随弯锯机与普通锯机模拟锯解弯曲原木的比较

把数控技术应用于制材行业，建立了数控随弯锯机和普通锯机下锯图模型，应用ＴｕｒｂｏＣ语言自编程序，优化出随弯锯机与普通锯机的下锯图方案，经比较分析，应用数控随弯锯机锯解弯曲小径级原木，可明显提高原木出材率。     

小径木削片制材工艺及设备

小径木削片制材工艺及设备该成果采用自行研制的ＭＱ２８７小径木削片制方机，与剥皮机、ＭＪ３２１２跑车带踞机、ＭＪ３１１０带据机、ＭＪ１４３多锯片分锯及其他配套设备组成小径木削片制方与制材复合生产线，或与剥皮机、双轴多锯片裁分锯、单轴ＭＪ１４３多锯片裁分...     

浮动导向木工圆锯的研究

浮动导向木工圆锯的研究路鹏程，陈欣，习宝田１圆锯制材的发展前景圆锯是木材加工中应用最广的通用设备。用圆锯加工原木或毛方时，据统计：一般锯片直径在６００ｍｍ以上，锯片厚度３～５ｍｍ，锯口宽５～７ｍｍ；其锯材的锯割偏差０．７～１．０ｍｍ，锯痕高（表面粗糙...     

双联圆锯径切板优化下锯研究

面对我国森林资源不足、质量不高的状况,研究和应用优化下锯理论实现原木最优下锯,提高木材出材率已成为缓解木材供需矛盾的重要途径之一。本文提出了以最优化技术为基础的原木优化下锯法,以最小余料为目标函数的原木优化下锯方法,采用解析法建立原木优化下锯数学模型,通过计算机辅助排样求解,得出了一种基于梯形下锯法锯切原木的优化下锯算法,为数控双联圆锯径切板优化下锯提供了数学方法和基础,并给出应用实例。     

捷克采用无锯屑制材机

捷克一些制材厂采用了一种无锯屑制材机锯解原木。这个制材机系由10个旋转轴粗锯片纵割所组成。锯解原木时,只生产木片,而无锯屑。这样就可使针叶锯材原木得到要充分的利用。每生产10万立方米的锯材,大约可得到8,500立方米的木片,供生产刨花板(见图1)。     

原木裁板皮过程的建模理论与仿真方法

带锯制材的第一道工序就是裁板皮,数控带锯机的裁板皮过程必须进行软件设计,而软件设计的基础是数学理论的建立,提出板皮裁边的数控加工数学模型、仿真加工过程,为板材最优下锯提供计算机编程方程,为视频再现提供数学方法,为板皮锯切、板皮材积精确检测提供理论依据,为数字化控制提供理论.通过数控技术与现代制材工艺结合,将使传统木材加工工艺数控化,可以推进木材工业加工过程中计算机数学描述研究的发展,推进木材工业加工过程数学描述研究理论的开展.     

行业简讯

新型原木加工高效双轴圆锯为满足现代木材加工对高效率和灵活性的要求,一种将原木锯解加工成规格锯材和标准方材的新型双轴圆锯被成功开发,并被广泛用于原木锯解生产。新型双轴圆锯生产线的采用微机采集原木数据,配合锯切方案数据库以及变频和伺服控制,大大提高了加工效率和精度,使得高速、大量生产成为可能。与传统使用的开料排锯相比,双轴圆锯机的优势主要表现在:1)无需原木径级预分类。双轴圆锯机的上下共有4根轴,轴间距可调整;每轴装有6套位置可调的圆锯片。在接收到计算机发出的指令后,通过液压伺服机构,立刻调整锯片锯轴位置,完全避免…     

原木扫描技术在我国应用前景分析

原木扫描技术主要用于精确识别原木外廓形状、尺寸和各种缺陷，为原木管理、优化加工提供原始信息资料。该项技术在木材加工领域应用广泛，是未来国内外木材加工研究的一个重要方向。 木材的最初加工都是从原木开始的，因此，认识原木的外廓形状，包括尖削度、弯曲度、开裂、节子、腐朽等缺陷，以及如何根据加工的需要对这些缺陷进行有效的处理和分选、分等，是木材加工中具有普遍意义的问题，也是提高木材加工利用率的一个关键问题。据有关资料报道，对原木外形扫描识别由计算机控制分选、分等来确定下锯方案，可使原木出材率提高５％以上…     

