Comparison of advantages and disadvantages of various cutting processes

As a traditional cutting equipment, there are mainly (CNC and non CNC) shears, punches, flame cutting, plasma cutting, high-pressure water cutting and other means. These equipment occupy a considerable market share in the market. On the one hand, they are well known, and on the other hand, they are cheap. Although they have obvious disadvantages compared with modern technologies such as laser cutting, they also have their own unique advantages.

1. (CNC) shearing machine

Because it is mainly straight cutting, although it can cut up to 4m long plates with one knife, it can only be used for sheet metal processing that only requires straight cutting. It is generally used in industries that only need straight cutting, such as cutting after the plate is flattened.

2. (CNC/turret) punch

It has more flexibility in curve processing. A punch can have one or more sets of square, round or other special requirements punches. It can process some specific sheet metal workpieces at a time. The most common is the case and cabinet industry. The processing technology they require is mainly cutting straight lines, square holes, round holes, etc. The patterns are relatively simple and fixed. They mainly face the carbon steel plate with the width of 2.5m × 1.25m。 The stainless steel with a thickness of more than 1.5mm is too viscous to use a die, and generally does not use a punch.

Its advantage is that it can process simple figures and thin plates quickly, while its disadvantage is that it has limited ability to punch thick steel plates. Even if it can be punched, the workpiece surface will collapse, which will cost mold. The mold development cycle is long, the cost is high, and the degree of flexibility is not high enough. In foreign countries, more modern laser cutting is generally used for cutting steel plates of more than 2mm, instead of using a punch. On the one hand, the surface quality of thick steel plates is not high when punching and shearing; on the other hand, punching thick steel plates requires a punch with larger tonnage, wasting resources; on the other hand, the noise is too loud when punching thick steel plates, which is not conducive to environmental protection.

3. Flame cutting

As the original traditional cutting method, due to its low investment, the requirements for processing quality were not high in the past. If the requirements were too high, it could be solved by adding a machining process. The market is very large. Now it is mainly used to cut thick steel plates with a thickness of more than 40mm. Its disadvantage is that the thermal deformation during cutting is too large, the kerf is too wide, wasting materials, and the processing speed is too slow, which is only suitable for rough processing.

4. Plasma cutting and fine plasma cutting

Similar to flame cutting, the heat affected zone is too large, but its precision is much larger than that of flame cutting. The speed also has an order of magnitude leap, becoming the main force of medium plate processing.

The actual cutting accuracy of the top CNC fine plasma cutting machine in China has reached the lower limit of laser cutting. When cutting 22mm carbon steel plate, it has reached a speed of more than 2 meters per minute, and the cutting end face is smooth and flat. The best slope can be controlled within 1.5 degrees. The disadvantage is that when cutting thin steel plates, the thermal deformation is too large, the slope is also large, and there is nothing to do when the accuracy is required. Consumables are expensive.

5. High pressure water cutting

It uses the high speed water jet doped with emery to cut the sheet metal. It has almost no restrictions on the material, and the cutting thickness can almost reach more than 100mm. It can also cut the materials that are easy to burst when using thermal cutting such as ceramics and glass. Copper, aluminum and other materials can be cut with the laser high reflection material water jet, but laser cutting has a big obstacle.

The disadvantage of water cutting is that the processing speed is too slow, it is too dirty, it is not environmentally friendly, and the consumables are also high.

6. Laser cutting

It is a technological revolution in the processing and blanking process. Laser cutting is characterized by high flexibility, fast cutting speed, high production efficiency and short production cycle, which has won a wide market for customers. Laser cutting without cutting force, processing without deformation; No tool wear, good material adaptability; No matter simple or complex parts, they can be cut by laser precision rapid prototyping in one time; The cutting seam is narrow, the cutting quality is good, the degree of automation is high, the operation is simple, the labor intensity is low, and there is no pollution; It can realize automatic cutting layout and nesting, improve the utilization rate of materials, lower production cost and good economic benefits. The effective life of this technology is long. At present, most of the super structured 2mm plates abroad use laser cutting. Many foreign experts agree that the next 30-40 years is the golden age for the development of laser processing technology.