大豆蛋白胶黏剂用于竹柳中密度纤维板试验

以大豆蛋白胶为胶黏剂,分别采用剥皮和未剥皮的竹柳枝桠材制备中密度纤维板.探讨了枝桠材树皮与木质部的比例和纤维得浆率,研究了树皮含量、施胶量和板材密度对竹柳纤维板物理力学性能的影响,优化了板材的制备工艺参数,并与脲醛树脂胶制备的剥皮竹柳中密度纤维板进行性能对比分析.结果表明:竹柳枝桠材的树皮含量这30.5％,其纤维得浆率比剥皮枝桠材低约4％;纤维板的性能随着密度和施胶量的增加而明显提高;剥皮竹柳所制纤维板的性能优于未剥皮的,未剥皮竹柳所制纤维板在密度为0.80 g/cm3,施胶量为16％时,其物理力学性能可满足GB/T 11718-2009的要求;而剥皮竹柳所制纤维板在密度为0.75 g/cm3,施胶量为14％时即可达到国标要求;大豆蛋白胶所制纤维极性能略低于脲醛树脂所制纤维板,但基本可以满足国标要求.     

动物蛋白改性剂添加量对难燃中密度纤维板静曲强度的影响

以粉状和膏状动物蛋白为改性剂,研究不同添加量对难燃中密度纤维板静曲强度的影响,结果表明:粉状动物蛋白改性剂,在一定范围内随着添加量的增加,可以使难燃中密度纤维板的静曲强度数值得到提高,最佳添加量为8%;添加膏状动物蛋白改性剂,最佳添加量为2%,随着添加量的增加,会导致难燃中密度纤维板的静曲强度降低。在提高难燃中密度纤维板静曲强度性能上,粉状动物蛋白改性剂好于膏状动物蛋白改性剂。     

双组份豆粕基中密度纤维板的制备及性能研究

为解决传统中密度纤维板甲醛释放的问题,实验以豆粕粉为原料,研制出双组份生物质基环保型胶黏剂,并用其制备了中密度纤维板。通过单因素法研究了胶液、豆粕粉用量,木纤维含水率及热压时间对豆粕基中密度纤维板物理力学性能的影响。结果表明:1)在热压温度180℃条件下,胶液用量100 kg/m~3,豆粕粉用量60 kg/m~3,热压时间27 s/mm,木质纤维含水率(12±1)%为较优的制备工艺;2)较优条件下制备的中密度纤维板密度(ρ)为760 kg/m~3,内结合强度(IB为0.71 MPa,24 h吸水厚度膨胀率(24 h-TS)为9.3%,静曲强度(MOR)为33.2 NPa,弹性模量(MOE)为3 319 MPa,各项指标均符合国家标准;3)穿孔萃取法测试甲醛释放量为0.2 mg/100 g,优于国家E_0级纤维板标准;4)总挥发性有机化合物(TVOC)的释放率合格,挥发率达到A~+级。     

Applications of wavelet transformation in the nondestructive test of medium density fiberboard

Taking medium density fiberboards (MDF) as samples, the feasibility of the applications of wavelet analysis in a nondestructive test is discussed in this paper. The main results are as follows: the modulus of elasticity of longitudinal resonance, measured by wavelet analysis, can replace the conventional static modulus of elasticity. Their correlation coefficient is significant (p < 0.01). The defect of samples can be judged by wavelet analysis, which is superior because it is a nondestructive test. __________ Translated from Scientia Silvae Sinicae, 2006, 42(10): 91–94 [译自: 林业科学]     

杨村新无性系木材物理力学性质的研究

研究了7个杨树新无性系和I－69杨的木材物理力学性质。结果表明，杨木新无性系的物理力学性质等主要指标均属于小至甚小级，无性系间物理力学性质差异显著，据此可用木材物理力学性质因子选育优良无性系。尽管新无性系的生长速度超过I－69杨，但由于其某些强度指标低于I－69杨，8年生的速生材尚不能完全替代11年生的I－69杨使用，因此不能作为建筑结构材使用。     

Manufacture and properties of ultra-low-density fiberboard

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     

红石中密度纤维板厂清洁生产评析及改进对策

依据国家环境保护部发布的中密度纤维板清洁生产标准,对红石中密度纤维板厂清洁生产现状进行了评析,针对存在的薄弱环节,提出了进一步推行清洁生产的对策:提高思想认识,树立清洁生产观念;健全组织机构,明确清洁生产目标;针对薄弱环节,制订清洁生产方案;加快技术进步,提高清洁生产水平;建立激励机制,促进清洁生产落实。     

