Reconstruction of MDF board wastes in MDF production

In this thesis study, effects of different Medium Density Fiberboard (MDF) recycling processes on fiber length distribution and some technical board properties have been investigated. Five different recycling methods were used for waste MDF samples obtained from two different fiber compositions, 100% hardwood and 70% hardwood+30% softwood fibers. Fibers were refibrillated from waste MDF samples by using phosphoric acid, formic acid, microwave and chemi-thermo-mechanical (WKI) methods. Obtained recycled fibers were classified based on size distributions method and monitoring proper technics and experimental MDF panel samples were produced. Some mechanical and physical properties including modulus of rupture (MOR), modulus of elasticity (MOE), water absorption and thickness swelling of the samples were determined. As a result, the acidic methods resulted in a significantly decrease in the fiber lengths and panel properties but WKI and microwave methods insignificantly affected the fiber lengths and panel properties. Keywords: Fiberboard, recycling