WOOD RESEARCH Volume 62, Number 4, 2017
Inácio Lhate, Luís Cristóvão, and Mats Ekevad

Machining properties of lesser used wood species from Mozambique

The present study was aiming at measuring cutting forces for wood of lesser used species from Mozambique such as Acacia nigrescens Oliv (namuno), Pericopsis angolensis Meeweven (muanga), Pseudolachnostylis maprounaefolia Pax (ntholo) and Sterculia appendiculata K. Schum (metil). Another aim was to use an expeditious method to compare performance of the species when cut. A machinability index calculated using Digraph and Matrix Methods was used for ranking the performance of the species when cut. Two different cutting tools 20o and 30o rake angle were used. Main cutting force in 90°-90° and 90°-0°cutting directions were measured by piezoelectric gauge. The results of the experiments showed that cutting forces followed normal trends to increase with density and decrease with increasing rake angle. The ratio between wood density and cutting forces in cutting directions 90°-90° and 90°-0° were 7 s2m-4 and 17.3 s2m-4, respectively. The most difficult species to be machined was Namuno, whereas the easiest species to be machined was Metil.

WOOD RESEARCH Volume 62, Number 2, 2017
Krzysztof Szwajka and Tomasz Trzepieciński

An examination of the tool life and surface quality during drilling melamine faced chipboard

An analysis of the cutting process and tool wear during machining from metal materials has been the subject of many studies. On the other hand, the tool life when machining from wood materials has not received much attention. Optimisation of the cutting process consists of the appropriate selection of major processing parameters as the cutting depth, feed rate and cutting speed in order to ensure adequate machining accuracy at minimum cost, and appropriate process efficiency. Here, we present the results of experimental tests of wearing drills with carbide blades during processing of melamine faced chipboard (MFC). To evaluate the surface quality of the chipboard the maximum radius and area of delamination around the chipboard blind hole are adopted. These parameters are determined independently at the hole entry and exit. Statistical analysis of results using multifactor analysis of variance was carried out. The tool life of drills depends on many combinations of cutting parameters and the wear of the drill blade. In the drilling process, the value of the thrust force mainly depended on wear of tool flank and the feed rate. The cutting speed has little effect on the amount of thrust force and cutting torque.

WOOD RESEARCH Volume 62, Number 1, 2017
Zhaolong Zhu, Xiaolei Guo, Bin Na, Xingyu Liang, Mats Ekevad, and Futang Ji

Research on cutting performance of ceramic cutting tools in milling high density fiberboard

The effect of cutting parameters and tool parameters on cutting forces and tool wear were investigated in high density fiberboard (HDF) peripheral up-milling using toughened ceramic cutting tools. The results showed that whether at low speed cutting or high speed cutting, the tangential forces Ft and normal forces Fr increased slowly with the increase of cutting length. The tangential forces Ft and normal forces Fr at low speed cutting were higher than that at high speed cutting. The tangential forces Ft and normal forces Fr decreased with the decrease of wedge angle in the same rake angle. Then, the effect of high cutting speed on the flank wear was greater than that at low cutting speed. The bigger wedge angle tools led to the serious flank wear. The main wear pattern in milling HDF consisted of pull-out of the grain, flaking, chipping and cracking, the main wear mechanism were adhesive and abrasive wear.

WOOD RESEARCH Volume 63, Number 3, 2018
Hong Wei, Xiaolei Guo, Zhaolong Zhu, Pingxiang Cao, Baojin Wang, and Mats Ekevad

Analysis of cutting performance in high density fiberboard milling by ceramic cutting tools

In order to study the cutting performance of TiC reinforced Al2O3 ceramic cutting tools in milling high density fiberboard, the effects of cutting parameter on the cutting forces, tool wear and cutting quality were investigated. Under the condition of same average chip thickness, feed per tooth and geometry angles, firstly, the change rate of maximum cutting forces were higher than that of average cutting forces at two different cutting speeds, and the cutting forces at high speed cutting was less than that at low speed cutting. Secondly, the flank wear at high speed cutting was more pronounced than that at low speed cutting, whose abnormal wear were pull-out of grain, cracking, chipping and flanking. Thirdly, the machining quality at high speed cutting was better than that at low speed cutting. Fourthly, the tendencies of cutting forces, tool wear and surface roughness relative to cutting length were similar, but the change rates were different, especially at the initial stage. Finally, high speed cuttingare plausible to use in HDF processing, which not only improves machining quality, but also promotes production efficiency.