Band Sawing Research Articles

Active runout compensation using the guide elements on metal band saws for a longer tool life and reduced material loss

AbstractAt a time of rising energy and material costs, manufacturing process efficiency is becoming increasingly important. This is one reason why cutting and especially sawing processes, usually the first step in most manufacturing chains in discrete part production, have to be investigated more intensively. Due to problems with runout and poor surface finishes, raw material is conventionally cut to oversize by either circular sawing or band sawing. This oversize has to be removed by following processes, costing extra energy and wasting material. Since the problem of runout increases with increasing tool wear due to higher deflections of the thin and compliant tools, an even larger oversize is required. This paper describes an approach to reduce the need of oversize even with increasing tool wear in band sawing by tilting the saw band in order to compensate for tool deflections during cutting. To achieve this, it is necessary to measure and understand the saw band runout. The next step is to present a system design and controller for tilting the saw band. Finally, tests are carried out to analyse the effectiveness of the system. In addition, the approach allows the use of increased process parameters to the end of the tool life without losing more material. The tool can therefore be used productively for a longer time period.

Capacity of surface production of band sawing in manufacture of oak floor upper layers

Thin lamellae, corresponding to the layer components of structural glued members, i.e., 2-ply or 3-ply glued flooring, can be manufactured in re-sawing operations of kiln-dried wood blocks or in wet technologies, which currently seem to be more common because of the shorter drying time. The re-sawing process in wet technology is conducted on dedicated thin-cutting band sawing machines with stellite-tipped band saws. The goal of this research was to demonstrate the capacity of surface production (m2/ tool life) of visible layers of oak engineered flooring composites in a function of both a new band saw and a re-sharpened band saw blade. Additionally, the state of teeth of each band saw blade was examined at the end of the tool life. A series of cutting tests were performed in sawmill production conditions. The conducted tests revealed that a three times higher capacity of surface production was obtained for the new tool compared to re-sharpened tool. Additional microscopic observations of some re-sharpened teeth showed deformed plastic characteristics.

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.

Improving the quality of the band saw cut

This article is devoted to the study of the dynamic characteristics of the band sawing process to improve their efficiency. The object of study is: band saw, softwood. A screening experiment was carried out when sawing with band saws to identify key influencing factors on the quality of the treated surface (roughness) and sawing force (sawing power). Rational values of key influencing factors were determined. The effectiveness of the sawing regimes with band saws was evaluated. In the course of laboratory tests of the new saw, it was found that the moisture content of the wood has the maximum effect on the quality of the sawing walls. According to the degree of influence of factors, the roughness of the cut depends on the moisture content of the wood, the feed per tooth, the type of cutting relative to the wood grain and the height of the cut. As a result of a multivariate experiment, two regression equations were obtained for the assumed roughness of the cut and the cutting power. The estimation of the significance of the coefficients in the given interval of variation of the influencing factors is carried out.

A Critical Reanalysis of Uncontrollable Washboarding Phenomenon in Metal Band Sawing.

The article analyzes the cutting process of hard bars. Investigations conducted in industrial conditions demonstrated the presence of surface errors in the machined workpieces in the form of washboard patterns. The purpose of this study was to analyze the results of cutting on band sawing machines with different band saw blades. The cutting processes were conducted on three different horizontal band sawing machine types. Analyzed material was an alloy steel Ø40 mm rod with a hardened surface covered with a thin layer of chromium. The hardness of the outer layer was 547 HV with a core hardness of 180 HV. The surface topography measurements of the processed workpieces were carried out with the 3D Optical Profiler, which supplied information on the irregularities of the processed material texture. In each of the analyzed cases, a corrugated surface was obtained after sawing, which is the effect of the occurrence of the washboarding phenomenon, despite the fact that the teeth of each band saw had variable pitches. The washboarding phenomenon when cutting rods with hard surfaces is caused by the phenomenon of wave regeneration. Despite the use of variable pitch saw blades, the cutting process results in rippling of the sawn surface, which is caused by the high hardness of the outer layer of the workpiece, as well as by the type of tool with spring setting of teeth.

