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1.
This paper describes the features of binderless particleboard manufactured from sugarcane bagasse, under a high pressing temperature of 200–280 °C. Mechanical properties [i.e., modulus of rupture (MOR) and elasticity (MOE) in dry and wet conditions, internal bonding strength (IB)] and dimensional stability [i.e., thickness swelling (TS)] of the board were evaluated to investigate the effect of high pressing temperature. Recycled chip binderless particleboards were manufactured under the same conditions for comparison, and particleboards bonded with polymeric methylene diphenyl diisocyanate (PMDI) resin were manufactured as reference material. The target density was 0.8 g/cm3 for all of the boards. The results showed that the mechanical properties and dimensional stability of both types of binderless boards were improved by increasing the pressing temperature. Bagasse showed better performance than that of recycled chip as a raw material in all evaluations. Bagasse binderless particleboard manufactured at 260 °C had an MOE value of 3.5 GPa, which was equivalent to the PMDI particleboard, and a lower TS value of 3.7 % than that of PMDI particleboard. The MOR retention ratio under the dry and wet conditions was 87.0 %, while the ratio for the PMDI particleboard was only 54.6 %. The obtained results showed the possibility of manufacturing high-durability binderless particleboard, with good dimensional stability and water resistance, which previously were points of weakness for binderless boards. Manufacturing binderless boards under high temperature was effective even when using particles with poor contact area, and it was possible to express acceptable properties to allow the manufacture of particleboards. Further chemical analysis indicated a contribution of a saccharide in the bagasse to the improvement of the board properties. 相似文献
2.
We investigated the properties of composite board formed using base sheets of aluminum foil-laminated and polyethylene (PE)
plastic-laminated liquid packaging paperboard (LP) as an alternative to recycling these items in wastepaper stream. Boards
of different specific gravities ranging from 0.55 to 0.75 were made by pressing shredded LP blended with urea resin having
resin content of 6%–10% at 180°C. Subsequently, we also prepared mixed particleboard [wood (WD) particles and LP mixed], three-layered
particleboard (LP as the middle layer, WD in the upper and lower layers), and wood particleboard all having resin content
of 10% and various specific gravities. Static bending and internal bonding strengths and thickness swelling of the specimens
were determined to examine their properties. At the same specific gravity, the properties of LP particleboards were affected
by their resin content. The modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond strength of the LP particleboards
increased with increasing specific gravity of the boards at the same resin content, but thickness swelling of the LP particleboards
showed the reverse trend. The average MOR of the LP particleboards approximated that of the mixed particleboards and was greater
than those of the three-layered particleboards and wood particleboards. Internal bond strength and thickness swelling of the
LP particleboards were smaller than those of the other particleboards. Based on the above observations, we deemed that LP
can be made into composite boards with adequate properties either alone or mixed with wood particles. 相似文献
3.
石膏刨花板研究综述 总被引：2，自引：0，他引：2
石膏板具有优异的抗火性能,在轻型木结构中主要用作楼板和墙板的抗火覆面板。通过在石膏基体中复合木材刨花等植物纤维制备石膏刨花板,可不改变板材原有的生产制备工艺而提高其力学性能。生产石膏刨花板的石膏原料主要来源于工业石膏,刨花主要为农业或工业副产品,兼顾变废为宝和材料成本可控等优势,因此具有广泛的应用前景。文中综述了石膏刨花板中不同缓凝剂的作用机理、不同植物纤维类型的增强效果、后处理方式和外加剂对板材性能改善的机理等板材制备工艺,以及石膏刨花板的物理力学性能和抗火性能等研究现状,指出目前土木工程用石膏刨花板存在的不足及需进一步研究的方向,可为石膏刨花板的进一步系统研究以及工程应用提供参考。 相似文献
4.
Binderless particleboards were manufactured from sugi (Cryptomeria japonica D. Don) heartwood and sapwood by hot-pressing (pressure: 5 MPa; temperatures: 180°, 200°, and 220°C; times: 10, 20, and 30
min), and the board properties [internal bonding (IB), thickness swelling (TS), water absorption (WA)] were investigated to
evaluate the self-bonding ability. The IB, TS, and WA of the boards from sugi heartwood were better than those of the boards
from sugi sapwood at any hot-pressing condition. Therefore, it was suggested that the self-bonding ability of sugi heartwood
was superior to that of sugi sapwood. Then, sugi heartwood and sapwood powder with grain size 10 βm were used as a binder
for plywoods. Four kinds of plywood were manufactured from the combination of powder and veneer, both of which were prepared
from sugi heartwood and sapwood under the same hot-pressing conditions as the binderless particleboard, and the adhesive shear
strength and wood failure of the plywood were investigated. As a result, the plywood composed of sugi heartwood veneer met
the second grade of JAS for plywood, when either powder was used as a binder, when they were pressed at 200°C for 20–30 min
and 220°C for 10 min. 相似文献
5.
