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1.
Wayan Darmawan Chiaki Tanaka Hiroshi Usuki Tadashi Ohtani 《Journal of Wood Science》2001,47(5):342-349
This paper reports on the performance of coated carbide tools in turning wood-chip cement board. The coating materials studied were titanium carbonitride (TiCN), titanium nitride (TiN), chromium nitride (CrN), and titanium nitride/aluminum nitride (TiN/AlN), which were synthesized on the P30 carbide substrate. The aim is to investigate the effect of coating materials and cutting speeds on the wear characteristics of the coated carbide tools. Cutting tests were performed when turning wood-chip cement board at cutting speeds of 30, 40, 50 and 60 m/s, a depth of cut of 1mm, and a feed of 0.05 mm/rev. The results of the study show that the coated carbide tools provided better performance than the P30 carbide tool, especially in terms of reducing the progression of the wear rate and clearance wear. The TiN/AlN-coated carbide tool showed the smallest increase in both wear rate and clearance wear with an increase in cutting speed and had the longest tool life among the coated carbide tools investigated. Though the TiCN-coated carbide tool was observed to have a low wear rate and low clearance wear for cutting speeds of 30 and 40m/s, when the cutting speeds were >50m/s its wear rate and clearance wear were almost the same as those of CrN-and TiN-coated carbide tools, which had high values for these parameters.Part of this paper was presented at the 21st IUFRO World Congress, August 2000, Kuala Lumpur, Malaysia 相似文献
2.
Takao Morita Kaoru Banshoya Takahiro Tsutsumoto Yasuhide Murase 《Journal of Wood Science》1999,45(6):463-469
Continuous milling tests with diamond-coated and uncoated cemented carbide tools and polycrystalline diamond tools were carried out on air-dried and wet melapi (Shorea sp.) and western redcedar (Thuja plicata D. Don). These tools were examined for corrosive-wear characteristics of the tool-edge appearance, cutting-edge profile, edge recession, and cutting-power consumption. The tool surfaces were observed with a scanning electron microscope and were analyzed by energy-dispersive X-ray spectroscopy. Based on these examinations, the occurrence of corrosive wear while cutting wet woods was confirmed for the uncoated and polycrystalline diamond tools. In contrast, the coated tools did not exhibit corrosive wear, nor did delamitation or wear of the diamond film occur with any of the work materials. The diamond-coated tools showed high resistance not only to mechanical wear but also to corrosive wear.The results of this work were presented at the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998 相似文献
3.
Published research on the wear processes of cemented tungsten carbide tools used for machining reconstituted wood products was reviewed, and the current state of knowledge in this area was evaluated. Underlying assumptions and conclusions regarding high-temperature oxidation/corrosion wear during machining were examined in view of known reaction kinetics of cemented tungsten carbide alloys in oxidative and corrosive environments at temperatures that may occur at the cutting edge. This examination indicated that some wear mechanisms other than high-temperature oxidation/corrosion are likely to be rate-controlling when machining reconstituted wood products such as particleboard and fiberboard. 相似文献
4.
Binderless boards were prepared from steam-exploded fiber of oil palm(Elaeis guineensis Jacq.) frond at six levels of explosion conditions. Their properties were investigated and evaluated. The mechanical properties (i.e., modulus of rupture, modulus of elasticity, and internal bonding strength) of the boards increased linearly with increasing board density as the usual hardboard. The boards made from fibers treated under a steam explosion condition of 25 kgf/cm2 (steam pressure) and 5 min (digestion period) exhibited the maximum strength. These boards at a density of 1.2 g/cm3 met the requirement of S-20 grade of JIS A 5905 — 1994 (fiberboard). Thickness swelling of the boards ranged from 6% to 14% under the JIS A 5908 — 1994 (particleboard) test condition and showed no significant changes with increasing board density. The main bonding strength of the board is believed to be due to a ligninfurfural linkage. Considering the chemical components of oil palm frond, which is rich in hemicellulose, there seems to be a good possibility for producing binderless boards using steam-exploded fibers of oil palm frond.This study was presented in part at the 2nd International Wood Science Seminar, Serpong, Indonesia, November 1998 相似文献
5.
Influence of technical and chemical characteristics of industrial wood milling tools on its wear was analysed. Four tools of different manufacturers were subjected to the research. Lithuanian oak wood was chosen for the research as a reference material. Behaviour of cutting tools was assessed on the adopted industrial thickness planer SR3-6 with cutting speed of 31 m/s. Wear performance was evaluated on milling the specimens until 3200 m of true cutting length. Summarising achieved results, the following can be stated: chemical composition of tool and heat treatment schedule has great impact on the tool edge wear. The highest wear resistance was reached on testing tools made of CT01M-LA2; tools made of high-alloyed tool steel 8X6HΦT have presented the highest cutting edge radius and edge recession in each type of test as compared with tools made of high-speed tool steels Z80WCV18-04-01/18-0-1 and HS18-0-1, respectively. All these tools are suitable for oak wood processing. The high-alloyed tool steel shows similar wear performance as high-speed tool steels. 相似文献
6.
