Sawing Parameters Research Articles

Optimization of oak sawing parameters based on energy consumption and surface roughness

AbstractHigh energy consumption and poor processing quality are common problems in wood sawing. To address these issues, in this article, specific cutting energy and surface roughness were investigated with saw blade speed as control variables. Analysing the effect of parameters on specific cutting energy and surface roughness. The sawing parameters were optimised with the objectives of minimum specific cutting energy and minimum surface roughness. The findings indicate that specific cutting energy and surface roughness reduction with increasing rake angle; specific cutting energy and surface roughness decrease with increasing spindle speed; specific cutting energy decreases and surface roughness increases with increasing feed rate. ANOVA analysis reveals that sawing speed (n) has the most significant impact on specific cutting energy during oak cutting. The optimal solution derived from TOPSIS suggests a specific cutting energy of 2E7 J/m3 and a surface roughness of 1.758 μm. The innovation of this paper is the study of the specific cutting energy and the optimisation of parameters. These findings provide valuable theoretical and practical guidance for enhancing the efficiency and quality of oak processing while minimizing energy consumption.

Evaluation of wood chips terminal velocity and some morphological properties in a wind tunnel experiment

AbstractThe removal of wood dust and chips from the work area is also important for occupational health safety regulation and to avoid the risk of fire and dust explosion. Knowledge of the terminal velocity is an important condition for the effective and economical operation of commonly used wood dust-chip extraction systems. While the largest particles are important from the point of view of the operation of the extraction system, knowledge of the terminal velocity of small particles (under 1 mm) is desirable from the point of view of separation and occupational health safety. New measuring and calculation method is developed in order to determine the terminal velocity of wood particles. We built an experimental device to measure the terminal velocity of wood dust-chip particles, and using the experimental results, we modified the calculated terminal velocity based on the modified equivalent particle density (100–130 kg/m3) in the 1–150 μm size range. The terminal velocity of wood particles under 150 μm more and more deviates from the theoretical values. As a result of mechanical processing, the resulting wood particles’ shape is in most cases flat. The average thickness of the wood particles is mainly determined by the sawing parameters. The flat shape of particles increases the specific surface area in a certain extent depending on the distribution parameters.

Wire Bow In Situ Measurement for Monitoring the Evolution of Sawing Capability of Diamond Wire Saw during Slicing Sapphire.

Electroplated diamond wire sawing is widely used as a processing method to cut hard and brittle difficult-to-machine materials. Currently, obtaining the sawing capability of diamond wire saw through the wire bow is still difficult. In this paper, a method for calculating the sawing capability of diamond wire saw in real-time based on the wire bow is proposed. The influence of the renewed length per round trip, crystal orientation of sapphire, wire speed, and feed rate on the wire sawing capability has been revealed via slicing experiments. The results indicate that renewing the diamond wire saw, and reducing the wire speed and feed rate can delay the reduction in sawing capability. Furthermore, controlling the value of renewed length per round trip can make the diamond wire saw enter a stable cutting state, in which the capability of the wire saw no longer decreases. The sawing capability of diamond wire saw cutting in the A-plane of the sapphire is smaller than that of the C-plane, and a suitable feed rate or wire speed within the range of sawing parameters studied in this study can avoid a rapid decrease in the sawing capability of the wire saw during the cutting process. The knowledge obtained in this study provides a theoretical basis for monitoring the performance of the wire saw, and guidance for the wire cutting process in semiconductor manufacturing. In the future, it may even be possible to provide real-time performance parameters of diamond wire saw for the digital twin model of wire sawing.

现代苹果园修剪机械的设计与试验

In response to the problems of low efficiency and difficulty of pruning operations in modern dwarf dense orchards, an adjustable position saw blade pruning machine was designed, mainly consisting of a pruning device, a regulating device and a hydraulic system. Through the mechanical and modal analysis of the circular saw blade, the limit speed of the circular saw blade was derived. A finite element model of the sawing process was established, and a single-factor simulation analysis was conducted for three important parameters: feed rate, circular saw blade speed and branch diameter, and a three-factor, three-level quadratic regression orthogonal test was designed to derive the best matching sawing parameters, which was verified in field tests. The test results showed that the average passing rate was 92.8% at the feed rate of 4 km/h under the circular saw blade speed of 2800 rpm, which was higher than 88.8% at 3 km/h and 88.9% at 5 km/h. The optimum sawing parameters were: the circular saw blade speed of 2800 rpm and feed rate of 4 km/h, which were consistent with the simulation results, and the passing rate of the cut was high at this time, meeting the technical requirements of orchard pruning.

