胶合成材

胶合成材北京天昌木工有限公司１胶合成材所谓胶合成材，是指通过胶合拼接等方法，将小规格木材沿纤维方向相互平行接长、加宽、增厚，加工成在性质和外观上都保留了实木固有特性的一类大规格材。目前国内已有指接材，地板块和胶合梁等产品，但都以特定产品的名称命名，尚...     

短周期工业材指接压力与强度性能的研究

短周期工业材指接压力与强度性能的研究何林，李琳（黑龙江省林产工业研究所）在指接材的加工条件中。影响其强度性能的因素较多，压力是其中一个重要因素。若压力不足，胶层将变厚，胶合性能降低；反之，则易产生指榫根部劈裂和缺胶现象，引起胶合不良。因此，对指榫施加...     

指接胶合木经济分析

将短方材或短板材开指榫,经胶合即可形成指接胶合木。中国林业科学研究院木材工业研究所在湖北省某林场试验生产的指接胶合木,已经批量投产,产品用做载重汽车的纵梁垫木和车箱底板。指接木对生产原料没有太高的要求,只是在指接部位不允许有死节、腐朽、虫眼、夹皮等缺陷。指接木的原料,可以是间伐小径木、短轮伐期的速生木材、弯曲材,甚至可以是大枝丫材。在实际生产中,利用的原料段最短只有25cm,加工出的成品可达4m、5m或更长。所以,用指接胶合的方法,可以达到短材接长、小材大用的效果,有利于合理利用木材,提高人工林经济价值,缓和大径级材的供需矛盾。     

指接材研究现状与进展

概述国内外指接材的研究和发展现状,对指接材发展中存在的产品质量差、指接强度不高、指接接合不严密、材面质量粗糙等问题进行分析,从指接刀具、胶黏剂、指接材性能评估方法等方面提出今后的研究方向.     

落叶松指接规格材弹性模量的研究

研究指接、锯材等级对兴安落叶松结构用指接材弹性模量的影响,分析不同检测方法评估落叶松指接规格材弹性模量的可靠性。以落叶松锯材为原料,根据纵向基频振动(FFT)测试结果将其分为M_E12、M_E14、M_E16、M_E18四组,制备截面为40 mm×90 mm的规格材和指接规格材;分别利用纵向基频振动(FFT)、横向振动(TV)、机械应力分等级(MSR)测试评估指接材的静态弹性模量。结果表明:落叶松规格材和指接规格材是一种高弹性模量的锯材,其平均弹性模量大于SPF目测二级规格材的弹性模量;分级后,不同等级指接材弹性模量差异显著;指接加工降低中低等级锯材的弹性模量,但不影响高等级锯材的弹性模量;利用MSR测试结果评估指接材的弹性模量效果最佳,但其设备复杂,结合FFT设备的优点,推荐工厂使用FFT在线检测落叶松指接规格材的弹性模量。     

指接材指榫的加工方法

指接是木材纵向接长的一种有效方法，同时又是集成材加工的主要工序。其特点是短料长用、劣材优用，可提高木材利用率。主要用于成材的指按，指接地板、集成材、家具及门窗料等方面。指接工艺流程为：木料准备→工件两端铣削指标→指标涂胶→指接加压→指接材加工。影响指接材产品质量的因素之一为直列式指按。因为不管其中哪个指样破坏，整个指接村就破坏。菩其中一个指样可靠性低，则视为整个指接材可靠性低。因此，每个指样的强度高低直接影响到整个指接产品，从指接工艺流程来看，指样加工是影响指接强度的重要因素。为此，本文主要探讨…     

结构用指接材制造中工艺参数对齿梳表面粗糙度的影响（英文）

指接材齿梳加工后的表面粗糙度对指接材的胶合质量具有重要影响,它受木材密度等性能指标和刀具磨损时间等加工工艺参数的影响。笔者研究了不同齿梳类型对其表面粗糙度及结构用指接材胶合性能的影响。试验用规格材材种为加拿大黑云杉(Picea mariana),分为1500f-1.4E和2250f-1.9E两个等级。齿梳长度分为12.7和28.3 mm两种。指接材试件在刀具切削磨损10和60 min后获取。试验用Veeco三维非接触式光学轮廓检测仪测量了齿梳表面粗糙度,并以平均粗糙度(Sa)和均方根梯度(Sdq)表示。此外,用力学试验机测量了指接材的弯曲弹性模量(MOR)和极限拉伸强度(UTS),以评价其胶合性能。研究结果表明:齿梳部位的Sa随着木材等级、齿梳长度和刀具磨损时间的增加而显著增加,但Sdq没有明显变化;Sa可以用作评价齿梳部位表面粗糙度的一个主要指标;所选用材料和加工参数均能获得具有良好胶合性能的指接材;在研究所选参数范围内,齿梳表面粗糙度对指接材的MOE和UTS没有显著影响。     

