Which cutting efficiency is higher, circular saw or band saw?

Discussion on sawing mode of aluminum alloy materials

At present, the sawing of aluminum alloy materials basically adopts disc sawing machine and high-speed band sawing machine. Many users often ask how to choose. Taking the specifications of common aluminum bars in the market as an example, this paper analyzes and compares the following points, discusses their advantages and disadvantages, and helps everyone to choose equipment reasonably and achieve the effect of economic cutting.

1.？ Sawing material properties:

Compared with steel, aluminum alloy has low melting point, high plasticity and soft texture, and is prone to bonding, deformation and vibration during sawing, so sawing speed, chip removal mode, saw blade selection and lubrication cooling mode are the key factors.

2.？ Sawing efficiency:

Different from black gold, high-speed sawing is suitable for aluminum alloy materials, which can reduce the cutting load of each sawtooth, promote chip removal and prevent the broken teeth and bending of the saw blade. The sawing speed depends on the linear speed, feed speed and machine tool rigidity, and the feed speed matches the linear speed, so the higher the linear speed, the faster the sawing speed.

At present, the linear speed of band saw is 10~20m/s, and that of circular saw is 60~80m/s, so the efficiency of circular saw is five times that of aluminum bar with the same diameter.

Of course, the band saw can cut multiple blades at the same time, and the horizontal band saw can cut multiple blades at the same time, so the efficiency can be compensated. However, it is more difficult for aluminium scrap to discharge in time, so it is not recommended to shorten the life of the saw blade in exchange for sawing speed. Therefore, the vertical band saw is mostly used for multi-pole sawing, and the vertical band saw is equivalent to single-pole sawing, with the same efficiency.

3.？ Saw seam width:

Generally speaking, the kerf width of a band saw is 1/3 of that of a circular saw. For aluminum processing manufacturers, the narrower the slit, the better the economic benefit, and the lower the sales price of waste aluminum. However, for aluminum rod casting manufacturers, the length of casting rod in the market is generally 6.3 meters, and the effective finished product length of saw head and tail is 5.8 meters, so the width of saw seam has no influence on casting manufacturers.

4.？ Chip removal mode, recovery rate of waste aluminum:

Chip removal mode: circular saw can easily lift chips along the cutting force direction and discharge them smoothly, and most of the heat generated during sawing is accompanied by aluminium scrap; The aluminium scrap of the band saw is stored between the serrations and brought out along with the advancing direction of the saw blade. Heat concentration is easy to stick to the knife, and what is more serious is the microstructure of aluminum abrasive particles, which will accelerate the wear of the saw blade.

Aluminium scrap recycling: The aluminium scrap of circular saw is flaky or fish scale-shaped, which is discharged into the chip collecting groove along the tangential stress direction, collected by centrifugal fan, recycled by briquetting machine or directly melted. During this period, the saw head was surrounded and the recovery rate reached 98%. Aluminium scrap of band saw is in powder form, and it is difficult to form after recycling. If it is directly melted, it will become aluminum ash, and the head is in an open state, so the recycling rate is not high.

5.？ Sawing surface finish

The disc saw has fast tangent speed, timely aluminium scrap discharge, high cutting accuracy and no scratches, and can achieve machining effect;

The linear speed of the band saw is high and low, and the aluminium scrap residence time is long, which increases the resistance of the sawtooth, easily scratches the cross section of the workpiece and affects the roughness.

6.？ Lubrication cooling

Most of the heat generated in the sawing process of circular saw is taken out with aluminium scrap, and only micro-jet lubrication and cooling are needed, and the oil injection amount is 2 ml/h; The heat generated by band saw sawing can not be eliminated in time, and a large amount of lubricant needs to be sprayed for lubrication and cooling, which affects the working environment and increases the use cost.

7.？ Saw blade cost:

At present, the technology of cemented carbide circular saw blade in China is relatively mature. Because of the complicated manufacturing process, most of the disc cemented carbide saw blades use foreign brands, and the cost is 3~5 times that of the disc cemented carbide saw blades.

8.？ Production cost:

The low linear speed of ordinary band saw can not meet the requirements of aluminum alloy sawing. Domestic aluminum alloy high-speed band saw is basically upgraded on the basis of ordinary black gold sawing machine. While strengthening the rigidity of the machine body and improving the assembly accuracy, variable frequency motor drive, ball screw drive and servo control system are adopted to improve the sawing speed and stability, and its manufacturing cost has exceeded that of the disc sawing machine.

9.？ Scope of application;

The power of band saw is relatively constant between 20 and 30 kW, and the power of circular sawing machine is related to the diameter of saw blade, and the diameter of saw blade is related to the diameter of bar. Combined with motor power and sawing efficiency, it has advantages in sawing aluminum bars below 18 ". The diameter of the saw blade of the circular boring machine above 18 "exceeds1.5m, so the manufacturing cost of the machine tool is high and the power exceeds 100KW. Band saws are mainly used for sawing.

To sum up, circular saw and band saw are both applicable in the field of sawing aluminum alloy bars, and users can choose according to the product characteristics. Of course, some special fields, such as aviation materials, have higher requirements for sawing surfaces, and circular saws will also be selected, which is only a special requirement. The development of band saw is constantly improving and upgrading, giving full play to advantages, improving disadvantages and improving sawing efficiency.