Fire-retardant and smoke-suppressant performance of an intumescent waterborne amino-resin fire-retardant coating for wood

An intumescent waterborne amino-resin fire-retardant coating for wood (C) was synthesized and its fire-retardant and smoke-suppressant properties were investigated. The main film-builder of C was urea-formaldehyde resin blended with polyvinyl acetate resin. The intumescent fire-retardant system of C consisted of guanylurea phosphate (GUP), ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). Specimens of plywood painted, respectively, with a commercial intumescent fire-retardant coating (A), a synthesized coating (C), and the main film-builder of coating C (B), as well as an unpainted plywood (S-JHB), were analyzed by cone calorimetry (CONE). The results show a marked decrease in the heat release rate (HRR) and the total heat release (THR), an increased mass of residual char (Mass), a marked postponement in time to ignition (TTI) and a reduced carbon monoxide production rate (P _CO). The smoke production rate (SPR) and total smoke production (TSP) of the plywood painted with coating C were observed with the CONE test. The overall fire-retardant and smoke-suppressant performance of the synthesized coating C was much better than that of the commercial coating A. The thermo-gravimetric analysis (TGA) results of coating C and its film-builder B indicated that the thermal degradation process of B was slowed down by the addition of the intumescent fire-retardant system; the increase in the amount of charring of coating C was considerable. __________ Translated from Scientia Silvae Sinicae, 2007, 43(12): 117–121 [译自: 林业科学]     

Evaluation of fire-retardant properties of edge-jointed lumber from tropical fast-growing woods using cone calorimetry and a standard fire test

 Some tropical fast-growing woods were converted to edge-jointed lumber, and their fire-retardant properties due to chemical coating were evaluated using cone calorimetry and a standard fire test. The woods used were Indonesian and Malaysian albizia and gmelina plantation trees, with Japanese hinoki as a reference. The lumber was coated with 100 g/m² of trimethylol melamine phosphoric acid in a 25% aqueous solution. The treated and untreated lumber was tested in a laboratory-scale exposure furnace in accordance with JIS A 1304 and the cone calorimeter test with heat flux of 40 kW/m² following the ISO 5660. Results showed that fire endurance of all lumber was enhanced by the treatment. The fire-retardant properties were improved with increasing surface density. Though a similar trend was seen, the fire-retardant properties of the lumber revealed by the cone calorimeter test were inferior to those seen with standard fire test. Addition of thermocouples to the cone calorimeter allowed us to obtain information on the critical temperature (260°C) and charring temperature (300°C) of the lumber. Received: January 23, 2002 / Accepted: July 15, 2002 Acknowledgment The authors thank Dr. Shigehisa Ishihara, Professor Emeritus of the Wood Research Institute, Kyoto University for his suggestions about this experiment.     

Improvement of dimensional stability and weatherability of composite board made from water-vapor-exploded wood elements by liquefied wood resin impregnation

High-density and high-resin-content boards were produced by phenolic resin impregnation into board materials prepared by the water-vapor-explosion process (WVE) to develop high-durability wood composite boards for exterior use. Wet-dry cyclic tests and accelerated weathering tests were conducted, and the fundamental properties were determined to examine the effect of resin impregnation on board qualities. Bending and internal bond strength of resin-impregnated boards (I-board) satisfied the criterion for 18-type particleboard described in JIS A 5908. Thickness swelling (TS) after 24-h water immersion was approximately 2%. Resin impregnation improved the dimensional stability of the boards. In wet—dry cyclic testing, TS of I-board was the same as that of plywood. The retention ratio of modulus of rupture of I-board was large; thus, I-board had high bond durability. Color change of I-board was less than that of ordinary particleboard after a 500-h accelerated weathering test. I-Board had lower surface roughness than boards produced by a spray application method (S-board) and higher water repellency, although the difference in resin contents of the face layer was small. Thus, it is suggested that the surface properties and weatherability of I-board were improved by impregnation of phenolic resin. High-density and resin-impregnated boards made from the WVE elements are expected to withstand actual exterior use. Part of this report was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004     

