Implications of fiber characteristics and mat densification on permeability, compaction and properties of kenaf fiber panels

• High density panels with excellent mechanical properties can be made with kenaf bast fibers.
• Kenaf bast fibers mats are seven to ten times more permeable than that of wood fiber mats at same mat density.
• Decrease in fiber length can improve panel's permeability and dimensional properties.
• Increase in panel density has shown significant improvement in physciomechanical properties.

In the manufacturing of medium density and high density fiberboards the fiber characteristics and mat density substantially influence mat permeability, compaction pressure and panel's physicomechanical properties. In this paper, the permeability and compaction response of kenaf bast fiber mats are experimentally determined at three fiber lengths for both dry and resinated fiber mats with various levels of mat densification. The mats of long fibers have demonstrated higher permeability and require higher compaction pressure than short fiber mats at the same level of densification. Furthermore, kenaf panels in the density range of 800 kg/m3 to 1100 kg/m3 are manufactured with commercial melamine urea formaldehyde resin and three fiber categories. The panels are evaluated to demonstrate the effects of these factors on a panel's physicomechanical properties. The higher compaction pressure and good stress distribution with long fibers have resulted in higher mechanical properties than those of short fiber panels. On the other hand, a decrease in fiber length has lowered the mat permeability, resulting in significant improvements in dimensional properties. The panel physicomechanical properties can also significantly improve by increasing the panel density. The high density kenaf panels have shown excellent mechanical properties which are well above the standard requirements of MDF and HDF panels according to (ANSI, A208.2: 2009) and (ANSI, A135.4-2012) standards.