Improvement in Durability of Oil Heat Treated 16-Year-Old Acacia mangium in Laboratory Tests

R Wahab,M S Rasat,M T Mustafa,I N S Ahmad Mazalan,A R Mojiol

doi:10.5539/jas.v9n6p251

Abstract

Improvement in the durability of oil heat treated Acacia mangium through accelerated laboratory tests was studied. A. mangium logs of 16-year-old harvested and segregated into the bottom, middle, and top portions. These were oil-heat treated in a stainless steel tank with oil palm oil as a heating medium at temperatures 180, 200 and 220 °C for the duration of 30, 60 and 90 minutes respectively. The wood samples dried and grounded into sawdust, air-dried again before undergoing durability tests. Accelerated 12 weeks laboratory durability studies conducted on the treated A. mangium. Fungi of Pycnoporus sanguineus, Gloeophyllum trabeum and Coriolus versicolors inoculated on the woods. Untreated samples used as controls. The results showed that durability of the wood improved with an increase in temperature and duration of the treatment. The oil heat treatment process reduced the attack of G. trabeum from 5.02%, 4.41% and 4.38% in the control samples to 0.54-4.55%, 0.91-4.41% and 1.08-4.38% at the bottom, middle and top portions, respectively. The attack of C. versicolors reduced from 11.48%, 14.27% and 15.68% in the control samples to 1.87-10.19%, 3.10-12.69 and 4.78-15.10% at the bottom, middle and top portions. However, the attacked of P. sanguineus were less effective with 31.42%, 18.24% and 10.53% in control samples to 3.71-10.18%, 5.74-14.59% and 4.37-17.08% at the bottom, middle and top portions. Heavy colonization of mycelia occurs in vessels of the untreated A. mangium wood in comparison to the oil heat treated wood observed through scanning electron microscope.

Highlights

IntroductionThis fast wood growing species, has some disadvantage in which the wood contains a high proportion of juvenile wood and poorly developed heartwood at the ages between 14 to 18-year-old (Razak et al, 2010a)
Ease of growth and adaptability has made Acacia mangium one of the most popular plantation species in Malaysia
The fungi attack dropped when the temperatures and treatment duration increases. These results proved that the oil-heat treatment process could apply to reduce the fungal attack of A. mangium woods

Summary

Introduction

This fast wood growing species, has some disadvantage in which the wood contains a high proportion of juvenile wood and poorly developed heartwood at the ages between 14 to 18-year-old (Razak et al, 2010a). The heat treatment is one of the wood modification processes used in the wood industry compared to other processes (Esteves & Pereira, 2009). This treatment is considered an environmental-friendly process since it does not use chemicals (Izyan et al, 2010; Razak et al, 2011)

Methods

Results

Conclusion