人造板热压应力研究

在不同的制板工艺条件下压制纤维板和刨花板,并在线记录热压过程中的油压力.通过比较分析不同板材密度和厚度、板坯含水率及热压温度时,试板在热压过程中的油压力-时间曲线,总结人造板在热压过程中热压应力的变化规律.     

Preparation of composite board using foil-laminated and plastic-laminated liquid packaging paperboard as raw materials

We investigated the properties of composite board formed using base sheets of aluminum foil-laminated and polyethylene (PE) plastic-laminated liquid packaging paperboard (LP) as an alternative to recycling these items in wastepaper stream. Boards of different specific gravities ranging from 0.55 to 0.75 were made by pressing shredded LP blended with urea resin having resin content of 6%–10% at 180°C. Subsequently, we also prepared mixed particleboard [wood (WD) particles and LP mixed], three-layered particleboard (LP as the middle layer, WD in the upper and lower layers), and wood particleboard all having resin content of 10% and various specific gravities. Static bending and internal bonding strengths and thickness swelling of the specimens were determined to examine their properties. At the same specific gravity, the properties of LP particleboards were affected by their resin content. The modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond strength of the LP particleboards increased with increasing specific gravity of the boards at the same resin content, but thickness swelling of the LP particleboards showed the reverse trend. The average MOR of the LP particleboards approximated that of the mixed particleboards and was greater than those of the three-layered particleboards and wood particleboards. Internal bond strength and thickness swelling of the LP particleboards were smaller than those of the other particleboards. Based on the above observations, we deemed that LP can be made into composite boards with adequate properties either alone or mixed with wood particles.     

废旧刨花板循环利用技术的研究

探讨利用废旧刨花板循环制造刨花板的技术.采用高压水煮、水煮、汽蒸和直接粉碎4种方法制备刨花,通过比较刨花的筛分值和压制刨花板的主要物理力学性能,得出最佳的处理方法为水煮.试验压制的一次循环水煮和二次循环水煮刨花板的性能,可分别达到GB/T 4897.5-2003和GB/T 4897.3-2003的要求.     

工艺因素对竹刨花模压制品性能的影响

以我国云南两种典型的丛生竹种--黄竹和云南龙竹的加工剩余物为原料,采用先预压、再热压模压的"两步法"生产工艺,进行了竹刨花模压制品的试验研究,分析了材种、板坯密度、施胶量等工艺因素对板材性能的影响,并与相思木刨花模压制品相比较.结果表明:按本研究设计的工艺技术路线是可行的,制成的竹刨花模压制品的性能优于相思木刨花模压制品,产品可用于装饰用途.     

Upgrading of urea formaldehyde-bonded reed and wheat straw particleboards using silane coupling agents

Reed and wheat straw particleboards bonded with urea formaldehyde (UF) resin were manufactured from two different material configurations (i.e., fine and coarse particles). The board densities were in the range of 0.550–.90g/cm³. The effects of particle size and board density on the board properties were examined. The properties of particleboard produced from fine particles were better than those made from coarse particles. An increase in board density resulted in a corresponding improvement in the board properties. The properties of OF bonded reed and wheat straw particleboards were relatively lower than those of commercial particleboards. Three silane coupling agents were used to improve the bondability between the reed and wheat particles and OF resin. Results of this study indicate that all the board properties were improved by the addition of silane coupling agent. The degree of improvement achieved from each coupling agent was different; epoxide silane was found to be more effective for reed straw particleboard, and amino silane was better for wheat straw particleboard.     

Biological performance of particleboard incorporated with boron minerals

We compared resistance to decay, mold fungi,termites and insect larvae of particleboards incorporated with the raw boron minerals ulexite and colemanite to that of particleboards impregnated with the commercial boron preservative zinc borate, or boric acid plus a borax mixture.We also quantified water absorption, thickness swell and boron release of particleboards. Ulexite had the best decay resistance, and colemanite had the best termite resistance.However, ulexite and colemanite were not as effective as zinc borate or the boric acid/borax mixture in preventing mold growth. In general, the boric acid/borax mixture combination was more effective against Anobium larvae than the other treatments. Less boron was released by specimens containing zinc borate and colemanite than bythose containing ulexite or the boric acid/borax mixture. In general, water absorption and thickness swell were similar among the different treatments, but both were slightly higher in the ulexite-incorporated specimens. Further mechanical tests will be needed to evaluate the particleboard properties and thereby the compatibility of these boron minerals with various manufacturing processes.     