人工林木材燃烧性能的研究

利用锥形量热仪对人工林杉木、杨木和马尾松的燃烧性进行了研究。木材从受热开始到结束有两个释热峰 ;木材失重过程与释热过程有着相似的变化曲线 ,这是失重和释热密切相关的结果 ;木材开始受热到着火前和炭化过程结束后发烟最大 ,炭化过程和无焰燃烧阶段发烟最低。对同一树种而言 ,热源辐射强度、加热面种类和样品厚度对燃烧特性有不同程度影响。热源辐射强度愈强 ,着火所需时间也越短 ,木材释热和失重速度越快 ,烟气浓度和发烟总量增加。加热面为横切面 (R×T)的样品着火所需时间比纵切面 (L×T或L×R)的长 ,而且第二释热峰极值增大 ,平均失重率呈增大趋势。样品厚度对木材引燃时间、燃烧 1 80s的总释热量影响不大 ,但样品厚度增加使第二释热峰出现延迟且峰值有所下降。当加热面为横切面时 ,样品厚度增加使平均失重率有下降趋势     

氧浓度对阻燃木材发烟性能的影响

采用可控气氛锥形量热仪,在辐射功率为50 kW·m-2,氧浓度为15%～21%的条件下,对磷酸二氢铵(MAP)阻燃紫椴木材及其素材的燃烧发烟性能进行对比研究.通过对烟释放速率(RSR)、总烟释放量(TSR)、比消光面积(SEA)以及一氧化碳(CO)生成速率(PCO)和CO产率(YCO)等相关动态烟参数的综合分析,总结不同氧浓度下,MAP阻燃紫椴木材及其素材燃烧时的浓烟和有毒气体CO的释放规律.结果表明:对于所有试样,有焰燃烧阶段的浓烟释放(RSR、TSR和SEA)要远大于红热燃烧阶段.当氧浓度在16%左右时,MAP阻燃木材和素材的烟释放(RSR、TSR和SEA)相当.在相同的氧浓度下,当氧浓度在16%以上时,MAP阻燃木材燃烧过程中的浓烟释放(RSR、TSR和SEA)小于素材;而当氧浓度在16%以下时,MAP阻燃木材燃烧过程中的浓烟释放(RSR、TSR和SEA)反而高于素材.在试验氧浓度范围内,MAP阻燃木材的CO释放(PCO和YCO)要高于素材.随着氧浓度的增加,MAP阻燃木材燃烧过程中的烟释放(RSR、TSR和SEA)和CO释放(PCO和YCO)均降低;素材燃烧过程中的烟释放(RSR、TSR和SEA)和CO生成速率(PCO)均增加,但CO产率(YCO)降低,前者主要是由于素材燃烧过快而使体系缺氧造成的,而后者主要是由于在单位木材质量损失下热解产物更充分燃烧.总之,随着空气中氧浓度的降低,MAP阻燃木材燃烧时的烟(包括CO)释放均呈增加趋势.     

微生物对杉木木材渗透性的影响

分别在杉木产区古杉的创伤处采集被微生物感染木材样品和活体杉木上采集感染病的叶进行分离培养，培养后得到交链胞(Paeudomonas cunuinghamiae Nanjing F.)和多毛胞(Pestalotia zhirdiana P.Henn.)将两种微生物接种到杉木木材上，处理90d后，木材液体渗透性提高达55．3％-60．5％，经方差分析，对照与处理差异显著；微生物处理对心材没有作用；微生物处理改善杉木木材渗透性主要作用在边材，前6h的单位体积吸水量占总吸水量为55．3％-60．5％，达到24h后吸水量差异甚微。     

硼化物及磷酸盐处理人工林木材的燃烧性能比较

利用锥形量热仪评价了阻燃处理人工林木材的燃烧性能,比较了硼化物及磷酸二氢铵阻燃物质对点燃、释热、发烟的作用效果.结果表明,硼化物对抑制木材点燃、释热,减少失重等作用效果不及磷酸二氢铵,但其抑烟效果优于磷酸二氢铵,这与两者作用机理不同有关.     