Manufacture and properties of ultra-low-density fiberboard 总被引：6，自引：0，他引：6
Low-density fiberboards with densities ranging from 0.05 to 0.50g/cm3 were manufactured with steam injection pressing. Bond-type and foam-type isocyanate compound resin adhesives were used separately at 10% and 30% resin content levels. Two types of different-size fibers from softwood were used. Mechanical, dimensional, thermal, and sound insulation properties of the fiberboards were tested. The results are as follows: (1) Bond-type isocyanate adhesive showed higher mechanical and dimensional properties of low-density fiberboards than the foam-type adhesive. (2) Fiberboards produced from small fibers have better mechanical and dimensional properties than those made from large fibers. (3) Thermal conductivity of fiberboards depends more on the board density than on the type of resin or fiber dimension. At a board density lower than 0.2 g/cm3, the thermal conductivity is almost equivalent to those of thermal insulation materials such as polystyrene foam and rock wool, (4) Generally, the sound absorption coefficient of low-density fiberboards tends to increase at higher sound frequency. As the board thickness increases, low-frequency sounds are more readily absorbed by boards.Part of this report was presented at the 46th annual meeting of the Japan Wood Research Society, Kumamoto, April 1996 相似文献
7.
The general aim of work reported here was to assist designers and operators of routers and similar tools for cutting wood-composite
boards, by providing a model predicting cutting force components from readily available material properties. This initial
study explored, for edge cutting, the variation within a single medium density fibre board across the thickness and in various
cutting directions in the plane of the board. Material properties of interest were specific gravity and friction coefficient.
In slow linear cutting on a modified milling machine, carbide router inserts cut the edges of layers cut from a medium density
fibre board. Specific gravity and coefficient of sliding friction were measured for each layer. Cuts were also made on full-thickness
edges in various directions in the plane of the board. Chip thickness was varied from 0.025 to 0.8 mm. Parallel and normal
force data and digital video images of chip formation were stored for analysis. Specific gravity increased as the fourth power
of the distance from the central plane to the surface. Friction coefficient values, estimated both from cutting forces and
from rubbing forces during return, varied about a value of 0.23, with no significant difference between layers. The values
for cutting force per mm width of cut increased progressively from the central plane to the surface, in a logarithmic relation
with specific gravity. The cutting forces did not vary with cutting direction in the plane of the board. For a sharp edge
with 32° rake angle cutting at chip thickness values above 0.1 mm, the normal force component was negative, indicating reduced
feed force and improved surface quality. With dulling, the threshold value of chip thickness for this increased. It is concluded
that elaboration of this approach would generate relationships suitable for incorporating in a useful general model. However,
it may be found that weight per unit area of board will suffice as a proxy for cutting resistance in modelling the cutting
of full-thickness edges.
Received 10 June 1999 相似文献
8.
Bolesław Porankiewicz 《Wood Science and Technology》2006,40(2):107-117
Theoretical simulation of cutting edge wearing when milling wood and melamine coated particle board based on stochastical and analytical methods is presented. Abrasion, high temperature corrosion (HTC) and frictional wearing effects are discussed. Results of computations show good correlation between the observed and predicted wear rate for three different experiments. Relations between predicted tool wear rate from HTC, content (C
CP) and size (S
CP) of particles of hard mineral contamination and density (D) of cut material is also presented and discussed. 相似文献
9.
A laser measuring instrument was installed in a computerized numerically controlled (CNC) router, and an automatic measurement
system, which was developed in a previous study, was used to automatically measure the cutting edge profile of throw-away
type straight bits without stopping the CNC router. In addition to the above-mentioned system, in this study, an adaptive
control program based on experimental data was installed, and an adaptive control grooving system that improved machining
accuracy and controlled the burr formation corresponding to the progression of tool wear under processing was developed. Verification
experiments of this system were carried out. The main results obtained are summarized as follows: (1) the between-process
method was adopted for this system, and three types of processing methods (type 1, 2, 3), which consisted of a combination
of an up-milling surface and a down-milling surface after processing, were investigated; (2) from the results of verification
experiments, type 2 and type 3 methods showed remarkable ability to improve the machining accuracy and control the burr formation;
and (3) it was found that the system employing adaptive control processing corresponding to the progression of tool wear in
grooving is very effective.
Part of this article was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002 相似文献
10.
