Preučevanje fizikalnih, mehanskih in sušilnih karakteristik ksilita

Kalorične lastnosti ksilita, litotipa lignita, so dobro raziskane, saj se pretežno uporablja kot gorivo. Natančnejše poznavanje njegove anatomske zgradbe ter fizikalnih in mehanskih lastnosti bi omogočilo izdelavo tudi uporabnejših izdelkov. Z mikroskopsko karakterizacijo zgradbe ksilita in proučevanjem osnovnih sorpcijskih in krčitvenih lastnosti smo določili sušilne parametre ter jih preverili v laboratorijskih pogojih. Gostota ksilita (ro=1229 kg/m3) je primerljiva z najgostejšimi listavci to povzroča močno krčenje. Na veliko nestabilnost kažejo tudi neugodno diferencialno nabrekanje, koeficient nabrekanja in sorpcijski kvocient. Sušilna krivulja izkazuje zelo kratek linearni odsek in velik difuzijski upor v 2. in 3. fazi sušenja. Zaradi različnih vključkov, deorientiranosti tkiva in velikih sušilnih napetosti je kohezivnost tkiva slaba, kar zmanjšuje kakovost in izkoristek osušenega ksilita. Calorific properties of xylite, litotype of lignite, are well researched, because it is used mainly as a fuel. If we knew the anatomical structure, physical and mechanical properties better, it would allow us to expand the use of xylite to some other areas. Using microscopic characterization drying parameters were defined and verified in laboratory conditions. Density of xylite (ro=1229 kg/m3) is comparable with highest densities of hardwoods. As a result xylite has high shrinking rate, differential shrinkage, shrinking and sorption coefficient. Drying curve has very short linear part and great diffusion resistance in 2nd and 3rd phase of drying. Poor cohesion of xylite tissues, caused by mineral inserts and deorientation of tissues, and great drying tensions are responsible for low efficiency of drying process.