Miscanthus sacchariflorus straw was used as a raw material for the manufacture of Miscanthus–wood particle composite board with Douglas-fir particles in ratios of 100/0, 80/20, 60/40, 40/60, 20/80, and 0/100. A commercial phenol–formaldehyde resin was used as a binder at 9 and 11 % for target densities of 0.50 and 0.65 g/cm3, respectively. The effects of the Miscanthus/wood particle ratio on the composite board properties were investigated. In addition, the density profile was also examined to improve the understanding of the composite board manufacturing process. Results indicate that the internal bonding value increased drastically in the board containing up to 50 % wood particles, providing a valuable parameter for subsequent research. The board properties were greatly improved with increasing density and binder addition level. 相似文献
6.
The deterioration of particleboards for construction use was investigated by outdoor exposure tests at eight sites in Japan over 7 years. Two types of particleboard with different water resistances were tested and the deterioration of mechanical properties such as modulus of rupture, internal bond strength and lateral nail resistance was investigated. In order to eliminate regional differences in the board deterioration and also to standardize a deterioration factor for the board exposed to varying climate conditions, we introduced the weathering intensity (WI) defined by monthly precipitation multiplied by monthly average temperature. The significance of this factor was investigated by correlation analysis. Three conventional climate indexes relevant to the durability of wood were also investigated to analyze their significance to WI for particleboard deterioration. It was found that our definition of weathering intensity was the most accurate and the exposure period that reduces initial bending strength by half was calculated by the use of regression analysis for several different sites worldwide. 相似文献
7.
8.
利用杨树人工林剩余物生产刨花板可行性研究 总被引：1，自引：0，他引：1
The composite board industry in Iran is obliged to use residues from forest operation as well as wood industry for competing
with paper industry because of shortage of wood. In the present study we investigated the residues from poplar plantation
used for particleboard production. Three kinds of wood materials, poplar branches, small diameter poplar wood (3–8 cm) and
beech wood, were used in the experiment of particleboard production. The results demonstrated that the characteristic of particleboard
made from poplar branches and small diameter wood is comparable to that made from mature beech wood. To avoid too much residual
acid in the final board, the properties of boards produced with 1.5% hardener at 175°C press temperature are acceptable, although
the properties of particleboard produced with 2% hardener were higher than were higher than that of the board produced with
lower hardener (1% or 1.5%).. The MOR, MOE and IB of particleboard made from branches were measured as 14.57, 2015, and 1.32
MPa, respectively, while The MOR, MOE and IB of particleboard produced from small diameter poplar wood were 19.90, 2199, and
1.86 MPa, respectively. The thickness swelling of boards made from branches after 2 and 24 h immersion in water was 20.14%
and 31.26%. The utilization of branches and very small diameter wood of poplar is recommended for the survival and developments
of particleboard industry in Iran. 相似文献
9.
Particleboard made from hammer milled black spruce bark residues 总被引：1，自引：0，他引：1
Summary The disposal of bark residues is an important problem for the forest industry. An important proportion of the bark produced
by the paper and lumber industries is used for energy production, but a significant amount of bark is still unused. The objective
of this study was to determine the technical feasibility of making particleboards from black spruce bark residues bonded with
urea formaldehyde resin and meeting the indoor performance requirements for wood particleboards. In the positive case, this
would define a new use for black spruce bark residues. Fresh black spruce bark residues were obtained from a sawmill located
in the northeast part of the province of Quebec, Canada. The bark was kiln-dried at 60 °C, the particles were generated from
a hammermill and sieved. Particles from 0.02 to 2.0 mm were used in the surface layers and particles from 2.0 to 6.0 mm were
used in the core layer. Particleboards of 540 × 560 × 16 mm were made with a laboratory hot press following a factorial design
with two manufacturing variables at three levels: (1) wood particles content of the surface layers (0, 25, 50 percent); and
(2) UF resin content of the surface layers (12, 14 and 16 percent) with a UF resin content in the core of 8 percent. This
resulted in a factorial design of 9 different combinations repeated 3 times for a total of 27 boards. It was observed that
the heating kinetics varied according to the wood particles content in the surface layers. The compression ratio of the mat
and the board internal bond, modulus of elasticity, modulus of rupture, linear expansion and thickness swell were determined.