原木锯口位置对正器

制材生产在划线下锯时,原木进锯前和锯解过程中,锯路对正的准确与否,直接影响原木的出材率和锯机的生产效率。因此,在划线下锯法制材生产中,找出一种有效可行的对正方法是非常必要的。一、对正器工作原理本文所介绍的原木锯口置对正器,基本原理是利用光学中的凸透镜聚焦成像的原理,把普通光源发出的光汇集成一点,使这聚集的光点落在原木小头端面上,指示跑车的摇尺进给,最后使汇集的光点与原木端面已划好线的锯口位置重合,达到精确摇尺下锯的目的。为了提高对线的准确性和扩大对线范围,可配制4～5组相     

原木锯口位置对正器的研制

在制材生产的划线下锯中,原木进锯前和锯解过程中.锯路对正与否是直接影响锯机生产率和木材利用率的技术关键之一。为此,我们研制了锯口位置对正器,现将有关情况简介如下。一、工作原理原木锯口位置对正器,是利用光学中凸透镜聚焦成像的原理,把普通光源的光点,落于原木端面已划好线的锯口位置上,指示跑车的摇尺进给,达到精确摇尺和下锯的目的。为了提高对线的准确性和扩大对线的范     

Mathematical Simulation of Small Log Ripped by Slasher Saw

Withthesmallsawlogwidespreadused,theuncut-boardsandslabsarecutbythemulti-bitrippingedgerinthejhoberindustw.AfersawingripPed,theunedgedboedaccuratelyvolumeisfAnotherparametCrsaredefinitebyadrawing,theaPProimatevolumeforn1ulateofunedgedboardistx,y,~inatC,x'…     

Deep may not be meaningful: Cost and effectiveness of various ripping tine configurations in a plantation cultivation trial in eastern Australia

Deep ripping (subsoiling) is one of the more significant costs of establishing tree plantations on ex-pasture sites with compact soils. Ripping cost increases with depth, but the appropriate ripping depth required for successful tree establishment and growth is rarely clear. Tine modifications such as winged shanks and shallow leading tines have been shown to improve the work efficiency (volume soil loosened per unit drawbar pull) of deep ripping. We investigated whether increased work efficiency also translated to greater cost efficiency (volume soil loosened per unit cost), and whether additional depth and volume of loosened soil improved tree growth on a compact, medium clay, soil. We measured the operating costs for nine different ripping tine configurations, applied in conjunction with bed mounding, and compared early tree (Eucalyptus pilularis Sm.) growth and survival between the nine treatments and a no-cultivation control. Tine variations included presence or absence of wings, presence or absence of shallow leading tines, and depth (0.8 m, 0.6 m and 0.4 m). In most cases, increasing ripping depth or adding wings to the main tine increased operating cost but also tended to increase cost efficiency. The most cost efficient arrangement was for a winged main tine operating at 0.6 m with no leading tines. All cultivation treatments greatly enhanced survival and more than doubled growth to age 19 months compared to the control, but no cultivation treatment resulted in significantly better growth or survival than any other. Our provisional conclusion is that, when performed in conjunction with mounding, ripping beyond 0.4 to 0.6 m is not needed for satisfactory establishment on similar sites.     

Long-term soil and shortleaf pine responses to site preparation ripping

A shortleaf pine (Pinus echinata Mill.) ripping study was established by the Missouri Department of Conservation in March 1988 at the Logan Creek Conservation Area, USA. The objective of the study was to evaluate the effects of ripping on soil chemical and physical properties, on free-to-grow status, and on survival and growth of planted shortleaf pine seedlings. After 16 years, ripping increased exchangeable calcium; however, it had no long-term effects on soil particle size, organic carbon, pH, exchangeable potassium and exchangeable magnesium. Ripping increased the percentage of free-to-grow saplings by 3.8% after two growing seasons. Ripping improved survival by 4% during the 1st three growing seasons and by 7.1% at age 16. After two growing seasons, ripping improved crown spread by 13.6%, height by 14.2%, diameter by 14%, and volume by 41.2%. At age 16, ripping no longer had an effect on shortleaf pine height and had reduced diameter by 5.3% and volume by 11.0%. Our results suggest that ripping 1) had no effect on long-term physical properties or chemical properties of the soil, 2) had no effect on the number of free-to-grow seedlings, and 3) produced short-term benefits on survival and growth of planted shortleaf pine.     