Experimental study on the formation mechanism of saw marks in wire sawing

Saw marks generated by the wire sawing process significantly deteriorate the flatness and surface quality of wafers. In this paper, the influence of sawing parameters on the geometric of saw marks is systematically studied. Based on the observation results of the saw marks morphology, the formation mechanism of saw marks is analyzed. The experimental results indicate that the cross-sectional shape of the saw marks approximates a triangular wave, and its peak-to-valley value increases with the rise of the feed rate, the wire speed, and the wire reciprocation period. The wavelength of saw marks approximates the feed distance during each wire reciprocation period. The formation of saw marks can be ascribed to the periodic lateral force originating from the twisting of the wire during the wire reciprocating. The lateral force is only about 2.7–6.2 % of the feed force, and its magnitude increases with the increasing feed rate and reciprocation period, and the decreasing wire speed. This study provides new insights for a deeper understanding of the formation mechanism of saw marks.

An analytical dynamic force model for sawing force prediction considering the material removal mode

Diamond circular saw blades are indispensable tools in the industry of granite processing. Accurate prediction of sawing force is essential for optimizing the processing in advance. In this study, the calculation method for uncut chip thickness and instantaneous chip thickness was improved based on granite sawing characteristics. Furthermore, an analytical prediction force model was proposed in view of deep and intermittent grinding, which comprehensively considers the characteristics of diamond grits (including grit size, location distribution, and protrusion height) and material removal mode. The error between the predicted results and the experimental results is <12 %, indicating that the model can accurately predict the cutting force. The proposed analytical model provides a method to optimize the sawing parameters without the need for extensive experiments. This model can also extend to calculate parameters such as energy consumption and carbon emissions in the stone processing industry.

Influence of Diamond Wire Saw Processing Parameters on the Sawn Surface Characteristics of Silicon Nitride Ceramics.

For the slicing of superhard silicon nitride ceramics, diamond wire sawing technology has great potential for application, and its slicing surface characteristics are an important indicator of cutting quality. In this paper, the sawing experiments of silicon nitride ceramics were carried out within the range of industrial processing parameters of diamond wire sawing (saw wire speed: 800-1600 m/min, workpiece feed speed 0.1-0.4 mm/min). The effects of cutting parameters on the surface morphology, surface roughness and waviness of the as-sawn slices were analyzed. The results show that within the range of sawing parameters for industrial applications, the material on the diamond wire as-sawn surface of silicon nitride ceramics is removed mainly in a brittle mode, with the slice morphology showing brittle pits and regularly distributed wire marks in the 20-55 μm scale range. The surface roughness of the slices along the workpiece feed direction ranges from 0.27 to 0.38 μm and decreases with increasing saw wire speed and decreasing feed rate. The surface waviness ranges from 0.09 to 0.21 μm, which is in good agreement with the changing trend of the sliced-surface roughness. The results of the study provide an experimental reference for promoting the engineering application of diamond wire sawing technology to the processing of silicon nitride ceramic slices.

Study on the dynamic stability of circular saw blade during medium density fiberboard sawing process with thermo-mechanical coupling

The dynamic stability of the circular saw blade determines whether the sawing process can smoothly proceed. The sawing heat significantly affects the dynamic stability of the circular saw blade. This study proposes a sawing heat simulation method which allows to analyze the temperature, stress, and natural frequency of a blade sawing medium density fiberboard (MDF). The edge temperature of the saw blade in high-speed cutting is higher than that in low-speed cutting, which leads to the formation of a large temperature gradient and reduces the natural frequency of the saw blade. However, the centrifugal stress more significantly increases the natural frequency during high-speed cutting, the saw blade still has better dynamic stability than during low-speed cutting. The simulated saw blade temperature field and static natural frequency are consistent with the experimental results, which validates the proposed method. The proposed model allows to predict the saw blade temperature distributions and to effectively set the sawing parameters.

