The manufacture of medium density fiberboards using rhododendron (R. Ponticum L.) biomass

The aim of this thesis was to investigate the suitability of Rhododendronponticum L. as a raw material for Medium Density Fiberboard (MDF)manufacturing. The Rhododendron ponticum L. is a biomass resource in the BleackSea Region of Turkey.Chemical properties, such as holocellulose, alfa-cellulose, lignin and ashcontents, alcohol-benzene, solubility in dilute alkali (1% NaOH), and hot and coldwater solubility, were determined. The Rhododendron ponticum L. woods fiberproperties such as fiber length, diameters and cell-wall thickness values are wereinvestigatedMedium Density Fiberboard panels (2100x4900x 8 mm) were manufacturedat Divapan Integrated Wood Company located in Duzce, Turkey. The panels weremade form The Rhododendron ponticum L. and industrial wood pine, oak mixed(Pinus sylvestris L., Quercus Robur L) furnishes in various proportions were used asthe raw material for MDF. The mixing ratios were 100:0, 75:25, 50:50, 25:75 and0:100 of The Rhododendron ponticum L.and industrial wood fiber in theexperiments. A total of 40 panels, 8 for each type of furnish, were tested. The chipsVhaving an average dimension of 20 by 25 by 5 mm were produced from low-qualityroundwood. Raw material was converted into fiber furnish in an Asplund defibratorusing a steam pressure of 7.8 bar at a temperature of 175 oC for 3.5 minutes. Thefollowing were added to the fiber furnish: 1 percent wax, 0.8 percent NH4Cl ashardener, and 11 percent urea-formaldehyde (UF) resin. Mats with an averagemoisture content of 11.2 percent were pressed at temperature of 175 oC for 4minutes at a pressure of 38 kg/cm2 . The panels were sanded with a sequence 0f 50,80 and 120 grit size following the cooling process. Tests were made on samplesconditioned at 20±20C and 65±5% relative humidity (RH) with a moistre content of12 %. Analysis of variance and multiple-range test (Duncan) were used to evaluatetest results. The results (arithmetical means) are as follows.