The results show that it is technically possible to make particleboard from bark residues meeting the American National Standard
Institute indoor requirement for wood particleboard under certain conditions. The modulus of rupture of the boards was the
most critical property in this study. The best mechanical properties were obtained with a 50 percent wood content and 14 percent
resin content in the surface layers. The particleboards produced in this study did not meet the minimal requirements for linear
expansion. The temperature measurements performed in the core of the mat during hot pressing show that heat transfer improves
with an increase in wood particles content in the surface layers.
Received 15 June 1998 相似文献
10.
11.
《Wood material science & engineering》2013,8(4):217-224
Abstract Considering ongoing global deforestation and the increased demand for raw materials in all wood-processing sectors it is necessary to seek and employ alternative resources. Agricultural residues are potential sources of alternative lignocellulose-based raw materials. Research on substitute materials for wood panel production mainly focused on physical and mechanical properties of boards while much remains to be learned about machining. Therefore, studies were carried out to analyse the relationship between ash and silica content and their impact on tool wear. Ash and silica contents of agricultural residues were determined following ISO 3340. Particle morphology and elemental composition of selected materials were analysed using scanning electron microscopy and energy-dispersive X-ray analysis. Tool wear tests were carried out using particleboards made from wheat straw, canola straw and spruce. Analyses of various plant materials displayed no correlation between ash and silica content. Bio-mineralised silica structures in wheat and canola were different compared to coarse silica found in wood-based particleboard. Tool wear caused by these agricultural residues was just moderately increased compared to wood, despite the fact that their silica contents were many times higher. Furthermore, the impact of abrasive substances on wear behaviour was influenced by the density of the panels. 相似文献
12.
This study was conducted to investigate the susceptibility of various wood composite panels exposed to wood-deteriorating fungi. Five wood-attacking fungi (three mold fungi, one brown rot fungus, one white rot fungus) were inoculated into four types of commercial wood composite panels (plywood, oriented strand board, particleboard, and medium-density fiberboard). One solid wood sample was included as a control. The attacking patterns of the fungi in each panel was observed by scanning electron microscopy. The weight losses due to the exposure were compared. All wood composites were more or less susceptible to all fungi inoculated. The attacking mode of the fungi was highly dependent on the types of wood composite, which had inherently different shapes of voids owing to different shapes and characteristics of the raw furnish materials used. Plywood and medium-density fiberboard showed a large weight loss after an 8-week exposure to decay fungi. Plywood is the most susceptible to white and brown rot fungi. This study indicates that all wood composite panels should undergo careful consideration to prevent fungal deterioration when they are used for exterior and humid interior applications. 相似文献
13.
14.
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
15.
Upgrading of urea formaldehyde-bonded reed and wheat straw particleboards using silane coupling agents 总被引：3，自引：0，他引：3
Guangping Han Changwu Zhang Dongmei Zhang Kenji Umemura Shuichi Kawai 《Journal of Wood Science》1998,44(4):282-286
Reed and wheat straw particleboards bonded with urea formaldehyde (UF) resin were manufactured from two different material configurations (i.e., fine and coarse particles). The board densities were in the range of 0.550–.90g/cm3. The effects of particle size and board density on the board properties were examined. The properties of particleboard produced from fine particles were better than those made from coarse particles. An increase in board density resulted in a corresponding improvement in the board properties. The properties of OF bonded reed and wheat straw particleboards were relatively lower than those of commercial particleboards. Three silane coupling agents were used to improve the bondability between the reed and wheat particles and OF resin. Results of this study indicate that all the board properties were improved by the addition of silane coupling agent. The degree of improvement achieved from each coupling agent was different; epoxide silane was found to be more effective for reed straw particleboard, and amino silane was better for wheat straw particleboard. 相似文献
16.
刨花板是家具制造业的首选板材,在潮湿的环境中使用易出现翘曲变形、膨胀及分层等现象。为改善刨花板防潮性能,提高其尺寸稳定性,将甲基三甲氧基硅烷(MTMS)与0.1mol/L的盐酸以4∶1的体积比混合,将混合溶液置于冰浴中超声水解360 min,然后利用MTMS水解溶液对刨花板进行5 min的浸渍处理。分析了改性前后刨花板的润湿性、抗紫外老化性、粗糙度、表面化学结构及物理力学性能。研究结果表明:经MTMS水解溶液浸渍改性的刨花板具有稳定的拒水、拒油及抗老化性能,尺寸稳定性得到改善,板坯的表面密度增加,力学性能提高。 相似文献
17.
