The Effect of Press Temperature and Duration on the Bonding Strength of American Poplar Laminated Veneer Lumber

Abstract

In this study, the effect of press temperature and duration on bonding strength of laminated veneer lumber (LVL) was investigated. For this purpose, LVLs were produced from I 77/51 American poplar clone (Populus deltoides) by using 2 different press temperatures (140 and 170⁰C) and 3 press duration (10, 15 and 20 minutes). Phenol formaldehyde (PF) adhesive was used for bonding of poplar veneers. The bonding strength and wood failure rate of produced LVLs were determined according to TS EN 314-1 standard. According to experimental results, the LVLs pressed at 170⁰C showed better bonding strength compared to LVLs pressed at 140⁰C. On the other hand, a decrease was observed in the wood failure rate due to the increase in temperature. The highest bonding strength was obtained by press duration of 10 minutes at press temperature of 170⁰C and a significant decrease in bonding strength was observed when press duration was extended.

Keywords

• Press temperature
• press duration
• bonding strength
• laminated veneer lumber
• American poplar
• phenol formaldehyde

Pres Sıcaklık ve Süresinin Amerikan Kavağı Tabakalı Kaplama Kerestenin Yapışma Dayanımı Üzerine Etkisi

Öz

Bu çalışmada, tabakalı kaplama kereste (TKK) üretiminde pres sıcaklığı ve pres süresinin yapışma direnci üzerine etkisi incelenmiştir. Bu maksatla I-77/51 Amerikan Kavağı klonu (Populus deltoides) kaplamaların, fenol formaldehit (FF) yapıştırıcısı kullanılarak 140⁰C’de 10 dakika, 170⁰C’de 10, 15 ve 20 dakika süreyle preslenmesiyle TKK’ler üretilmiştir. Elde edilen TKK’lerin yapışma dirençleri ve odun kırılma oranları TS EN 314-1 standardına göre belirlenmiştir. Deney sonuçlarına göre 170⁰C’de preslenen numunelerin yapışma direnci 140⁰C’de preslenenlere göre daha yüksek bulunmuştur. Diğer yandan, pres sıcaklığındaki artış sonucunda odun kırılma oranında düşme gözlemlenmiştir. Pres süresi incelendiğinde en yüksek yapışma direnci 170⁰C’de 10 dakika preslenerek üretilen TKK’lerden elde edilmiş ve pres süresi uzatıldığında yapışma direncinde düşüş gözlemlenmiştir.

Anahtar Kelimeler

• Pres sıcaklığı
• pres süresi
• yapışma direnci
• tabakalı kaplama kereste
• Amerikan kavağı
• fenol formaldehit

References

1. Aydemir, D., Gunduz, G., Onat, S. M. (2010). The impacts of heat treatment on lap joint shear strength of black pine wood. Journal of Adhesion, 86(9): 904–912.
2. Bao, F., Fu, F., Choong, E., Hse, C.-Y. (2001). Contribution factor of wood properties of three poplar clones to strength of laminated veneer lumber. Wood and Fiber Science, 33(3): 345–352.
3. Behkhta, P., Ortynska, G., Sedliacik, J. (2014). Properties of modified phenol-formaldehyde adhesive for plywood panels manufactured from high moisture content veneer. Drvna Industrija, 65(4): 293-301.
4. Bliem, P., Konnerth, J., Frömel-Frybort, S., Gartner, C., Mauritz, R., van Herwijnen, H. W. G. (2020). Influence of drying and curing parameters on phenol-formaldehyde impregnated wood veneers. Journal of Adhesion, 96(1–4): 253–271.
5. Chow, S. (1972). Thermal analysis of liquid phenol-formaldehyde resin curing. Holzforschung, 26(6): 229–232.
6. Dunky, M. and Niemz, P. (2002). Holzwerkstoffe und Leime. Springer Verlag: Berlin, Heidelberg.
7. Furuno, T. S., Goto, T., Harada, H. (1983). Penetration of glue into the tracheid lumina of softwood and the morphology of fractures by tensile-shear tests. Journal of the Japan Wood Research Society, 29(1): 43-53.
8. Gerhards, C. C. (1982). Effect of moisture content and temperature on the mechanical properties of wood: an analysis of immediate effects. Wood and Fiber Science, 14(1): 4–36.