我国中密度纤维板质量现状分析

根据国家人造板质量监督检验中心１９９７年第２季度中密度纤维板国家监督抽查的结果和掌握的资料人造板 国中密度纤维板质量现状，并对存在的问题提出了建议，与同行共勉。     

小型中纤板厂的技术改造措施

本文对我国小型中纤板企业技术改造的迫切性和必要性进行了分析．并提出了相关的技术改造措施。实践表明：适当的技术改造可大幅度增加产量，改善产品质量，增加产品品种；技改投资少、见效快，是企业发展的必由之路。     

树龄对日本落叶松木材物理力学性质的影响

选取日本落叶松为试验材料,开展不同树龄日本落叶松物理力学性质的比较研究.结果表明:43年生、30年生和17年生日本落叶松木材气干密度分别为0.607,0.567和0.507 g/cm3,气干体积干缩率分别为7.7％,7.7％和7.1％;全干到气干体积湿胀率分别为5.1％,4.9％和4.5％;抗弯弹性模量分别为17.527,16.775和12.510 GPa,抗弯强度分别为121.1,110.3和90.9 MPa,顺纹抗压强度分别为56.8,51.8和44.0 MPa.随着树龄增大,日本落叶松木材密度、顺纹抗压强度、抗弯强度和抗弯弹性模量等各项物理力学性能指标提高,差异干缩逐渐变小.日本落叶松木材的气干密度与抗弯弹性模量、抗弯强度、顺纹抗压强度呈线性正相关,相关系数分别为0.760,0.816和0.900.     

Technological properties and fire performance of medium density fibreboard (MDF) treated with selected polyphosphate-based fire retardants

ABSTRACT

The objective of the work was to evaluate the efficacy of two new polyphosphate-based fire retardants (FRs) and one commercial product named Siriono^® on the fire performance and physical–mechanical properties of medium density fibreboard (MDF) fabricated in the laboratory from Scots pine (Pinus sylvestris L.) wood. The fibres were treated with aqueous solutions of fire retardants, at 12% loading (dry salt on dry wood), and bonded with a melamine urea formaldehyde (MUF) adhesive. The physical and mechanical properties of panels were assessed using the European standards, whereas their fire performance was evaluated using an in-house method and the Cone calorimeter. In overall, the chemicals added enhanced the fire and smoke properties of the panels to varying degrees. Critical FR parameters such as peak heat release rate (peak HRR), total heat release (THR) and total smoke production (TSP) were significantly improved in the FR-treated panels, as exhibited in cone calorimeter tests. However, the internal bond strength of treated panels largely decreased by the addition of fire retardants, while thickness swell and water absorption negatively affected to a significant extent. In contrast, the formaldehyde release of the panels was considerably decreased at the E1 class level, with the incorporation of the polyphosphate-based additives.     

中密度纤维板砂光机的改进及降耗

笔者分析了中密度纤维板砂光机消耗较高、质量较差的原因，提出了改进措施。实施结果表明，砂光机运行正常，砂光产量和质量同步提高，消耗和成本下降，污染减轻。     

Effects of surface laminate type and recycled fiber content on properties of three-layer medium density fiberboard

ABSTRACT

High global production of medium-density fiberboard (MDF) in recent years could generate an equal quantity of waste MDF at the end of its service life, requiring recycling of waste MDF instead of landfilling or incineration. This study investigated effects of the addition of recycled fiber (RF) obtained from surface laminated MDFs with three different materials to the properties of three-layer recycled MDF (rMDF). Three types of surface laminates such as low-pressure laminate, polyethylene terephthalate, and polyester coating were hammer milled, and then went through a patent-pending fiber recovery system to obtain the resultant RFs that were added to the core layer of rMDF. These RFs at three contents (10, 20, and 30%) were blended with 12% of urea-formaldehyde (UF) resin prior to hot-pressing. Statistical analysis showed that the best internal bonding strength, modulus of rupture, and modulus of elasticity of rMDF panels were obtained for LPL-rMDF with a 20% RF content. Thickness swelling, water absorption, and formaldehyde emission of rMDF were reduced by increasing the RF content. These findings suggest that a minimum RF content of 20% can be replaced with virgin fibers for the rMDF manufacture, indicating the feasibility of recycling waste laminated MDF into three-layer rMDF.     

Effects of nanoclay on physical and mechanical properties of wood-plastic composites

Effects of nanoclay (NC) on physical and mechanical properties of wood-plastic composite (WPC) were studied here. Virgin, recycled, and mixed (50/50% of virgin/recycled) polyvinyl chloride (PVC) were used as the matrix in the WPC. Specimens with three NC contents of 1.5%, 3%, and 5% were manufactured; they were then compared with control specimens. Totally, 12 treatments were manufactured. The physical and mechanical properties were measured in accordance with the ASTM standards. The highest properties were found in specimens made from virgin PVC. Addition of recycled PVC resulted in significant decrease in all properties. NC improved all physical and mechanical properties studied in the present research project; the highest properties were observed in specimens with 5% of NC content. The improvement in properties was as a result of formation of bonds between the hydroxyl groups of NC with the wood flour components. It was concluded that NC would significantly improve the properties in all the three PVC types of virgin, recycled, and mixed. From an industrial point of view, it was concluded that mixing virgin and recycled PVC can be recommended not only to decrease production costs, but also to partially solve the problem of PVC residue which are not bio-degradable.     

