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  • 1.
    Ah Shenga, Pedro
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Broman, Olof
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    A review of Mozambican wood exploitation: map of the processing chain2013In: Proceedings of the 21th International Wood Machining Semina: August 4th – 7th, Tsukuba International Congress Center, Japan, 2013, p. 293-301Conference paper (Other academic)
  • 2.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Machining properties for some Mozambican wood species2010Licentiate thesis, comprehensive summary (Other academic)
  • 3.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Machining properties of wood: Tool wear, cutting force and tensioning of blades2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cutting processes, in general, and wood cutting processes, in particular, are complex to explain and describe with many influencing factors. Wood, in contrast to man-made fabricated materials, is not a homogenous and distinct material, but a multifaceted and nonhomogeneous biological material. A fundamental understanding of wood cutting processes and the machining properties of wood can be obtained by investigating the interaction of wood properties, cutting tools and machining parameters. Such an understanding provides possibilities for improving product quality, increasing production efficiency, or otherwise improving the machining processes. The aim of this thesis was to find ways of improving the machining properties of some wood species, focusing on tool wear, cutting forces and the tensioning of circular sawblades. The studied wood species were five Mozambican tropical species, namely: Swartzia Madagascariensis (ironwood); Pseudolachnostylis maprounaefolia (ntholo); Sterculia appendiculata (metil); Acacia nigrescens (namuno); Pericopsis angolensis (muanga) and two main Swedish wood species: Pinus sylvestris L. (Scots pine); and Picea abies (L.) Karst. (Norway spruce). A series of experimental tests were conducted to determine the suitability of different cutting tool materials when machining these wood species. Machining tropical hardwood and Swedish frozen wood under winter conditions is still a challenge when it comes to the choice of which cutting tool material to use. Tool wear was used as a criterion to evaluate the performance of the cutting tool materials. Additionally, the relationship between tool wear and some chemical and physical properties for Mozambican tropical wood species was analysed. Different wear mechanisms were identified using a scanning electron microscope. It was concluded that tool hardness alone was not the only factor affecting tool wear; a certain amount of tool toughness was also needed to obtain low tool wear. The predominant wearing mechanisms for the tropical wood species tested were abrasion and edge-chipping. Furthermore, tropical hardwood species were subjected to cutting force tests. A standard single saw tooth, mounted on a piezoelectric load cell, was used to evaluate cutting forces. The theoretical approach used for the prediction of the main cutting forces was based on surface response methodology. Among the studied variables, chip thickness and cutting direction had the greatest effect on the main cutting force level, while wood density, moisture and rake angle had the least effect.Power consumption using double arbour circular saw machines was investigated. The experiments were carried out, under normal production, in two Swedish sawmills. The climb-sawing model in both sawmills was able to estimate the power consumption better than the counter-sawing model. Climb-sawing had higher power consumption than counter-sawing. The lowest power consumption was found using a higher overlap between circular sawblades. Finally, experimental and theoretical models to improve circular sawblade dynamic lateral stability were developed. Different methods for monitoring flatness and tensioning in circular sawblades for wood cutting were discussed. Additionally, the effects of the magnitude of the roller load, number of grooves and groove positions were tested. The roll-tensioning effects were evaluated by measuring the shift in natural frequencies of several vibration modes. Natural frequencies obtained with the finite element method were in good agreement with the experimental test results. The magnitude of the roller load, number of grooves, and groove positions all affected the natural frequencies.

  • 4.
    Cristovao, Luis
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Broman, Olof
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Ekevad, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Sitoe, Rui
    Eduardo Mondlane University.
    Main cutting force models for two species of tropical wood2011In: Proceedings of the 20th International Wood Machining Seminar, Skellefteå, 2011, p. 428-435Conference paper (Refereed)
  • 5. Cristovao, Luis
    et al.
    Broman, Olof
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Ekevad, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Sitoe, Rui
    Main cutting force models for two species of tropical wood2012In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 7, no 3, p. 143-149Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to evaluate the main cutting force for two species of tropical Mozambican wood and to develop predictive models. Cutting these hardwoods is difficult. Determination of cutting parameters is required to optimize cutting processes, machines and tools in the cutting operations. This determination would enable the forestry and wood sector to achieve higher financial results. Samples of a lesser-known wood species Pseudolachnostylis maprounaefolia (ntholo) and a well-known wood species Swartzia madagascariensis (ironwood) were machined in a test apparatus. A standard single saw tooth mounted on a piezoelectric load cell was used to evaluate the main cutting force. Data were captured using an A/D converter integrated with National Instruments LabVIEW software. The measured signals were recorded at a sampling frequency of 25 kHz. The experimental set-up used response surface methodology for developing predictive models. The experimental clearly determined the relationship between the main cutting force and edge radius, wood density, rake angle, chip thickness, moisture content (MC) and cutting direction (CD). Among the studied variables, chip thickness and CD had the highest effect on the main cutting force level while wood density, MC and rake angle had the lowest effect.