STUDY ON THE EFFECT OF WOOD MOISTURE CONTENT ON PERMEABILITY IN THE HYGROSCOPIC RANGE

Woodpermeabilityhascloserrelationshipwiththemanyfiledsofwoodworkingandusing,woodfluidpermeabi1-ityisrelatedtoinprocessingsuchaswooddrying;fireretartenttreatmen;pup1ingandpaper;woodpreservation.Theflowoffluidinwoodincludestwokindsoftransportprocess.Oneispenetrationfromwoodoutsidetoinside,suchas'woodpreservationandfireretartenttreatment,anotherisdiffusionfromwoodinsidetooutside'suchaswooddrying,Infact,woodpermeabilityinfulenceddirectlythequalityofwoodwaterheattreatment,Forthisreasontheresearchin…     

阻燃剂的种类及添加方法对刨花板性能影响的研究

研究了不同的阻燃剂及不同施加方法对刨花板阻燃性能的影响。试验结果表明:①单独使用硼系阻燃剂或磷-氮系阻燃剂(P-N),当其添加量在≤9刨花板的阻燃性会随着阻燃剂添加量的增加而提高。板也具有较好的物理力学性能。当阻燃剂的添加量>12％时,板阻燃性的提高不明显,板的物理力学性能却明显降低。②同样,当混合阻燃剂在适当的范围内,刨花板具有高的阻燃性和好的物理力学性能。③阻燃剂的添加方法对刨花板的阻燃性和物理力学性能也有一定的影响。本试验中添加方法1和2制的板具有好的阻燃性和高的物理力学性能。方法4的板具有较低的胶合性能是由于胶粘剂中的大分子阻燃剂影响脲醛树脂胶的胶合。     

脲醛@环氧树脂微胶囊的制备及对水性木器涂料的影响

通过原位聚合法的二步法制备脲醛@环氧树脂微胶囊,囊壁以尿素和甲醛为原料,囊芯用环氧树脂制备,将其添加进木器水性涂料中形成木器涂膜,探究微胶囊对水性涂膜的性能影响及其自修复效果。通过扫描电子显微镜和红外光谱测试仪对制备的不同芯壁比的微胶囊形貌特征和组成成分进行了观测,并将微胶囊分别以不同浓度添加量加入水性涂层,对涂层的光泽度、硬度、附着力、抗冲击力性能进行了评价。结果表明:在水性涂层中,微胶囊质量分数为10%,芯壁材质量比为0.83∶1时,水性涂层综合性能较好,对涂层各性能的负面影响较少。划痕实验表明,微胶囊质量分数为10%时涂层具有良好的修复能力。通过水性自修复涂层的制备和性能表征,探讨了微胶囊自修复技术应用于水性涂料的可能性,为后续涂料的工程应用研究奠定了基础。     

COMPARATIVE STUDY OF WOOD PROPERTIES BETWEENWHITE WOOD OF DAHURIAN LARCH AND MONGOLIANSCOTCH PINE

DahurianlarchandMongolianscotchpinearetwomajorconunerciaIconilbroustTeesinDaxing'anlingForesnyArea.Itisob-viousthattbcwoodproPertiesandworkability'ofthetWoplantsarecompletelydifferent.Butlnrecert'years,ltlsfoundthattherearetwodiffer':nttypesinparameterofwood'scolour.phy'sicalandmechanicalproPertiesandwork-ability'inDahurianlarch,namelyredwoodandx"hite..od.l']Andthepropertiesofwhite`voodaresligl1tlyyellow-white,medianweightandhardness,goodinworkability'andLard-ness,goodinwodability'anduneas…     

韩国森林中枯死木及地被物对小型鼠类丰富度的影响(英文)

