Vpliv vrste lepila pri izdelavi ivernih plošč na tlak sproščanja ob izpostavitvi delovanju vode
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.
2008
2014-07-11 12:24:51
1060
iverne plošče, UF lepilo, MF lepilo, debelinski nabrek, sila nabreka
particleboard, UF resin, MF resin, thickness swelling, swelling stress
m5
[U. Firšt]
Uroš
Firšt
70
Sergej
Medved
991
Dominika
Gornik Bučar
901
UDK
4
630*862.2:630*824.86
COBISS_ID
3
1619081
dn_first_uros.pdf
441878
Predstavitvena datoteka
2020-08-24 15:05:00