A STUDY ON THE APPROPRIATE CONDITIONS OF THE PRESS-CYCLE FOR THE MANUFACTURE OF PALM MIDRIB-CORE BLOCKBOARDS

Abstract

Due to shortage in local resources of wood, it is important to search for other resources that could substitute imported solid wood. Date palm leaves' midribs (DPLM) are available as a cheap secondary product resulting from annual pruning of palms. Air-dried DPLM of known species were conve11ed into strips of8 x 12 mm cross-section, to be a substitute for the core layer of block board Board specimens of 400 x 400 mm and 12 mm thick have been produced in a test rig under 3 different levels of pressure from 50 N/cm2 to I00 N/cm 2 and 4 levels of pressing time from 5 to I 5 min. and 3 levels of within the temperature range from 90"C to I 20"C. The gluing process was co[lducted using Urea-formaldehyde as a resin and ammonium chloride as a hardener The modulus of rupture (MOR) and the modulus of elasticity I (MOE) in bending, compressive strength (Csm"'), tensile strength (Ts,,.,) and the glue bond strength (GBS) were determined. The results indicate that the strength properties ofDPLM-core blackboards are comparable to those of the common Sp1•uce-core blackboards. The results show also that, there is a specific set of pressing conditions at which the strength properties attain their highest level.

The aforementioned findings open the possibility of wide use of DPLM in core layer as a substitute of imported Spruce wood in block boards. This could be a real suppon to the relatively new blackboard industry in Egypt Key words: Blackboard, CorePiywood. Date Palm Leaves' Midribs, Mechanical Properties.