Laser cutting is a thermal cutting technique that involves shining a laser beam onto a material to heat, melt and vaporize it, then blowing away the molten material with high-pressure gas to create holes and ultimately cuts. In most cases, this process requires a small hole to be punched in the board before cutting, except in a few cases where it can be started from the edge of the board.
To create these holes, laser perforation is used, which involves irradiating the surface of a metal sheet with a laser beam to create a molten pool of metal. The energy absorbed by the metal causes it to melt, and the increased absorption rate of the molten metal relative to the metal surface causes it to absorb more energy, accelerating the melting process. With proper control of energy and air pressure, molten metal can be removed from the pool, allowing the pool to deepen until the metal is penetrated.
There are two commonly used perforation methods: pulse perforation and blast perforation.
Pulse perforation is to use high peak power and low duty cycle pulse laser to melt or vaporize a small amount of material, gradually penetrate the material, and then discharge it under the joint action of continuous beating and auxiliary gas. The laser exposure time is intermittent and the average energy used is relatively low, resulting in less residual heat around the perforation and smaller holes with regular shape and size. This method is suitable for precision cutting and has little effect on primary cutting.
On the other hand, blasting perforation is to use a continuous wave laser beam with a certain energy to melt the material to form a pit, and then remove it through the auxiliary gas to form a hole to achieve rapid penetration. This method is not suitable for precision cutting, because the continuous irradiation of the laser will produce a larger aperture and more spatter.
In most cases, pulse piercing is preferred over blast piercing because of its better quality and precision. However, blast perforation can be used in applications that require fast penetration and do not require high precision.
In addition to the advantages of pulsed piercing, laser cutters offer many other advantages. Laser cutting is a versatile process that can cut a wide variety of materials, including metal, wood and plastic, with high precision and speed. The non-contact cutting method minimizes material deformation and reduces the need for post-processing. Laser cutters are also low maintenance and can be easily programmed for automatic cutting.
Overall, laser machines offer many advantages for a variety of applications, including high precision, speed, versatility, and low maintenance costs. Understanding the principles and techniques of laser perforation can help users choose the method that best suits their specific needs.