橡胶木的防变色试验

通过不同浓度的不同防变色剂分别对未处理和经过硼防腐剂和Parachem防腐剂加压处理的橡胶木锯材进行浸沾处理，对其防变色效果进行了研究。结果表明，无论经过硼防腐剂处理与否，用防变色剂进行短时间（30s)的浸沾处理，均可有效地防止橡胶木的蓝变和发霉，保护期可达4周以上。     

樟子松生材的防霉防变色处理

近年来我国从俄罗斯进口大量樟子松木材，因新采伐的樟子松原木和湿锯材极易被霉菌和变色茵感染，在温暖潮湿季节引起边材严重变色而降等。为有效防止霉菌和变色茵的侵害，采用TBQ木材防腐剂对其进行防霉、防变色处理试验。结果表明：将湿锯材样品在6％TBQ溶液中浸泡1h后，其防霉、防变色效果可达到98％．说明TBQ木材防腐剂有良好的防霉、防变色效果。建议在木材产区或进口口岸制材并就地进行防霉、防蓝变处理后再运往国内市场。     

橡胶木胶合板阻燃技术研究 Ⅱ.WFR阻燃剂处理橡胶木胶合板的抗霉变效果

对已经ＷＦＲ１－２－ａ阻燃剂处理的橡胶木胶合板进行抗霉变效力测定，结果表明：处理试样对橡胶木常见表面霉菌有一定的防治效力，对蓝变菌的防治效力达１００％，未处理试样发霉变色严重     

橡胶木胶合板阻燃技术研究：Ⅱ.WFR阻燃剂处理橡胶木胶合板的抗霉 …

对已经ＷＦＲ１－２－ａ阻燃剂处理的橡胶木胶合板进行抗霉弯效力测定，结果表明：处理试样对橡胶木常见表面霉菌有一定的防治效力，对蓝变菌的防治效力达１００％，未处理试样发霉变色严重。     

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     

TMO防霉剂防止马尾松锯材发霉和蓝变试验研究

马尾松木材易发霉蓝变，造成材质下降，药剂防治是保护木材免受侵害的有效措施。用低毒ＴＭＯ防霉剂浸渍新鲜马尾松板材的试验结果表明，用０．３％－０．７％的ＴＭＯ水溶液浸渍３０分钟以上，即可有效地防止马尾松锯材发霉与蓝变。处理工艺简便，费用低。     

TMO防霉剂防止马尾松锯材发霉和蓝变试验研究

马尾松木材易发霉蓝变，造成材质下降，药剂防治是保护木材免受侵害的有效措施。用低毒ＴＭＯ防霉剂浸渍新鲜马尾松板材的试验结果表明，用０．３％～０．７％的ＴＭＯ水溶液浸渍３０分钟以上，即可有效地防止马尾松锯材发霉与蓝变。处理工艺简便，费用低。     

新型橡胶木防腐剂“TWP”研制成功

我国橡胶木防腐剂自1980年采用硼酚合剂以来,至今仍在普遍使用。海南省年产橡胶木约10万m~3,经防腐和干燥处理后出口,价值1000多万美元。但由于硼酚合剂含有25—35％五氯酚钠,具有刺激性气味。国外还发现氯化酚除莠剂中含有二噁英(dioxins)杂质,对哺乳类动物的毒性较大。1978年瑞典首先禁止使用五氯酚钠防治木材蓝变,接着日本,印度尼西亚以及其他国家也相继禁止或控制使用。我国也已把五氯酚钠列为高毒农药。目前,广东和海南等省通过进口防腐剂以代替硼酚合剂,化费大量外汇。因此,寻找新型不含氯化酚的     

苹果及橙类果实的生物防腐保鲜技术研究

用PRS5菌剂浸涂苹果的防腐保鲜试验表明：低温条件下，“PRS5菌剂 塑膜包装”、“PRS5菌剂 藕粉成膜”及“PRS5菌剂 羧甲基纤维素钠成膜”保鲜效果最优，120天的腐烂率仅为6．7％，相对防效达79．9％，以保鲜膜处理的苹果失水率最低，色泽新鲜。在恒温条件下，以“PRS5菌剂 塑膜包装”和“PRS5菌剂单独处理的效果最佳，120天腐烂率均为13．3％，相对防效达81．9％，但前者果实表面无皱缩，失水率较低。对脐橙而言，PRS5含量越高，防腐效果越好，失水率越低；PRS5菌剂经热处理后，相对防效可下降33．6％；一定时间内，防腐作用随处理时间的延长而增加。在自然条件下，对罗伯森脐橙的相对防腐效果(72天)高达95．15％，与优质化学防腐剂“施保克”效果相当。     

