Termo-Vakum İşlem Verimliliğini Tahmin Etmek İçin Bazı Sertlik Yöntemlerinin Karşılaştırılması

Abstract

Durometre sertliği (Shore D), genellikle termoplastik elastomerler, vulkanize kauçuklar ve bazı plastiklerin sertliğini ölçmek için kullanılmaktadır. Bu çalışmada ise Shore D sertlik ölçüm yönteminin, ahşap sertliğinin belirlen-mesinde uygulanabilirliği araştırılmıştır. Ayrıca termo-vakum işlem görmüş malzemede elde edilen değerlerin, işlem görmemiş malzemeye göre farklı olup olmadığı da incelenmiştir. Çünkü yöntem, nispeten daha küçük olan ölçüm iğnesi ile bir tahribatsız değerlendirme yöntemi olarak yerinde ölçüm yapma potansiyeline sahiptir. Bu çalışmada, işlem görmemiş (kontrol) ve 200^oC'de termo-vakum (Termovuoto®) işlemine tabi tutulmuş sarıçam (Pinus sylvestris) örnekleri kullanılmıştır. İğne boyutu, yöntem prensibi ve yıllık halka yapısının getirdiği heterojenlik nedeniyle, tam radyal ve radyal numuneler hazırlanmış ve her grupta ilkbahar ve yaz odunu sertlikleri ölçülmüştür. Ayrıca verimliliği değerlendirmek amacıyla Shore D sertlik yöntemi, statik Janka sertlik yöntemiyle de karşılaştırılmıştır. Sonuçlar, anatomik özellikler dikkate alınarak durometre sertlik ölçüm cihazı ile ısıl işlem görme durumunun tahmin edilebileceğini göstermiştir. Kesiş yöntemi açısından, tam radyal ve radyal kesilmiş numunelerde elde edilen veriler benzer çıkmıştır. Yıllık halkalar esas alındığında; ilkbahar ve yaz odununda farklı sonuçlar elde edilmiştir. Ayrıca yaz odunu tabakası hem işlem görmemiş hem de işlem görmüş hem tam radyal ve hem de radyal kesilmiş numunelerde daha yüksek sonuçlar elde edilmiştir. Literatür incelendiğinde ise sarıçamda Shore D yöntemiyle elde edilen sonuçların geniş varyasyonda olduğu, bu çalışmadaki sonuçlarla anatomik farklılıkların dikkate alınmasıyla varyasyonun azalabileceği tespit edilmiştir. Diğer yandan Shore D yöntemiyle ilgili standartlarda diğer malzemelerin sertlik ölçümlerinde belirli ağırlıklar önerilmesine karşın, bu çalışmada testler insan kuvvetiyle heterojen bir şekilde gerçekleştirilse de düşük varyasyonlar elde edilmiştir. 

Keywords

• Durometre
• janka
• sarıçam
• shore D
• termal modifikasyon

Comparing Some Hardness Methods for Estimating Thermo-Vacuum Treatment Efficiency

Abstract

Durometer hardness (Shore D) is generally used for measuring hardness of the thermoplastic elastomers, vulcanized rubber, some plastics etc. In this study, availability of the Shore D hardness method for wood hardness was investigated. In addition, it was investigated whether the values ​​obtained from thermo-vacuum treated material differed from those obtained from untreated material. Because the method has potential for in-situ measurements as a non-destructive evaluation method with its relatively smaller measurement needle. Untreated and thermo-vacuum (Termovuoto®) treated at 200^oC treated Scots pine (Pinus sylvestris) samples were used in this study. Due to the needle size, method principle, and heterogeneity caused by annual ring structure, full radial and radial specimens were prepared, and earlywood and latewood hardness values were measured in each group. In addition, the Shore D hardness method was compared with the static Janka hardness method to evaluate efficiency. The results showed that the thermal treatment can be predicted using a durometer hardness tester with taking anatomical features into account. In terms of cutting method, the data obtained from fully radial and radially cut samples were similar. Based on annual rings, different results were obtained in early- and latewood. Furthermore, higher results were obtained in both untreated and treated latewood layers, and in both fully radial and radially cut samples. However, a review of the literature reveals that the results obtained using the Shore D method in Scots pine show significant variations. In light of the results of this study, it is suggested that anatomical differences should also be taken into account in order to eliminate variation dependent on macroscopic variables. Otherwise, although the standards related to the Shore D method recommend the application of standard weights in hardness measurements of other materials, in this study, low variations were obtained even though the tests were performed heterogeneously using human force.

