家具和地板用浸渍改性杉木研究进展

杉木是我国南方重要的速生林树种之一,但其木材存在诸多缺陷,极大地限制了其在家具、地板中的进一步开发利用。将杉木进行浸渍改性以提高综合利用率是解决全球木材的供需矛盾和家具、地板用材短缺的重要手段之一。浸渍改性目前主要应用的树脂有UF树脂、PF树脂、聚乙烯醇缩甲醛、MF树脂等,其中以PF应用较常见,其改性效果较为显著。浸渍改性过程中,主要有真空处理、真空加压、抽提后常压浸渍或真空浸渍等浸注方法,辊压浸注作为常温常压条件下高效快速浸注处理木材的方法也可用于杉木的浸渍改性,真空-叠压法既能保证改性药剂完全渗入杉木木材,也能防止杉木试材在压力下被压溃。不同的浸渍工艺参数和树脂固化条件对改性后杉木性能影响不同:浸渍时间对浸渍材的吸水率及吸水厚度膨胀率影响较大,热压温度、热压时间与压缩变形恢复率、静曲强度密切相关,各工艺因素间存在一定的相互关系和影响。最后讨论了浸渍改性杉木在家具、地板业中的发展方向与应用前景,为杉木浸渍改性的进一步研究和应用提供参考。     

PF树脂浸渍ACQ防腐杨木的基本特性

采用低分子量酚醛树脂对ACQ防腐后的速生杨木进行浸渍处理、干燥定型后制得改性材.试验表明,ACQ防腐处理对酚醛树脂的浸渍没有影响,PF树脂对杨木具有较好的浸注性,但不同杨木试件的浸注性差异较大.通过分析杨木自身材性及试件不同尺寸与增重率的关系,发现不同的杨木树株和木材纹理对杨木浸注性有显著的影响.     

热固性树脂真空加压浸注工艺条件的研究

以西南桦和械木为研究对象，探索不同种类的热固性树脂和不同浸注条件与树脂浸入量和改性材尺寸稳定性的关系。研究结果表明，不同树脂，甚至同一树脂对不同树种的木材具有不同的浸注性，其浸入量随加压浸注时间的延长而增加；木材心边材对树脂的接收能力有所不同；木材性能的改善程度因树种和树脂浸入量而异。     

UF树脂浸注改性橡胶木的物理力学性质

采用尿素-甲醛(UF)共聚树脂浸注处理人工林橡胶树(Hevea brasiliensis)木材,分析树脂增重率(WPG)对各项物理力学性能指标的影响。结果表明:UF树脂浸注对橡胶木的密度、平衡含水率(EMC)、湿胀性和硬度改善明显,并且WPG越大改善效果越好;而对弹性模量(MOE)和冲击韧性影响或高或低,且变化幅度有限;对抗弯强度(MOR)的影响,低WPG时不明显,而在高WPG时提高明显。     

天然有机物改性木材工艺条件研究

用天然有机物木材浸注液对杉木、湿地松、藜蒴、南洋楹、马占相思等5个树材进行了真空加压浸注试验,结果表明在同样试验条件下,不同的树种其增重率不同,其中杉木最高达64.6%,最低的是南洋楹,只有23.8%;经处理的木材,密度都有增加,可以提高处理材的力学性能。     

浅谈辊压法木材防护浸注技术

简述了国内外木材浸注技术的最新研究进展;重点论述了木材防护浸注厅法--辊压法,讨论了辊压法的浸注原理,以及与传统木材浸注方法--真空加压法在设备、工艺方面的比较,明确了控制压缩率的重要作用,并尝试应用计算机图像处理技术测量计算木材体积空隙率来确定压缩率,建议辊压浸注处理大青杨时,压缩率可试取50％及以下。     

短周期桉树与相思人工林木材处理性及浸注性研究

通过测定４－９年生的桉树和马占相思木材密度，并用５％ＣＣＢ防腐剂以常温常压浸泡法，热冷槽法及劳菜空细胞加压进行防腐处理，再测定处理材的防腐吸收量及渗透深度来评估木材的处理性及浸注性，结果表明，１．速生人工林的赤桉，尾叶桉，马占相思木材属较难处理性木材；２．ＣＣＢ防腐剂对桉树和马占相思木材有浸注性较好，硼渗透较深且均匀，铜较浅．３．可用热冷槽法和加压法对木材进行防腐处理，这有利于药剂的渗透及提高工效     

不同干燥方法对杉木人工林木材浸注性的影响

采用高频真空干燥、常规窑干和高温干燥3种方法对杉木人工林木材的心、边板材进行干燥处理,用毛细管上升法评价干燥后试样的浸注性能,用半薄切片法测定干燥试样具缘纹孔的闭塞率,最后用扫描电子显微镜观察干燥试样微观构造的变化,比较分析3种干燥方法对杉木人工林木材浸注性的影响机理.结果表明:对于杉木边材,经高频真空干燥后试样的浸注性显著高于常规干燥和高温干燥后试样的浸注性,后2种干燥方法对试样浸注性影响的差异并不显著;对于杉木心材,高频真空干燥与高温干燥后试样的浸注性存在显著差异,而高频真空干燥与常规干燥之间、高温干燥与常规干燥之间对试样浸注性的影响差异均不显著;3种干燥方法处理后,杉木边材的浸注性均显著高于心材的浸注性;具缘纹孔的闭塞率较低以及部分具缘纹孔周缘破裂是高频真空干燥后木材浸注性提高的主要原因.     