Predicting cutting power for band sawing process of pine and beech wood dried with the use of four different methods

Wood drying is an important stage in the woodworking process. After drying, wood is subject to a re-sawing process, for which a high quality surface, low material loss, and high efficiency are often required. In this paper, forecasted values were presented of cutting power for the re-sawing process of pine and beech wood that were dried with four different methods. Forecasting of cutting power for an industrial band saw machine that works daily in a Polish sawmill was determined. Values of cutting power were forecasted for a full range of feed speeds of the analyzed band saw machine. The achieved results allowed the observation of noticeable changes in the forecasted cutting power for a given sawing process as a function of the wood drying method applied. Significant changes were observed for pine wood, especially between air-dried pine wood and wood dried with warm air-steam mixture, and between pine wood dried in a conventional kiln and with warm air-steam mixture.

The Mechanical Modeling and design of saw frame in band sawing machine

현대 제조 공업이 고효율, 고정밀도와 경제적인 방향으로 발전 하면서 금속을 절단하는 띠톱 기계는 이미 철강, 기계, 자동차, 조선, 석유, 광산, 항공 우주 등 다양한 영역에서 광범위 하게 활용 되고 있다. 하지만 기존의 띠톱 기계들은 경험적으로 설계 되어져 왔으며 따라서 낮은 수명, 톱질 동작 상태에서 낮은 정밀도 및 저효율을 문제와 높은 제조원가 문제를 가지고 있다. 본 논문에서는 띠톱의 역학적 해석을 통해 띠톱 톱대의 설계 파라미터를 개선하는 방법을 제시 하였다. 실제로 빈번하게 사용 되고 있는 띠톱 기계를 모델링 하여 응력 분석, 피로해석을 시행 하였으며 이에 따라 톱대의 상세한 설계 파라미터를 도출 하였다. 그 결과 피로 강도가 피로 요구 사항을 만족 시키고 띠톱 기계의 정밀도와 효율이 크게 향상 되는 것을 확인할 수 있었다.

Prognozowanie wartości mocy skrawania dla procesu przecinania impregnowanego drewna sosnowego na pilarce taśmowej

In this paper the predicted values of cutting power for band sawing machine (ST100R), which is used in the Polish sawmills, were presented. The values of cutting power were determined for wood of Scots pine (Pinus sylvestris L.), which was impregnated and not impregnated. These values were estimated using an innovative method of forecasting cutting forces, which takes into account the elements of fracture mechanics. The forecasts obtained in this way are compared with the values of cutting power estimated with the use of the classical method, which is based on the specific cutting resistance.

Design and Development of a Guide Bracket for Horizontal band Sawing Machine by Geometrical Optimization

All modern manufacturing units are striving to develop a cost effective product with optimized reduced weight by using CAE driven design process. In this scenario the product design is stimulated by structural optimization tools like geometrical (topology) optimization, shape optimization or size optimization. For conservation of natural resources and optimum energy utilization, weight reduction has been the main focus of machine tool manufacturers in the present scenario. Weight reduction can be achieved by the introduction of better material, better manufacturing processes and design optimization. In automobile and aircraft sector, geometrical optimization has become an integral tool of product design and development. Geometry (topology) assisted design model gives optimized results which are better and innovative in terms of product design with enhanced structural performance and stability. In other words, simulation saves time, reduces costs, and strengthens the competitiveness of companies, thus strengthened market position.

Influence of spectral acquisition technique and wood anisotropy on the statistics of predictive near infrared–based models for wood density

Wood density is an important criterion for material classification, as it is directly related to quality of wood for structural use. Several studies have shown promising results for the estimation of wood density by near infrared spectroscopy. However, the optimal conditions for spectral acquisition need to be investigated in order to develop predictive models and to understand how anisotropy and surface roughness affect the statistics of predictive partial least square regression models. The aim of this study was to evaluate how the spectral acquisition technique, wood surface, and the surface quality influence the ability of partial least square–based models to estimate wood density. Near infrared spectra were recorded using an integrating sphere and fiber-optic probe on the tangential, radial, and transverse surfaces machined by circular and band saws in 278 wood specimens of six-year-old Eucalyptus hybrids. The basic density values determined by the conventional method were then correlated with near infrared spectra acquired using an integrating sphere and fiber-optic probe on the wood surfaces by means of partial least square regressions. The most promising models for predicting wood density were generated from near infrared spectra obtained from the transverse surface machined by the bandsaw, via an integrating sphere ([Formula: see text], RMSEP = 23 kg m−3 and RPD = 3.0) as well as for the optic fiber ([Formula: see text], RMSEP = 35 kg m−3 and RPD = 2.1). Surface quality affected the spectral information and robustness of predictive models with a rougher surface, caused by band sawing, showing better results.

