Termo–mekanik yoğunlaştırma işleminin ahşap malzemenin fiziksel özellikleri üzerine etkisi

Öz

Düşük yoğunluklu ve ticari değeri zayıf olan ağaç türleri sıkıştırmak suretiyle, yüksek dayanımlı ve değerli ürünler haline getirilebilir. Bu amaçla yapılan çalışmada, karaçam (Pinus nigra) ve Uludağ göknarı (Abies nordmanniana subsp. bornmulleriana) ağaç türleri çevreci bir modifikasyon yöntemi olan Termo-mekanik (TM) yöntemle 140 oC sıcaklık ve %25 ve %50 iki farklı oranda (radyal yönde) sıkıştırılarak yoğunlaştırılmıştır. Hava kurusu rutubetteki sıkıştırma oranı, yoğunlaştırma sonrası geri esneme (yaylanma) oranı ve hava kurusu yoğunluklara ait fiziksel özellikler belirlenmiştir. Elde edilen veriler, MSTAT-C programında istatistiksel analize tabi tutulmuştur. Sonuçlara göre ağaç türü, yoğunlaştırma şekli ve bunların tüm karşılıklı etkileşimleri hava kurusu rutubetteki sıkıştırma oranı üzerinde ve geri esneme oranı üzerinde etkili bulunmuştur. Hava kurusu rutubetteki sıkıştırma oranı, geri esneme etkisine bağlı olarak karaçama göre Uludağ göknarında daha düşük (Uludağ göknarı: 0.40 gr/cm³, karaçam: 0.49 gr/cm³) elde edilmiştir. Hacimsel geri kazanım (spring-back) oranları ortalama olarak Uludağ göknarında %15.44 iken karaçamda %19.40 olarak tespit edilmiştir. Yoğunlaştırma işlemi sonrası hava kurusu yoğunluk değer artışı, Uludağ göknarına göre karaçamda daha düşük yani; Uludağ göknarında %35.94 ve karaçamda %34.53 seviyesinde belirlenmiştir.

Anahtar Kelimeler

• Karaçam
• Uludağ Göknarı
• Fiziksel özellikler
• Termo-mekanik yoğunlaştırma

The effect of thermo-mechanical densification process on the physical properties of wood material

Öz

It can be made into high strength, and valuable products by compacting low density, and low commercial value wood species. In this study, black pine (Pinus nigra) and Uludağ fir (Abies nordmanniana subsp. bornmulleriana) tree species were densified by using Thermo-mechanical (TM) method, which is an environmental modification method, at 140 oC and two different ratios of 25% and 50% (in the radial direction). Compression ratio in air-dry moisture, spring-back ratio after densification, and physical properties of air-dry densities were determined. The obtained data were subjected to statistical analysis in the MSTAT-C program. According to the results, wood type, densification type, and all their interactions were found to be effective on the compression ratio, and spring-back ratio in air dry moisture. The compression ratio in air-dried moisture was lower in Uludağ fir (Uludağ fir: 0.40 gr/cm³, black pine: 0.49 gr/cm³) compared to black pine due to the spring-back effect. While the volumetric recovery (spring-back) rates were 15.44% in Uludağ fir, it was determined as 19.40% in black pine. After the condensation process, the air-dry density value increase was lower in black pine compared to Uludağ fir, and it was determined as 35.94% in Uludağ fir and 34.53% in Black Pine

