加入聚脂纤维对马歇尔实验指标的影响

纤维的加入会影响沥青的路用性能，同时又对混合料有着加筋与阻裂的作用。研究表明，纤维在混合料中的质量百分比以及纤维的分散特性均对纤维沥青混合料有着明显影响。苯文通过对加入不同纤维用量沥青混合料的马歇尔实验，研究沥青混合料马歇尔实验指标的变化，特别是最佳沥青用量和密度，同时分析其产生变化的原因，为指导纤维混合料设计和施工提供依据。     

浅析SBS改性沥青混合料及玻纤聚酯防裂布在道路中的应用

公路、市政道路沥青中聚合物可改善沥青性能,能明显延长公路、市政道路沥青路面寿命、降低噪声、提高行车舒适性和安全性;高性能专用玻纤聚酯防裂布应铺筑于基层和加铺面层之间应用,目的是防止渗水、减缓反射裂缝及加强层间结合。     

北美地区杨树木材利用现状与前景

过去20多年, 北美地区的杨树已经从杂草树种转变为产生巨大经济效益的用材林树种, 杨树木材因其具有较高纤维素含量和较低的木质素含量, 适合用作纸浆和纸制品的原料。杨木制浆方法有机械法、化学法、半化学法和化学机械法, 杨木浆可以作为高级纸、纸板、新闻纸和包装纸。杨木牛皮纸浆与针叶材牛皮纸浆混合, 具有良好的成纸性能, 透明度高, 适合制作高级用纸。杨木也是传统的锯材、单板和胶合板工业的原材料, 用来生产锯材、单板、胶合板、木质复合板、包装箱、集装箱、火柴杆和筷子等。最近10年杨木定向刨花板和结构复合板产量显著增加, 利用前景广阔。从资源生产的角度来看, 在改良木材化学组成、纤维质量和自然耐久性等方面进行木材性质改良的转基因杨树研究取得了长足进展。从资源利用角度来看, 高价值的工程复合板和高得率的纸浆和纸产品将会在未来发展中快速增长。     

XYPEX和CFRP在桥梁补强中的应用

采用XYPEX赛柏斯防水材料修补混凝土梁纵向裂缝和CFRP修补混凝土连续梁横向裂缝,是近几年来在我国应用较为广泛的一项新型桥梁补强技术.本文以无锡市工运桥为例,阐述了采用这两种材料加固修补桥梁的施工工艺和质量控制.     

新型竹木复合板的研制

将竹材加工剩余物加工成一定规格形状的竹碎料,与木纤维均匀混合,按3层结构组成板坯,经热压胶合成一种竹碎料/木纤维复合板.依据GB/T 17657-1999标准检测,该产品静曲强度达到31.5MPa,弹性模量达到3 041MPa,2h吸水厚度膨胀率为1.7%,内结合强度高达1.52MPa,表明该产品是一种具有良好性能的新型竹木复合板.     

Theoretical computation and analysis of benefits of wood cutting power

This paper studies the problem of high energy waste in the course of the wood fiber processing in the wood-based panel industry. In the light of the energy economy principle, the cutting theory on the micron and long-slice wood fiber was put forward. In this paper, by means of analyzing the power waste in traditional processing, a series of analytical measures, such as, cytology, super precision work theory and fiber processing, and so on were utilized in the micron wood fiber formation process, and the cutting conception of the micron and long-slice wood fiber was put forward. Accordingly, the study of the micron and long-slice wood fiber was put into the microstructure study. This paper scientifically explains the reasons why the traditional wood fiber processing consumes more energy and the fiber quality low. In an example, the cutting power on the micron and long-slice wood fiber was calculated, which was compared with the traditional cutting power. The result showed that the energy waste by machining at micron is much lower than by heat grind and the high quality and long-slice wood fiber was gained. Thus, a revolutionary step was taken in the paper-making and wood-based panel industry of China. __________ Translated from Scientia Silvae Sinicae, 2006, 42(3): 44–46 [译自: 林业科学 2006, 42(3): 44–46]     

Combination treatment of kenaf bast fiber for high viscosity pulp

The viscosity of kenaf bast fiber has been found to be highly sensitive and variable with different pulping methods; therefore, it is important to choose proper chemicals and conditions for pulping and bleaching of kenaf bast fiber. From several pulping experiments, a nonconventional pulping method with a combination of ammonium oxalate pretreatment followed by soda pulping at normal pressure and then acidic chlorite delignification was developed to obtain high-viscosity pulp (162 centipoise). The optimum level of alkali dosage of soda pulping for high-viscosity pulp was found to be 15% (on pulp as NaOH). Pulps showed linear relations between viscosity and xylose or glucose contents, but the combination pulping method gave extremely high pulp viscosity, beyond the relations. The highest viscosity pulp from kenaf bast fiber demonstrated a tear index about twofold and a folding endurance 6.2-fold higher than those of Manila hemp pulp with comparable tensile and burst indexes. The high-viscosity pulp could be used in the production of high-quality currency paper or longevity paper for special uses.Part of this paper was presented at the 43rd Lignin Symposium, Fuchu, Tokyo, October 26–27, 1998     

油棕丝中密度纤维板的研制与开发

介绍开发油棕丝的必要性和可行性,工业性试验表明油棕丝MDF,其质量不亚于木质MDF,目前国内可提供成套的油棕丝MDF制造设备,不仅可以使国产人造板生产线进入国际市场,且为我国海南、广东、福建等地区开发利用油棕丝MDF创造了条件,拓宽了人造板生产的原料来源。     

JN型微米木纤维减震器

[目的]利用微米木纤维为原材料代替难以降解的橡胶和塑料,制作出适用于机械设备或汽车减震装置的JN型木纤维减震器,研究JN型木纤维减震器的选材、加工工艺及数学建模方法,为减震器数控加工机床和数控系统的研制与开发提供理论依据.[方法]以密度为0.439 g·cm-3、含水率为12％ ～ 15％、平均厚度可达到52μm的红松微米木纤维为基材,利用冷硫化和复合材组构理论,采用热压模具定型方法制作出JN型微米木纤维减震器样品,测量样品的质量、体积并观察样品浸泡在水中24 h后的外形状态.在基本假设的基础上,用包络法和规则几何体建模法建立JN型微米木纤维减震器的数学模型,并利用Matlab软件对JN型微米木纤维减震器进行仿真分析.[结果]JN型微米木纤维减震器样品的密度在0.91 ～1.36 g·cm-3之间,质量在1.4～2.0 kg之间,在水中浸泡24 h不会变形.仿真分析结果证明JN型微米木纤维减震器数学模型具有一定的通用性和准确性.[结论]按规定的加工工艺制备的JN型微米木纤维减震器样品符合密度、弹性要求,并且具有抗水性;JN型木纤维减震器的建模由底座和规则梯形台构成,模型参数具有通用性,直接将底座和规则梯形面相关尺寸参数输入模型方程,可获得JN型木纤维减震器的不同加工尺寸;为保证JN型木纤维减震器的实用尺寸和外观,降低生产成本,整个模压加工过程必须在一套模具上完成.     

树皮含量对纤维热磨机能耗与纤维质量的影响

对以杨木为主的纤维热磨试验数据进行统计,分析树皮含量与纤维热磨机能耗、纤维质量之间的关系.结果表明,树皮含量对热磨机能耗与纤维质量产生较大影响,热磨机能耗随着树皮杨木比(简称“皮木比”)的降低而减小,纤维筛分值随皮木比的增加呈现先升后降的趋势;对包装基材和地板基材用纤维板,允许的树皮含量分别为16％和14％,既保证产品质量,又降低原料成本.