基于灰度直方图分析的原木CT图象分割

通过断层扫描成象技术,非破坏地探测原木内部结构的数据信息,并将其图象化。首先将原木CT图象中冗余信息进行去除处理,对处理后CT图象再用灰度直方图方法进行分割,确定原木CT图象中背景、各种缺陷、树皮以及无疵木材的灰度分布。基于灰度直方图的图象分割,可为原木内部缺陷的自动识别打下基础,进一步可为合理确定原木用途和加工方案提供帮助。     

木材的变色及其预防和控制

1木材的变色及其种类 木材变色,简单地说,就是由于受环境(阳光、氧气、水份、温度)和微生物(真菌)的作用,其表面发生的颜色变化。原木、锯材、木制品都可能发生变色。树木砍伐后,原木端头及不完好树皮下容易发生变色。原木加工后,锯材(板材、方材)在存放、加工过程中,也容易发生蓝变、褐变、霉变等。木材制成木制品后,在使用过程中仍有可能发生变色。木材颜色变化的种类很多,从木材本色(白色/淡黄色/浅褐色等)变为粉色、红色、蓝色、绿色、灰色、深灰色、褐色、灰褐色、深褐色、黑色等等。     

连续式圆筒剥皮机在齐齐哈尔造纸厂的使用情况

我厂是以木材为原料生产新闻纸的纸厂,三十多年来,原木加工一直采用滚刀剥皮机和手工剥皮。滚刀剥皮机剥皮木耗高达5—7％。手工剥皮木耗虽在1.5％左右,但劳动强度大,效率低;而且冬天树皮因受冻,不易剥掉,冬春两季只得用滚刀剥皮机剥皮。因此降低原木剥皮木耗,提高效率,减轻工人的笨重体力劳动,是我厂的一个重要课题。1975年扩建时,轻工     

国外期刊论文摘要

Ｔａｐｐｉ Ｊｏｕｒｎａｌ—２００１，Ｖｏｌ．８４，Ｎｏ．１利用图像分析来确定剥皮制浆木材中的残留树皮Ｄｅｔｅｒｍｉｎａｔｉｏｎ ｏｆ　ｒｅｓｉｄｕａｌ ｂａｒｋ ｉｎ ｄｅｂａｒｋｅｄ ｐｕｌｐｗｏｏｄ ｕｓｉｎｇ ｉｍａｇｅ ａｎａｌｙｓｉｓ 研究提出了一种新的、自动测定木片中的残留树皮的方法。此方法是根据从均匀切碎的木材中所得到的影像从而确定残余树皮 主要概念是通过对目标原料的均匀化从而避免复杂的影像处理。此法的另一个优点是与整根原木或木片流成像的方法相比，目标范围很小。这就减小了所需的影像组分数量…     

一种自动输送截木机

针对现有原木锯切加工中存在的问题,设计了一种集自动输送、自动卡紧及自动锯切于一体的自动输送截木机,可有效提高木材加工的生产效率,降低劳动强度,提升原木锯切加工过程的安全性及平稳性。     

佳木斯造纸厂积极利用林区“四剩物”

佳木斯造纸厂是个年产17万吨浆纸的综合性制浆造纸厂,每年耗用木材80多万米~3。为了降低木材消耗和生产成本,他们在改造大口径原木削片机并开展回收利用短材和扭曲严重、不易劈开的根节     

国内首个微波处理集装箱载进境原木示范工程落户大连

正据《大连日报》9月18日报道,辽宁检验检疫局9月16日与清华大学、大连港集团在北京举行"辽宁大连口岸微波介电加热处理项目研发"签约仪式。国内首个微波介电加热处理集装箱载进境原木示范工程正式落户大连保税区,将推动大窑湾口岸集装箱装载高货值阔叶树材进口贸易。按照现行政策规定,带树皮的原木须在国外完成检疫处理后方可进境。由于国外对原木的熏蒸处理存在价格高、效率低等问题,已成为我国进口原木的主要瓶颈。而目前国内外普遍采用的原木检疫处理方法     

环式剥皮机剖析

制材用原木经剥皮后再锯剖有利于判断锯口、保护锯条、提高制材效率;量材时利于判断,贮存时有利于防止虫蚀。当剥皮作业能很好地组织进原木楞场工作流程时,也可直接在制材企业进行,同时剥下的树皮又可提供多种用途,因而在许多制材较发达的国家早已将原木剥皮工序作为现代化原木楞场的一个固定组成部分。     

计算机模拟离散原木最优定心理论方法的研究

为了提高木材的利用率和经济效益 ,精确确定原木的回转中心在木材加工生产中是十分重要的。本文系统研究了计算机模拟离散原木定中心的理论方法。结果表明 ,利用计算机强大的图形处理和计算及逻辑判断能力 ,可极大的提高原木的定心精度。该研究在实践应用中具有重要价值。     

CT技术在木材工业中的应用

介绍了作者应用CT技术实现原木内部缺陷的无损检测、原木图象的三维重建和虚拟加工、以及木材内部密度和干燥过程中水分的分布等方面的初步研究成果,并对CT技术在木材科学研究中的一些问题和工业中的应用前景作了探讨.     

木浆生产线的备木技术

介绍了当前广泛应用的备木生产线中原木剥皮、削片、木片筛选、过大木片再碎、木片贮存、树皮及木屑处理以及原木冲洗等系统的特点,通过分析不同剥皮鼓的喂料及卸料方式、不同削片机的喂料及卸料方式以及各种备木生产设备运行的情况,对备木设备的改进以及设备布置的方式提出了一些建议。     

木材备料方案的选择

介绍了近年来部分引进的木浆生产线的原木备料系统的流程和设备.     