Anahtar Kelimeler

• Black Pine
• Uludağ Fir
• Physical properties
• Termo-mechanical densification

Kaynakça

1. Arısüt U (2021) The effect of thermo-mechanical densification on some surface properties and morphological structure of wood materials impregnated with hydrophobic substances. Master’s Thesis, Düzce University Graduate School of Natural and Applied Sciences, Department of Wood Products Industrial Engineering, Düzce, Turkey.
2. Arruda LM and del Menezzi CHS (2013) Effect of thermo-mechanical treatment on Physical properties of wood veneers, Int. Wood Prod. J., 4 (4):217–224.
3. Blomberg J, Person B (2004) Plastic deformation in small clear pieces of Scots pine (Pinus sylvestris L.) during densification with the CaLignum process. Journal of Wood Science, 50: 307-314.
4. Blomberg J, Persson B and Bexell U (2006) Effects of semi-isostatic densification on anatomy and cell-shape recovery on soaking. Holzforschung 60: 322-331.
5. Blomberg J, Persson B, Blomberg A (2005) Effects of semi-isostatic densification of wood on the variation in strength properties with density. Wood Science and Technology 39:339–350.
6. Dubey MK (2010) Improvements in stability, durability and mechanical properties of radiata pine wood after heat-treatment in a vegetable oil. Doctorate Thesis, University of Canterbury Christchurch New Zealand.
7. Gong M, Lamason C (2007) Improvement of surface properties of low-density wood: mechanical modification with heat treatment (Project No. UNB57). University of New Brunswick, Fredericton, Canada.
8. Heger F, Groux M, Girardet F, Welzbacher C, Rapp A O, Navi P (2004) Mechanical and durability performance of THM densified wood. Final Workshop COST Action E22, Environmental Optimisation of Wood Protection, Lisboa: 1-10.