9. Gunduz, G., Aydemir, D., Karakas, G. (2009). The effects of thermal treatment on the mechanical properties of wild Pear (Pyrus elaeagnifolia Pall.) wood and changes in physical properties. Materials and Design, 30(10): 4391–4395.
10. Huang, C. L. (2010). Delamination in wood, wood products and wood-based composites. In: V. Bucur editor. Delamination in Wood, Wood Products and Wood-Based Composites. Dordrecht: Springer, pp. 215-236.
11. İlçe, C., Budakçı, M., Özdemir, S., Akkuş, M. (2015). Analysis of usability in furniture production of wood plastic laminated board. BioResources, 10(3): 4300–4314.
12. Kamke, F. A. and Lee, J. N. (2007). Adhesive penetration in wood - A review. Wood and Fiber Science, 39(2): 205–220.
13. Kollmann, F. F. P., Kuenzi, E. W., Stamm, A. J. (1975). Principles of Wood Science and Technology II: Wood Based Materials. Springer-Verlag: Berlin, Heidelberg.
14. Kurt, R., Cil, M., Aslan, K., Cavus, V. (2011). Effect of pressure duration on physical, mechanical, and combustibility characteristics of laminated veneer lumber (LVL) made with hybrid poplar clones. BioResources, 6(4): 4886–4894.
15. Kurt, R., Meriç, H., Aslan, K., Çil, M. (2012). Laminated veneer lumber (LVL) manufacturing using three hybrid poplar clones. Turkish Journal of Agriculture and Forestry, 36(2012):237-245.
16. Lin, W. S. and Lee, W. J. (2018). Influence of curing temperature on the bonding strength of heat-treated plywood made with melamine-urea-formaldehyde and phenol–formaldehyde resins. European Journal of Wood and Wood Products, 76(1): 297–303.
17. Luy, J. A., Sexton, E. E., Whalin, R. W. (1968). Laminating and Bending: A Base Syllabus on Woodtechnology. EKU Graphic Arts Department: Kentucky.
18. Mengeloğlu, F. and Kurt, R. (2004). Mühendislik ürünü ağaç malzemeler 1 - Tabakalanmış kaplama kereste (TAK) ve tabakalanmış ağaç malzeme (TAM). KSÜ Fen ve Mühendislik Dergisi, 7(1): 39–44.
19. Pangh, H. and Doosthoseini, K. (2017). Optimization of press time and properties of laminated veneer lumber panels by means of a punching technique. BioResources, 12(2): 2254–2268.
20. Sedliačik, J., Bekhta, P., Potapova, O. (2010). Technology of low-temperature production of plywood bonded with modified phenol-formaldehyde resin. Wood Research, 55(4): 123–130.
21. Sernek, M. and Kamke, F. A. (2007). Application of dielectric analysis for monitoring the cure process of phenol formaldehyde adhesive. International Journal of Adhesion and Adhesives, 27(7): 562–567.
22. Sinha, A., Nairn, J. A., Gupta, R. (2011). Thermal degradation of bending strength of plywood and oriented strand board: A kinetics approach. Wood Science and Technology, 45(2): 315–330.
23. TS EN 314-1 (1998). Kontrplak kaplanmış-Yapışma kalitesi bölüm 1: Deney metotları, Türkiye Standartları Enstitüsü (TSE), Ankara.
24. TS EN 323 (1999). Ahşap esaslı levhalar-Birim hacim ağırlığının tayini, Türkiye Standartları Enstitüsü (TSE), Ankara.
25. Zhou, J., Hu, C., Hu, S., Yun, H., Jiang, G., Zhang, S. (2012). Effects of temperature on the bending performance of wood-based panels. BioResources, 7(3): 3597–3606.