Impact of Aspen Log Storage with and without Protection on OSB Performance

Outdoor log storage without protection can change the mechanical and chemical properties of wood due to infection by various fungi. To understand how outdoor log storage affects the wood and, subsequently, the strandboard quality, two piles of aspen logs were set up outside and stored for a period of four months (July to November). One of the piles was treated with a biological solution to prevent fungal growth. The other one was stored without treatment. Both piles contained non-debarked and partially debarked logs. Evaluation of sap stain development indicated that all logs had been colonized by staining fungi with average stain coverage of 9.37 to 57.18% and maximum stain penetration of 3.58 to 7.27 cm over the log cross section. The variation of fungal colonization depended on log treatment and bark condition. The most effective way to prevent stain growth was the combination of biological treatment and partial debarking. A series of strandboard was prepared from fresh and aged aspen logs. All boards made from stored logs were statistically comparable to or superior to the control boards made from fresh aspen logs. The boards made from treated/partially debarked and untreated/non-debarked logs were statistically comparable to each other except for wet MOR. In addition, these two board types were statistically stronger than other boards made from treated/non-debarked and untreated/partially debarked logs in terms of IB and water resistance. Some individual stained strands were observed on the finished board surface. Less staining was found in the boards prepared from biologically treated and partially debarked logs, compared with those made from other stored logs.     

大叶相思制CTMP及配抄箱纸板

对大叶相思木材的纤维形态、化学组分进行了分析,并对木材制CTMP及其配抄纸板进行了研究。结果表明,此种木材虽纤维长度偏短,但纤维系含量较高,壁腔比小,木素含量高,采用NaOH和Na2SO3 混合液浸渍的一般磨浆工艺能生产出高得率的CTMP,配抄箱纸要的以质量符合国家要求。     

Utilization of bark flours as additive in plywood manufacturing

Increasing demand for wood based panel products and shortage of wood as raw material have triggered many efforts to utilize residues generated annually by the forest industries including a large portion of bark in panel production. In this study, the effects of using bark flours as additives obtained from different wood species (walnut, chestnut, fir and spruce), having much polyphenol content, on some physical and mechanical properties and formaldehyde emission of plywood panels were examined. Wheat flour, which has been used widely as additive in plywood manufacturing, served as control. Plane tree (Platanus orientalis) logs were obtained for veneer manufacturing. Urea formaldehyde (UF) resin with 55 % solids content was used as adhesive. The bonding shear strength, bending strength, modulus of elasticity (MOE), density, equilibrium moisture content and formaldehyde emission of plywood panels were determined according to related standards. It was found that the use of flours obtained from the barks of chestnut and fir trees in the glue mixture decreased the formaldehyde emission of panels. The bonding strength values of the test panels made using the glue mixture including the flour of walnut and spruce barks as additive were lower than those of the panels with adhesive containing the flour of fir and chestnut barks. The panels manufactured with adhesives including the flour of fir bark gave the highest bending strength and modulus of elasticity values.     

Behavior of Decayed Spruce (Picea abies) during Kraft Pulping

This study indicated that by applying an improved classification system to decayed large-diameter Norway spruce (Picea abies) wood, its use as raw material for kraft pulping without loss of pulp quality could be essentially increased. This is based on the fact that although the cooking yield of decayed spruce material which has been sorted according to these new recommendations is somewhat lower and Kappa number higher than those of sound wood material, the greatest part of the decayed stem (the outer part of the stem) contains long-fiber wood material which produces pulp of good quality. Therefore, large-diameter spruce logs can also be separately used, for example, in the manufacture of reinforcement pulp.     

Roundwood pre-grading with longitudinal acoustic waves for production of structural boards

The assessment of timber quality at any stage of the production chain promises to be an advantage for the forest and timber industry. This paper presents results of wood pre-grading by means of the dynamic modulus of elasticity, which was performed along the complete processing chain—from standing trees to sawn timber. The measurements were conducted on 154 forty-year-old trees of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) from two forest experimental stands in Southern Germany. Long logs of about 13 m were bucked into short logs of 4.1 m; the dataset contained 1,820 boards cut out of 332 short logs. Pre-grading was performed at different levels: standing tree, long log, and short log. The boards were machine strength graded by a ViSCAN-COMPACT grading machine. The investigation showed high correlations between different stages in the production chain of timber. For strength classes C24 and C30 an increase in yield of about 10 percentage points by rejecting the 25 % worst logs (short or long) was observed. It did not matter if pre-grading was realized at the stage of long logs or short logs. However, methods of pre-grading at standing tree must be improved to obtain reliable prediction of dry sawn timber quality of managed forest stands (r² = 0.17).     

思茅松热处理木材吸湿率的研究

采用油浴法对思茅松木材进行热处理工艺的研究,从而分析研究热处理后思茅松木材的吸湿性.     

浅析实木弯曲及其软化处理技术

为了使方材弯曲成型能顺利进行,软化处理是必备的一个环节。本文从方材弯曲的原理出发,分析了弯曲技术及木材软化处理的一些方法。     

提高木材干燥质量与效率——QC小组活动一例

通过在企业中开展QC小组活动,各部门相互配合,不但使相关人员工作主动性和工作技能得到提升.而且有效地提高了木材干燥生产的质量与效率。