  • 6.
    Cristovao, Luis
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Ekevad, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Industrial sawing of Pinus Sylvestris L.: power consumption2013In: Proceedings of the 21th International Wood Machining Seminar: August 4th – 7th, 2013, Tsukuba International Congress Center, Japan, 2013, p. 189-198Conference paper (Other academic)
    Abstract [en]

    Wood industry continues to strive to reduce production cost and increase productivity to maintain competiveness. Hence, knowledge of the effect of wood cutting parameters on power consumption would enable increase energy efficiency, thus, reduce operating costs and enhance profitability. Also measurement of power consumption gives knowledge of other specifics such as: tool edge wear, occurrence of catastrophic failures and other parameters which affect the quality of the sawn boards and the momentary efficiency of the break-down process. In this study, power consumption during sawing of Pinus sylvestris L. using double arbour circular saw was investigated. Both climb-sawing and counter-sawing were considered. The experiments were carried out, under normal production, in two Swedish sawmills. The relationship between cutting parameters and calculated power consumption is discussed. The experimental power consumption increased 11-35% during an 8 hour shift mainly due to increase of the tooth radius. Further, this study also showed the climb-sawing had higher power consumption than counter-sawing.

  • 7.
    Cristovao, Luis
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Ekevad, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Industrial Sawing of Pinus Sylvestris L.: Power consumption2013In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 8, no 4, p. 6044-6053Article in journal (Refereed)
    Abstract [en]

    The wood industry continues to strive to reduce production costs and increase productivity to remain competitive. Knowledge of the effect of wood cutting parameters on power consumption could increase energy efficiency, reducing operating costs and increasing profitability. Measuring power consumption also provides information about other variables, such as tool edge wear, occurrence of catastrophic failures, and other parameters that affect the quality of the sawn boards and the momentary efficiency of the breakdown process. In this work, power consumption during sawing of Pinus sylvestris L. using a double arbor circular saw was investigated. Both climb-sawing and counter-sawing were considered. The experiments were carried out under normal production circumstances in two Swedish sawmills. The relationship between cutting parameters and theoretical power consumption was investigated. The experimental power consumption increased by 11 to 35% during an 8-h shift, mainly due to an increase in the tooth radius. Additionally, this study showed that climb-sawing consumed more power than counter-sawing.

  • 8.
    Cristovao, Luis
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Ekevad, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Natural frequencies of roll-tensioned circular sawblades: Effects of roller loads, number of grooves and groove positions2012In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 7, no 2, p. 2209-2219Article in journal (Refereed)
  • 9. Cristovao, Luis
    et al.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Sitoe, Rui
    Ekevad, Mats
    Marklund, Birger
    Brittleness of cutting tools when cutting different wood species2009In: Proceedings of the 19th International Wood Machining Seminar / [ed] Handong Zhou; Nanfeng Zhu; Tao Ding, Nanjing: Nanjing Forestry University , 2009Conference paper (Refereed)
  • 10. Cristovao, Luis
    et al.
    Lhate, Imacio
    Swedish University of Agricultural Sciences.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Ekevad, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Sitoe, Rui
    Department of Mechanical Engineering, Eduardo Mondlane University, Maputo.
    Tool wear for lesser known tropical wood species2011In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 6, no 3, p. 155-161Article in journal (Refereed)
    Abstract [en]