In the face of dwindling fossil fuel resources and the environmental imperative to reduce emissions associated with petrochemistry, there is strong demand for a wood composite bonding procedure using natural alternatives. In this study, particleboards were manufactured with a new material adhesive composed of tannin and sucrose, and hot-pressed at 200 °C for 10 min, to a target density of 0.8 g/cm3. We found optimal values for the mat moisture content, the ratio of tannin to sucrose and the resin content of 3–6 wt%, 25/75 and 30–40 wt%, respectively. When the particleboards were manufactured under these optimum conditions, the modulus of rupture and the modulus of elasticity were in the range of 19.6–21.2 MPa and 4.6–5.0 GPa, respectively. The internal bond strength was in the range of 1.1–1.3 MPa. Based on these results, the mechanical properties of particleboard bonded with tannin and sucrose were higher than the requirements of the JIS A 5908 type 18 standard (2003). In the thickness swelling test (TS), the value was in the range of 20–23 %; as the ratio of sucrose and resin content increased, the TS value decreased. The reaction mechanism between tannin and sucrose was studied by fourier transform infrared spectroscopy, and the dimethylene ether bridges were observed. Consequently, it is possible that a tannin and sucrose mixture can be used as a natural adhesive for particleboard. 相似文献
18.
Boštjan Lesar Miha Humar Frederick A. Kamke Andreja Kutnar 《Wood Science and Technology》2013,47(5):977-992
Hybrid poplar (Populus deltoides × Populus trichocarpa) and Douglas-fir (Pseudotsuga menziesii) wood specimens were densified with three variations of thermo-hydro-mechanical (THM) treatment. The THM treatments differed in the steam environment, including transient steam (TS), saturated steam (SS), and saturated steam with 1-min post–heat treatment at 200 °C (SS+PHT). The bending properties, FTIR spectra, and colour of the THM wood specimens were studied before and after exposure to two different wood decay fungi, brown rot Gloeophyllum trabeum, and white rot Trametes versicolor. The results showed that the performance of densified hybrid poplar wood was considerably poorer than the performance of Douglas-fir heartwood. The FTIR spectra measurements did not show changes in the densified hybrid poplar wood, while some changes were evident in densified Douglas-fir specimens. After fungal degradation, the most prominent changes were observed on the SS+PHT specimens. Colour is one of the most important parameter predominantly influenced by the wood species and the intensity of the densification process for both wood species, while after fungal exposure, the colour of all densified Douglas-fir specimens obtained more or less the same appearance, and densified hybrid poplar specimens resulted in lighter colour tones, indicating that the pattern of degradation of the densified and non-densified specimens are similar. The 3-point bending test results determined that the THM treatment significantly increased the modulus of rupture (MOR) and modulus of elasticity (MOE) of the densified wood specimens, while fungal exposure decreased the MOE and MOR in hybrid poplar and Douglas-fir specimens. 相似文献
19.
陈伟红 《林业机械与木工设备》2014,(4):28-31
随着刨花板在板式家具中的大量应用,其质量对板式家具的影响日益显著,尤其是刨花板的厚度偏差对板式家具质量影响很大。我国刨花板厚度偏差的控制水平与国际上家具用板的要求相比还存在一定差距。以昆明某刨花板厂生产的刨花板为研究对象,分析生产原料、板坯铺装质量和压机等因素导致的产品厚度偏差及其控制方法。 相似文献
20.
Binderless particleboards were manufactured from sugarcane (Saccharum officinarum L.) bagasse by steam-injection pressing and by using hot pressing as a reference method. The inner layer (core/pith) and
the outer hard fibrous layer (face/rind) of bagasse were used as raw materials. The effects of bagasse type, manufacturing
process, and storage method on the mechanical properties of binderless particleboards were investigated. The results showed
that the bagasse pith particles provided better board properties than bagasse rind particles. It seemed that bagasse pith
particles were more easily deformed than bagasse rind particles, enlarging the bonding contact area. The severe conditions
of steam-injection pressing caused delamination on the bagasse pith binderless boards with densities of 0.6 g/cm3 or higher, and gave poor bonding quality. However, steam-pressed boards showed relatively higher board properties than hot-pressed
boards. The storage method of sugarcane bagasse affected the chemical composition and the board properties. It was shown that
the extent of self-bonding formation depends on the chemical and morphological properties of lignocellulosic materials, as
well as on the manufacturing conditions.
Part of this paper was presented at the 5th International Wood Science Symposium, Kyoto, Japan, September 2004 相似文献