Study on surface characteristics of as-sawn sapphire crystal wafer considering diamond saw wire wear

Sapphire crystal is widely used as Light Emitting Diode (LED) substrate and window materials for electronic devices. During the sawing process of sapphire crystal, the wear of saw wire leads to different sawing performance. In this paper, the abrasives wear state, the diameter change and wear rate of the saw wire, the change of surface morphology and surface roughness (SR) of as-sawn sapphire crystal wafer during the whole service cycle of saw wire under typical sawing parameters were analyzed, and the stable service period of diamond saw wire was determined. Further, sawing experiments were conducted during the stable service period of diamond saw wire, and the effects of sawing parameters within the industrial production on the as-sawn sapphire crystal wafers surface characteristics were studied. The results show that within range of sawing parameters adopted in this paper, the abrasives mainly remove the material in a brittle mode, and the SR of the as-sawn wafers decreases as the saw wire speed increases (from 1000 m/min to 1600 m/min), and the as-sawn wafer surface morphology is improved. As the specimen feed speed increases (from 0.05 mm/min to 0.5 mm/min), the SR increases, and the consistency of the as-sawn wafer surface morphology deteriorates.

Effect of a liquid bridge on the dynamic behavior of diamond wires during slicing

Diamond wire sawing with narrower kerf losses and thinner as-cut wafers is a critical technology to further reduce wafering costs in the semiconductor industry. Nevertheless, as the scale of the wire web decreases, the effect of the liquid bridge formed by the capillary condensation of the cutting fluid between the diamond wires becomes significant. Moreover, the transverse wire vibration reduces the wire web gap at certain moments, which makes it easier for the wires to adhere to each other after wetting, thus hindering the slicing process. Therefore, a dynamical model for a double-wire system with liquid bridge action was developed in this study based on the transverse vibration theory of a diamond wire under support excitations to reveal the action mechanism of the liquid bridge between diamond wires. The dynamic adhesion process between the diamond wires moving with the supports is discussed. The effects of the guide wheel manufacturing error and the sawing parameters on the critical gap for spontaneous adhesion between the diamond wires are analyzed. The results show that the static double-wire system does not generate spontaneous adhesion when the surface gap of the wires is between the critical gap for spontaneous adhesion and the maximum adhesion gap. The support excitation causes the transverse wire displacement, which increases the critical gap for spontaneous adhesion to increase the risk of wires adhesion. The critical gap for spontaneous adhesion increases with increases in the guide wheel manufacturing error and the wire span as well as the wire speed and decreases with increases in the wire groove diameter and the wire tension. When the manufacturing error is doubled, the critical gap for spontaneous adhesion will increase more than twice this error increment. Strict control of the guide wheel manufacturing error is the most effective way of reducing the risk of wires adhesion during processing. Increases in the guide wheel diameter and decreases in the wire span and the wire speed within a reasonable range, or enhancing the mechanical properties of the wire to improve its breaking force, also help to reduce the critical gap for spontaneous adhesion.

Influence of bandsawing processing parameters on the preparation of cortical bone flake

Natural cortical bone is an important source of bionic bone repair materials. Sawing cortical bone is the first and important process in fabrication bone repair materials. However, the high sawing temperature could cause damage to bone tissue and nerves, and surface roughness should decrease osteoinductivity. In order to improve the cutting performance during sawing cortical bone, and the quality of prepared cortical bone slices, the band sawing process should be investigated and improved. In this paper, the novel cortical bone sawing experiment was designed with different feed rate and tooth pitch. Then, the influence of experimental parameters on temperature and roughness were analyzed with Analysis of Variance (ANOVA). The experimental results show that the lowest value of temperature is 35.5°C (tooth pitch is 8.46 mm, feed rate is 35 mm/s), the highest one is 73.8°C (tooth pitch is 4.20 mm, feed rate is 5 mm/s). And the turning point of surface roughness appear when the feed rate is 20 mm/s. Otherwise, the prediction model of sawing temperature and surface roughness could help to find optimal band sawing parameters of natural cortical bone.

