竹木复合定向刨花板强度性能研究

本文论述了竹材、意大利杨复合定向刨花板的强度性能,就胶种、刨花厚度、竹材所占比率、板密度、板坯结构、施胶量等诸因子对板材强度性能的影响进行了探讨。结果表明:(1)胶种对竹木复合定向刨花板的强度影响不大;(2)降低刨花厚度或提高板密度均可使板材强度提高;(3)单层结构的复合定向刨花板强度最高;(4)提高板材中竹材的比率可使板子强度明显改善;但竹材比率过高时,板材强重比反而下降,呈开口向下的抛物线型变化;(5)酚醛树脂定向刨花板的强度随原料酸性增大而降低。     

银杏木空心刨花板复合墙体的传热性能

运用非稳态法测定银杏木空心刨花板的导热系数,同时探讨了不同厚度空气层对复合墙体传热阻的影响.结果表明,绝干时空心刨花板的导热系数为0.136 W/(m·K),可以作为保温材料;当空气层厚度<74 mm时,复合墙体的传热阻随空气层厚度的增加而增大.     

灰木比对水泥刨花板力学性能的影响

对不同灰木配比的水泥刨花板力学性能进行试验研究,结果表明:在研究范围内水泥刨花板的密度、内结合强度、弹性模量和静曲强度都随灰木比的升高而增强,吸水厚度膨胀率随着灰木比的升高而降低。当灰木比为1:1时,板材的静曲强度为8.4 MPa;当灰木比为1.5:1时,板材的静曲强度为14.6 MPa;当灰木比为2:1时,板材的静曲强度为15.6 MPa水泥刨花板的力学强度在灰木比为2:1时达到最高。     

重组木再现美国市场

重组木发明初始,大径级的原木锯材资源还很丰富,并且价格低廉,很容易得到,但现在情况大不相同,大力开发重组木产品的时机已经来临。TimTek澳大利亚有限公司是一家新成立的公司,该公司拥有世界上唯一的重组木技术知识产权。     

木纤维与麦秸刨花制造纤维刨花板的工艺研究

对以木纤维及麦秸刨花为原料制造纤维刨花板的制造工艺及板材性能进行了研究。结果表明，利用木材及麦秸原料制造纤维刨花板的工艺可行，板板的性能完全可以达到中密度纤维板国家标准的要求。     

银杏木空心刨花板复合墙体隔声性能

在现代平台式轻型木结构墙体中分别填充30mm厚岩棉、33mm厚一层空心刨花板和33mm厚两层空心刨花板,形成三种不同的复合外墙,并测试三种墙体的隔声性能,得到了隔声效果的单一评价值.实验结果表明:空心刨花板复合墙体存在隔低频声差,隔高频声好的隔声特性.空心刨花板复合墙体隔声性能优于类似填实岩棉等吸声材料的墙体结构,而且其隔声性能(计权隔声量)都接近或超过40dB,符合住宅隔声标准要求.     

国外两种重组木生产线介绍

前言为充分合理利用木质原料的原有特性,人们设想在不打乱原来木质纤维排列方向、保留木材基本性能的前提下,设计和开发出一种类似天然木材的产品—重组木。就是将枝桠材、小径材解离成通长的、相互交联并保持原有纤维排列方向和特性的疏松网状木纤维束,然后经干燥、施胶、组坯成型、     

云南省发展重组木的可行性

重组木是一种新型的人造板材,与其它人造板材相比,它不但能保持较好的木材天然纹理,且具有强度大、变形小,握持力高,加工性能好,用途广泛等优点,其生产工艺过程相对简单,成本低、利润高,市场潜力较大,云南省发展重组木有丰富的后续资源,可带来较高的经济、生态和社会效益。     

提高重组木产品表面质量的途径

重组木是一种优质的新兴人造板材，但其表面质量却是困扰其更广泛应用的一大难题。本文试就其表面质量问题提出三种改进方法，即表面贴面处理、重组未复合刨花板、塑膜重组木等，以期使重组木产品的表面质量得以改善，并使重组木产品在更广泛的领域得以应用。     

重组木国内外概况及发展趋势

速生丰产林木材和间伐材的合理利用是当今国内外木材工业面临的重大课题。近年来,澳大利亚等国开发的重组木(Scrimber)问世,为小径材的加工利用开辟了一条新路,引起世界各国的关注,我国亦甚感兴趣。兹简要介绍如下。     