Effects of post-fire management practices and slope-aspect on medium-term Spanish black pine regeneration: implications of using a direct seeding strategy in burnt areas

The natural regeneration of non-serotinous Spanish black pine (Pinus nigra Arn. ssp. salzmannii) is known to be null or limited after severe wildfires. However, it remains challenging to define efficient management strategies within the burnt area, which can help to increase the post-fire resilience of this species. We conducted a direct seeding experiment during 2011–2015 to assess the effect of different post-fire management treatments (control, soil ripping, woodchips, and soil ripping?+?woodchips) performed in opposite slope-aspects (north- and south-facing) on pine emergence, seed predation, survival, growth, and biomass allocation during the early stages of seedling development (1–5 years) after a severe wildfire. Our results showed that the slope-aspect did not have an important effect in both the seedling emergence and seed predation rates. In contrast, the influence of slope-aspect was significant as both survival and growth of pine seedlings were reduced at the south-facing slope-aspect compared to the north-facing slope-aspect due to harsher environmental conditions. A variable and reduced impact on seedling emergence and seed predation rates was induced by both soil ripping and woodchips treatments. Overall, post-fire management treatments helped to enhance survival rates during early growth stages, although this effect was short-lasting. This knowledge can be used to define post-fire seeding management strategies oriented to enhance the resilience of severely burnt pine forest stands; therefore, while both the soil ripping and woodchips treatments might not be practices leading to increase their post-fire regeneration, direct seeding at north-facing slope-aspects could be a more appropriate management strategy.     

Growth performance and chestnut blight incidence (Cryphonectria parasitica) of backcrossed chestnut seedlings in surface mine restoration

Anthropogenic disturbances such as mining for coal have caused significant disturbance to the Appalachian forests of North America. Recovery of these disturbances is highly dependent on restoration methods that encourage natural succession. Unfortunately, current reclamation protocols have resulted in soil compaction and aggressive herbaceous groundcovers that impede the recovery of native trees. To overcome this, methods such as deep ripping and plow and disking were applied to a reclaimed mine land in Ohio, USA Plantings of pure American chestnut (Castanea dentata) and two seedling types (BC₁F₃ and BC₂F₃) bred for resistance to chestnut blight fungus (Cryphonectria parasitica) were assessed among different soil preparation treatments over five field seasons. Seedling mortality due to natural infection by chestnut blight was recorded and related to the disease resistance potential of the BC₁F₃ and BC₂F₃ seedlings. The growth and survival of chestnuts in plots that employed either ripping, plow disking, or the combination of the two methods were significantly greater than the control plots. After five seasons, differences existed among the soil treatments; plots that applied deep ripping had the highest survival and growth. When chestnut types were compared, pure American chestnut was the tallest. However, BC₂F₃ chestnut seedlings had the highest survival and lower disease incidence. Results suggest that employing deep ripping with backcrossed chestnut seedlings provides a method for establishing hardwood seedlings in soils impacted by surface mining. Planting methods that promote vigorous growth can be applied more broadly to other regions where anthropogenic disturbances create soil conditions that hinder seedling establishment.     

竹材刨切工艺的初步研究

毛竹经横截、去节、冲条、刨削等工序，加工成长条；再经干燥、涂胶、组坯、热压等工序，制成竹方；然后经高温水煮软化处理，在刨切机上进行横向热刨切，刨切成竹单板，用于高档贴面装饰，减少贵重木材的消耗。     