9. Homan W, Tjeerdsma B, Beckers E, Jorissen A (2000) Structural and other properties of modified wood. World Conference on Timber Engineering, 5, British Columbia.
10. Inoue M, Sekino N, Morooka T, Rowell RM, Norimoto M (2008) Fixation of compressive deformation in wood by pre-steaming. J Trop For Sci 20(4): 273-281.
11. ISO 3129 (2019) Wood sampling methods and general requirements for physical and mechanical testing of small clear wood specimen. Switzerland: International Organization for Standardization.
12. Kadivar C, Gauss G, Mármol AD, desá Fioroni K, Ghavami H (2019) The influence of the initial moisture content on densification process of D. asper bamboo: Physical-chemical and bending characterization Verlag, Constr. Build. Mater., 229 p. 116896.
13. Kollmann FFP, Côté WA (1968) Principles of Wood Science and Technology. Vol. I. Solid Wood, Springer-Verlag, Berlin.
14. Kollmann FFP, Kuenzi EW, Stamm AJ (1975) Principles of Wood Science and Technology. Vol. II. Wood Based Materials, Springer-Verlag, Berlin, 139-149.
15. Kultikova EV (1999) Structure and properties relationships of densified wood. M.S. Thesis, Virginia Polytechnic Institute and State University, Virginia, USA.
16. Kutnar A, Šernek M (2007) Densification of wood. Zbornik Gozdarstva in Lesarstva 82: 53-62.
17. Laine K (2014) Improving the properties of wood by surface densification. Aalto University publication series Doctoral Dissertations 133/2014 (Vol. 53, Issue 9). Aalto University publication series, S.59, Finland.
18. Laine K, Rautkari L, Hughes M, Kutnar A (2013) Reducing the set-recovery of surface densified solid Scots pine wood by hydrothermal post treatment. European Journal of Wood and Wood Products, 71 (1): 17-23.
19. Morsing N (2000) Densification of wood the influence of hygrothermal treatment on compression of beech perpendicular to the grain. Ph.D. Thesis, Technical University of Denmark, Department of Structural Engineering and Materials.
20. Navi P, Girardet F (2000) Effects of thermo-hydro-mechanical treatment on the structure and properties of wood. Holzforschung, 54 (3): 287–293.
21. Özdemir S (2020) The application of thermo-mechanical densification in production of curved laminated veneer lumber and the effect on mechanical properties. Ph.D. Thesis, Bartın University Graduate School of Natural and Applied Sciences Department of Forest Industry Engineering, Bartın, Turkey.
22. Pelit H (2014) Yoğunlaştırma ve ısıl işlemin doğu kayını ve sarıçamın bazı teknolojik özellikleriyle üst-yüzey işlemlerine etkisi. Gazi Üniversitesi Fen Bilimleri Enstitüsü Doktora Tezi, Ankara.
23. Pelit H, Sönmez A, Budakçı M (2014) Effects of ThermoWood® process combined with thermo-mechanical densification on some physical properties of Scots Pine (Pinus sylvestris L.). BioResources, (9):3.
24. Pelit H, Sönmez A, Budakçı M (2015) Effects of thermo-mechanical densification and heat treatment on density and Brinell hardness of Scots pine (Pinus sylvestris Lipsky.) and Eastern beech (Fagus orientalis L.). BioRes., 10(2): 3097-3111.
25. Pelit H, Budakçı M, Sönmez A (2016) Effects of heat post-treatment on dimensional stability and water absorption behaviours of mechanically densified Uludağ Fir and Black Poplar Woods. BioResources, 11(2): 3215-3229.
26. Perçin O, Peker H, Atilgan A (2016) The effect of heat treatment on the some physical and mechanical properties of beech (Fagus orientalis lipsky) wood. Wood Research, 61(3): 443-456.
27. Rautkari L, Properzi M, Pichelin F, Hughes M (2009) Surface modification of wood using friction. Wood Sci. Technol., 43 (3-4): 291–299.
28. Sadatnezhad SH, Khazaeian A, Sandberg D, Tabarsa T (2017) Continuous surface densification of wood: A new concept for large-scale industrial processing. BioRes, 12(2): 3122-3132.
29. Sandberg D, Kutnar A, Mantanis G (2017) Wood modification technologies-a review. Forest Biogeosciences and Forestry, 10(6): 895-908.
30. Seborg RM, Millett MA, Stamm AJ (1956) Heat-stabilized compressed wood (Staypak). FPL Report No: 1580 (revised).
31. Sofuoglu SD (2022) Effect of thermo-mechanical densification on brightness and hardness in wood material. Turkish Journal of Engineering Research and Education, 1(1): 15-19.
32. Sofuoglu SD, Tosun M, Atılgan A (2023) Determination of the machining characteristics of Uludağ fir (Abies nordmanniana Mattf.) densified by compressing. Wood Material Science & Engineering, 18 (3): 841-851. Şenol S (2018) Termo-Vibro-Mekanik (TVM) işlem görmüş bazı ağaç malzemelerin fiziksel, mekanik ve teknolojik özelliklerinin belirlenmesi. Doktora Tezi Fen Bilimleri Enstitüsü Düzce Üniversitesi, Düzce.
33. Şenol S, Budakçı M (2016) Mechanical wood modification methods. Mugla Journal of Science and Technology, 2(2): 53-59.
34. Tosun M (2021) Termo-Mekanik yoğunlaştırmanın masif ağaç malzemenin işlenme özellikleri üzerine. Yüksek Lisans Tezi, Fen Bilimleri Enstitüsü, Kütahya Dumlupınar Üniversitesi, Kütahya.
35. Tosun M, Sofuoğlu SD (2021) Ağaç malzemenin sıkıştırılarak yoğunlaştırılması konusunda yapılan çalışmalar. Mobilya ve Ahşap Malzeme Araştırmaları Dergisi, 4(1): 91-102.
36. TS ISO 13061-1 (2021) Odunun fiziksel ve mekanik özellikleri-kusursuz küçük ahşap numunelerin deney yöntemleri. Bölüm 1: Fiziksel ve Mekanik Deneyler için Nem Muhtevasının Belirlenmesi. Ankara.
37. TS ISO 13061-2 (2021) Odunun fiziksel ve mekanik özellikleri-kusursuz küçük ahşap numunelerin deney yöntemleri. Bölüm 2: Fiziksel ve mekanik deneyler için yoğunluğun belirlenmesi, Ankara.
38. Ulker O, Imirzil O, Burdurlu E (2012) The effect of densification temperature on somephysical and mechanical properties of scots pine (Pinus sylvestris L.). BioResources, 7 (4): 5581–5592.
39. Welzbacher CR, Wehsener J, Rapp AO, Haller P (2008) Thermo-mechanical densification combined with thermal modification of Norway spruce (Picea abies Karst) in industrial scale-Dimensional stability and durability aspects. Holz Roh Werkst, 66: 39–49.