一种制备(3R,4R)-4,7,7-三甲基-6-氧杂二环[3.2.1]辛烷-3,4-二醇的新方法

在催化剂过氧磷钨酸十二烷基吡啶盐(Cat-PW4)的作用下,α-蒎烯与H2O2反应生成主要产物(3R,4R)-4,7,7-三甲基-6-氧杂二环[3.2.1]辛烷-3,4-二醇。不同反应条件对反应转化率和选择性的实验结果表明,最佳反应条件为:12.8 mmolα-蒎烯、5 m L溶剂三氯甲烷、0.2 g催化剂、3.3 m L 30%H2O2,反应温度40℃,反应时间3 h,α-蒎烯转化率和产物的选择性分别为94.7%和39.8%。反应结束后,该产物存在于水相和有机相中,通过萃取和重结晶分离提纯,得率11%,纯度达到98%;其分子结构通过红外光谱、紫外光谱、1H核磁共振谱、13C核磁共振谱、低分辨率质谱及高分辨率质谱确证。     

微波磷酸法中密度纤维板厂废料制备活性炭

以中密度纤维板(MDF)厂废料为原料,采用微波辐射磷酸法制备活性炭。探讨了在微波功率900W条件下磷料比、水料比、辐照时间对产品活性炭各项主要指标的影响。得到了试验条件下微波辐射磷酸法制备活性炭的最佳工艺: 磷料比3．5:1,水料比1:1,辐照时间9min。用此工艺制备活性炭产品的得率39．44％,碘吸附值949．08mg／g,亚甲基蓝脱色力10．76mL／0．1g,苯酚吸附值350．25mg／g。本工艺方法为中密度纤维板厂废料的综合利用找到了新的途径。     

谈应用CoreldrawX3软件绘制林业工程作业设计图方法

新形势下林业制图既要图面整洁、美观大方,又要高效、简单,手工制图已不符合现代林业发展要求,正逐渐被淘汰。笔者对应用CorelDrawX3绘制林业工程作业设计图的方法和技巧,包括图框绘制、小班勾绘、着色、求积以及绘图成果打印等进行了详细介绍,容易掌握、色彩丰富、制图效率高。CorelDrawX3是绘制林业工程设计图的实用...     

Benzofuran from seeds of Styrax officinalis

A new benzofuran was isolated from seeds of Styrax officinalis and has been identified as 5-[3"-(2-methylbutanoyloxy) propyl]-7-methoxy-2-(3',4'-dimethoxyphenyl) benzofuran (1) by means of spectroscopic analysis.     

Protection of spruce from colonization by the bark beetle, Ips perturbatus, in Alaska

Field bioassays were conducted in south-central Alaska in a stand of Lutz spruce, Picea × lutzii, to determine whether a semiochemical interruptant (verbenone and trans-conophthorin) and/or a defense-inducing plant hormone (methyl jasmonate, MJ) could be used to protect individual standing trees from bark beetle attack. During two experiments (initiated in May 2004 and 2005, respectively), attacks by Ips perturbatus on standing trees were induced by using a three-component aggregation pheromone (ipsenol, cis-verbenol, and ipsdienol) and prevented by using the interruptant. In 2005, treatments from 2004 were repeated and additional treatments were evaluated by using MJ spray or injection with and without the interruptant. Aggregation began before 3 or 7 June, and attack density was monitored through 3 or 16 August. During both years, tree mortality caused by I. perturbatus was recorded twice (in August, and in May of the following year). In both experiments, attack density was greatest on trees baited with the three-component attractive pheromone, but was significantly reduced by addition of the semiochemical interruptant to trees baited with the attractant. There were no significant differences in attack density between attractant + interruptant-treated trees and unbaited trees. In 2004, mortality was highest among attractant-baited trees, whereas addition of the interruptant significantly reduced the level of initial (10 week post-treatment) and final (54 week post-treatment) mortality. In 2005, no significant reduction in attack density occurred on trees baited with the attractant when MJ was sprayed or injected. The highest initial (10.6 week post-treatment) and final (49.4 week post-treatment) mortality was observed among trees that had been injected with MJ and baited with the attractant. Mortality at the final assessment was significantly lower in all other treatment groups. As in 2004, addition of the interruptant to attractant-baited trees significantly reduced the level of final mortality compared to attractant-baited trees. MJ was not attractive or interruptive to I. perturbatus or associated bark beetles in a flight trapping study. However, MJ-treated trees (sprayed or injected) exuded copious amounts of resin on the bark surface. Anatomical analyses of felled trees from four treatment groups [Tween (solvent)-sprayed, MJ-sprayed, Tween-injected, and MJ-injected + attractant baited] showed that treatment with MJ increased the number and size of resin ducts produced following treatment. These analyses also revealed a reduction in radial growth in MJ-treated trees. Our results show that during both years, treatment with a simple, two-component interruptant system of verbenone and trans-conophthorin significantly reduced I. perturbatus attack density and tree mortality on attractant-baited trees and provided a full year of protection from bark beetle attack.