橡胶木防霉防蓝变药剂的现场试验

现场试验的结果表明，F1/F2混剂处理的橡胶木圆盘、单板的防霉及防蓝变效果较F2及五氯酚钠要好。F1/F2及五氯酚钠各制剂处理的板材基本上无霉菌感染及蓝变。在真空加压试验中，0.02?可保持橡胶木板材在气干过程中12天基本不霉变及蓝变，但对白霉的防治效果较差；0.0094?与0.018?混合剂可保持像胶木板材气干时15天不长霉或蓝变，增加F1/F2的浓度可能会在气干时保持更长的时间。     

Assessment of the properties,utilization, and preservation of rubberwood (<Emphasis Type="Italic">Hevea brasiliensis</Emphasis>): a case study in Malaysia

Rubber trees were introduced into the Malay Peninsula more than a century ago. The normal economical lifespan of a rubber tree is about 25 years, and, traditionally, rubberwood was used as firewood by the rural community. In recent decades, rubberwood has become an important timber for wood products, particularly in the furniture manufacturing sector, due to its attractive features, cream color, and good working properties. Sapstain, mold, and wooddecaying fungi are serious threats to rubberwood. Conventional chemical control has been a successful method of preventing staining fungal growth, but the effects of these chemicals are of concern because they create problems for the environment and public health. Thus, biological control has been recognized as an alternative approach to the problem. This article reviews the properties, potential utilization, and problems of protecting rubberwood against sapstain, mold, and wood-decaying fungi, and discusses the treatment methods available. Advances in biological control, particularly biofungicides, are emphasized as an alternative method for rubberwood treatment.     

Estimation of rubberwood production in Cambodia

We estimated the production of rubberwood from 1996 to 2011 in Cambodia. We employed data from interview surveys with three rubberwood processing companies and statistics from estate rubber plantations and wood retailing companies. The result was that the end use of rubberwood in Cambodia was the sawntimber products, being exported to Vietnam and China. The yield rate from rubberwood stumpage into sawn timber was between 11.6 and 14.9%, closely matching the rates of Malaysia and Thailand. The average production of rubberwood roundwood from 1996 to 2011 was 254,697 m³/year, of which sawn timber as well as residuals in secondary processing was 84,559 and 170,138 m³/year, respectively. Although the timber production of Cambodia has declined sharply due to the strict restriction of natural forest logging, rubberwood could explain more than 60% of the domestic industrial roundwood production from 2000. We suggest the necessity of monitoring the expansion of rubber plantations in new rubber producing countries and linking the rubberwood production with the regional wood resource management.     

Importance of rubberwood in wood export of Malaysia and Thailand

We examined the contribution of rubberwood to the timber export markets of Malaysia and Thailand. In Malaysia, rubberwood has grown from 26% of total exported wood products in 1998 to 35% in 2007. A high proportion of furniture products (80%) is rubberwood, whereas the contribution of rubberwood to other wooden products is less than 20%. Only 10% of sawn timber and logs is rubberwood. In Thailand, rubberwood contributes to around 60% of total exported wood products, arising from a high share of not only furniture products (70%) but also other wood products (around 50%) and sawn timber and logs, which have increased in share from 40% in 1998 to 79% in 2007. We conclude that the high proportion of rubberwood products in the wood export markets of these two countries is a result of: (1) scarcity of raw wood materials because of strict controls on the logging of natural forests; and (2) governmental support to rubberwood production, including financial support to rubber planters and technical assistance to downstream timber processors.     

