Laser cutting machines are indispensable equipment in modern manufacturing. They can improve efficiency and precision and occupy an important position in metal processing. So, what is a laser cutter and how does it work? This article will describe in detail how a laser beam is generated and directed to the material for cutting.
What is a Laser Cutter?
A laser cutter is a machine that uses a laser beam to cut or engrave materials such as wood, plastic, or metal. It works by directing the laser beam through a series of mirrors and lenses to focus the energy onto a small spot, melting or vaporizing the material based on instructions from a computer.
Steps of How A Laser Cutter Works:
Step 1: Generation of G-code File
1.The Reason Of Generating G-code
Prior to executing any cutting, it’s necessary to produce the G-code necessary for the cutting task. G-code comprises machine-readable directives guiding the machine towards the positioning of the laser cutting head. Hand-operated instructions for basic shapes are producible by the operator.
2.G-code From The Provided CAD
For intricate designs, it’s essential to have CAM (computer-aided manufacturing) software to autonomously produce the G-code from the provided CAD (computer-aided design) file. Subsequently, this G-code needs to be transmitted to the device via a Wi-Fi link or a USB drive.
Step 2: Laser Beam Generation
1.The mechanism of laser beam generation
Various laser technologies employ distinct mediums for their generation. Nevertheless, beam production physics remains consistent across various laser technologies. An electron, upon being stimulated by a photon, absorbs energy, transitioning towards a state of greater energy. The electron is set to plummet to a lower orbital within an exceedingly brief duration. The cause of this degradation is minor swings in the quantum vacuum, leading to its return to a lower energy level. Upon decay, a photon will be emitted.
2.Solutions to the problem
Metastable Material
As a solution to this problem, lasers employ materials that have a metastable condition. If a photon engages with a metastable, already energized electron, this can lead to the electron reverting to a lower energy orbital position.
Stimulated Emission
As an electron does this, it emits a photon possessing identical attributes to the photon that initially disturbed it, in terms of frequency, phase, and polarization. Named stimulated emission, this technique serves to generate laser beams. When the procedure begins, it triggers a barrage of photons that subsequently move along the tube.
Step 3: Laser Amplification
When the initial phase of spontaneous radiation occurs, photons are emitted in any direction. However, some will perpendicular to two mirrors at opposite ends of the laser medium. This produces two light waves, which creates a standing wave of constructive and destructive interference. When these standing waves are generated, this is called resonance. The intensity of the light increases to the point where the semi-reflector allows some light to pass through, creating a laser beam of energy.
Step 4: Beam Direction and Focusing
1.Be Amplified
When the beam is amplified and exits the laser medium, it passes either through a fibre-optic cable (in the case of fiber laser) or through a series of mirrors (in the case of CO2 and Nd:YAG lasers).
2.Through A Lens
The beam is directed through a lens into a thin sheet of material, through which laser energy is focused to a very small diameter to create a local high energy point. It should be noted that the laser has only one strong focus and the cutting intensity of the entire beam is not the same.
3.Intensity
The difference in the intensity of laser cutters is due to the limited thickness of materials that can be cut by laser cutters, because the laser intensity of laser cutters decreases above and below the focal point.
Step 5: Material Cutting
Once the beam is focused, it begins to melt or vaporize the material. In the case of non-molten materials, such as wood, the laser will burn through the material. For metals, the laser beam will melt the material, and a jet of high-pressure gas will blow away the molten material being cut. The gas, which can be inert nitrogen or argon, or oxygen, is used to speed up the cutting of steel.
Final Thoughts
Laser cutting machines are vital in modern manufacturing for precision cutting of materials like metal, wood, and plastic. The process begins with creating a G-code file that guides the laser head. A laser beam is generated by energizing electrons, which emit photons to form a coherent beam. This beam is amplified and directed through optics to focus precisely on the material. The intense focus of the laser melts or vaporizes the material, and a high-pressure gas jet then removes the molten material to achieve clean cuts. This technology is crucial for efficient and precise manufacturing operations.