共查询到20条相似文献，搜索用时 203 毫秒
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杨木胶合板用低毒不脱水脲醛树脂胶 总被引：3，自引：0，他引：3
为适应短周期工业材－杨木采用低压，快速热压胶合工艺对胶粘剂的特殊要求，通过对树脂合成工艺和杨木单板胶合工艺的一系列试验而研制出低毒，不脱水脲醛树脂胶，试验结果证明使用该胶粘剂压制的新疆杨，１－６９杨，Ｉ－７２杨等杨木胶合板，其胶合强度均符合ＧＢ９８４６－８８胶合板国家标准的要求，胶合板游离甲醛释放量视单板树不同分别达到ＪＡＳ规定的Ｆ２级和Ｆ３级指标。 相似文献
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膨润土改性脲醛树脂胶粘剂研究 总被引：3，自引：0，他引：3
从膨润土结构说明脲醛树脂胶粘剂改性机理，与面粉、轻质碳酸钙填料相比，膨润土改性脲醛树脂胶粘剂具有较低游离甲醛，良好胶合强度。加入偶联剂，有利于提高膨润土改性脲醛树脂胶粘剂的耐水性与胶合强度。 相似文献
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广宁县竹香骨下脚料制备竹碎料刨花板及其复合改性研究 总被引：1，自引：0，他引：1
采用竹香骨下脚料为原料,以脲醛树脂和三聚氰胺改性脲醛树脂胶粘剂制备竹碎料刨花板,并与木纤维复合改性,检测并分析了内结合强度、静曲强度、弹性模量和吸水性。结果表明,在热压温度为160℃时,竹碎料板和竹木复合碎料板的物理力学性能均满足国标规定在干燥状态下使用的普通用板要求。当木纤维与竹碎料复合后,复合板材的静曲强度和弹性模量有一定程度提高,但内结合强度降低。 相似文献
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以火车集装箱底板加工剩余物为原料,经过去贴面、磨砂等简单的处理后与杨木单板重组成一种层层交错结构的竹木复合建筑混凝土模板。用单因素实验方法,分析不同热压工艺参数下的静曲强度、弹性模量、含水率,从而确定热压温度、压力、时间的工艺参数范围。用正交实验法测试静曲强度、弹性模量、湿态胶合强度、密度等性能,并进行了方差分析和平均值分析。结果表明:与传统建筑混凝土模板制备方法相比,该工艺省去了去竹青、竹黄、竹节和软化等复杂的竹片材料制备方法。成品的竹材加工剩余物的体积利用率占竹木复合建筑混凝土模板的80%以上,同时节约了生产成本。通过极差分析,热压工艺因素对静曲强度、弹性模量、湿态胶合强度的影响程度都是:热压压力>热压时间>热压温度。通过平均值分析,最优热压参数为:3 MPa、50 s·mm^-1、135℃。 相似文献
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《林产工业》2021,58(7)
以竹单板、泡沫铝为原材料,采用中温固化型酚醛树脂胶黏剂制备竹单板泡沫铝夹芯复合材料。应用单因素试验结合响应曲面法,探究施胶量、热压温度和热压时间三因素对复合材料静曲强度和胶合强度的影响规律,对制备工艺进行优化。结果表明:三因素按影响复合材料力学性能程度大小依次排序为施胶量热压温度热压时间。通过构建复合材料的力学性能与施胶量、热压温度和热压时间之间的回归方程模型,得出优化的制备工艺条件为:施胶量340 g/m~2、热压温度132℃、热压时间1.5 mm/min,在此条件下制得的复合材料静曲强度为122.6 MPa,胶合强度为3.20 MPa,测量误差在3%以内。 相似文献
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该研究以杂种毛白杨无性系（ＰｏｐｕｌｕｓｔｏｍｅｎｔｏｓａＢＬ）４年生幼龄格为原料，应用喷蒸坟和传统热压两种方法来生产杨木刨花板．刨花板内施胶量为１０％的脲醛树脂胶（ＵＦ），目标厚度分别取１０，１５，２０，２５ｍｍ，热压温度固定在１８０℃．喷蒸热压时所用饱和蒸汽的压力为０３～０５ＭＰａ，每种厚度下喷时间一定，取两个压时间；传统热压时每种厚度下各取４个热压时间．然后测定刨花板试件的力学强度和物理性能．在这部分里，主要讨论了责任中热压法生产的刨花板的静曲强度和内结合强度．结论为：相对于传统热压法，喷蒸热压可以明显缩短杨木刨花板生产所需的热压时间，而且使刨花板具有优异的内结合强度；但是，它对饱花板的静曲强度并没有显著影响 相似文献
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Particleboards with thickness of 10 mm and densities of 0.6, 0.7 and 0.8 g/cm3 were manufactured from high-moisture particles using urea–formaldehyde resin and the effectiveness of air injection was examined. The temperature in the 0.6 and 0.7 g/cm3 boards was lower with air injection than without during the initial to middle stages of pressing, while the temperature in the 0.8 g/cm3 board remained lower with air injection than without throughout the entire pressing process. Air injection reduced the pressing time required to manufacture the 0.6 and 0.7 g/cm3 boards and also increased the internal bond strength of boards of all densities. In the 0.6 and 0.7 g/cm3 boards, air injection reduced the modulus of rupture (MOR), while in the 0.8 g/cm3 boards, the MOR was similar between those manufactured by injecting and not injecting air. Air injection was also found to be effective for boards of high densities. The effectiveness of the air injection on thick boards was investigated by manufacturing 20-mm-thick boards of 0.7 g/cm3. Without air injection, it was not possible to manufacture the 20-mm-thick boards, even by extended hot pressing, but air injection allowed the boards to be manufactured by pressing for 16 min. Air injection was also shown to be effective for manufacturing thick boards. 相似文献
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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
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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
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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