在南韩东北部,1997-1998年间,自4月至12月对人工林和无枯死木生境及采伐后保留地被物的落叶次生林中的小型鼠类种群特征进行了调查。在两块林地中各选择1 hm2(100m100m)样地作为控制区和处理区。两块研究地的中上层林冠结构基本相似,但倒木及地被物的数量及比例却显示控制区大于处理区。两区域中共捕到两种小型鼠类,其中棕背 (Eothenomys regulus)211只,占总数的55.5%,大林姬鼠(Apodemus peninsulae)169只,占44.5%。这两种鼠类的丰富度及种群稳定性在控制区明显优于处理区。两地小型鼠类的不同捕获量主要来自两地鼠类繁殖率和居留率的不同。显然,森林地被结构对小型鼠类的生存具有重要意义。因此,采伐迹地中保留枯死木及地被物是维持小型鼠类种群所必须的。     

The effect of compression and incision on wood veneer and plywood physical and mechanical properties

ABSTRACT

Drying takes the largest share of energy in plywood production, and varying moisture content of veneers necessitates re-drying that often leads to over-dry veneers with deactivated surfaces, which may promote imperfect bonding. In order to decrease the drying time, reduce the need for re-drying of veneers, and improve the quality of plywood, birch and spruce veneers were subjected to pre-treatment by cold compression, incision, or a combination of the two. The effects of pre-treatment on the veneer and plywood quality were assessed by standard tests. Compression had a beneficial effect on water removal of the wettest veneers (spruce sapwood (SW) and birch), but some thickness reduction was observed in the veneers as well as the finished birch plywood. Compression led to thickness reduction of spruce veneers, but had no effect on SW plywood thickness likely due to higher viscoelasticity. Both compression and the combination of incising and compression levelled the moisture variation within the compressed stacks. Incision improved the modulus of elasticity of birch plywood, shear strength of SW plywood, and both bending and shear strengths of heartwood plywood. Higher surface pressure decreased the drying time of spruce SW in both plain compression and combined incision and compression pre-treatment.     

速生材增强处理技术研究进展及发展趋势

本文阐述了人工林速生材木材增强处理的机理、方法和国内外研究进展,分析了木材增强处理技术在产业化应用中存在的问题和未来发展趋势。     

木材真菌染色研究现状及发展趋势

木材真菌染色是由于真菌侵染而导致材色改变,包括菌纹线、白腐和染色。木材真菌染色可形成特殊肌理和色泽,改善木材的装饰特性,为木质产品的设计带来多样化的塑造空间。作为一种全新、天然的染色方式,真菌染色技术对于木材的美学价值和综合利用率都有较大提高。目前,分析木材真菌染色机理及染色工艺改进是开发真菌染色木材的关键。菌纹线是由于真菌的种间或种内的对抗形成,染色是由于真菌在细胞外部分泌色素或是伴随真菌自身在木材内部的生长形成。笔者从木材真菌染色机理、染色方法、染色条件、真菌染色木材性能等方面综述了木材真菌染色的研究进展。重点介绍了针对不同表现形式的不同染色方法,并对存在的问题进行了分析,提出了后续研究的方向为采用多种真菌的组合运用、环保色素溶剂的筛选、探寻更多的真菌色相用于色素提取方法染色、结合染料渗透机理改进染色工艺等。     

The effect of cutting height and frequency on the forage,wood and seed production of sixSesbania sesban accessions

The forage, wood and seed production of sixSesbania sesban accessions was assessed under irrigated conditions for two cutting frequencies and heights. Control trees were left uncut to measure their seed production potential. The trial was conducted over an 18-month period. The fastest growing accession produced almost 10 t/ha total dry matter (DM) after six months of growth, 40% of it being leaves. Total DM yield was higher at the six-month cutting interval compared to the three months' interval with yields between 25–42 t/ha/year. Some accessions could not sustain their high level of production but showed drastic drops in yield after repeated cutting. In general leaf DM production increased with increased cutting height. When cut at 150 cm the DM leaf yield at the three-month cutting interval ranged form 9.7–18.2 t/ha. More plants survived at the three-month cutting frequency. Seed yields varied considerably between accessions (0.02–1.56 t/ha at the six months' interval). After 18 months of undisturbed growth the trees yielded 36.5–83.7 t/ha total DM comprising 21% leaves. Fresh wood biomass ranged between 56.4–138.0 t/ha and seed yields 2.7–6.6 t/ha.     