杨木单板层积材复合装饰结构型材的制造及性能

研制杨木单板层积材和MDF复合装饰结构型材,并对其物理力学等性能进行测试分析,提出生产该复合型材时采用的成型工艺和相关热压工艺参数等。     

Effects of heat treatment on some properties of MDF (medium-density fiberboard)

This work investigated some mechanical, physical and free formaldehyde emission properties of heat-treated MDF. For this purpose, MDF panels were subjected to varying heat treatment temperatures (155°C, 165°C and 175°C), durations (2.5?h., 3.5?h. and 4.5?h.) and waiting times after hot pressing (30?min., 120?min. and 600?min). Thickness swelling (TS), water absorption (WA), free formaldehyde emission (FFE), bending strength (BS), modulus of elasticity (MOE), tensile strength perpendicular to fibers (TSPF) for treated and untreated samples were tested and evaluated statistically. Consequently, after the heat treatment values of tensile strength, bending strength and modulus of elasticity were almost negatively affected relatively, but the thickness swelling and water absorption and quantities of free formaldehyde were improved positively of MDF samples.     

Characterization of the morphological,physical, and mechanical properties of seven nonwood plant fiber bundles

The morphological, physical, and mechanical properties of the nonwood plant fiber bundles of ramie, pineapple, sansevieria, kenaf, abaca, sisal, and coconut fiber bundles were investigated. All fibers except those of coconut fiber had noncircular cross-sectional shapes. The crosssectional area of the fiber bundles was evaluated by an improved method using scanning electron microscope images. The coefficient factor defined as the ratio of the cross-sectional area determined by diameter measurement, to the cross-sectional area determined by image analysis was between 0.92 and 0.96 for all fibers. This indicated that the area determined by diameter measurement was available. The densities of the fiber bundles decreased with increasing diameters. The diameters of each fiber species had small variation of around 3.4%-9.8% within a specimen. The tensile strength and Young’s modulus of ramie, pineapple, and sansevieria fiber bundles showed excellent values in comparison with the other fibers. The tensile strength and Young’s modulus showed a decreasing trend with increasing diameter of fiber bundles.     

江汉平原水杉、池杉、落羽杉物理力学性能比较研究

对江汉平原水杉、池杉、落羽杉人工林物理力学性能进行了研究,结果表明:落羽杉的密度和硬度最大;落羽杉、水杉、池杉的抗弯强度差异不大;水杉的弹性模量最大,约为落羽杉的2.3倍,落羽杉的弹性模量与池杉的比较接近。南北方向对水杉、池杉、落羽杉的密度、顺纹抗压强度在5%水平上差异均不显著,对池杉、水杉抗弯强度在5%水平上差异不显著,对落羽杉抗弯强度在1%水平上差异显著,对落羽杉、池杉的弹性模量在1%水平上差异显著,对水杉的弹性模量在5%水平上差异不显著。三杉南北面近树皮处木材的密度、抗弯强度、弹性模量、顺纹抗压强度均大于髓心处。对水杉、池杉、落羽杉物理力学性能比较研究,旨在为其培育及合理利用提供依据。     

人工林落羽杉力学性能研究

对江汉平原人工林落羽杉物理力学性能进行了研究,结果表明:落羽杉的气干密度为0.413 g/cm3,气干密度等级为轻;综合强度为74 MPa,强度等级为Ⅰ级;径向横纹抗压强度略大于弦向横纹抗压强度;端面硬度最高,弦面硬度与径面硬度差别不大。落羽杉南北面近树皮处木材的密度、抗弯强度、弹性模量、顺纹抗压强度均大于近髓心处,南北方向对落羽杉的密度、顺纹抗压强度在5%水平上差异均不显著,而对其抗弯强度、弹性模量在1%水平上差异显著。     

常规与低温纤维干燥工艺的热、(火用)评价

为实现中密度纤维板(MDF)生产的节能降耗,提高能量利用率,对MDF生产线的常规和低温纤维干燥工段进行了热、(火用)利用的对比分析.结果表明:与常规纤维干燥工艺相比,低温干燥工艺的热效率更高,干燥过程消耗热能低,且低温干燥设备的(火用)效率较高,可更有效地利用干燥能量.针对上述结果,从(火用)分析的角度,提出了MDF生产线节能改造、提高能量利用效率的建议.