Factors affecting the fungal colonization of pine lumber

This study investigated whether the physiological condition of wood influenced patterns of colonization by mould and sapstain fungi. The extent of fungal defacement on sawn pine lumber Pinus nigra var. maritima that had been killed by gamma‐irradiation was compared with the defacement on untreated, still living timber that had been aged for up to 16 weeks prior to being sawn. All the sawn lumber was exposed to the natural inoculum of sapstain and mould fungi in a working sawmill environment over a 4‐week period. The results indicated that the pattern of fungal defacement differed markedly in dead or aged wood compared with untreated wood. Mould fungi were most prevalent on the dead irradiated wood, whereas sapstain fungi dominated the freshly sawn lumber which was still living. The differences appear to be independent of wood moisture content and may be related to the production of inhibitory compounds by living cells in wood as it becomes senescent and dies.     

Potential for increasing volume yield by reducing planing allowance

About half the volume of sawlogs ends up as sawn and planed timber. The rest is lost due to drying shrinkage or is turned into by products. As the raw material is a major expense for a sawmill, it is important to reduce waste. To investigate how much the volume yield in the production of sawn and planed timber could be increased by reducing the target dimensions in the sawing stage in a sawmill, two groups of sawn timber were planed under similar conditions. One group consisted of sawn Scots pine timber with a large variation in twist. The other group consisted of sawn Norway spruce timber planed under different pressure settings. Using X-ray images, the minimum dimension for avoiding planer misses was calculated for each board, to find the smallest green target dimension. This was compared to actual measured dimensions. It was found that most sawn timber had unnecessarily large dimensions, and it was also found that a reduction in the target dimensions could increase the volume yield for sawn and planed timber by more than 3 percentage points. Boards with large twist would however need a higher planing allowance. The effect of the planer pressure setting was negligible.     

云杉属木材纵向和径向声振动特性参数关系的研究

采集7种我国具有代表性的云杉属木材及1种作对比用的美国产西加云杉试件,通过纵、横向木材试件在高次振动模式下的试验,测量木材各项声振动参数.研究发现:纵向材与径向材振动参数比之间存在着一定的相关性,据此可以选择各向异性适中,韧性好,纵向、径向振动受剪切影响小的木材制作乐器的音板.     

Combined production of sawn timber and firewood billets at a birch sawmill in Finland: A simulation approach

Abstract

Growing markets for chopped firewood have created alternative uses for the by-products of sawmills. Based on empirical data and simulated results, the potential of birch (Betula pendula Roth, Betula pubescens Ehrh.) from commercial thinnings for combined industrial production of sawn timber and firewood billets was investigated. In the simulations, different sawing patterns were used for logs intended to combine production of sawn timber and billets for chopped firewood (‘sawlogs’), and for logs intended only to firewood production (‘firewood logs’). Finally, economical feasibility analysis was done concerning the differences between the sawmills’ traditional business concept and the novel concept combining sawn wood and firewood production. The bucking results for the volume yield of different timber assortments varied only slightly between the different bucking options, i.e. the combinations of timber assortments. The main differences in the volumes of timber assortments were due to the stand type where the birch trees were sampled (planted, naturally regenerated, mixed birch–spruce). In the sawing procedure, the output of sawn timber varied between 24% and 42% of the log volume in the sawlogs, depending on the log diameter class. As the volume yield of sawn timber and firewood billets was counted together in the case of sawlogs, the log consumption was c. 1.75 m³ of roundwood per 1 m³ of sawn timber and firewood billets. In the case of the firewood logs, the log consumption rate was considerably lower, only c. 1.35. The economic calculations showed that using the firewood approach in sawing may increase the net added value of products by €1.9–5.4 m^?3 of logs, depending on their diameter class. As a conclusion, parallel production of sawn timber and firewood from logs from the first and second commercial thinning of birch-dominated stands is a concept that could work as an alliance between a sawmiller and a firewood entrepreneur. The concept could be competitive compared with both traditional sawmilling and production of chopped firewood.     

THE WATTLE BARK INDUSTRY

The growing stock in the artificially established pine plantations in the Republic, the different silvicultural systems under which they have developed and the bearing this could have on the quality of the timber are described briefly.

The timber characteristics responsible for the undesirable behaviour of sawn constructional timber on seasoning are discussed and the silvicultural and management systems which could be applied to improve the timber quality are briefly indicated. The role which tree-breeding could play in improving the quality and profitability of future tree crops is sketched.