    This study investigated the relationship between tool wear and some chemical and physical properties for four different Mozambican lesser known tropical species,: Pseudolachnostylis maprounaefolia (ntholo), Sterculia appendiculata (metil), Acacia nigrescens (namuno) and Pericopsis angolensis (muanga). Tool wear is an important aspect for sawmilling and for the woodworking industry. For Mozambique, the utilization of available lesser known wood species will help to increase domestic industry and the economic usage viability of sustainable forest management. A set of experiments was performed on a shaper with a mechanical feed mechanism. Tools of a cemented carbide grade for woodworking were used, and the cutting parameters were fixed. Edge recession and tool wear radius were measured for monitoring tool wear. The wear mechanism was investigated using a scanning electron microscope. The experimental results showed that the chemical properties of the wood species have a great effect on tool wear. Wood silica content was the most important factor affecting tool wear. Wood density and extractives had a low influence on tool wear. The highest tool wear was observed in ntholo, which also had the highest ash and silica contents. A single parameter for evaluation of tool wear was not sufficient to describe the amount of total tool wear

  • 11.
    Ekevad, Mats
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Axelsson, Ann
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Cristovao, Luis
    Model for forces on a cutting tooth of a circular saw blade for wood rip sawing2011Conference paper (Refereed)
    Abstract [en]

    Forces from cutting appear on the front edge and side edges of a straight cutting tooth of a circular saw blade intended for rip sawing of wooden logs. The forces on these three edges add up to a net force on the tooth with three components in the main, normal and lateral directions. Especially the net lateral force is interesting for the stability of a circular saw blade during rip sawing due to the low stiffness of the saw blade in the lateral direction. In this paper, a model for calculating the net force on a cutting tooth is proposed and discussed. The forces on the front cutting edge and the two side cutting edges may for each edge be calculated from literature and experimental data of main and normal forces as a function of cutting parameters such as rake angle, clearance angle, bevel angle, cutting depth and wood cutting direction. The net force is the vectorial sum of the forces on the front and side cutting edges. Thin saw blades cut relatively more with the side edges than thick saw blades for the same cutting depth.A net lateral force appears on the tooth if there are unequal normal forces on the side edges. The reasons for unequal normal forces may be unequal side cutting depths due to a lateral deflection of the saw blade or inhomogenities in the wood material. The net cutting forces from the cutting force model may be applied on the teeth of a mechanical model of the circular saw blade in order to calculate lateral displacements and thus stability of the circular saw blade. Lateral displacement of the saw blade generates unequal side edge cutting forces and thus there is coupling between lateral force and lateral deflection.

  • 12.
    Ekevad, Mats
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristovao, Luis
    Grönlund, Anders
    Different methods for monitoring of flatness and tensioning in circular saw blades2009In: Proceedings of the 19th International Wood Machining Seminar / [ed] andong Zhou; Nanfeng Zhu; Tao Ding, Nanjing: Nanjing Forestry University , 2009, p. 78-86Conference paper (Refereed)
    Abstract [en]

    The performance of a circular-saw blade during sawing depends greatly on the mechanical and geometrical properties of the individual saw blade in question. In order to characterize an individual saw blade when manufacturing saw blades or when doing maintenance of the saw blades, flatness and tensioning are important aspects. Flatness and tensioning influence the lateral stability of the saw blade during sawing and thus affect the sawing result, e.g., the accuracy of the dimensions of the sawn timber. Tests and comparisons of different methods for characterizing individual saw blades were done. New and used saw blades with different amounts of tensioning and flatness were used. The tested saw blades had several radial slots and were intended for use in double-arbour saws with collars and no guides. The compared methods were static and dynamic flatness measurements, natural-frequency measurements and theoretical finite-element calculations with different excitation methods and boundary conditions.The results show some of the qualities of the different methods. The benefits and disadvantages are provided, as well. Especially tensioning can be accurately measured and predicted from natural frequency measurements and finite-element calculations

  • 13.
    Ekevad, Mats
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Öhman, Micael
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Geometry of Kerf when Curve Sawing with a Circular Rip-Saw2013In: Proceedings of the 21th International Wood Machining Semina: August 4th – 7th, Tsukuba International Congress Center, Japan, 2013, p. 206-213Conference paper (Refereed)
    Abstract [en]