人工林杨树木材液体纵向渗透性研究

通过系列化试验，用常压和减压浸渍的方法，研究了人工林杨树木材的渗透工艺及工艺参数对纵向渗透性能的影响。试验结果表明：（1）真空浸渍优于常压浸渍；（2）渗透剂的加入对杨树木材的液体纵向渗透性有很大的影响；（3）增加浸渍时间，可显著增大深度，浸渍24h渗透深度是浸渍4hN10倍，但再延长时间效果不明显；（4）提高染液温度在较短的时间内能较好地改善杨树木材的渗透性，染液温度达到95℃时，纵向渗透深度最深可达38mm。染色的最佳温度为85～90℃。     

西南桤木木塑复合材料处理工艺的研究

以西南桤木作为试材,注入不饱和烯烃类单体。通过正交试验,分析了真空度、真空时间、浸注压力和加压时间4个因素对木材单体留存率的影响。并用光学显微镜和扫描电镜检测浸渍处理后高聚物在木材细胞壁内的分布情况。提出了较为理想的西南桤木木塑复合材处理工艺参数,能初步实现西南桤木木塑复合材的有效制备。     

Preparation of Chinese fir wood/MMT nanocomposites and the factors affecting it

The nano intercalation compounding of wood and MMT has important implications for the modification of wood and for the development of new materials. With water-soluble phenol formaldehyde resin as an intermediary, the nanocomposites of Chinese fir (Cunninghamia lanceolata) wood and montmorillonite (MMT) were prepared via three impregnation methods, i.e. normal pres-sure, once and twice vacuum methods. Based on the weight percent gain (WPG) of impregnated wood, the effects of compounding wood and MMT in term...     

Manufacture of compressed wood fixed by phenolic resin impregnation through drilled holes

An aqueous solution of phenolic resin was impregnated through drilled holes in wood, and we manufactured compressed wood with the deformation fixed by the phenolic resin. The methods of impregnation used in this study were an in-liquid platen-pressing method and a vacuum treatment. The effect of the drilled holes on solution retention was examined. Moreover, the control of solution retention was examined under the application of compression drying. The impregnation of resin into the specimens without drilled holes was insufficient, and the deformation could not be fixed. On the other hand, sufficient impregnation was possible in the specimen with drilled holes, and the deformation fixation was observed. At the stage of compression when the solution was squeezed out of the specimen, the solution retention of each specimen was accurately controlled in the specimens with drilled holes. At the stage of compressive deformation and deformation fixation using a hot press, the specimens without drilled holes could not be processed normally because swelling occurred. However, swelling did not occur in the specimens with drilled holes. Part of this report was presented at the 16th Annual Meeting of the Chubu Branch of the Japan Wood Research Society in Matsumoto, November 2006     

不同浸渍处理方式对毛竹淀粉含量的影响

采用常压水浸渍、真空水浸渍、常压碱液浸渍3种浸渍方式对毛竹进行处理,探讨不同浸渍方式对毛竹中淀粉含量的影响。研究结果表明:竹材内淀粉含量随着浸渍处理时间的延长而减少,经过120 h浸渍后,毛竹中的淀粉含量从高到低依次为常压水浸渍、真空水浸渍、常压碱液浸渍。在相同碱液浓度的条件下,毛竹中的淀粉含量随着浸渍时间的增加而减小。经过120 h的碱液浸渍处理,碱液浓度最大(1.5%)的组溶解抽提出来的淀粉含量最多。真空水浸渍可以降低毛竹中的淀粉含量,但不同真空压力之间对淀粉含量的影响不大,真空压力对淀粉含量的影响有效时间为72 h以内,超过72 h淀粉含量减少缓慢。     

Study of the transverse liquid flow paths in pine and spruce using scanning electron microscopy

Samples of pine (Pinus sylvestris) and spruce (Picea abies) were impregnated with a low-viscous epoxy resin using a vacuum process. The epoxy was cured in situ and the specimens sectioned. Deposits of the cured epoxy was then observed in the wood cavities using a scanning electron microscope. The investigation concentrated on tracing the transverse movements of a viscous liquid in the wood, and special attention was therefore given to the cross-field area between ray cells and longitudinal tracheids. A damage hypothesis is proposed based on the results obtained in the present investigation in combination with those from earlier studies on linseed oil-impregnated pine: In addition to the morphology of the bordered pits, viscous liquid flow in wood is dependent on damage that occurs during the impregnation procedure. For pine sapwood, liquid flow is enabled through disrupted window pit membranes, which divide the longitudinal tracheids and the ray parenchyma cells. A mechanism accounting for the reduced permeability of pine heartwood is believed to be deposits of higher-molecular-weight substances (extractives) in the ray parenchyma cells and on the cell walls. In spruce the thicker ray cells in combination with the smaller pits, which are connected to the longitudinal tracheids, reduce permeability considerably.     