Prediction model development for material removal rate in band sawing using dimensional analysis approach

Bandsawing is an accurate and fast process to cut various raw materials. Material removal rate (MRR) is the important parameter in bandsawing to judge its performance. To the best of knowledge of the author, almost none of the researchers has developed semi empirical model to study combined effect of process, material and machine parameters for bandsawing process. Hence, in the present research work, semi empirical model is developed for MRR using dimensional analysis approach. In this work, Taguchi's technique is used to conduct experiments. As per ANOVA, feed (58%), speed (17.44%) and top arm angle (13.55%) found as significant parameters. The model is formulated as a function of these parameters and validated calculating mean error (0.024), root mean square error (0.029) and percentage average error (6.63%). The model is verified by randomly substituting the values from experiment data set. The predicted results were found in close agreement with the experiment results.

Study on the Cutting Efficiency of High-Speed Band Saw Blade by Taylor Tool Life and Fractal Equations

The study proposed the chip formation steady-state model and cutting efficiency model for multi-cutters by Taylor tool life and fractal equation according to uniform chip thickness in high-speed band sawing process. Furthermore, a kind of new hook-tooth can be successfully applied on continuously uniformed chip formation in order to raise the production precision. The study developed MDOF cutting dynamics, which can be applied on multi-cutting process by Taylor tool life and fractal equations. Factors of affecting band-sawing included the cutting force, the cutting geometry, the cutting heat, the local stress-strain and the chip thickness formation uniformity. These factors had an important influence on tool wear, surface roughness, production precision and cutting efficiency in high-speed sawing process. The simulated results shown that, the wear resistance property is better at coating TiN 0.6 μm. In high-speed cutting process, the cutting improvement rate can be increased at least 13%. While the hook-tooth cutting speed achieved 120 m/min, comparing with non-coating cutting tooth, coating 0.6μm coating-layer can make the temperature decreased, obviously.

Prediction model development for material removal rate in band sawing using dimensional analysis approach

Prediction model development for material removal rate in band sawing using dimensional analysis approach

A study on the compensation of secondary distortion effect in the cutting process of a welded structure

Lug structures are commonly used in heavy industries. Welded lugs with holes could be hooked onto and transported by a crane. After setting up, the lugs are typically cut away using a flame cutting process. As undesirable damage is caused by concentrated heat input, the band saw cutting process is more appropriate. However, re-establishment of equilibrium within the remaining part of the structure causes secondary distortion owing to the redistribution of the residual stresses. Additionally, in the cutting procedure, the stiction problem always occurs because of the squeezing of the saw blade between the materials. A compensation method, which uses an additional procedure before the cutting process, is proposed in this study. The top side of the lug is thermally heated to induce the redistribution of residual stress and make the amount of distortion same as that in the final state after cutting. Comparing the results from experiment sets, the stiction problem in the band sawing of a lug was alleviated using this additional procedure. The additional heating procedure did not intensify the final welding distortion. The compensation effect of thermal heating was confirmed in this study.

Characterization of Sawdust Produced from Circular, Chain and Band Sawing Machines

Particle size distribution (PSD) of sawdust produced from circular, chain and band sawing machines has been carried out in order to study the influence of different saws on sawdust produced and its characterization. The raw materials were collected from the mill sites and screened, then vibrated on mechanical sieves. Four major fractional classification of particle sizes are identified; oversize particles (OS), coarse particle (CPS), pin particle (PSP) and fine (FSP). The particle size distribution in all the three mills shows a similar pattern of distribution on log sieve graph. The proportion of particle size distribution in FPS produced by all the saw showed slight variations with the least (30.0 ± 1.2%) variation in bandsaw, followed in increasing order by chainsaw and circular saw (37.2 ± 1.3%). Analysis of variance revealed that blade type, particle size, wood density, and particle density are significantly affected by porosity.

