Sheet Metal Laser Cutting Machine Technology Knowledge

1. What is “Flying Optics Path”?

To ensure stable laser output, the laser generator is usually fixed. To meet different processing needs, the laser beam’s transmission path is dynamically changed using optical elements like reflectors. This design, where the source is fixed but the reflectors and focusing lens move while maintaining stable output power, is called the “Flying Optics Path”.

2. Main Laser Cutting Processes

• Melt Cutting: High-power laser melts the material locally, and an assist gas blows away the molten slag.

• Vaporization Cutting: Extremely high power density vaporizes the material instantly, resulting in a clean edge with minimal burrs.

• Flame Cutting (Oxidation Cutting): Uses oxygen to create an exothermic reaction, providing additional heat. Commonly used for carbon steel.

• Controlled Fracture Cutting: A laser beam creates a thermal gradient in brittle materials, causing them to crack along a predetermined path.

3. Key Technologies for CO₂ Laser Cutting

1. Auto-Focus Technology: Focus position directly affects cutting accuracy and edge quality; auto-focus systems adjust according to material thickness.

2. Piercing Technology: A small hole is pierced before cutting along the contour to start the process.

3. Nozzle & Gas Flow Design: Assist gases (e.g., oxygen, nitrogen, compressed air) remove slag, protect the lens, improve cut quality, and can even accelerate chemical reactions.

4. Operating Precautions

• Safety: Never look directly at the invisible laser beam; the focusing lens contains hazardous elements (ZnSe), and discarded lenses require special disposal.

• Health Protection: Processing high-reflectivity materials like aluminum generates harmful dust; wear a mask. Prolonged viewing of cutting sparks can damage eyes; use protective goggles or automated operation.

• Equipment Protection: High-reflectivity materials (e.g., aluminum, copper) can reflect the laser and damage the cutting head; use protective devices.

5. Is it Harmful to the Human Body?

Laser cutting is more environmentally friendly than plasma or flame cutting, producing less dust, noise, and light.

However, all machinery has risks. Following safety protocols (e.g., wearing goggles and masks, avoiding direct eye contact) minimizes potential harm.

6. Classification by Structure

• Bench-type Laser Cutting Machine: The laser is fixed, and the beam is transmitted via an external optical path. Processing areas are typically 1.5×3m or 2×4m, ideal for sheet metal, medical devices, and lighting.

• Gantry-type Laser Cutting Machine: The laser is mounted on the gantry, moving with the machine for a constant optical path. It can process large-format plates (width 2-6m, length up to dozens of meters), used in heavy industries like engineering machinery and shipbuilding.

7. Classification by Workpiece

• Metal Laser Cutting Machine: High power (500W-3000W+), for cutting carbon steel, stainless steel, aluminum, copper, etc.

• Non-metal Laser Cutting Machine: Lower power, for cutting acrylic, leather, fabric, etc.

• Tube Laser Cutting Machine: Dedicated or combined plate-and-tube machines for cutting pipes and flat sheets.

8. Functions of Assist Gases

1. Blow away molten slag to ensure a clean cut.

2. Protect the lens from slag adhesion.

3. Using nitrogen achieves an oxide-free, smooth cut (precision cutting).

4. Using oxygen accelerates the cutting speed through combustion.

9. Quality Metrics for Laser Cutting

1. Surface roughness (Rz).

2. Amount of burr and dross on the cut edge.

3. Perpendicularity and bevel angle of the cut edge.

4. Size of the edge rounding at the start point.

5. Depth of cutting striations.

6. Flatness of the cut surface.

7. Maximum cutting thickness under the same power.