Medium density fiberboard made from phenolic resin and wood residues of mixed species

Medium density fiberboard (MDF) (or medium density hardboard) made from steam-pressure-refined wood residues (a mixture of 70% hardwoods and 30% softwood species) met most of the specifications required for service class hardboard and achieved equal to or better strength properties than commercial plywood. The MDF included wood residues from red lauan, white meranti, ash, birch, oak, lindens, true fir, Douglas-fir, and larch fibers. Dependent variables included three phenol-formaldehyde (PF) resin levels, three mat moisture content (MC) levels, and three press temperature levels. The analyses indicated that these three main factors affected the modulus of rupture (MOR), internal bond (IB), linear expansion (LE), water absorption (WA), and thickness swelling (TS) of MDF with only a few exceptions. The mat MC plays an important role in influencing all properties of MDF. It is shown that a functional linear relationship exists between properties such as MOR and IB, MOR and SG, MOR and WA, IB and WA, SG and WA, and TS and SG. From the tests performed, it was concluded that MDF made from wood residues and bonded with 8 percent PF resin can be used in the manufacture of railway carriages and other uses in China.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member