    Rip-sawing following the curvature of a crooked log means advantages for yield. However, the possibility to saw in a narrow curve with a circular saw blade is limited because of the inherent flat geometry of circular sawblades. For a double arbour circular saw the situation is even more problematic because the two blades have a certain overlap and thus the two arbours are not positioned in the same horizontal position. In this study a theoretical geometrical study of the creation of a kerf with a single circular sawblade and with a double arbour circular saw with two sawblades is viewed upon. Input parameters in the study for the double arbour saw are blade diameter, overlap, margin between blades, cant height, curve centre horizontal position and curve radius. Output is the geometry of the kerf that is cut by the teeth. Theoretical results for stiff saw blades show that the kerfs become in general curved and inclined (tilted) in the vertical direction and also that the width of the kerfs for double arbour saws become wider at the top and bottom of the cant than in the middle. Sawing takes place not only in the front part of the blades but also on the back of the blades (back sawing). Parts of the cutting edges of the teeth are cutting when back sawing and not the whole of the width of the teeth. A result is that boards that are cut out of the cant get varying thickness along their width because of the varying kerf width. A comparison with experimental thickness data from four test sawings at a sawmill indicates that the theoretical results are valid and that curve sawn boards become thinner than straight sawn boards.

  • 14.
    Ekevad, Mats
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Öhman, Micael
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Geometry of kerf when curve sawing with a circular rip-saw2014In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 72, no 6, p. 809-814Article in journal (Refereed)
    Abstract [en]

    Rip-sawing following the curvature of a crooked log means advantages for yield. However, the possibility to saw in a narrow curve with a circular saw blade is limited because of the inherently flat geometry of circular saw blades. For a double arbour circular saw the situation is even more problematic because the two blades have a certain overlap and thus, the two arbours are not positioned in the same horizontal position. In this study, a theoretical geometrical study of the creation of a kerf with a single circular saw blade and with a double arbour circular saw with two saw blades was examined. Results for stiff saw blades show that the kerfs become in general curved and inclined (tilted) in the vertical direction and also that the width of the kerfs for double arbour saws becomes wider at the top and bottom of the cant than in the middle. Additionally, the sawn boards obtain varying thickness along their width because of the varying kerf width. A comparison with experimental thickness data from four test sawings at a sawmill indicates that the theoretical results are valid and that curve sawn boards become thinner than straight sawn boards.

  • 15.
    Ekevad, Mats
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Marklund, Birger
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Lateral cutting forces for different tooth geometries and cutting directions2012In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 7, no 3, p. 126-133Article in journal (Refereed)
    Abstract [en]

    Lateral (sideways) cutting forces were measured for 6 different tooth geometries when cutting green spruce and pine heartwood. The teeth were intended for use on circular saw blades for the rip sawing of logs. The 6 tooth geometries were designated straight, pointed, bevelled, rounded, trapezoidal and hollowed out. Cutting speed was 15 m/s, feed per tooth was 0.3 mm and the cutting directions were 90°–90° (rip sawing) and 90°–0° (milling), with two different variants of growth ring angles for each direction. The tools were tested in sharp conditions, in dull conditions and in a dull condition with a corner broken off. All lateral forces were small when cutting with sharp teeth, except for the rounded and bevelled teeth. Lateral forces increased with wear, except for a period of initial wear where the lateral forces were reduced. High wear resulted in greater lateral forces, most probably due to unsymmetrical wear. Growth ring direction did not generally affect lateral forces. The teeth with acute corners, which were the straight and hollowed out tooth, were most sensitive to a broken off corner. The lateral forces in the cases of wood cutting at 90°–90° increased less with wear compared to the 90°–0° cases.

  • 16.
    Ekevad, Mats
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Marklund, Birger
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Wear of teeth of circular saw blades2012In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 7, no 3, p. 150-153Article in journal (Refereed)
    Abstract [en]

    Measured wear data is presented for three different carbide grades. The data were collected during rip sawing wood with a double arbour saw. The purpose of the test was to determine the suitability of different grades for sawing frozen timber. A set of circular saw blades of diameter 350 mm was equipped with teeth comprised of three different cemented carbide grades, denoted A, B and C. The double arbour saw was equipped with six saw blades for cutting two centre boards and two side boards. The six saw blades with different teeth were mounted in a mixed manner on the arbours, and after sawing a number of logs the wear of teeth was measured. The thickness of boards was also measured and the standard deviation was calculated. The results showed that grade A had the highest wear and grades B and C the lowest wear. There was no significant edge damage during the tests. Grade C did not suffer problems of chipping from cutting edges and was found to be suitable for sawing frozen timber. The thickness standard deviations were constant at about 0.2 mm, and not a function of the number of logs sawn.

