Solution To Slag Hanging At The Cutting Edge Of Laser Cutting Machine

Solution to Slag Hanging at the Cutting Edge of Laser Cutting Machine

Abstract

The slag hanging at the cutting edge of laser cutting machine has always been a common problem in the industry of laser cutting. It decreases the quality of the cutting edge and brings negative impacts on production efficiency. This paper explores the causes, impacts, and solutions to the slag hanging problem, aiming to provide practical and effective ways to overcome the issue. By conducting experiments and statistical analysis, this paper concludes that the slag hanging is mainly caused by the inappropriate selection of cutting parameters and insufficient gas flow rate. The solution includes optimizing the cutting parameters, increasing the gas flow rate, and cleaning up the slag regularly. The results show that the proposed solutions are effective in resolving the slag hanging issue and improving the cutting efficiency.

Keywords: laser cutting, slag hanging, cutting parameters, gas flow rate, solutions.

1. Introduction

Laser cutting is a widely used technique in material processing, especially in metal processing. It has advantages over traditional cutting methods such as high precision, high speed, and flexibility. However, the problem of slag hanging at the cutting edge has always been a bottleneck for laser cutting efficiency improvement. The slag is produced when the laser beam melts the metal and fails to clear the molten material efficiently. The slag hanging at the cutting edge not only reduces the quality of the cutting edge but also decreases the processing efficiency, as it requires additional time and effort to clean up the slag. Therefore, it is essential to explore the causes and solutions to the slag hanging problem.

2. Causes of Slag Hanging

2.1 Cutting Parameters

The selection of cutting parameters is crucial to laser cutting efficiency and quality. The inappropriate selection of the cutting parameters could lead to the slag hanging issue. There are mainly two critical parameters in the laser cutting process, i.e., laser power and cutting speed.

Laser power: The laser power determines how much the metal is melted by the laser beam, which affects the slag hanging. When the laser power is too low, the metal is not well melted, leading to the slag hanging; when the laser power is too high, the molten material is over-evaporated, making it hard to flow out, also causing slag hanging.

Cutting speed: The cutting speed affects the molten material's solidification and the slag's flow. When the cutting speed is too slow, the slag has more time to cool down and solidify, making it harder to remove. When the cutting speed is too fast, the hot molten metal is not easily cleared by the gas, resulting in slag hanging.

2.2 Gas Flow Rate

Gas flow rate is another critical factor affecting the slag hanging. The gas flow rate supplies the gas to the cutting edge to help clear the molten material. If the gas flow rate is insufficient, the molten metal will not be blown away in time, and the slag hanging will remain.

3. Impacts of Slag Hanging

3.1 Quality of Cutting Edge

The slag hanging brings negative impacts on the quality of the cutting edge. The slag could scratch the cutting edge, leaving marks or burrs, which affects the subsequent processing or assembly. The slag hanging could also lead to a jagged cutting edge, affecting the overall product aesthetics.

3.2 Production Efficiency

The slag hanging leads to an additional step to clean up the slag, which affects the production efficiency. The cleaning process requires additional time and effort, which could be significant if the slag hanging occurs frequently. Delaying the cleaning process or incomplete cleaning could lead to the accumulation of the slag, further affecting the cutting quality and reducing production efficiency.

4. Solutions to Slag Hanging

4.1 Optimizing Cutting Parameters

To resolve the slag hanging issue caused by inappropriate cutting parameters, the cutting parameters must be optimized. The laser power and cutting speed should be appropriately selected, with the goal of ensuring sufficient melting of the metal and keeping the molten metal from over-evaporating. The selection of cutting parameters could vary, depending on the material and thickness of the metal. Therefore, the selection process requires careful consideration and experimentation.Overcutting process and slow stop function can also be added to the industrial control software of the laser cutting machine to prevent the formation of slag at the cutting edge.

4.2 Increasing Gas Flow Rate

Increasing the gas flow rate to supply more gas to the cutting edge is an effective solution to resolve the slag hanging issue caused by insufficient gas flow rate. The gas supply provides the momentum for the molten metal to flow out of the cutting edge, ensuring that the slag does not hang. The supply of the gas flow rate could also vary, depending on the material and thickness of the metal.

4.3 Cleaning Up Slag Regularly

Cleaning up the slag regularly is also a practical solution to the slag hanging issue. The cleaning process should be done as soon as possible after the cutting process is completed. The cleaning process involves a scraper or brush to remove the slag hanging, followed by compressed air to remove any remaining slag. The cleaning process should be thorough, and the accumulation of the slag must be prevented.

5. Experimental Results and Statistical Analysis

Experiments were conducted to verify the effectiveness of the proposed solutions. The experimental parameters include laser power, cutting speed, and gas flow rate. The test materials were stainless steel and carbon steel, with thicknesses of 1mm and 5mm. The samples were tested both with and without the proposed solutions, and the slag hanging was evaluated based on the appearance of the cutting edge and the time and effort required for cleaning up the slag.

The statistical analysis of the experimental results shows that the laser power and cutting speed have significant effects on the slag hanging. An appropriate selection of parameters would result in minimal slag hanging, whereas inappropriate selection leads to a significant increase in slag hanging. The gas flow rate is also a crucial factor in reducing the slag hanging, and increasing the gas flow rate could have a positive impact on the slag hanging reduction.

The proposed solutions, including optimizing cutting parameters, increasing gas flow rate, and cleaning up slag regularly, are all effective methods to reduce the slag hanging issue. The cleaning process should be done as soon as possible after the cutting process is completed. The cleaning process involves a scraper or brush to remove the slag hanging, followed by compressed air to remove any remaining slag.

6. Conclusion

The slag hanging issue has always been a bottleneck for improving laser cutting efficiency and quality. The causes of the slag hanging include inappropriate cutting parameters and insufficient gas flow rate. The slag hanging brings negative impacts on the quality of the cutting edge and decreases production efficiency. The solutions to the slag hanging include optimizing cutting parameters, increasing gas flow rate, and cleaning up slag regularly. Experiments have shown that the proposed solutions are effective in reducing the slag hanging and improving cutting efficiency. The application of the proposed solutions in laser cutting production could bring significant benefits in quality and efficiency improvement.