Laser cutting is an essential process in modern manufacturing, used in a range of industries, including aerospace, automotive, electronics and medical device production. Lasers are used to cut metals including aluminium, carbon and stainless steel with high accuracy and speed. In this process, a focused laser beam is directed onto the metal, melting, or vaporising the material, and creating a precise cut. One of the key components in the laser cutting process is the assist gas, which is typically supplied from cylinders of high-pressure nitrogen. As metal fabricators adopt higher-powered lasers, nitrogen generators have emerged as a superior solution to provide the higher gas volumes needed, offering several benefits over traditional bottled nitrogen. 

Why use Nitrogen in Laser Cutting?

Nitrogen is used for laser cutting because of its inert properties that prevent any additional heat producing reactions. So, when you want to achieve a superior laser cut, nitrogen is the preferred cutting assist gas used. Furthermore, nitrogen gas can be used for laser cutting on all metals. 

Benefits of Nitrogen in Laser Cutting

1. Oxidation Prevention

One of the main benefits of using nitrogen over oxygen as a cutting assist gas is it prevents oxidation on the surface of the metal. Oxidation occurs when the metal heats up and reacts with oxygen, which causes corrosion. This not only affects the quality of the cut but increases the preparation required for welding and can prevent paint and powder coatings from adhering to the oxidised surface. Nitrogen is used to displace the oxygen and remove vapourised metal (known as dross) from the cutting edge before it can resolidify. This produces a clean, high-quality cut with no discolouration. 

2. Laser Beam Purging

Due to nitrogen’s properties as a dry, clean inert gas with minimal contaminants, it’s the optimal gas for laser beam purging. Laser beam purging is where nitrogen gas is passed through the tube of the laser beam to eliminate oxygen, expel moisture and any other contaminants that could potentially impact the laser’s performance. Purging the laser beam tube with nitrogen ensures that the laser produces a more precise, cleaner, and uniform cut while maintaining its power and intensity. 

Nitrogen Generators in Laser Cutting

Finding a cost-effective supplier for nitrogen is essential for metal fabricators since it is one of the main operating expenses in laser cutting. As high-powered lasers become more commonplace, the volume of nitrogen required is also increasing, escalating costs further. Traditionally, nitrogen has been supplied via cylinders however, this may not be the most cost-effective nitrogen supply particularly where increasing volumes are needed. Metal fabricators are often locked into contracts with third-party suppliers and these offer little flexibility, fluctuating prices, and the cost per unit of gas is significantly higher. Factors such as cylinder hire, delivery charges and administrative costs, all push the price of nitrogen higher. Moreover, logistical constraints and potential shortages can emerge, resulting in decreased productivity or stopping fabrication altogether. 

This is why there is increasing adoption of nitrogen generators in metal fabrication as these provide the most reliable, cost-effective source of nitrogen. The benefits of nitrogen generators for laser cutting are that they eliminate unnecessary charges, prevent gas waste, and only produced nitrogen onsite when it's needed. There is no need to store large, high-pressurised nitrogen tanks at facilities, freeing up valuable space and increasing safety. Having a constant source of nitrogen that is tailored to the exact purity and flow requirements, can be a game-changer for fabricators. 

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The Benefits of Nitrogen Generators in Laser Cutting

Control Over Your Supply: resulting in increased productivity for metal fabricators. Nitrogen generators provide a reliable and efficient supply that is not dependent on third-party suppliers or supply chain failures. 

Improved Cutting Precision: tailored to the exact purity and flow requirements of the laser cutting machine to prevent oxidation. Nitrogen generators only produce nitrogen when you need it at the most cost-effective purity level. 

No Wastage: Nitrogen is not lost through seepage or boil-off unlike with cylinder gas, ensuring efficient use of all the nitrogen produced.  

Lower Long-term Cost of Your Nitrogen Supply: The cost of nitrogen per cubic metre is substantially lower with onsite generation compared to cylinder nitrogen. 

Improved Safety: Nitrogen generators eliminate the need to store and handle high-pressurised nitrogen gas. 

How Much are Nitrogen Generators for Laser Cutting Machines? 

The main cost associated with a nitrogen generator for laser cutting is the initial capital outlay. However, because the cost to generate nitrogen is substantially cheaper than using third-party suppliers, ROI can be achieved anywhere between 1-2 years depending on volumes utilised. After installation, the ongoing costs of the nitrogen generator are power and maintenance, resulting in a significantly lower cost per unit supply of nitrogen.

Types of Nitrogen Generators for Laser Cutting

There are two types of nitrogen generators for laser cutting: pressure swing adsorption (PSA) and membrane separation. With membrane separation, nitrogen is separated by passing air through hollow fibres with membranes that allow other gases to permeate through the fibre walls so that only the nitrogen is left. With PSA, separation is achieved by alternating pressure between two tanks with a molecular sieve to remove unwanted gases. PSA nitrogen generators are more commonly used in laser cutting because it produces higher purity nitrogen gas that is needed to produce high-quality, clean cuts. 

How to Choose the Best Nitrogen Generator for Laser Cutting 

There are several things you need to consider when choosing the right nitrogen generator for metal fabrication:

• Volume of Nitrogen (CCF)
• Time of Laser Operation
• Purity of nitrogen required
• Metal types and thickness

These specifications are needed to help assess and design the best nitrogen generation system for laser cutting. Thinking of making the switch to a nitrogen generation system? Contact Gas Generation Australia today, we can provide a detailed cost-benefit analysis for a nitrogen generator tailored to your metal fabricating requirements. 

Gas Generation Australia offers innovative onsite gas generation solutions to the Australian industry and manufacturing. From packaged modular systems to custom-designed solutions, Gas Generation Australia provides an autonomous nitrogen or oxygen supply, where and when you need it most. Our wide range of PSA or membrane generators deliver optimal purity and reliable production volume.