  • 17.
    Ekevad, Mats
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Marklund, Birger
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristovao, Luis
    Wear of teeth of circular saw blades2011Conference paper (Refereed)
    Abstract [en]

    Measured wear data is presented for 3 different carbide grades. The data were collected during rip sawing wood with a double arbour saw. The purpose of the test was to determine the suitability of different grades for sawing frozen timber. A set of circular saw blades of diameter 350 mm was equipped with teeth comprised of 3 different cemented carbide grades, denoted A, B and C. These 3 grades were chosen out of 6 grades in an earlier preliminary laboratory test. Grade A was a relatively soft and tough standard grade (K1C=17, HV30=1150) normally used in sawmills in winter conditions for frozen wood, grade B was harder and more brittle (K1C=11, HV30=1600) and grade C was even harder and more brittle (K1C=9.5, HV30=1950). The double arbour saw (with vertical arbours) was equipped with 6 saw blades (3 on each arbour) for cutting 2 centre boards and 2 side boards. The 6 saw blades with different teeth were mounted in a mixed manner on the arbours, and after sawing a number of logs the wear of teeth was measured. After some time the blades were removed, inspected, ground and used again for sawing. The thickness of boards was also measured and the standard deviation was calculated.The results show cutting edge radii as a function of the number of logs sawn and also the standard deviation of the thickness of the sawn boards. Grade A had the highest wear and grades B and C the lowest wear. There was no significant edge damage during the tests. Grade C did not suffer problems of chipping from cutting edges and was found to be suitable for sawing frozen timber. The thickness standard deviations were constant at about 0.2 mm, and not a function of the number of logs sawn.

  • 18.
    Grönlund, Anders
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristóvão, Luis
    Proceedings of the 20th International Wood Machining Seminar: June 7 – 10, 2011 Skellefteå Sweden2011Collection (editor) (Other academic)
  • 19.
    Guo, Xiaolei
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering. Nanjing Forestry University, Faculty of Material Science & Engneering.
    Li, Rongrong
    Nanjing Forestry University, Nanjing Forestry University, Faculty of Material Science & Engneering.
    Cao, Pingxiang
    Nanjing Forestry University, Nanjing Forestry University, Faculty of Material Science & Engneering.
    Ekevad, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Marklund, Birger
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Grönlund, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Effect of average chip thickness and cutting speed on cutting forces and surface roughness during peripheral up milling of wood flour/polyvenyl chloride composite2015In: Wood research, ISSN 1336-4561, Vol. 60, no 1, p. 147-156Article in journal (Refereed)
    Abstract [en]

    Wood flour/polyvinyl chloride composite (WFPVCC) is a kind of composite material that, over the years, is becoming more popular in constructions applications. In this work, cutting forces and machined surface roughness were studied during peripheral up milling of WFPVCC under different average chip thickness which was obtained by adjusting rotation speed and feed rate at both high and low speed cutting conditions. The results indicated that cutting forces components, parallel force (F-x) and normal force (F-y) greatly varied during the cutting process. Maximum F-x, maximum F-y and surface roughness increased with the increase of average chip thickness. Maximum F-x and maximum F-y at high speed cutting conditions were lower than that at low speed cutting conditions at a same average chip thickness. The machined surface roughness at high speed cutting conditions was better than that at low speed cutting conditions at a same average chip thickness. When meeting the requirement of certain surface roughness, higher cutting speed can allow higher chip thickness and then decrease the tool wear than lower speed cutting condition. Maximum negative F-y had great impact in machined surface roughness. Machined surface roughness increased with the increase of maximum negative F-y. Thus, high speed cutting conditions not only increase the machining productivity, but also decrease machined surface roughness during the peripheral up milling of WFPVCC

  • 20. Lhate, Imacio
    et al.
    Cristovao, Luis
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Ekevad, Mats
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Wood Science and Engineering.
    Sitoe, Rui
    Cutting forces for wood of lesser used species from Mozambique2011In: Proceedings of the 20th International Wood Machining Seminar, Skellefteå, 2011, p. 444-451Conference paper (Refereed)
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