新型木材指接设备

新型木材指接设备郝金城（黑龙江省林产工业研究所）指接是把短木接长的有效办法，它可以提高木材利用率，减少木材资源的浪费。指接材可作为室内装修和家具制作的非结构部件用材，也可作为结构承重部件用材。特别是包括指接工序的集成材制造的家具和指接地板，其材质优良...     

结构用指接材的研究现状北大核心

通过对建筑材料结构用指接技术的研究,介绍了指接技术概念,概括了木材结构用指接材齿榫几何参数、指接形式、指榫嵌合齿类型、以及胶黏剂的选择、施胶情况、层间接头距离研究与发展现状,拓宽了指接用木材的适用范围,讨论了指接用木材的适用性,此指接材相关适用性内容包括:胶接性能好坏、木材本身强度对指接部位强度影响、胶层厚度对指接材强度影响、层间接头距离对整体指接构件影响,并探讨了结构用指接材今后可能的研发趋势。     

立木芯胶合门板的研制

以杉木间伐材为原料锯切成小木芯块作为胶合门的芯层材料，研究了立木芯胶合门生产工艺参数对产品性能的影响，确定了优化的生产工艺条件。     

Determination of diffusion coefficients for sub-alpine fir

Estimates of the drying rate for sub-alpine fir lumber and the effect of process variables on final moisture contents are valuable information for kiln operators. The diffusion approach offers one generalized way to estimate the drying time required and the final moisture content distribution. The diffusion coefficients of normal wood and wet wood of sub-alpine fir lumber were determined by two types of approaches in this study: the traditional method and the inverse moisture diffusion algorithm. The results from both approaches indicate that the diffusion coefficient of normal wood is greater than that of wet wood for sub-alpine fir.     

25mm厚进口桃花心木干燥基准的优化

采用实验室干燥试验设备,按企业生产干燥基准进行25 mm厚桃花心木干燥试验,并通过锯材干燥质量检测和分析,制定出常规干燥基准的优化方案。结果表明:采用优化的干燥基准,干燥周期由企业原基准的12 d缩短为6 d,干燥效率提高一倍,残余干燥应力值显著降低,锯材综合干燥质量由3级提升至2级,可满足家具、地板等实木制品对锯材质量的要求。     

Experimental Study on Sawing Characteristics of Planted Eucalyptus grandis

INTRODUCTION Eucalyptus plantations have been important plantations in South China for its fast-growth rate. And the overall planted area is beyond 1.6 million ha, mainly distributed in the provinces of Guangdong, Guangxi, Yunnan, Fujian, etc. But, the main utilization is limited to wood chips currently. Along with the natural forest protection policy implementation, the wood resource has transferred from the natural forest to plantation forests, and the value-added application of plant…     

Calculation of CFP and verification of effect on CO2 emission reduction for the use of certified wood in Kyoto Prefecture

The representative carbon footprint of product (CFP) value of “certified wood in Kyoto Prefecture” was calculated as 241?kg-CO₂/m³. The CFP value was 158?kg-CO₂/m³ when wood was not kiln dried and final processing was not involved, whereas that of “kiln-dried, finished wood” was 284?kg-CO₂/m³. Comparisons of different types of wood were also conducted to examine CO₂ emission-reducing effects of “certified wood in Kyoto Prefecture”. We compared the CFP of lumber produced (in Japan) from logs supplied from Japan and other countries and that of “certified wood in Kyoto Prefecture”; the lumber products as a target for comparison are shipped to markets throughout the country. The CFP of “certified wood in Kyoto Prefecture” was approximately 50% lower compared to that of North American wood lumbered in Japan and shipped to markets throughout the country, and about 30% lower compared to the mean CFP of lumber produced (in Japan) from logs supplied from Japan and other countries and shipped to markets throughout the country. We then compared the CFP of “products imported from other countries after being cut into lumber” to that of “certified wood in Kyoto Prefecture”. The CFPs of lumber products from North America and Europe were lower than that of “certified wood in Kyoto Prefecture” (kiln-dried, finished wood). However, when only woodchips were used as a heat source in the process of kiln drying, the CFP of “certified wood in Kyoto Prefecture” was lower than any other kiln-dried lumber products. Regarding “certified wood in Kyoto Prefecture”, the use of woodchips as a heat source in the process of kiln drying or a shift to air drying decreases the CFP.     

