Effects of panel density and mat moisture content on processing medium density fiberboard

Abstract

Development of a fundamental understanding of heat transfer and resin curing during hot- pressing will help to optimize the manufacturing process of medium density fiberboard (MDF) allowing increased productivity, improved product quality, and enhanced durability. Effect of mat moisture content (MC) and panel density on performance of MDF panels, heat transfer, internal steam pressure, and pre-curing on the surface were systematically studied in this project. Both panel density and mat MC have significant effects on the internal steam pressure and internal bonding. We found that if the maximum internal steam pressure exceeded 100 kPa (15 psi), delamination would occur. Our analysis indicated that the optimized mat MC for internal bonding performance was dependent on panel density. For low-density panels (673 kg/m3), the optimized mat MC was between 12.1 and 15.3 percent. For medium (769 kg/m3) and high (833 kg/m3) density panels, the range of the optimized mat MC was narrowed and shifted to lower values. Panel density showed a positive relationship with mechanical performance, internal steam pressure, and maximum core temperature, but it slowed down the rate of temperature increase in the core and reduced the pre-cure thickness gradient (distance from face to position of maximum density). Mat MC also showed a positive relationship with internal steam pressure and the maximum core temperature.

Citation

Cai, Zhiyong; Muehl, James H.; Winandy, Jerrold E. 2006. Effects of panel density and mat moisture content on processing medium density fiberboard. Forest products journal. Vol. 56, no. 10 (Oct. 2006): pages 20-25.