The influences of circular saws with sawteeth of mic-zero-degree radial clearance angles on surface roughness in wood rip sawing Weiguang Li, Zhankuan Zhang, Xiaorui Peng, Bo Li To cite this version: Weiguang Li, Zhankuan Zhang, Xiaorui Peng, Bo Li. The influences of circular saws with sawteeth of mic-zero-degree radial clearance angles on surface roughness in wood rip sawing. Annals of Forest Science, Springer Nature (since 2011)/EDP Science (until 2010), 2017, 74 (2), pp.37. 10.1007/s13595- 017-0632-3. hal-02976531 HAL Id: hal-02976531 https://hal.archives-ouvertes.fr/hal-02976531 Submitted on 23 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Annals of Forest Science (2017) 74: 37 DOI 10.1007/s13595-017-0632-3 ORIGINAL PAPER The influences of circular saws with sawteeth of mic-zero-degree radial clearance angles on surface roughness in wood rip sawing Weiguang Li 1 & Zhankuan Zhang1 & Xiaorui Peng 1 & Bo Li1 Received: 23 July 2016 /Accepted: 10 April 2017 /Published online: 25 April 2017 # INRA and Springer-Verlag France 2017 Abstract count the influences of length and angle of the side edges on & Key message The sawtooth parameters of the side edges surface roughness. Thus, adaptive parameters for the side likely affect surface roughness to a large extent in wood edges should be proposed. sawing. Our results point out the need to optimize the & Aims This study analyzes how the different parameters of parameters of the side edges in order to maximize wood side edges influence surface roughness when circular saws are surface quality. used, and aims to resolve disparities between high feed speeds & Context Improving surface roughness of wood in rip sawing and better surface roughness. by optimizing the sawtooth parameters is a significant topic of & Methods In particular, this article presents the use of a saw- focus in the research of wood processing. However, existing tooth with a mic-zero-degree radial clearance angle. Northeast research focuses mainly on the optimization of the sawtooth China ash (Fraxinus spp.) serves as the material for parameters of the major cutting edges without taking into ac- conducting this rip-sawing experiment. Nine types of saw- tooth geometries at different feed speeds are used to study the influences of both the different radial clearance angles and the straight length of the zero-degree radial clearance an- gle on surface roughness (Ra). Handling Editor: Jean-Michel Leban & Results Surface roughness increases with the increase in Contribution of the co-authors Weiguang Li: laboratory experiments, feed speed, and the smaller the radial clearance angle of the data collection, running the data analysis, analysis and discussion of the sawteeth, the smaller the surface roughness. When the saw- data, and writing the paper. teeth have a mic-zero-degree radial clearance angle, the saw- Zhankuan Zhang: laboratory experiments, data collection, analysis, and discussion of the data. ing surface roughness is lower than that of the value of saw- Xiaorui Peng: experimental design and laboratory experiments. teeth with radial clearance angles, especially when the straight Bo Li: experimental design and supervising the work. length of the zero-degree radial clearance increases from 0 to 0.5 mm, in which case the decrease is most obvious. * Weiguang Li & Conclusion Surface roughness depends, to a certain extent, [email protected] on the depth of the saw notch. A small part of the side edge that forms the sawing surface participates in the actual cutting, Zhankuan Zhang [email protected] and the length of this section is approximately equal to the feed per tooth. Sawteeth with mic-zero-degree radial clearance Xiaorui Peng angles can improve the surface quality of sawing. Also, if the [email protected] other cutting factors remain unchanged, surface roughness can Bo Li be improved and friction can be reduced between the side [email protected] edges and the wood by increasing the feed speed. 1 Research Institute of Wood Industry, Chinese Academy of Forestry, Dongxiaofu2#, Xiangshan Road, Haidian District, Beijing 100091, Keywords Surface roughness . Sawtooth . Radial clearance China angle . Wood sawing . Side edge 37 Page 2 of 9 Annals of Forest Science (2017) 74: 37 1 Introduction the quality of the surface obtained from routing (Costes 2001; Korkut and Donertas 2007). Another way to improve the saw- Circular rip sawing is applied mainly in the conversion of logs ing process is to identify the best match between the cutting into solid wood products and in the production of furniture. material and the blade geometry (Simonin et al. 2009). The woodcutting process, when rip-sawing wood with circu- In recent years, much research has focused on efficient, lar