Kakovost lepilnega spoja okenskih profilov iz termično modificirane smrekovine : diplomsko delo - visokošolski strokovni študij

Božič, Robert (author), Šernek, Milan (mentor), Kariž, Mirko (comentor), Kitek Kuzman, Manja (reviewer)

Termična modifikacija je sodoben postopek zaščite lesa, kateri mu izboljša dimenzijsko stabilnost in obstojnost. Tako zaščiteno leseno okno je kvalitetnejše in konkurenčnejše na trgu. V diplomski nalogi smo zato proučevali vpliv termične modifikacije na kakovost lepljenja okenskega profila iz smrekovine. Uporabili smo smrekov les in tri različne vrste lepil (PVAc, PU, EPI), s katerimi smo zlepili termično modificiran in nemodificiran les. Zlepljenim preizkušancem smo ugotavljali strižno trdnost spojev in delež loma po lesu po standardu EN 392. Da bi ugotovili vpliv vode na lepilne spoje, pa smo del preizkušancev izpostavili 24 urnem namakanju v vodi s sobno temperaturo. Pri termični modifikaciji se smreki spremenijo lastnosti, ki posredno ali pa neposredno vplivajo na utrjevanje lepil in kakovost lepilnih spojev. Rezultati testa strižne trdnosti so pokazali, da je termično modificiran les možno kvalitetno zlepiti z PU in EPI lepili. Da zagotovimo kvaliteten lepilni spoj moramo postopek lepljenja prilagoditi spremenjenim lastnostim modificiranega lesa. Obe vrsti lepil utrjujeta kemično in za reakcijo potrebujeta višjo vlažnost kot jo ima modificiran les. Pred lepljenjem zato lepilne površine dodatno navlažimo, čas stiskanja pa povečamo. PVAc lepilo pa je manj kvalitetno zlepilo termično modificiran les, kar se je pokazalo predvsem pri testiranju mokrih preizkušancev.

• Language: Slovenian
• Keywords: lepljenje, termično modificiran les, strižna trdnost, trdnost spoja
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: R. Božič
• Year: 2016
• Number of pages: IX, 22 f., [6] f. pril.
• PID: 20.500.12556/RUL-158782
• UDC: 630*824.7
• COBISS.SI-ID: 2641545
• Publication date in RUL: 20.06.2024

Secondary language

• Language: English
• Title: The quality of the adhesive bond of window profiles from thermally modified spruce : graduation thesis - higher professional studies

Abstract

The thermal modification of wood is a modern procedure which improves the dimensional stability of wood and its resistance. In such a way protected wooden- window is better in quality and more competitive in market. In the thesis the influence of the thermal modification on the quality of bonding window profile from spruce wood was investigated. Spruce wood and three different types of adhesives were used (PVAc, PU, EPI) to bond thermal modified and non-modified wood (technical dry).The shear strength adhesive bond and percentage of wood failure were determined according to the EN 392. To find out the influence of water on adhesive bonds, part of specimens were soaked in water for 24 h at room temperature. It was found out, that after thermal modification the properties of spruce wood was changed, which has direct or indirect influence on adhesive curing and quality of adhesive bonds. The test results of the shear strength showed that the thermally modified wood can be bonded with (PU and EPI) adhesives. To assure the quality of adhesive bonds in thermally modified wood, the method of bonding needs to be adapted. The both types of adhesives cure chemically and for the reaction they need higher moistur content as the modified wood has. Therefore, the surfaces of wood have to be additionally wetted during the bonding, and the time of pressing has to be increased. The quality of PVAc adhesivebond of thermally modified wood was lower, which was particularly evident at testing specimens.

• Keywords: bonding, heat treated wood, shear strenght, bond strength