杉木无性系木材尺寸稳定性研究

以29个12年生杉木无性系为试材,采用随机区组法取样,3株小区,3次重复,对其进行生长锥无损取样分析。结果表明:杉木无性系间木材径向全干干缩率差异显著或极显著;性状遗传力为0.20,变异系数为23.4%,遗传变异系数为14.9%,无性系间木材径向全干干缩率差值变动幅度为0%~2.3%。     

心材提取物和专用木材防腐剂作为木材保护剂的相对功效

本文调查了三种耐用木材(Afzelia africana J.E. Smith; Erythrophleum suaveolens (Guill & Perr.) Brenam. Syn. E guinensis G.Don. or Milicia excelsa (Welw) C.C. Berg. Syn. Chlorophora excelsa (Welw) Benth.)的心材提取物（在60%的甲醇中风干提取）和两种专用木材防腐剂（CCA和Penta）在暴露的土壤区组设计条件下，抑制三种木材腐朽菌(Coridopsis Polyzona Klotzch; Lenzites trabea; or Trametes cingulata Fr.)对见血封喉边材的侵袭的相对潜能，并测定其阈值。提取物和防腐剂的剂量分别是8.009、24.778、48.056、96.111、144.167 kg·m-3 ，样品的暴露处理时间与ASTM D1413-72规定的一致分别是14周和18周。结果显示：在阈值范围内，任何一种心材提取物或木材防腐剂在研究中对木材腐朽菌的抑制能力在0.01的显著水平下，差异显著。这些生物杀灭剂的相对功效是取决于真菌的种类。没有任何一种心材提取物或木材防腐剂（除在用最高的存留水平处理被侵袭的非洲毒箭木的条件下）对于被处理的木材能够授予"非常持久"等级。本土树种的心材提取物相对持久力的减少的可能原因是复杂的。在最高的存留量（144.167 kg·m-3）水平下，在0.05显著水平下每种心材提取物和任一种专用木材防腐剂（CCA和Penta）之间的功效差异不显著.     

添加阻燃剂对三层实木复合地板生产工艺的影响

以三层实木复合地板为对象,探讨阻燃剂对其生产工艺的影响,结果表明:芯板、背板浸渍阻燃剂时,单板的增重率随着浸渍时间的延长而增加,当浸渍时间超过30 min后,增重率增加不明显;随着阻燃剂施加量增加氧指数增大,含水率、静曲强度随着施加量增加而降低;含水率、静曲强度、甲醛释放量和氧指数随着涂胶量的增加而增大;热压温度和热压时间对含水率、静曲强度、甲醛释放量和氧指数影响不明显。最佳热压工艺条件为:阻燃剂施加量8%,涂胶量360g·m-2,热压温度120℃,热压时间12 min。     

STUDIES ON PHYSICAL AND MECHANICAL PROPERTIES OF DAHURIAN LARCH-WOOD OF TWO WOOD COLOURS

Dahurian1arch[Larixgmelini(Rupr.)Rupr.jisamaintimbertreespe-ciesinDaxing'anLingForestRegion,and'itisalsoafast-growingandregenerationtreeinNorthChina-Becauseitsecologicalamplitudeisverywild,therearemanyva-riabletypesinvarioushabitats.Themostsignificativetypes,whichhavebeenfoundrecentlyininvestigation,aretheredwoodandwhitewood.Theformerisfromyellow-browntored-brown,andthelat-tCrisfrompaleyellowtowhite.Theyaresimilarto'Redscotchpine#and'Whitescotchpine#.Theparametersofwoodcol-ourandphysico-…