Laser cutting is a technology in which laser beams are used for cutting and engraving on fabrics, papers, metals, woods, etc. It is widely used in industry. Laser cutting machines work by focusing the output beam of a powerful laser on the materials. Industrial lasers are used in various industries such as military, construction, aerospace, medicine, laboratory and research, communications, physics, chemistry and etc.

Types of laser cutting

In general, laser cutting tasks are done as laser cutting of metals and laser cutting of non-metals.

Laser cutting of non-metals

This method can be used to cut many non-metallic materials such as MDF, Plexiglas, fabrics, natural and synthetic leather, plastics and some rubbers. Laser cutting machine usually works with CO2 laser and it can be used to cut most non-metallic materials except mineral materials such as tiles, ceramics, glass and mirrors.

 

Laser cutting of metals

For cutting metals, various methods can be used, such as laser cutting, waterjet cutting, air cutting, plasma cutting, cutting with cutting blades and etc. Laser cutting is used in cases where the user wants to cut metals with a thin thickness (usually less than 8 mm) and also when the desired tolerance is low or in other words, the cutting accuracy is high. Of course, there are laser machines that can cut steel up to a few centimeters, but their use is not common due to high purchase costs and high power consumption.

 

Old methods of metal cutting

Older methods of metal cutting include milling, lathing, air-gas cutting, plasma cutting, waterjet cutting and guillotine cutting. The thickness of the cut in all these methods varies from 1 mm to 200 mm. Today, there is the modern method of laser cutting, which is used for cutting metals in most cases due to the accuracy of micrometer cutting (a thousand times more accurate than the old methods), time and cost savings, as well as higher quality of cutting.

 

Advantages of laser cutting over traditional methods

 

The speed of the laser pulse is about 100 nanoseconds in laser cutting (one million times faster than 0.1 seconds). At this speed, the material piece is cut before heating and deformation. As a result, in laser cutting, no burns will be observed on the surface of the material and the pleat behind the material. Also, the mechanical and physical properties of the material will be preserved.

During the cutting, the laser device has no contact with the surface of the material and the physical pressure is not applied to the material. So there won’t be crushing at the edges of the material.

Due to the high power of the laser source, laser devices have a high speed for the laser cutting of the materials.

The cross-sectional area of ​​the laser spot in the laser cutting is between 30 and 100 micrometers. This makes the accuracy of laser cutting at least a thousand times higher than the traditional methods. As a result, the laser machine can make holes and cuts with dimensions of 50 micrometers. But, this accuracy varies depending on the thickness of the material.

 

The beam of cutting laser is incident on the surface of the material with a CNC device and a shape is designed digitally by using a computer, without hand intervention. The advantages of using CNC laser cutting machines are as follows:

1.     Very high precision in cutting without creating pleats up to 0.1 mm

2.     Complex designs and two-dimensional drawings and any drawn designs by tools such as AutoCAD and … can be implemented in metal laser cutting technology, easily.

3.     In laser cutting, you do not need traditional methods (molding and pressing) and the materials do not need to be re-machined after CNC laser cutting.

4.     Creating any desired and complex shape in the material based on the customer's wishes without restrictions

5.     High level smoothness of the surface

6.     Since the laser does not come into contact with the material, no contact stress is created and the focusing accuracy in laser cutting is maintained

7.     No burns due to cutting

8.     Low material waste

 

Therefore, due to their micrometer accuracy and lack of burns and stress in the material, it can be said that cutting lasers are widely used in various industries such as military, construction, aerospace, medicine, laboratory and research, communications, physics, chemistry and etc.

 

An example of dimensions and materials of the sheets for cutting with the CNC laser machine.

Material	Thickness	Length	Width
Iron sheet (steel)	20 mm	6000 mm	2000 mm
Stainless steel sheet (SS)	12 mm	6000 mm	2000 mm
Aluminum sheet (AL)	8 mm	6000 mm	2000 mm
Other super-alloy metals	6 mm	6000 mm	2000 mm