diplomsko delo - univerzitetni študij
Matej Rozman (Author), Marko Petrič (Reviewer), Miha Humar (Mentor), Andreja Kutnar (Co-mentor)

Abstract

Viskoelastično toplotno zgoščen les (Viscoelastic Thermal Compressed wood, VTC les) ima zaradi visoke gostote in s tem izboljšanih mehanskih lastnosti velik potencial pri razvoju visokokakovostnih lesnih produktov. Širšo uporabo omejuje v največji meri povratek tlačne deformacije, do katerega pride ob izpostavitvi VTC lesa območjem s povišano vlažnostjo. Termična modifikacija pa je eden od načinov, s katerim lahko izboljšamo dimenzijsko obstojnost lesa in odpornost na lesne glive. V diplomski nalogi smo se osredotočili na dimenzijsko stabilnost tlačne deformacije VTC lesa. Vzorce smrekovega in bukovega lesa, ki so bili predhodno zgoščeni po postopku VTC, in kontrolne nezgoščene vzorce smo termično modificirali pri različnih temperaturah (190 °C, 200 °C, 210 °C in 220 °C). Obstojnost tlačne deformacije smo preverili z namakanjem v vodi. Postopek namakanja smo ponovili v petih ciklih, kjer smo ugotovili, da je povratek tlačne deformacije odvisen od temperature termične modifikacije in lesne vrste. Ugotovili smo, da je obstojnost VTC lesa neposredno povezana z izgubo mase, nastale med postopkom termične modifikacije. Pri termični modifikaciji pri najvišji uporabljeni temperaturi, t. j. 220 °C, pride do večje izgube mase lesa, pri čemer dosežemo boljšo obstojnost in zmanjšamo povratno tlačno deformacijo ter s tem izboljšamo dimenzijsko stabilnost VTC lesa.

Keywords

les;termična modifikacija;toplotna zgostitev;tlačna deformacija;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [M. Rozman]
UDC: 630*842
COBISS: 2277001 Link will open in a new window
Views: 388
Downloads: 113
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Other data

Secondary language: English
Secondary title: Influence of thermal modification of wood on set recovery of compressive deformation of thermal compressed wood
Secondary abstract: Viscoelastic thermal compressed (VTC) wood has due to the high wood density and thus improved mechanical properties great potential in the development of high-quality wood products. Its wider utilization is limited by set recovery of compressive deformation, which occurs when VTC wood is exposed to environment of increased humidity. Thermal modification is one of the process which can improve the dimensional stability of wood and resistance to fungal decay. In this thesis the problem of set recovery of compressive deformation was studied. Samples of spruce and beech wood, which were previously densified by the VTC process, were thermally modified with a thermal modification process at different temperatures (190 °C, 200 °C, 210 °C, and 220 °C). Set recovery of compressive deformation was examined after 5 water soaking cycles. It was found that set recovery of compressive deformation depended on the temperature of thermal modification and wood species. It was determined that stability of compression deformations of the VTC wood depends on the level of thermal modification. Thermal modification at temperature 220 °C caused significant mass loss, better stability, and reduced set recovery of compressive deformation, and thus improved the properties of VTC wood.
Secondary keywords: wood;wood modification;thermal compression;compressive deformation;
Type (COBISS): Undergraduate thesis
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za lesarstvo
Pages: X, 43 f., [5] f. pril.
ID: 11904376