WOOD RESEARCH Volume 62, Number 5, 2017
Lina Karlinasari, M. Irfan Danu, Dodi Nandika, and Maman Tujaman

Drilling resistance method to evaluate density and hardness properties of resinous wood of agarwood (Aquilaria malaccensis)

Gaharu or agarwood is produced by certain trees in response to fungal infections and wounds. The response is a pathological process that alters the physiological and chemical compounds produced in tree wood, yielding a fragrant resinous material. We investigated the density and hardness properties of agarwood using the drilling resistance method in 25 disks of Aquilaria malaccensis that had previously been inoculated with Fusarium solani. A micro drilling technique was applied in two directions across the diameter of the disks to measure resistance, starting in the part containing agarwood. In addition, hardness properties were determined based on the Janka test and density was measured based on the gravimetric method. We found that hardness properties varied greatly in disks containing agarwood. A low correlation was found between the amplitude of resistance and hardness and density, indicating that other variables beyond density are also involved in the changes of wood properties in agarwood. A strong correlation was observed between hardness and wood density.

WOOD RESEARCH Volume 66, Number 4, 2021
Kidung Tirtayasa Putra Pangestu, WAYAN DARMAWAN, Dodi Nandika, Imam Wahyudi, Lumongga Dumasari, and Hiroshi Usuki

Performance of coated tungsten carbide in milling composite boards

The purpose of this research was to analyze the performance (wear resistance, surface roughness, chip formation, and noise level) of AlCrN, TiN, and TiAlN coated tungsten carbides in cutting composite boards. The composite boards of wood plastic composite, laminated veneer lumber, and oriented strand board were cut by the coated tungsten carbide tools in a computer numerical control router. The results show that the differences in structure among the composite boards resulted in the difference in clearance wear, chip formation, surface roughness, and noise level phenomenon. The abrasive materials in wood plastic composite generated the highest clearance wear on the coated carbide tools tested. TiAlN coated carbide tool provided better wear resistance, smoother composite boards surfaces, and lower noise levels.

WOOD RESEARCH Volume 64, Number 4, 2019
WAYAN DARMAWAN, Muhammad Azhari, Istie S. Rahayu, Dodi Nandika, Rumanintya L. Putri, and Satoru Nishio Malela

The chips generated during up milling and down milling of pine wood by helical router-bits

Development of new helical edge router bits (helix angle 15°, 30°, 45°, and 60°) with a cutting circle diameter of 8 mm was studied. The purpose of the research work was to investigate chips formation and surface roughness characteristics in milling the pine wood by the straight and helical edge bits. The generated chips were classified in four types by sieving into spiral chip (5 mesh), flow chip (10 mesh), thin chip (30 mesh), and granule chip (< 30 mesh). The experimental results showed that the spiral chip was generated most often (on a weight percentage basis) by the bits during down milling process. More flow and thin chips were produced by the bits during up milling process. Better surface roughness was produced by bits during down milling compared to up milling. When the helix angle of the bits increased the amount of spiral and flow chips were increased and granule chip was reduced. The machined surface was better in roughness (lower Ra values) as the helix angle of the bits increased both in up milling and down milling processes.