Summary In order to study the wear of tungsten carbide tipped circular saws, three kinds of carbide tips (fine, medium and coarse grained ones) were employed, when sawing particleboards. The saw with coarse grained carbide tips showed the longest working life, while the fine-grained carbide tipped saw retained its usefulness for only a short period of sawing. In an experiment using a saw with all three kinds of carbide tips, it was also confirmed that the fine grained tips wore most and the coarse least. From the observations of the worn tips, it was found that the wear boundary on the clearance face was quite distinct for these tips, although for the fine grained one it was remarkably indented. There were many striations on the wear surface of the fine grained tip, but they scarcely appeared on those of the other two tips. The wear mechanism and the wearing process of the carbide tips are discussed.This paper was presented at the 22nd Annual Meeting of the Japan Wood Research Society at Tokyo, April, 1972The authors wish to express their appreciation to Dr. T. Kawakita, Sumitomo Electric Industries, Ltd., for supplying the carbide tips and to Mr. M. Hiraiwa, Nittokukan Saw Mfg. Co., Ltd., for manufacturing the saws. They are also greatly indebted to Dr. H. Saiki, Wood Structure Laboratory, Kyoto University, for taking scanning electron micrographs and for his valuable advice. This investigation was supported in part by Grants in Aid for Scientific Research in 1972 and 1973 from the Ministry of Education, Japan 相似文献
11.
The effectiveness of air injection for preventing the blowout of particleboards manufactured using a radio-frequency hot press was investigated by evaluating the board properties under artificially created conditions that were conducive to blowout. For evaluation, 10-mm-thick boards with densities of 0.7 and 0.8 g/cm3 and 20-mm-thick boards with a density of 0.7 g/cm3 were manufactured. Pressing times for the 10-mm-thick boards were 2, 4, 6, and 8 min, and those for the 20-mm-thick boards were 4, 6, 8, and 10 min. Without air injection, blowout occurred in all manufactured boards. With air injection, however, blowout did not occur in the 10-mm-thick boards with a density of 0.7 g/cm3. Moreover, air injection prevented blowout even when the board density and board thickness were increased to 0.8 g/cm3 (for 10-mm-thick boards) and 20 mm (the density was kept at 0.7 g/cm3), respectively. Air-injection radio-frequency pressing reduced the pressing time from 4 to 2 min for 10-mm-thick boards, and from 6 to 4 min for 20-mm-thick boards. Moreover, this reduction in the pressing time was achieved without a large reduction in the internal bond strength of the boards. 相似文献
12.
Binderless boards were prepared from finely ground powders of kenaf (Hibiscus cannabinus L.) core under varying manufacturing conditions. This research was designed to investigate their mechanical properties and evaluate the various manufacturing conditions: pressing temperature and time, pressing pressure, board density, board thickness, grain size of raw materials, and addition of furfural. The mechanical properties (i.e., modulus of rupture and elasticity, internal bonding strength) of boards increased with increasing board density and met the requirement for 15 type medium-density fiberboard (MDF) by JIS A 5905-1994. Thickness swelling and water absorption of boards exceeded the maximum permitted levels for 15 type MDF and S20 grade hardboard by JIS A 5905-1994, which indicates the low water-resistant property of binderless boards. In contrast to that in usual wood-based materials, internal bonding strength showed significant correlations with other board properties: modulus of rupture and elasticity, thickness swelling, and water absorption. We confirmed experimentally that the best manufacturing conditions proved to be as follows: pressing temperature 180°C, time 10min; pressing pressure 5.3MPa; board thickness 5mm; board density 1.0g/cm3; average grain size 53µm; and powder with no furfural content.Part of this paper was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002 相似文献
13.
The balance of strength between the flange and web parts of veneer strand flanged I-beam was investigated by the following
methods: (1) use of different web material types, such as plywood, oriented strand board (OSB), particleboard (PB), and medium
density fiberboard (MDF), that have different strength properties; and (2) fabrication of I-beams with low-density flanges
using low-density strands with PB web material. Replacing PB or MDF with plywood showed slight significant improvement in
the modulus of rupture but not in the modulus of elasticity of the entire I-beam. However, PB and MDF showed competent performance
in comparison with OSB, thus strengthening the promising future of the use of PB or MDF as web material to fabricate I-beams.
Hot-pressing conditions used for I-beam production exerted slightly adverse effects on the bending properties of PB, but not
on MDF, OSB, and plywood web materials. The flange density of 0.60 g/cm3 was considered to be the lower limit that provides I-beams with balanced mechanical properties and dimensional stability. 相似文献
14.