控制锯材变形的方法

针对影响锯材变形的因素。从降低原木残余生长应力、对干缩湿胀和干缩应力的干燥工艺处理，到下锯法的合理选择，以及通过木材改性达到尺寸稳定等几方面进行了全面探讨，为提高锯材和木材品产品质量供参考。     

杉木生材含水率分布及其对气干的影响

以人工林杉木为研究对象,研究生材状态下不同厚度锯材含水率的差异,比较含髓心、钝棱与其他类型等3类锯材的含水率差异,建立生长轮宽度与锯材含水率的关系,分析生材状态含水率对锯材气干周期的影响。研究结果显示,25mm和40 mm的锯材含水率差异极显著;含髓心锯材含水率最低,其次是其他类的,最大是含钝棱锯材;随着生长轮宽度减少,锯材含水率增大;生长轮宽度为4 mm时,是生材含水率分界线,即当生长轮平均宽度小于和不小于4.0 mm时,锯材含水率差异极显著;25 mm和40 mm厚不同含水率锯材各2组气干至含水率25%,低含水率锯材较高含水率的气干周期分别缩短57%和66%。     

提高集成材出材率的措施

集成材生产是木材综合利用的有效途径,是木材加工业的重要组成部分,我国集成材生产中普遍存在出材率低、成本高、影响经济效益等问题,结合我国集成材生产实践,提出几点提高集成材出材率的措施。     

Modeling lumber yield of white spruce in Alberta,Canada: a comparative approach

Estimation of lumber yield from a forest inventory is important in determining the optimal utilization of available regional wood supply. In this study, we review existing approaches of lumber yield estimation, including knowledge-based empirical board-foot log rules used in the United States and some regions of Canada, survey-based wood conversion factors, and optimization technology-based computer simulations. Lumber yields estimated from different approaches are then compared using six datasets from a white spruce commercial thinning experiment in Alberta, Canada. Our results indicated that (1) estimated lumber yield can be significantly different when different methods are employed; (2) board-foot log rules often underestimate lumber yield; (3) wood conversion factors represent regional average of lumber yield as a constant and thus are unsuitable for forest inventory-based lumber yield estimation; and (4) optimization technology-based computer simulations can provide the best estimate of lumber yield for a given forest inventory as long as the mill conditions and lumber dimensions from market demand are specified. Forestry investment in applying computer simulation methods should be encouraged in sawmill operations to improve lumber yield and enhance environmental protection, because, for a given amount of lumber, improving lumber yield means reduced demand for harvest operations.     

The temperature and moisture content in lumber during preheating and drying

Summary The time required to thoroughly preheat/presteam green 8/4 (51 mm) thick red pine and white birch lumber was determined. Thermocouples imbedded in the centre of samples were used to determine presteaming/preheating times for experimental material. These data were then compared to time determined by analytical methods (using formulae developed by Kollmann). No significant differences were found.During the subsequent drying period data were collected on interior wood temperature, mousture content and gradient. Results of the drying tests indicated: i) interior temperature increases in direct relation to elapsed time, ii) moisture content drops exponentially with elapsed time, and iii) an exponential relationship exists between average moisture content and the core temperature of the lumber.Results indicate that monitoring of the lumber drying process through measurements of interior wood temperature may be feasible.The first author was visiting Canada under the Chinese Scholar Program established by the Council of Ministers of Education, Canada. His research work was carried out at Forintek Canada Corp., Eastern Laboratory, OttawaThe authors would like to acknowledge the assistance and support of the following: Dr. M. Y. Cech, Manager, Lumber Manufacturing Technology, Forintek Canada Corp., Eastern Forest Products Laboratory-Senior Project Supervisor, and Mr. F. Pfaff, Research Scientist, Forintek Canada Corp     

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.