The influence of curing conditions on the chemical distribution in wood modified with thermosetting resins

Scots pine (Pinus sylvestris L.) sapwood was impregnated with aqueous solutions of phenol formaldehyde and methylated melamine formaldehyde resins and subsequently cured in an oven. One set of specimens was cured in plastic bags to avoid drying (wet curing) while another set of samples was heated and water was allowed to freely evaporate (dry curing). Macroscopic resin distribution was investigated using X-ray densitometry and infrared spectroscopy (FTIR-ATR). During dry curing, the resins migrated to the wood surface resulting in a gradient. Wet curing resulted in even distribution of the resins because it was immobilized due to condensation and precipitation in the wood. Neither densitometry nor FTIR-ATR was found to be generally applicable for investigating resin distribution in modified wood. Wet curing resulted in low cell wall bulking as compared to dry curing, probably because resin precipitated before drying. Storing impregnated wood prior to curing under non-drying conditions (“diffusion phase”) also reduced cell wall penetration and bulking.     

改性辐射松木材物理力学性能研究

研究了辐射松树脂浸渍材与热空气热处理树脂浸渍材、热压热处理树脂浸渍材的物理力学性能,为后续辐射松改性处理和加工利用提供参考。结果表明:相对于未处理材,浸渍处理提高了木材的密度、尺寸稳定性、力学性能;相对于浸渍材,热处理可进一步提高尺寸稳定性,但一定程度降低了力学强度。     

电气石/木材复合材制备及微观结构分析

电气石具有释放负氧离子等特殊功能,可以改善环境质量以及促进各种产品的功能化。本研究将电气石以浸渍的方式引入木材中,通过树脂固化的方式将其固定于木材内部,从而得到具有释放负氧离子的功能性木质材料。利用满细胞法,经MUF处理,电气石浓度在5%,偶联剂浓度为4%,浸渍时间为60 min,木材浸渍增重率达到36.9%且分布均匀,负氧离子释放量约为1 086个/cm^3。PEG处理材流失率为15.7%,MUF浸渍处理材的流失率仅为1.3%。     

真空浸渍法制备纳米Ag/TiO_2木基复合材料的工艺优化

近年来,纳米Ag/TiO_2防霉剂因具有化学性质稳定、催化活性高、成本低、环境友好等特点而受到广泛关注。但纳米Ag/TiO_2极易团聚,其使用范围和效果受到了限制。笔者采用真空浸渍法,得出纳米Ag/TiO_2防霉剂浸渍木材的理想工艺和防霉性能。通过直观分析和方差分析探究真空度、真空时间、防霉剂浓度三因素对樟子松载药量和抗流失率的影响。采用模糊数学综合评判法对载药量和抗流失率进行综合评判。研究发现,防霉效果较浸渍前提高14.5倍,防治效果达到96.67%。     

有机/无机复合浸渍液对杨木的改性处理

利用脲醛树脂／丙烯酸酯乳液／硅溶胶三元复合浸渍液制备复合木材,并与杨木素材为对照。采用红外光谱研究复合木材的组成变化,热分析研究其热稳定性的变化,并研究了复合木材的力学性能。结果表明,杨木中的功能基团与复合浸渍液中的脲醛树脂可发生键合作用,使改性木材的热稳定性及力学性能均有所提高。     

Impregnation of Scots pine and beech with tannin solutions: effect of viscosity and wood anatomy in wood infiltration

The impregnation process of Scots pine and beech samples with tannin solutions was investigated. The two materials involved in the process (impregnation solution and wood samples) are studied in depth. Viscosity of mimosa tannin solutions and the anatomical aspect of beech and Scots pine were analysed and correlated. The viscosity of tannin solutions presents a non-newtonian behaviour when its pH level increases, and in the case of addition of hexamine as a hardener, the crosslinking of the flavonoids turns out to be of great importance. During the impregnation of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.), the liquid and solid uptakes were monitored while taking into consideration the different conditions of the impregnation process. This method allowed to identify the best conditions needed in order to get a successful preservative uptake for each wooden substrate. The penetration mechanism within the wood of both species was revealed with the aid of a microscopic analysis. Scots pine is impregnated through the tracheids in the longitudinal direction and through parenchyma rays in the radial direction, whereas in beech, the penetration occurs almost completely through longitudinal vessels.