Atmawi Darwis

This study investigated the qualitative anatomical characteristics and fiber quality of tapped Styrax sumatrana wood to facilitate its further utilization. The transverse surface of the tapped S. sumatrana was light or greyish brown in the sapwood and reddish brown in the heartwood. The resin canals of the tapped wood were formed along the growth rings at the boundaries between the heartwood and sapwood. Furthermore, microscopic analyses revealed an irregular outline and rounded epithelial cells at the edges of the intercellular traumatic canal (TC). Approximately 8–16 epithelial cells surrounded the resin canals. The fibers in the tapped S. sumatrana were generally thin-walled, whereas those near the TC were thick-walled. Moreover, S. sumatrana were diffuse-porous and exhibited intermediately distinct or indistinct growth ring boundaries. The vessels were mainly radial multiples and clusters of 3–5. In addition, they showed a diagonal-to-radial pattern arrangement and a few tangential bands. Deposits were observed in some vessels in the tapped part but were absent in the untapped part. The fiber length of the tapped S. sumatrana wood was classified as moderate to extensive and categorized as second-grade pulp quality. Finally, the cell walls were classified as thin to moderate.

This study investigated the anatomical characteristics and pulp quality of tapped Styrax sumatrana wood to facilitate its further utilization. The transverse surface of the tapped S. sumatrana was light or greyish brown in the sapwood and reddish brown in the heartwood. The resin canals of the tapped wood were formed along the growth rings at the boundaries between the heartwood and sapwood. Furthermore, microscopic analyses revealed an irregular outline and rounded epithelial cells at the edges of the intercellular traumatic resin canal (TC). Approximately 8–16 epithelial cells surrounded the resin canals. The fibers in the tapped S. sumatrana were generally thin-walled, whereas those near the TC were thick-walled. Moreover, S. sumatrana were diffuse-porous and exhibited intermediately distinct or indistinct growth ring boundaries. The vessels were mainly in radial multiples and clusters of 3–5. In addition, they showed a diagonal-to-radial pattern arrangement and a few tangential bands. Deposits were observed in some vessels in the tapped part but were absent in the untapped part. The fiber length of the tapped S. sumatrana wood was classified as moderate to extensive and categorized as 2nd grade pulp quality. Finally, the cell walls were classified as thin to moderate.

Laminated veneer lumber (LVL) and modified grain orientation of LVL (LVB) are composite products made from veneer that are predicted to replace construction timber. The purpose of this study was to determine the physical and mechanical properties of LVL and LVB of mahoni (Swietenia macrophylla), manglid (Manglietia glauca), and gmelina (Gmelina moluccana) and to compare their characteristics. The results showed that the physical and mechanical properties of LVL and LVB generally meet the standards for use in construction. Differences in the properties of LVL and LVB occurred in the properties of hardness and screw tests, while the other properties were similar. The parallel fiber direction was better in terms of adhesive strength, while the compaction density was slightly higher than LVL. The LVL flexural strength was better than LVB in flat and edge test directions. This difference correlates with the adhesive strength in the shear strength test due to the different orientation of the fiber directions.

As a composite product, particleboard has disadvantages related to low dimensional stability. The research purpose was to analyze the effect of immersion in acetic acid and NaOH solution on the quality of the particleboard sandwich. Sandwich particleboard (SPb) was made in a size of 25 cm length and 25 cm width. The target thickness and density are 1 cm and 0.75 g/cm³, respectively. The adhesive used was isocyanate adhesive with a content of 7%. First, The particles, which were in the form of wood shavings and bamboo strands, were soaked in a solution of acetic acid and NaOH at various concentrations (0, 1, 2, and 3%). The moisture content of the particles to be made SPb was set at 7%. After evenly mixing the particles (wood shavings and bamboo strands) and the adhesive, the sheet was created. The board sheets were made into three layers, namely 40% face layer in the form of a bamboo strand, 20% core layer in the form of wood shavings, and 40% back layer in the form of the bamboo strand. The next stage was the hot pressing process at 160 °C for 5 min and 30 kg/cm²pressure. The following process was conditioning the board for seven days. Testing of quality refers to the standard JIS A5908 (2003). The results showed that the immersion of Raru wood particles in acetic acid and NaOH significantly affected the value of density, water absorption, thickness swelling, modulus of elasticity, modulus of rupture, and internal bond. Except for the moisture content on the AA3 and NA2 boards and the internal bond value on the untreated (control) board, all of the panel properties in this study met the standard.

The Journal of the Korean Wood Science and Technology (JKWST) launched in 1973 as an official publication of the Korean Society of Wood Science and Technology has been served as a core of knowledges on wood science and technology.

Characteristic of Vascular Bundles and Morphology of Gigantochloa apus (J.A. and J.H. Schulltes) Kurz Culm

Bond Quality of Laminated Wood Made from Surian (Toona sinensis Roem) and Sengon (Paraserianthes falcataria (L.) Nielsen)