20.500.12556/RUL-269 Vpliv vrste lepila pri izdelavi ivernih plošč na tlak sproščanja ob izpostavitvi delovanju vode diplomsko delo Impact of adhesive type at particleboard manufacturing at pressure relax when exposed to water activity univerzitetni študij Raziskali smo vpliv vrste in deleža lepila na debelinski nabrek in tlak sproščanja pri nabreku. Za izdelavo plošč smo uporabili iverje iz tovarne Otiški Vrh, UF in MF lepilo. Plošče smo izdelali pri laboratorijskih pogojih s 6,00 % do 9,00 % deleži lepila v srednjem sloju ter 10,00 % do 13,00 % v zunanjem. Med stiskanjem smo merili spremembo temperature v sredini plošče, v prehodu med zunanjim in srednjim slojem ter prehodom med iverno in grelno ploščo stiskalnice. Debelinski nabrek smo določevali z metodo 24 urne potopitve preizkušancev v vodo. Silo oz. tlak sproščanja ob potopitvi smo merili 24 ur. Ugotovili smo, da imajo plošče zlepljene z melamin-formaldehidnim lepilom manjši debelinski nabrek kot tiste zlepljene z urea-formaldehidnim. Pri uporabi melamin-formaldehidnega lepila smo prav tako ugotovili manjše sile, ki se sprostijo ob nabrekanju. Z manjšanjem debelinskega nabreka se manjša tudi sila (tlak sproščanja ob nabreku). Pri UF lepilu smo dosegli večje spremembe sile (tlak sproščanja ob nabreku) pri spreminjanju deleža lepila v srednjem sloju. Sila (tlak sproščanja ob nabreku) in debelinski nabrek hitreje naraščata v začetni fazi izpostavitve vodi. The impact of adhesive type and its share on swelling stress and thickness swelling of particleboards was researched. To make particleboards particles from Otiški Vrh Particleboard Factory were glued with urea-formaldehyde or melamine-formaldehyde resin. Particleboards were made in laboratory conditions with 6.00 % - 9.00 % share of glue in the core layer, and 10.00 % - 13.00 % in the surface layer. During the compression the temperature change was measured in the middle of the particleboard, intersection core and surface layer, and in intersection between surface layer and heating plate. Thickness swelling was determined with 24 hour water immersion test. Swelling stresses were measured for 24 hours. It was determined that particleboards glued with MF resin had lower thickness swelling than those glued with UF resin. Particleboards glued with MF resin had a lower swelling stress. It was also determined that by reducing the thickness swelling the swelling stress reduces too. Using UF resin we achieved bigger changes of swelling stress by changing the share of glue in core layer. Swelling stress and thickness swelling increase faster in 1st. phase when exposed to water. iverne plošče UF lepilo MF lepilo debelinski nabrek sila nabreka particleboard UF resin MF resin thickness swelling swelling stress true false false [U. Firšt] Slovenski jezik Angleški jezik Diplomsko delo 2014-07-11 12:24:51 2014-07-11 12:24:51 2022-07-11 10:15:14 0000-00-00 00:00:00 2008 0 Ljubljana 0 VIII, 45 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 630*862.2:630*824.86 1619081 dn_first_uros.pdf dn_first_uros.pdf 1 B77975B13060F21EE395D213786410B4 1d0438fa76305d192852fcc5cafcd58a3d592712e43490642958dd9fef55a8b8 5b140725-a1b9-11eb-a523-00155dcfd717 20.500.12556/rul/3d113692-f65a-4d24-9107-1f450cd4c3ee https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=132275 Biotehniška fakulteta 0 0 0