The air pressure setting of a laser cutting machine is one of the core process parameters, directly affecting the smoothness, perpendicularity, and slag adhesion of the cut surface. Appropriate air pressure results in a perfect cut, while inappropriate air pressure leads to various cutting defects.

I. Specific Effects of Air Pressure on the Cut Surface

1. Negative Effects of Excessively High Air Pressure

Disordered Cut Surface Texture: Excessive airflow generates vortices within the cutting kerf, resulting in excessive cooling and dispersion of laser energy, forming irregular grooves.

Increased Slag Adhesion at the Bottom: High-speed airflow prematurely cools the molten metal, preventing it from being completely blown away. Instead, it re-solidifies at the bottom of the sheet, forming slag adhesion.

Resource Waste: Unnecessarily increases gas consumption, directly raising production costs.

2. Negative Effects of Excessively Low Air Pressure

Rough and Darkened Cut Surface: Insufficient airflow power fails to promptly and thoroughly blow away the molten material. This molten material adheres to the cut surface, forming a rough, oxidized cut.

Metal burrs: A typical symptom of insufficient gas pressure, indicating incomplete separation of molten metal.

Risk of incomplete cut: Insufficient slag removal capacity leads to slag accumulation along the cutting path, hindering the cutting process.

II. Practical Suggestions for Optimizing Gas Pressure Settings 

To achieve optimal laser cutting surface quality, adjust the gas pressure according to the following points:

III. Material Type Determines Gas Type:

Carbon Steel: Uses oxygen, requiring relatively low pressure (e.g., 0.8-1.2 bar) as it participates in the combustion reaction.

Stainless Steel/Aluminum Alloy: Uses nitrogen, requiring higher pressure (e.g., 1.5-2.5 bar or higher) to achieve high-pressure slag removal and prevent oxidation.

IV. Plate Thickness is a Key Factor:

Thin Plates: Suitable for lower gas pressure to avoid energy dissipation.

Thick Plates: Requires higher gas pressure to ensure sufficient force to expel molten material from the bottom of the kerf.

V. Relevance of Nozzle Condition: 

Ensure the nozzle diameter matches the gas pressure, and that the nozzle itself is clean and undamaged. A damaged nozzle renders any air pressure setting meaningless.

In summary, air pressure is a critical variable determining the quality of the cut surface in a laser cutting machine. Operators need to understand its working principles and make precise adjustments based on different materials, thicknesses, and gas types. Through system optimization, your laser cutting machine will be able to consistently output smooth, dross-free, high-quality workpieces, effectively enhancing product competitiveness. If the above does not resolve your issue, please contact RITMAN Laser's professional after-sales engineers for assistance.