一年生植物作为石膏刨花板原料的适应性

本文叙述了使用德国及中国建筑石膏和甘蔗渣、竹材、棉秆、麦秸、稻草等一年生植物生产石膏刨花板的适应性,分析了石膏的成分和性能,测定了缓凝剂和植物原料对石膏水化的影响。制板时采用不同的配方和板的密度,以评价一年生植物的使用价值。在所使用的原料中,甘蔗渣是良好的石膏刨花板原料。     

Development of an air-injection press for preventing blowout of particleboard (III): effects of pressing temperature on board performance

An air-injection press, which has holes punched in the heating plates, injects high-pressure air through the holes of one plate into particleboards and discharges the air and vapor through the other plate during press heating. The press can manufacture particleboards from high-moisture particles by preventing blowouts of the boards. In this study, the effects of pressing temperature were investigated by pressing boards at 190, 210, and 230°C. The internal bond strength increased from 0.43 to 0.60?MPa by raising the temperature from 190 to 210°C, but did not increase further when the temperature was raised to 230°C. Raising the temperature from 190 to 210°C also helped improve the thickness swelling. No relationship was found between the modulus of rupture and pressing temperature.     

DETERMINATION OF STATIC AND DYNAMIC DIFFUSION COEFFICIENTS OF MOISTURE IN PARTICLEBOARDS

The static and dynamic diffusion coefficients are important coefficients todescribe the moisture transfer processes in particleboard.In this paper,the formula ofculculating the static and dynamic diffusion coefficients were deduced.At first,the staticdiffusion coefficients of four kinds of particleboards were determined by using diffusion cupmethod.The results demonstrated that the static diffusion coefficients parallel to panelsurface were 10-20 times as large as that of perpendicular to panel surface for test boards.To determine both dynamic diffusion coefficients and surface emission coefficients ofmoisture in particleboards in one experimental period,specimens in four different thickness-es of each kind of particleboard were used in the experiment.Then the method ofregression was used and the dynamic diffusion coefficients and surface emission coefficien-ts were determined based on the slope and intercept of the regressive line.     

甲基三甲氧基硅烷浸渍改性刨花板及其性能分析

刨花板是家具制造业的首选板材,在潮湿的环境中使用易出现翘曲变形、膨胀及分层等现象。为改善刨花板防潮性能,提高其尺寸稳定性,将甲基三甲氧基硅烷(MTMS)与0.1mol/L的盐酸以4∶1的体积比混合,将混合溶液置于冰浴中超声水解360 min,然后利用MTMS水解溶液对刨花板进行5 min的浸渍处理。分析了改性前后刨花板的润湿性、抗紫外老化性、粗糙度、表面化学结构及物理力学性能。研究结果表明:经MTMS水解溶液浸渍改性的刨花板具有稳定的拒水、拒油及抗老化性能,尺寸稳定性得到改善,板坯的表面密度增加,力学性能提高。     

喷蒸热压法和传统热压法生产杨木刨花板的比较(Ⅰ)喷蒸热压对刨花板力学强度的影响(英文)

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０３～０５ＭＰａ，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     

Long-term deformation of MDF panels under alternating humidity conditions

Summary Creep tests were carried out on 19 mm thick commercial MDF panels, raw and overlaid with melamin resin-impregnated 80 g/m² paper.The tests were carried out under cyclic environmental conditions with relative humidity levels of 30%–90%, a steady temperature of 20 °C, 3 different stress levels, 20%, 30% and 40%, and using mid-span loading.The relative creep of the MDF panels was considerably higher than that in particleboards with similar characteristics. Creep behaviour of the raw panels seems to be strongly influenced by melamin coating of the boards' surfaces but not by the edge coating, except when both were combined.This study debates the convenience of comparing the rheological behaviour of MDF and particleboards by means of the relative creep.     