Keywords

• Durometer
• janka
• scots pine
• shore D
• thermal modification

References

1. Akçay Ç. (2020). Determination of decay, larvae resistance, water uptake, color, and hardness properties of wood impregnated with honeybee wax. BioResources 15(4), 8339-8354. https://doi.org/10.15376/biores.15.4.8339-8354
2. Akçay Ç., Ayata Ü., Birinci E., Yalçın M., Kolaylı S. (2022). Some Physical, Biological, Hardness, and Color Properties of Wood Impregnated with Propolis. Forestist 72(3), 283-293. https://doi.org/10.5152/forestist.2022.21051
3. Allegretti O., Brunetti M., Cuccui I., Ferrari S., Nocetti M., Terziev N. (2012). Thermo-vacuum modification of spruce (Picea abies Karst.) and fir (Abies alba Mill.) wood. BioResources 7(3), 3656-3669. https://doi.org/10.15376/biores.7.3.3656-3669
4. Allegretti O., Cuccui I., Terziev N., Sorini L. (2021). A model to predict the kinetics of mass loss in wood during thermo-vacuum modification. Holzforschung 75(5), 474-479. https://doi.org/10.1515/hf-2020-0127
5. Anonymous (2003). ThermoWood ® Handbook, Finnish ThermoWood Association, Helsinki-Finland.
6. ASTM D 2240 (2021). Standard test method for rubber property-durometer hardness. American Society for Testing and Materials, WestConshohocken, Pennsylvania, United States. https://doi.org/10.1520/d2240-04
7. Ayata Ü., Dilik T. (2020). Investigation of Shore-D hardness and surface roughness parameters on fig wood (In Turkish). ArtGRID-Journal of Architecture Engineering and Fine Arts 2(2), 98-109. https://dergipark.org.tr/en/pub/artgrid/issue/59446/830515
8. Bal B.C. (2018). A comparative study of some of the mechanical properties of pine wood heat treated in vacuum, nitrogen, and air atmospheres. BioResources 13(3), 5504-5511. https://doi.org/10.15376/biores.13.3.5504-5511