合理的微坑型微织构已被证明具有改善木材和硬质合金表面间的摩擦特性。采用微凹坑型织构、微凹槽织构和微网格型织构3种织构形式,在相同织构面积占有率条件下,通过摩擦特性试验与理论分析相结合,研究不同织构形式对木材表面摩擦系数的影响。研究表明:在相同织构面积占有率条件下,不同织构的类型和表面形貌对硬质合金试样与木材表面摩擦的摩擦系数有不同的影响,受摩擦长度、凹槽微织构宽度、微织构角度等织构参数的影响。当微织构与木材发生摩擦时,摩擦区域织构面积越大说明两者间实际接触面积越小,且面积越大,捕捉磨屑和硬质点的能力越强;而主制动力越小,其产生的摩擦系数越小。在相同压力和织构面积占有率条件下,不同类型的织构试件与木材表面产生的摩擦系数均小于非织构(平面)型表面产生的摩擦系数。其中:微坑型织构产生的表面摩擦系数最小,为0.116;凹槽型织构产生的表面摩擦系数最大,为0.182;网格型织构随着织构角度的减小,其产生摩擦系数越小。 相似文献
15.
A hot press was used to manufacture particleboards (H boards). A radio-frequency hot press (for RH boards) and an air-injection radio-frequency hot press (for ARH board) were also used, and the effects of air injection on preventing blowout and board properties were analyzed. The thicknesses and densities of manufactured boards were 10 and 30 mm, and 0.6, 0.7, and 0.8 g/cm3, respectively. The investigation ascertained the effects of air injection in preventing blowout when a radio-frequency hot press is used. The increasing order of temperature was ARH board > RH board > H board during the final pressing stage. For the 30-mm-thick boards, the temperature of H board increased to 100 °C and remained constant at 100 °C even when the pressing time was extended. The temperature of the RH board increased to 100 °C more quickly than in the case of the H board and remained constant at 110–118 °C. The temperature of the ARH board increased linearly to 130–142 °C. For both the 10- and 30-mm-thick boards, the internal bond strength of the RH board was almost the same as that of the ARH board at densities of 0.6 and 0.7 g/cm3. In contrast, the internal bond strength of the RH board was lower than that of the ARH board at a density of 0.8 g/cm3. For the 10-mm-thick boards, the thickness swelling in the RH board was almost the same as that in the ARH board irrespective of the density. However, for the 30-mm-thick boards, the thickness swelling in the RH board was higher than that in the ARH board. The low plasticization of particles due to air injection presumably results in a high degree of thickness swelling. 相似文献
16.
采用半干法生产工艺对水泥稻草碎料板生产工艺进行了初步试验,研究了密度、添加剂用量、水胶比和胶草比等因子对水泥稻草碎料板物理力学性能的影响,确定了水泥稻草碎料板的最佳工艺参数为:板材密度为1 150 kg.m-3,胶稻草比为3∶1,水胶比为0.5∶1,添加剂(氯化钙)的用量为3.0%。 相似文献
17.
18.
This study examines the cyanoethylation and thermoplasticity of several cyanoethylated fiber materials. Cyanoethylated pulps with a degree of substitution of 1.43 have the lowest Vicat softening point. Cyanoethylated poplar with a weight gain of 18.2 % has the lowest melting temperature. Instead of traditional adhesives, cyanoethylated materials can be used to produce wood-based panels because of their good thermoplasticity. Plywood bonded with cyanoethylated pulp has a bonding strength of 2.06 MPa and an average wood failure of 62.7 %. Wheat straw particle board containing 40 % cyanoethylated pulp has an internal bonding strength of 0.49 MPa, a modulus of rupture (MOR) of 33 MPa, and a density between 0.5 and 0.6 g cm?3. Fiberboard containing 40 % cyanoethylated pulp has an internal bonding strength of 0.53 MPa, MOR of 38 MPa, modulus of elasticity of 4,200 MPa, and a density between 0.7 and 0.8 g cm?3. Its swelling in thickness is 41 %. 相似文献
19.
Factors influencing steel tool wear when milling wood 总被引：2，自引：0，他引：2
The wear of high speed steel cutting tools after milling wood of four selected wood species was studied. For the experiments wood specimens were chosen with very different silica contamination, wood density, and high temperature corrosivity (HTC) of wood towards tool material. Analyses performed show that the silica content and wood density display poor linear correlation with the cutting tools wear, while the correlation of the HTC appeared very good. The silica contamination and the HTC effects overshadow each other. Thus, a theoretical multivariable simulation of the cutting edge wearing process, employing all experimental variables, was applied, providing a very good explanation of the analyzed problem. 相似文献
20.
为解决小型台式多用木工机床加工硬质木材榫槽难的问题,设计了一款组合铣刀.以数块窄刀刃圆锯片组合代替宽刀刃,多刀刃代替双刀刃,组合时锯齿刀刃错位排列,各段直刃呈螺旋状,采用大前角改善切削性能,齿廓优化成刨削锯齿状以提高锯齿的耐用度和使用寿命.该铣刀具有分块式切削刀刃,切削性能优良,加工硬、软质木材榫槽时的进料速度比直齿双刃盘式成型铣刀提高3倍. 相似文献