The Study of Band Sawing Vibration and Cutting Performance

Band saws machine is the most efficient metal cutting machine. By losing less material, material qualitative, having big saw range and having low cutting costs are superiority of band saws. Band saws are acting with most long route and more limited support point in all cutting tools. In band sawing machine, band saws and structure are easy to produce vibration. Affect cutting life, costs of band saws and material surface topography. So this study focuses on analyzing what is vibration cause of band saws by vibration source and establishes the relationship between band saws natural frequency along and change cutting condition. In this research use the C-430GNC band saws machine, and use S45C material for cutting test. Accelerometers are used with a measurement system to capture sawing vibration data. By the fast Fourier transform to analyze spectrogram transform in order to identified characteristic spectrums, and find out vibration feature with band sawing operating conditions and unusual evens came from wear of blade. Minimum cutting vibration and best surface topography were compared to find out the best cutting condition.

Stability diagrams and chatter avoidance in horizontal band sawing

The paper presents recurrence plot based stability analysis of the horizontal band sawing process of structural steel profiles. The analysis is performed in the parameter space defined by the cutting speed, the distance between the blade supports, and the feed rate. The corresponding stability diagrams have been constructed using the recurrence plot characteristic, the determinism of the sound pressure emitted by the process, which quantifies the process predictability. The topology of the experimentally obtained stability diagrams revealed non-linear non-monotonic dynamic behaviour, which made two different chatter avoidance strategies possible by cutting speed variation.

Параметры рабочей поверхности отжимной аэростатической направляющей ленточнопильного станка

Параметры рабочей поверхности отжимной аэростатической направляющей ленточнопильного станка

Study on Online Detection and Fault Diagnosis of Band Saw Equipment

Due to the size and material changes and the hard impurities of the cutting workpieces in the band sawing process, the load of the band saw blades changes greatly so as to easily break the blades. The load of the band saw blades in the cutting process is unbalanced so as to easily produce the deviation of the saw blade’s cutting path, even seriously affect the accuracy of the sawing. On the occasion of the heavy cutting to some materials, the artificial cutting is time consuming and laborious, and the efficiency is low. So there is an urgent need to develop the automatic weighing and measuring device for the band sawing machine. At the same time, the CNC technology is widely used in the high-level band saw machine. So the online detection technology of the band saw equipment is an important foundation for the solution of the above problems and the application of the numerical control technology [1-4]. Aiming at the lower automation, accuracy and efficiency of the domestic band sawing machine, this paper studies the real-time detection technology based on the sawing load, and the control system of the constant power sawing. The real-time detection technology based on the micro-deviation of the band saw’s trajectory and the deviation-correction control system are studied. The weight-detection technology based on the scan reconstruction of the surface profile size and the control system of the fixed weight are researched. That can improve the accuracy and efficiency of the band sawing machine and provide the foundation for the realization of the digital control of the band sawing machine. The fault diagnosis for the band sawing machine at home supplies usually the alarm information and the alarm lamp output when the proximity switch or contact switch collects the information over the designated station [5]. The fairly advanced band sawing machine has the HMI display to supply the alarm information. Those are low in the automatic diagnosis. The high-level CNC band sawing machine has the complex structure, and influenced by many factors. If the failure in the processing state can be not timely and accurately diagnosed, the machine will not be able to protect the manufacturing quality and accuracy. It will cause the waste to increase, the productivity to decline, or even result in a significant loss of the machine scrap. That urgently needs to introduce the dynamic monitoring and control with the intelligent diagnostic technology. The abnormal recognition and intelligent maintenance On li V rsi on O nly .

Experimental Chatter Characterization in Metal Band Sawing

One of the most detrimental instability phenomena in metal band sawing is chatter, i.e. high amplitude vibrations of the tool and/or workpiece. In this paper, the influence of the cutting speed and of the distance between the blade supports on chatter phenomena is investigated. For this purpose a series of experiments with triangular cutting speed variation at several pre-selected distances between the blade supports was conducted on structural steel (St37, DIN 17100) workpieces. A feature for chatter detection was extracted from the power spectra of the machine vibration signal, and a set of characteristics was introduced for experimental chatter characterization. The results showed the presence of a chatter hysteresis which depended on the cutting speed. Additionally, apart from the blade support distance, the cutting speed was shown to be a strongly influencing parameter, and as such also promising for chatter control in band sawing processes.