Investigation on the sawing temperature in ultrasonic vibration assisted diamond wire sawing monocrystalline silicon

In this paper, the effects of different sawing parameters (wire saw speed vs, feed rate vw, workpiece rotation speed nw) and ultrasonic vibration on the sawing temperature in diamond wire sawing monocrystalline silicon were studied. Firstly, the finite element model in diamond wire sawing monocrystalline silicon is established with respect to the thermal transient analysis in ANSYS. Then the influence of different sawing parameters and ultrasonic vibration on the sawing temperature during the sawing process is simulated and analyzed. Finally, the experiment of diamond wire sawing monocrystalline silicon is accomplished to validate the simulation results. The results show that the highest sawing temperature in conventional diamond wire sawing (CWS) is 27.9 °C and that in ultrasonic vibration assisted diamond wire sawing (UAWS) is 29.9 °C. In addition, with the increase of wire saw speed, feed rate and workpiece rotation speed, the sawing temperature increases averagely by about 3.6 °C, 1.6 °C, and 2.0 °C respectinvely in CWS, and the sawing temperature in UAWS increases averagely by 3.7 °C, 1.5 °C and 1.5 °C. The sawing temperature in UAWS is about 1.5 °C higher than that in CWS under the same sawing parameters. The average error between the simulation and experimental results of highest sawing temperature is 8.6% and the maximum error is 14%, which verifies the simulation model.

Dynamic modeling and experimental validation of vibration for diamond beaded rope during granite cutting

The vibration characteristics of sintered diamond beaded rope (SDBR) for cutting granite are investigated both theoretically and experimentally. A theoretical relationship is established between the random sawing forces of a single diamond-beaded and the sawing parameters. The closed-form analytical solution of both free and forced vibration responses of the SDBR are obtained using Green's function, which is derived using an inverse Laplace transform. The influence of parameters, such as the tension of beaded rope, the linear speed of beaded rope, and the feeding speed of beaded rope and the different action positions of diamond beaded, on the vibration characteristics of the SDBR is analyzed, and compared with the single factor experiment of the SDBR subject to random sawing force, which validates the presented method. The results showed that the vibration response of the SDBR is asymmetrical to the left and right, the action positions of diamond beaded and tension of the SDBR are the key factor that cause the forced vibration response displacement of the beaded rope fluctuates, and the feeding speed of the SDBR is the most important factor affecting the removal of granite material. Therefore, it is crucial to balance the sawing force and cutting performance by optimizing the sawing parameters, especially the feed rate.

Fabrication of thin resin-bonded diamond wire and its application to ductile-mode wire sawing of mono-crystalline silicon

Fixed diamond wire has been the most common tool for slicing semiconductor ingots into wafers in fields of photovoltaics and integrated circuits. The diameter of diamond wire and thickness of wafers are decreasing dramatically to reduce material cost. Compared with electroplated diamond wire, resin-bonded diamond wire has a more uniform distribution of protrusion height, which leads to less crack damage, and therefore ensures further thinning of wafer thickness. However, due to the restriction of materials and resin-bonded diamond wire fabrication technology, the application of resin-bonded diamond wire is still limited. In this paper, thin resin-bonded diamond wire with core wire diameter of 60 μm is developed using a self-developed wire-fabricating device, and its corresponding morphology and sawing performance are evaluated. The examined quality of sawn wafers indicates that the thin resin-bonded diamond wire meets the requirement of wire sawing. Besides, a 3D morphology model for the thin wire is established considering the uniform distribution of protrusion height of abrasives. Wire sawing parameters to realize ductile-mode wire sawing of mono-crystalline silicon are determined using the established 3D morphology model.

Modelling internal knot distribution using external log features

The quality of the end product in the sawmill industry is highly dependent on the distribution of knots. If the internal structure of the logs used as raw material were known it would be possible to optimize the sawing process by controlling the locations of individual knots in the resulting boards. Methods such as Computer Tomography or Magnetic Resonance Imaging can be used to gain reliable information about the internal structure of the logs prior to sawing. Such scanners are, however, expensive or slow, which renders the use of these methods ill-suited to online integration in sawmill operations. Laser range scanners, on the other hand, are very fast but provide only external information. A method to estimate the internal log structure using only external information provided by a laser range scanner is proposed in this paper. The method comprises five major steps: point cloud filtering and centreline estimation, log surface heightmap generation, knot segmentation, volumetric reconstruction of knots and virtual sawing. The end result is the generation of images of virtual boards for the given sawing parameters. The method was evaluated on debarked softwood logs. The experimental part of the work demonstrates that the pixel intensities of the virtual boards generated using the proposed method correlate well with the probabilities of knots appearing in the corresponding locations in the final product. Virtual sawing allows exhaustive evaluation of different sawing parameters, thus making it possible to optimize sawing parameters prior to sawing.