9. Budakçı M., Karamanoğlu M. (2014). Effects of weathering on some physical properties of wood (In Turkish). Kastamonu University Journal of Forestry Faculty 14(1), 37-47. https://dergipark.org.tr/tr/pub/kastorman/issue/17229/179929
10. Esteves B.M., Pereira H.M. (2009). Wood modification by heat treatment: A review. BioResources 4(1), 370-404. https://doi.org/10.15376/biores.4.1.370-404
11. Esteves B., Şahin S., Ayata U., Domingos I., Ferreira J., Gürleyen L. (2021). Effect of heat treatment on shore-D hardness of some wood species. BioResources 16(1), 1482. https://doi.org/10.15376/biores.16.1.1482-1495
12. Gao H., Sun M.Y., Cheng H.Y., Gao W.L., Ding X.L. (2016). Effects of heat treatment under vacuum on properties of poplar. BioResources 11(1), 1031-1043. https://doi.org/10.15376/biores.11.1.1031-1043
13. Giudice V.L., Antov P., Koynov D., Kristak L., Lee S.H., Lubis M.A.R., Mecca M., Moretti N., Tiwari R., Todaro L. (2023). Effect of thermo-vacuum modification on selected chemical, physical, and mechanical properties of Siberian larch (Larix sibirica L.) wood. Wood Material Science & Engineering 18(6), 1991-2000. https://doi.org/10.1080/17480272.2023.2212253
14. Grekin M., Verkasalo E. (2013). Variations in and models for Brinell hardness of Scots pine wood from Finland and Sweden. Baltic Forestry 19(1), 128-136. https://balticforestry.lammc.lt/bf/PDF_Articles/2013-19[1]/Grekin%20Mika.pdf
15. Han X., Li R., Zhang Q., Pu J. (2017). Impregnation of Scots Pine with compound modifier and induction of in-situ polymerization by heating. Wood and Fiber Science 49(1), 43-51. https://wfs.swst.org/index.php/wfs/article/view/2469
16. Hill C. (2006). Wood modification-chemical, thermal and other processes. Wiley Series in Renewable Resources, John Wiley & Sons, Ltd. pp 239. https://doi.org/10.1002/0470021748.ch5
17. Hirata S., Ohta M., Honma Y. (2001). Hardness distribution on wood surface. Journal of Wood Science 47, 1-7. https://doi.org/10.1007/bf00776637
18. Holmberg H. (2000). Influence of grain angle on Brinell hardness of Scots pine (Pinus sylvestris L.). Holz Roh Werkst 58(1), 91-95. https://doi.org/10.1007/s001070050392
19. Imposa S., Mele G., Corrao M., Coco G., Battaglia G. (2014). Characterization of decay in the wooden roof of the S. Agata Church of Ragusa Ibla (Southeastern Sicily) by means of sonic tomography and resistograph penetration tests. International Journal of Architectural Heritage 8(2), 213-223. https://doi.org/10.1080/15583058.2012.685924
20. Jebrane M., Pockrandt M., Cuccui I., Allegretti O., Uetimane Jr E., Terziev N. (2018). Comparative study of two softwood species industrially modified by Thermowood® and thermo-vacuum process. BioResources 13(1), 715-728. https://doi.org/10.15376/biores.13.1.715-728
21. Karlman L., Mörling T., Martinsson O. (2005). Wood density, annual ring width and latewood content in larch and Scots pine. Eurasian Journal of Forest Research 8(2), 91-96. https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/22195/1/8(2)_P91-96.pdf
22. Koczan G., Karwat Z., Kozakiewicz P. (2021). An attempt to unify the Brinell, Janka and Monnin hardness of wood on the basis of Meyer law. Journal of Wood Science 67(1), 7. https://doi.org/10.1186/s10086-020-01938-4
23. Mai C., Militz H. (2023). Wood modification. In: Niemz, P., Teischinger, A., Sandberg, D. (eds) Springer handbook of wood science and technology. Springer Handbooks. Springer, Cham. pp 873. https://doi.org/10.1007/978-3-030-81315-4_16
24. Mareš V., Blahovec J. (2004). Variation of the tree ring micro-hardness demonstrated on spruce wood. Journal of Forest Science 50(3), 135-141. https://doi.org/10.17221/4608-jfs
25. Martins I.Z., Deldotti L.R., Soriano J., Faria D.L. (2022). Janka hardness of hardwood species evaluated by the nondestructive sclerometric method. Materials and Structures 55(9), 227. https://doi.org/10.1617/s11527-022-02064-x
26. Oral İ. (2023). Prediction of hardness values of some wooden materials using computer-aided tap testing. Necmettin Erbakan University Journal of Science and Engineering 5(2), 257-266. https://doi.org/10.47112/neufmbd.2023.23
27. Özkan O.E. (2022). Effect of freezing temperature on impact bending strength and shore-D hardness of some wood species. BioResources 17(4), 6123-6130. https://doi.org/10.15376/biores.17.4.6123-6130
28. Peker H., Ayata Ü., Çamlıbel O. (2023). Effect of heat treatment at 200 degrees on Shore D hardness values of wood materials of some tropical tree species. GreenTech 1(2), 2-6. https://journalgreentech.com/index.php/pub/article/view/12
29. Pellerin R.F., Ross R.J. (2002). Nondestructive evaluation of wood. Forest Products Society, Pub. No. 7250.
30. Salca E.A., Hızıroğlu S. (2014). Evaluation of hardness and surface quality of different wood species as function of heat treatment. Materials & Design 62, 416-423. https://doi.org/10.1016/j.matdes.2014.05.029
31. Sandak A., Sandak J., Allegretti O. (2015). Quality control of vacuum thermally modified wood with near infrared spectroscopy. Vacuum 114, 44-48. https://doi.org/10.1016/j.vacuum.2014.12.027
32. Sofuoglu S.D., Yeşil H. (2016). Comparison of wood hardness with different measuring methods (In Turkish). In Proc. IMCOFE International Multidisciplinary Congress of Eurasia (pp. 480-485). Odessa, Ukraine.
33. Sofuoğlu S.D. (2022). Effect of thermo-mechanical densification on brightness and hardness in wood material (In Turkish). Turkish Journal of Engineering Research and Education 1(1), 15-19. https://dergipark.org.tr/en/pub/tmaed/issue/76210/1265440
34. Sydor M., Pinkowski G., Kučerka M., Kminiak R., Antov P., Rogoziński T. (2022). Indentation hardness and elastic recovery of some hardwood species. Applied Sciences 12(10), 5049. https://doi.org/10.3390/app12105049
35. Şahin C.K., Topay M., Var A.A. (2020). A study on suitability of some wood species for landscape applications: surface color, hardness and roughness changes at outdoor conditions. Wood Research 65(3), 395-404. https://doi.org/10.37763/wr.1336-4561/65.3.395404
36. Todoroki C.L., Lowell E.C., Filipescu C.N. (2021). Wood density estimates of standing trees by micro-drilling and other non-destructive measures. New Zealand Journal of Forestry Science 51(6), 1-14. https://nzjforestryscience.nz/index.php/nzjfs/article/view/74
37. Todorović N., Popović Z. (2011). Relationship between colour change and surface hardness in thermally modified sessile oak wood. Forestry Ideas 17(2), 42. https://forestry-ideas.info/issues/issues_Index.php?pageNum_rsIssue=1&totalRows_rsIssue=14&journalFilter=42
38. TS 2479 (1976). Wood-determination of static hardness. Turkish Standards Institute, Ankara, Türkiye.
39. TS EN 844 (2019). Round and sawn timber. Terminology. Turkish Standards Institute, Ankara, Türkiye.
40. TS EN 13183-1 (2012). Moisture content of a piece of sawn timber. Part 1: Determination by oven dry method. Turkish Standards Institute, Ankara, Türkiye.
41. TS ISO 13061-12 (2021). Physical and mechanical properties of wood. Test methods for small clear wood specimens. Part 12: Determination of static hardness. Turkish Standards Institute, Ankara, Türkiye.
42. TSE CEN/TS 15679 (2010). Thermal Modified Timber. Definitions and characteristics, Turkish Standards Institute, Ankara, Türkiye.