滑模筒仓粮库施工总结及预防措施

作者根据工程实例,论述了滑模筒仓粮库施工过程中简仓壁混凝土产生裂缝的原因及防治措 施。     

Determining optimal primary sawing and ripping machine settings in the wood manufacturing chain

for wood manufacturers around the world, the single biggest cost factor is known to be its raw material. Maximum volume recovery of this raw material is, therefore, of key importance for the industry. The wood products industry consists of several interrelated manufacturing steps for converting trees into logs and logs into finished lumber. Each operation usually optimises its functionality in isolation from the preceding and following operations. It is a well documented fact that the optimisation of decisions through the whole chain of operations is considerably more profitable than the optimisation of individual operations. The objective of this study was to determine the optimal machine settings for two interrelated operations, namely the sawing and ripping operations which have tradition? ally been optimised individually. A model, having two decision variables, was developed which aims to satisfy market demand at a minimal cost. The first decision was how to saw the log supply into different thicknesses by choosing specific sawing patterns. The second was to decide on a rip saw's priority value settings, which determines how the products from the primary sawing operation are ripped into products of a certain thickness and width. The techniques used to determine the machine settings included static simulation with the SIMSAW software to represent the sawing operation and mixed integer programming to model the ripping operation. A metaheuristic, namely the Population Based Incremental Learning algorithm, was used to link the simulation and mixed integer models and to determine the optimal settings for the combined process. The model's objective function was to minimise the cost of production. This cost included the raw material waste cost and the over or under production cost. The over production cost included the stock keeping costs and the under production cost was estimated as the buy?in cost of under supplied products from another wood supplier. The model performed well against current decision software available, namely the Sawmill Production Planning System package, which combines simulation and mixed integer programming techniques to maximise profit. The model added further value by modelling and determining the ripping priority settings in addition to the primary sawing patterns.     

Early growth responses from weed control and planting larger stock of Pinus radiata are greater than that obtained from mechanical soil cultivation

Early growth of two grades ofbare-root Pinus radiata D.Don seedlingswere studied in response to four soilcultivation treatments and two weed controltreatments.Soil cultivation treatments included (i) pitsmade by hand, (ii) pits made with an auger,(iii) ripping alone, and (iv) ripping plusdisking. Weed treatments included (i) manualrelease 1 year after planting or (ii) totalweed control for 1 year involving the use ofherbicides and additional hoeing. Bare-rootseedlings were separated into either medium(4.1-mm average root-collar diameter; height25–31 cm) or small (2.8-mm average root-collardiameter; height 14–20 cm) size classes.Growth on this site was excellent and 7 yearsafter treatment, trees in the least expensivetreatment averaged 12.8 m in height. Use ofmedium seedlings and extra weed controlincreased merchantable volume by20 m³ ha^{minus 1} and 19 m³ ha^{minus 1},respectively. When combined, the increase was39 m³ ha^{minus 1}. However, none of the soilcultivation treatments caused a significantincrease in merchantable volume. Disking onthis site proved to be of no benefit. Aboundary-line analysis was used to examine themarginal returns from investing in intensivesilviculture.     

An economic and ecological multi-criteria evaluation of reforestation methods to recover burned Pinus nigra forests in NE Spain

Recurrence of recent large wildfires is threatening the permanence of Pinus nigra Arnold (Black pine) forests in central Catalonia (NE Spain), due to the almost nil post-fire regeneration of this non-serotinous pine. Potential practices to carry out extensive reforestation programs with P. nigra may differ widely in terms of their final success, economic cost and undesired ecological impact. In this framework, we have analysed different types of vegetation clearing (mechanical, controlled burning or grazing), soil preparation (ripping or planting holes) and reforestation methods (broadcast seeding, spot seeding and planting) to restore P. nigra forests. We have compared these practices in terms of seedling establishment, but also in the light of their economic costs and ecological impact, through a new multi-criteria analysis. Seedling establishment after sowing was very poor and not influenced by vegetation clearing. In plantations, seedling survival was higher in the ripper treatment than in planting holes for all vegetation clearing treatments except the control one. Nevertheless, the higher economic cost of the planting holes treatment and the negative impact of mechanical clearing and burning on the small mammals community made the stated differences in seedling survival irrelevant. Thus, the multi-criteria analysis revealed that the two most preferred options were planting in uncleared or lightly grazed areas with soil preparation through ripping. This study gives some valuable insights about the use of new decision-support tools in restoration programs and provides practical guidelines concerning the restoration of extensive burned P. nigra forests.