葵花秸碎料板生产工艺技术研究

对葵花秸碎料板的原材料收集加工、不同类型碎料的制备工艺过程及不同类型碎料对碎料板性能的影响等问题进行研究,探讨用葵花秸生产碎料板的生产工艺技术方案。     

杨木薄长刨花高密度板生产工艺的初步研究

研究热压温度、板材密度和施胶量3个生产工艺参数对薄长刨花板静曲强度、弹性模量、内结合强度及吸水厚度膨胀率的影响,得出最佳生产工艺条件。经过对实验数据进行分析,得出热压温度、板材密度和施胶量对刨花板各项物理力学性能均有一定的影响,其中板材密度和热压温度对板材各项物理力学性能影响最大。高密度刨花板最佳工艺条件为：热压温度155℃,板材密度0.88g／cm^3,施胶量12％     

石膏刨花板生产的工艺设计

由联邦德国科技部(BMFT)资助中国的项目“利用木质纤维生产人造板”,是由联邦德国弗劳霍夫木材研究所(WKI)和中国林科院木材工业研究所(CRIWI)承担。现进行了半干法生产石膏刨花板的工艺设计。为了确认原材料的适用性,中国派遣一名科技人员在WKI用中国原材料进行了试验。根据当地实际情况确定该厂的年生产能力。全部生产设备可分成热能生产、石膏煅烧和板生产三部分。     

Evaluation of particleboard deterioration under outdoor exposure using several different types of weathering intensity

The deterioration of particleboards for construction use was investigated by outdoor exposure tests at eight sites in Japan over 7 years. Two types of particleboard with different water resistances were tested and the deterioration of mechanical properties such as modulus of rupture, internal bond strength and lateral nail resistance was investigated. In order to eliminate regional differences in the board deterioration and also to standardize a deterioration factor for the board exposed to varying climate conditions, we introduced the weathering intensity (WI) defined by monthly precipitation multiplied by monthly average temperature. The significance of this factor was investigated by correlation analysis. Three conventional climate indexes relevant to the durability of wood were also investigated to analyze their significance to WI for particleboard deterioration. It was found that our definition of weathering intensity was the most accurate and the exposure period that reduces initial bending strength by half was calculated by the use of regression analysis for several different sites worldwide.     

几种防霉剂对提高非木材刨花板抗霉性能的研究

以17种防霉剂对竹材等4种非木材刨花板做了抗霉性能试验。结果8、9、7、6号防霉剂配方效果最好，分别施加这四种药剂的竹材等4种刨花板抗霉性能与落叶松刨花板相同，优于柳刨花板。将9号防霉剂施加于甘蔗渣、豆秸和玉秆刨花析对达到了较好的效果。     

不同热压方法对无胶竹碎料板力学性能影响

分别采用普通热压和喷蒸热压两种热压方法制备了无胶竹碎料板,对它们的物理力学性能进行了对比研究与分析.结果表明,与普通热压法相比,喷蒸热压法制备的无胶竹碎料板的静曲强度、弹性模量与内结合强度明显提高,吸水厚度膨胀率显著减小,这可能是因为两种热压法热压过程中竹碎料发生的化学变化不同所致.     

洋麻秆刨花板的实验室研究(Ⅱ)--胶粘剂体系和原料配比对板性的影响

采用异氰酸酯(MDI)和酚醛树脂(PF),试制了100％洋麻秆刨花板(密度:0.25、0.40、0.55、0.70、0.85g/cm3),即:KPB1(3％MDI)和KPB2(6％PF),以及“洋麻秆-雪杉”复合刨花板(KCPB,施胶量:3％MDI;密度:0.85g/cm3;洋麻秆替代率:0、20％、40％、50％、60％、80％、100％),根据ASTM D1037和ANSI A208.1标准测试和评价了板的性能。结果表明:(1)KPB1与KPB2的性能优劣与密度水平相关;(2)刨花板的施胶效率与密度密切相关;(3)洋麻秆与雪杉刨花可以任意比例混合,KCPB的性能不受明显影响。     

THE EFFECTS OF WETTING AND REDRYING CYCLE ON PHYSICAL PROPERTIES OF PARTICLEBOARD

INTR0DUCTI0NOvertheyearsmmpresearchershavefoundUFandPFparticleboardstoedsbitsimilarshorttermphysicalpropeniesatlowhumidityandtemperatUre(DeainandOstInan,l983).DifferentbehaviorpatternsbetWeentl1eresinsemefgeasrelativehumidityandtem-peratUrerise,finallycouldresultinthefailureofboards(R0dwell,l99l).AnumberofworkshavequestionedWhetherhydrolysisistheonlyfactorinvolvedinb0ndfailure.Irlereported(l986)thedifferenteffectsofwettingandredryingonthepropertiesofpureUFandPFresinfilms.Soitmaybeim…