigated, the CA and DOT-treated E. grandis laminates do not satisfy at least one of the shear strength and delamination requirements according to EN 14080:2013. Contrary to delamination, shear strength was significantly affected by the HW–SW difference. This study established the basis for further considerations on adapting bonding conditions for improved adhesive-bond performance in CA and DOT-treated E. grandis laminates towards manufacturing durable hardwood composite for tropical and subtropical environments.},
	number = {1},
	urldate = {2021-12-23},
	journal = {International Wood Products Journal},
	author = {Alade, Adefemi Adebisi and Naghizadeh, Zahra and Wessels, Coenraad Brand and Stolze, Hannes and Militz, Holger},
	month = dec,
	year = {2021},
	note = {Publisher: Taylor \& Francis
\_eprint: https://doi.org/10.1080/20426445.2021.2018101},
	keywords = {adhesion, wood composites, E. grandis, hardwood bonding, Wood durability treatment},
	pages = {57--69},
	file = {Alade et al. - 2021 - Compatibility of preservative with adhesive in Euc.pdf:/home/maicher/Zotero/storage/XFVIY46R/Alade et al. - 2021 - Compatibility of preservative with adhesive in Euc.pdf:application/pdf},
}

The fundamental factors responsible for the complexities in adhesive bonding of preservative-treated wood are predominantly wood species, preservative composition, and adhesive system. It is post-effect of these factors that process variables such as assembly times and bonding pressure exert secondary influences on adhesive-bond development in preservative-treated laminates. Hence, this study investigated the effect of copper azole (CA) and disodium octaborate tetrahydrate (DOT) impregnations on E. grandis heartwood (HW) and sapwood (SW) bonding with melamine–urea–formaldehyde and polyurethane adhesives. Based on the adhesives and bonding conditions investigated, the CA and DOT-treated E. grandis laminates do not satisfy at least one of the shear strength and delamination requirements according to EN 14080:2013. Contrary to delamination, shear strength was significantly affected by the HW–SW difference. This study established the basis for further considerations on adapting bonding conditions for improved adhesive-bond performance in CA and DOT-treated E. grandis laminates towards manufacturing durable hardwood composite for tropical and subtropical environments.

@techreport{stolze_spezifische_2016,
	address = {Göttingen},
	type = {Bachelorarbeit},
	title = {Spezifische {Sortierung} von {Prüfkörpern} aus {Buchen}- und {Kiefernsplintholz} nach {Kriterien} zur {Prüfung} von elasto-mechanischen {Eigenschaften} - {Specific} sorting of beech and pine sapwood according to the criteria for testing the elasto-mechanical characteristics},
	language = {deutsch},
	institution = {Georg-August-Universität Göttingen, Fakultät für Forstwissenschaften und Waldökologie, Abteilung Holzbiologie und Holzprodukte},
	author = {Stolze, Hannes},
	year = {2016},
	note = {1. Prüfer: Dr. Antje Gellerich
2. Prüfer: Prof. Dr. Holger Militz},
	file = {Stolze - 2016 - Spezifische Sortierung von Prüfkörpern aus Buchen-.pdf:/home/maicher/Zotero/storage/NVI2FNTI/Stolze - 2016 - Spezifische Sortierung von Prüfkörpern aus Buchen-.pdf:application/pdf},
}