Utrjevanje utekočinjenega lesa pri lepljenju termično modificirane smrekovine : diplomski projekt

Kompolšek, Urban (author), Šernek, Milan (mentor), Pohleven, Franc (reviewer)

Proučevali smo utrjevanje lepila iz utekočinjenega lesa. Uporabili smo les smreke, ki je bil termično modificiran pri temperaturah 150, 170, 190, 210 in 230 °C, ter lepilo iz utekočinjenega lesa. Meritve smo izvajali na reometru Ares G2, kjer smo namesto standardnih vzporednih diskov iz aluminija uporabili lesene diske. Diski so bili izdelani s pomočjo CNC-stroja in krožnega žagalnega stroja. Za meritve smo uporabili oscilatorni test z večvalovno tehniko merjenja. Uporabili smo diske iz nemodificirane in termično modificirane smrekovine, klimatizirane pri 65 % relativni zračni vlažnosti in temperaturi 20 °C, ter diske iz termično modificirane smrekovine, izpostavljene različnim relativnim zračnim vlažnostim. Ugotovili smo, da pri nemodificiranemu lesu lepilo iz utekočinjenega lesa potrebuje dlje časa, da želira. Pri višjih stopnjah modifikacije lesa je bil čas želiranja krajši. Točka zamreženja se je pri vzorcih z nemodificiranim in modificiranim lesom pojavila pri enakih časih, kar pomeni, da stopnja modifikacije ni vplivala na zamreževanje lepila iz utekočinjenega lesa. Vpliv je imela predvsem vlaga v lesu in delež hlapnih komponent v lepilu iz utekočinjenega lesa; to pomeni, da višja vlaga lesa podaljša čas, ki ga lepilo potrebuje, da zamreži.

• Language: Slovenian
• Keywords: utekočinjen les, reometer, termična modifikacija, elastični strižni modul
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [U. Kompolšek]
• Year: 2012
• Number of pages: VIII, 32 f.
• PID: 20.500.12556/RUL-670-45b5df73-e3d7-c660-e597-a8e3f04134d2
• UDC: 674.028.9
• COBISS.SI-ID: 2044297
• Publication date in RUL: 11.07.2014

Secondary language

• Language: English
• Title: Curing of liquefied wood at bonding of thermally treated spruce : B. Sc. thesis

Abstract

Curing of glue made from liquefied wood was researched. Spruce wood was heat treated at different temperatures (150, 170, 190, 210 and 230 °C) and glued using liquefied wood. The measurements were made with Ares G2 rheometer. Instead of standard aluminium discs, wooden discs made with CNC machine and circular saw were used. The oscillation test with the ŽmultiwaveŽ measurement technique was done. Discs from non-modified and thermally modified wood were prepared and air-conditioned at 65 % relative air humidity at 20 °C. The thermally modified wood was exposed to different values of relative air humidity. Based on measurements, it was concluded, that glue from liquefied wood needed more time for gelling than non-modified wood. The gelling time was shorter when using modified wood. The point of cross-link appeared at the same time at non-modified and modified wood. It means that the modification state does not influence the cross-linking of glue from liquefied wood. Humidity of wood has higher influence on glue so as the percentage of volatile able components in the glue from liquefied wood, meaning that the higher the humidity of wood takes longer to cross-link.

• Keywords: liquefied wood, rheometer, thermal modification, storage modulus