Physical and Mechanical Properties of Heat Treated Daniella oliveri (Africa Balsam Tree) Wood

Abstract

Aims: This work investigated the effect of thermal modification on some of the physical properties and mechanical properties of Daniella oliveri wood.
 Study Design: The study design used for this experiment was 3 x4 Factorial experiment in Completely Randomized Design.
 Place and Duration of Study: The study was conducted at the Federal University of Technology, Akure wood laboratory and the study lasted for 6 months.
 Methodology: Wood samples were thermally treated at the temperature of 120, 140, 160 and 180°C, for different durations of 1, 1.5 and 2 hours in a muffle furnace. The planks were air-dried to reduce the moisture content and then machined into the required dimensions in the direction parallel to grain with a circular saw. Thirty-nine defect-free samples of dimensions 20 mm × 20 mm × 60 mm were prepared for dimensional stability and compression test, static bending tests and the hardness tests to make a total of 117 samples.
 Results: The result showed that the average weight loss of the treated wood samples varied from 3.79% at 120°C for 1 hour to 7.51% at 180°C for 2 hours. The treatment led to reduction in density from 528 to 459 kg/m3 at 180°C for 2 hours. The heat treatment also led to reduction in water absorption and volumetric swelling of the treated samples. The mean value for Modulus of elasticity (MOE) ranges from 2.17x103 N/mm2 to 2.96 x 103 N/mm2 for the treated samples while the untreated was 2.22x103 N/mm2. Heat treatment brought about improvement in the maximum compressive strength and the Janka hardness parallel to the grain of wood samples. The value of compressive strength increased from 26.58 N/mm2 to 41.71 N/mm2 and hardness from 69.24 N to 75.5 N. It can therefore be concluded that thermal modification greatly enhanced the dimensional stability and mechanical properties of wood samples.

Acoustic Properties of Resonant Spruce Wood Modified Using Oil-Heat Treatment (OHT)

“…After determining the density and mechanical parameters of all samples, they were divided into 4 groups (of similar mean values), for modification under different temperature variants. Modification was carried out in 4 temperature variants: 140, 160, 180 and 200 • C. These are the temperatures used when modifying wood for testing [14,21], and in industry [15]. By using several variants of the modification temperature, it was possible to determine how the temperature affects the properties of the wood.…”

“…Absorption occurs when the oil temperature drops after the modification with samples still in the medium, or when the material is extracted from the oil immediately after the modification time. Studies have also shown changes of resonance parameters of wood after biological modification [20] and descriptions of changes in the mechanical parameters of wood after thermal modification in a superheated steam atmosphere [8,14,[21][22][23][24]. However, to date, we have found no study describing the direct impact of OHT modification on the acoustic parameters of resonant wood.…”

A review of indigenous knowledge and ethnopharmacological significance of African Copaiba Balsam Tree, Daniellia oliveri (Fabaceae)

“…The study revealed a three-time shoot density height (7250 ± 454 shoots ha −1 ) and rapid growth following clearance after 34 months compared to ones on weedy plots (2425 ± 215 shoots ha −1 ) suggesting regular cutting of the plant's branches (for use by local people for firewood purposes) could hasten the growth of the plant. Other available physiological findings on the plant are on determination of physicomechanical properties of the plant (wood) when heated at varying degrees of temperature [ 110 ], examination of anatomy and morphology of the root (a measure of proper identification) [ 111 ] and assessment of the plants' biomass [ 112 ].…”