Timber Properties and Cellulose Crystallites Size in Pine Wood Cut in Different Sawing Patterns after Pretreatment with CH3COOH and H2O2 and Densification

Andi Detti Yunianti,S Suhasman,A Agussalim,Heru Arisandi,Musrizal Muin

doi:10.3390/f12111607

Abstract

One process to improve wood quality is densification or wood surface compression. Our study analyzed the changes in some basic properties of pine wood, including its anatomical structure, density, modulus of elasticity (MOE), and dimensions of cellulose crystallites, after densification following soaking pretreatment in CH3COOH and H2O2 at a concentration of 20%. Samples were sawn in radial and tangential directions for analysis of the wood. The results showed a change in the shape of tracheid cells from hexagonal to oval, as well as damage to the ray cell constituents on the tangential surface. The thickness decrease of the samples was in accordance with the target, which meant that spring-back was short. In general, the tangential boards had a higher density than the radial boards, with a lower MOE and crystallite dimensions. Our findings showed that the densified tangential board was stronger than the radial board.

Highlights

The availability of wood from natural forests is becoming limited, which has affected forest product industries and led to increased use of wood from plantation forests
Results of this study indicated changes in the anatomical structure, thickness, density, and modulus of elasticity (MOE) of radial and tangential boards as an effect of the densification treatment
Samples soaked in a solution of H2O2 and CH3COOH at a concentration of 20% for 24 h at 80 ◦C prior to a densification process that used a pressure of 35 kg/cm2 at a temperature of 150 ◦C for 30 min, causing changes in the pine wood constituent cells

Summary

Introduction

The availability of wood from natural forests is becoming limited, which has affected forest product industries and led to increased use of wood from plantation forests. Wood from plantation forests is known to have lower quality than wood from natural forests because it is generally harvested at a young age It has a high portion of juvenile wood and low durability. According to Panshin and de Zeeuw [1] and Bowyer et al [2], juvenile wood is characterized by low specific gravity and density, short fibers, a large amount of longitudinal shrinkage, and a mostly flatter microfibril angle. It has less dimensional stability and lower amounts of the chemical components that compose cellulose, but it has a higher lignin content than mature wood. The processing is needed to improve the quality of wood from fast-growing wood species from plantation forests

Methods

Results

Conclusion