第2讲 板式家具部件的主要切削刀具

1 概述 板式家具是以各种贴面的人造板作为板式部件,借助五金联接件、圆棒榫等结合方式组装而成的家具.板式部件是贴面人造板基材和封边材料组成的复合结构材料.常用的基材有中密度纤维板、刨花板、多层胶合板、细木工拼板和单板层积材等人造板;贴面材料主要有三大类:木质、纸质和塑料.木质贴面材料包括灭然薄木、人造薄术和单板等;纸质贴面材料有印刷装饰纸、合成树脂浸渍纸和装饰板;塑料贴面材料有聚氯乙烯(PVC)薄膜和聚丙烯薄膜.     

巨桉仿黑胡桃的薄木染色工艺试验

利用简洁的工序,探索巨桉仿黑胡桃的染色工艺.结果表明:对0.65 mm厚的巨桉薄木染色,薄木不经漂白处理,添加研制的渗透剂W X 3,可直接染成黑胡桃色,染透仅需45 m in,染液总质量分数不大于0.3‰,并且可以连续利用3次;巨桉早晚材上色不一,经处理后材质纹理清晰,可以直接用于仿黑胡桃薄木贴面.     

薄木贴面聚氯乙烯基木塑复合材料贴面工艺参数对其性能的影响

探究热压温度、时间、压力因子对薄木贴面聚氯乙烯(PVC)基木塑复合材料表观质量的影响,并以硅烷偶联剂改善薄木与PVC木塑基材之间界面的胶接性能。结果显示,以质量分数1.4%的KH-550为偶联剂,在热压温度130℃、热压压力1.5 MPa、热压时间200 s的工艺下,薄木贴面PVC基木塑复合材料的综合性能最佳;薄木和PVC木塑基材之间形成了紧密的界面结合。     

紫檀薄木湿法贴面表面装饰效果影响因素的研究

以紫檀薄木、刨花板为研究材料,对薄木湿法贴面中装饰效果的主要影响因素,如薄木的含水率、涂胶量、热压的温度和时间等方面进行研究,以期为薄木湿法贴面的工业生产提供改进的理论依据。研究表明:在含水率为30%、热压温度为90℃、热压时间为2min、涂胶量为88.9g/m2时,对紫檀薄木进行湿法贴面能得到较好的表面装饰效果。     

三聚氰胺甲醛树脂浸渍薄木激光切割叠层拼花工艺

目前薄木拼花主要利用不同树种、颜色、纹理等的薄木,采用拼接或镶嵌工艺,按设计图形要求,拼接成一定图案并使之粘贴于基材之上[1～3].采用拼接或镶嵌工艺生产复杂图案时,对加工精度要求极高,如操作不当,易造成叠层或离缝现象,对制品质量造成影响.在采用拼花或镶嵌工艺完成设计图案后,需对其进行涂饰加工.笔者所述三聚氰胺甲醛树脂浸渍薄木叠层拼花工艺,采用经三聚氰胺甲醛树脂浸渍处理的各种颜色、纹理的浸渍薄木按照设计要求,加工成相应图形,直接按设计图案要求贴附到三聚氰胺浸渍薄木贴附层上后,与基材组合,按一定的工艺要求一次热压成型,制成叠层拼花制品或片材.所压制出的制品或片材表面无需再进行涂饰处理,制品薄木图案清晰,立体感强.利用薄木替代装饰纸,薄木通过浸渍三聚氰胺甲醛树脂,制备成三聚氰胺浸渍薄木.三聚氰胺浸渍薄木直接粘贴于基材上,在体现薄木的天然质感的同时,又保留了三聚氰胺浸渍纸的耐磨、耐热等优点.薄木与装饰纸的主要区别在于其具有不均匀性,薄木的横纹抗拉强度低,在浸渍和贴面操作时易损坏,贴面后表面易产生龟裂,特别是贴面温度高时,所产生的缺陷越明显等缺点.因此,采用常规浸渍纸用三聚氰胺甲醛树脂不能满足浸渍薄木的要求,浸渍薄木用三聚氰胺甲醛树脂应具有一定的韧性,低温、低压条件下具有良好的流动性,固化速度适中等特点.采用改性三聚氰胺甲醛树脂浸渍薄木,能够满足薄木浸渍要求;浸渍薄木适应叠花制品对低温、低压贴面工艺要求[4,5].三聚氰胺甲醛树脂浸渍薄木叠层拼花工艺可用于地板、人造板、工艺品、家具等的表面装饰."三聚氰胺甲醛树脂浸渍薄木激光切割叠层拼花制品工艺"已于2011年11月11日获得国家知识产权局发明专利受理,发明专利申请号:201110354826.4,公开(公告)日:2012.06.20.     

薄木贴面木纤维/聚乙烯复合材料的制备工艺及性能

薄木贴面是提升木塑复合材料（WPC）实木感、改善其装饰性能的有效方法。为了解决木纤维/聚乙烯复合材料（WF/PE）表面胶接困难的问题，选择两种热塑性树脂膜为胶接材料，采用分段热压工艺进行贴面加工，以外观质量、表面胶合强度和浸渍剥离长度为性能评价指标，探究热压工艺及胶接材料种类的影响。发现采用马来酸酐接枝聚乙烯（MAPE）膜为胶接材料，在两段式工艺：热压时间160+60 s、热压温度150 ℃、热压压力1.5 MPa条件下，薄木贴面WF/PE的综合性能最优。SEM表征证明，MAPE膜可以有效促使薄木和PE基WPC基材之间的界面结合。     

高频真空方法干燥刨切薄木的工艺探讨

刨切薄木(以下简称薄木)贴面质量和成本与薄木干燥有很大关系。薄木(常规)干燥容易产生碎裂、皱缩、不平整等缺陷,即使采用湿贴法也会产生二次加工中的贴面开裂、鼓泡等缺陷。而且湿薄木(含水率一般在100％以上)在存放和运输过程中很容易发霉、变色,从而降低薄木的利用率,影响薄木贴面质量和产品成本。为此本文介绍一种新     

杉木积成材薄木贴面工艺初探

采用正交试验法，探讨了杉木积成材薄木贴面的工艺过程。试验结果表明：利用杉木积成材进行薄木贴面．工艺切实可行，奥古曼薄木贴面的较佳工艺参数为：热压温度100℃，热压压力1．0MPa，热压时间4min，涂胶量120g／m^2。     

人造板薄木贴面工艺的研究

对人造板采用表面装饰的方法,是提高人造板使用价值的主要途径。主要做法有油漆、贴纸、贴塑、木纹印刷和贴薄木等。其中,珍贵木材刨切薄木贴面产品的木材真实感最强,贴面成本较低,颇受用户欢迎。但珍贵树种木材资源短缺,如何合理利用薄木,降低薄木厚度,是当前的重要课题之一。我们使用厚度0.3mm的薄木(目前多为     

用薄木贴面技术生产仿实木家具

本文介绍了薄木贴面技术在家具中的应用和异型部件真空膜压技术，探讨了采用板式部件生产仿实木家具的可能性。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。