Minimizing aerosol bone dust during autopsies.

When sawing bone for medical or medico-legal procedures, fine, airborne dust is produced (aerosols) that can pose a health hazard when inhaled. The aim of this study was to determine the influence of saw blade frequency and contact load, bone condition, test environment, and saw blade type, on the production of aerosol particles. A custom test setup was designed, manufactured and used in 8 bone sawing experiments, using a particle counter to determine the production of aerosol particles while varying the 5 chosen parameters. The number of counted particles was highest with higher saw blade frequencies, lower saw blade contact loads, in dry completely skeletonized bone compared to fresh bone, and using an electrical oscillating saw compared to hand-sawing. Under all conditions, the high amount of aerosol counted posed potential health risks. The ventilation system that we tested was adequate in removing the produced particles, but these high-tech systems are not always available in developing countries or emergency situations. The production of aerosols can be reduced by optimizing the sawing parameters. However, even the lowest number of aerosol particles counted during the current study was high enough to cause potential health risks to practitioners. Safety precautions should be taken, such as external ventilation, proper breathing gear, and adequate protocols, to truly minimize the risk in all bone sawing scenarios.

The effect of operational parameters on diamond tools of frame sawing system: Wear characteristics and optimization in stone processing

A series of sawing experiments was carried out to investigate the effect of operational parameters on the wear characteristics of diamond segment. And the wear mechanism of diamond segment was studied through micro-morphology. The analysis presented that the wear mechanisms of segment metal matrix are mainly attributed to abrasive wear and erosion wear, the wear mechanism of diamond particles mainly includes cleavage fracture caused by the impact load and abrasion caused by scratching. The effect of sawing parameters on the wear rate of segment matrix is consistent with that of diamond particles. The wear resistance of segment matrix increases with the increase of the proportion of diamond particles with micro-fractured and complete crystalline shape, and decreases with the increase of the proportion of diamond particles with macro-fractured and pulled-out. Furthermore, the predicted model was established to evaluate the segment wear per unit by using Design Expert software, and the optimum sawing parameters obtained as a result of the optimization was investigated to provide some guidance for the processing of the enterprise.

Investigation of the sawing performance of a new type of diamond frame saw machine

Generally the frame sawing with diamond segmented blades is the equipment in soft stones sawing process. In this work, a new type of frame saw machine used for cutting granite is introduced. The sawing trajectory and the theoretical relationship between the average chip thickness and the sawing parameters are established. Utilizing the new frame saw machine, an experimental study was carried out to investigate the sawing forces and segments wear in different strokes. It is concluded that no matter in forward stroke or in backward stroke, only half of the stroke is sawing the stone. The sawing forces of segments increase with the increase of the feed speed and cutting length, and show a decrease trend with the increase of the rotation speed of the crank. What's more, the forces in backward stroke are higher than that of forward stroke. Well-developed matrix tails are formed behind the diamond grits, while the wear of segments at the front end of the blade is severe than that in the middle and at the rear end, the shapes of the diamond segments changed from trapezoidal into rectangular.

Potentials for the optimization of sawing processes using the example of bandsawing machines

Sawing processes are the focus of process optimization in order to reduce material costs and save energy resources. Bandsawing machines allow fast processes but produce a low surface quality and great cutting losses of raw material up to now. The wear of saw blades is significant due to the cutting conditions as well as the thin and unstable tool design. Electromechanical drives can substitute inefficient hydraulic systems for workpiece clamping and for the prestressing of saw blades, and provide the precondition for autonomous process control. In order to adjust the sawing parameters during the process, the simultaneous identification of process stability is necessary. In this work, influences on the process stability were investigated by experiment and simulation in order to develop a stability criterion as a function of different process parameters. The focus here was on the behaviour of the saw blade in the kerf. A great influence of saw blade tension could be observed.

Finite element simulation and analysis of saw cutting

In this paper, Finite Element Analysis (FEA) used DEFORMTM 3D to construct 6061 aluminum sawing simulation. Before sawing, we pushed the speed and cutting speed under pressure as a sawing process parameters. Then there are three groups of combination conditions in the study. Analysis and discussion based on loading, effective stress, cutting temperature and blade wear. According to the impact parameters the structural design of the saw blade is improved by taking full account of the mutual influence of sawing parameters.