saw blades, occurs with each of several cutting teeth. The energy-saving, and cost-reducing sawing. Optimizing the cutting process of wood is considered a technological scheme sawtooth parameters to improve surface roughness has been that consists of several connected and relatively inseparable one of the most significant research topics. Figure 2 shows the parts such as that presented in Fig. 1 (Marko and Holík 2000; sawtooth shape and angle of a traditional circular saw. Kováč and Mikleš 2009). The surface quality of solid wood The cutting mechanics of woodworking regarding surface and wood-based panels is one of the most important properties quality in general have been studied and described by several influencing manufacturing processes such as finishing as well authors; for instance, Kirbach and Ngusya (1988) and Krilov as affecting adhesive strength characteristics. The surface (1988) have reported that saws with beveled teeth perform quality from sawing is a function of factors related to the better in plant trials than those with swage teeth. In North process (i.e., feed rate), factors related to the tooling system America, the “triple-chip” tooth design, which has chamfered (i.e., cutting angle), and factors related to the material (i.e., teeth alternating with swage teeth, is widely preferred for the moisture, density, or heterogeneity) (Thibaut et al. 2016). circular sawing of smooth surfaces. Krilov (1988) reported im- Many researchers have been interested in surface rough- proved performance in sawmill trials of a symmetrical full- ness (Koch 1964), which can be affected by different factors. Thibaut et al. (2016) summed up the influence factors on surface roughness in two sets of parameters: (i) Those linked to the material: anatomical, physical, chemical, and mechanical properties required to take into ac- count for the scale effects (Triboulot 1984; Triboulot et al. 1991; Brémaud et al. 2011). Thus, softwood, mainly consisting of tracheids, and hardwood, consisting of fibers and vessels, present a range of surface roughness (Leban and Triboulot 1994; Akbulut and Ayrilmis 2006; Bekhta et al. 2009). (ii) Those linked to the manufacturing process: vibrations of machines (Martin 1992); stability, wear of the cutting edges of the tools (Aguilera Leon 2000); and cutting conditions (Khazaeian 2006; Kilic et al. 2006). Thus, some authors have found that a higher cutting speed can, in some cases, improve Fig. 1 Technological system, “the cutting process” (Kováč and Mikleš 2009), consists of a four-part subsystem: workpiece (wood species, humidity, density, and toughness), cutting conditions (sum of conditions relating to workpiece, cutting tool, and cutting mechanism), cutting mechanism (mechanism of the main movement; feed; number of working movements; and procedure of performance, thickness, and width of a layer, which is cut; cutting angle; speed of cutting movement Fig. 2 Tooth tip geometry: a schematic of sawtooth from a circular saw; and feed; cutting forces; and friction forces), and a cutting tool (cutting b views of tooth geometry angles from A and B direction: B =widthof wedge angle, number of teeth, material properties, surface roughness, sawtooth; S′ = tooth side clearance; λ = radial clearance angle; γ = rake cutting edge length) angle; α = back-clearance angle; λ′ = tangential clearance angle Annals of Forest Science (2017) 74: 37 Page 3 of 9 37 width bevel design. Another design with symmetrically beveled top edges and slightly curved side edges was found by Heisel et al. (1998) to produce “extraordinary” improvement in surface quality. McKenzie (2000), in the USA, theoretically analyzes the influences of five-teeth shapes on surface roughness. The study of sawtooth with a zero-degree radial clearance angle was first presented by Meng and Qi (1999) in China. The results show that the band saw blade of a zero-degree radial clearance could improve the quality of surface cutting (Meng et al. 2001a, b). However, most of the previous work has fo- cused on the cutting quality of the main edge, whereas the in- Fig. 3 Basic cutting modes in wood cutting (McKenzie 1961; Laternser fluence of length and angle of the sawtooth side edge on the et al. 2003). The first number is the angle between the tool edge and the surface quality of sawing was not taken into account. In the fiber direction; the second, the angle between the cutting direction and the process of sawing wood, the side edge also plays a role in fiber direction cutting. In fact, with the extensive application of the ultrathin- cemented carbide circular saw for woodworking, the width of the main edge of the sawtooth continues to narrow, and the kerf surface) can be achieved after the motion of the sawtooth.