Laser cutting is a new high-tech technology that allows for precision and speed in cutting a variety of materials, including metal, wood, and acrylic. Many customers have overburned after purchasing a metal laser cutting machine – those black, charred, or rough marks left after cutting. These blemishes not only affect the appearance of the finished product, but also compromise the integrity of the material. How can you laser cut without burnt edges?
In this article, we will share an effective “How to Laser Cut Without Burnt Edges” to ensure a clean, smooth, and professional cut every time.
What Causes Burnt Edges in Laser Cutting?
- Excessive Heat: If the laser beam is too powerful or the cutting speed is too slow, it can overheat the material, causing it to burn.
- Inadequate Air Assist: Air assist is a feature that blows air directly onto the cutting area. Without it, smoke and debris can accumulate around the cut, leading to burnt edges.
- Material Type: Certain materials, like wood or acrylic, are more prone to burning than metals due to their composition.
- Improper Focus: If the laser beam is not focused correctly, the cut becomes less precise, causing heat buildup and burnt edges.
How to Avoid Overburn When Laser Cutting Sheet Metal?
1.Add cooling point at the corner
When cutting sharp-corner metal sheets, the location where overburning is more likely to occur is often at the sharp corners. Overburning will cut the sharp corners into a round shape. At this time, add a cooling point at the sharp corners and stop at the sharp corners. Click, blow.
2.Use high-power lasers
When cutting carbon steel, a higher power laser can be used, and a bright surface cutting process can be used to effectively avoid over-burning, and this cutting process can cut finished products with no burrs and bright cut surfaces.
- Lower the power: For materials like acrylic, wood, or plastic, you may need to use a lower laser power setting. This ensures that the laser doesn’t overheat the material.
- Increase the speed: Speeding up the cutting process allows the laser to move quickly enough to avoid lingering too long in one spot, which could cause burning.
3.Cutting with nitrogen
In sheet metal cutting with oxygen as the auxiliary gas, nitrogen can be used for cutting. When nitrogen cutting, the material completely relies on the laser energy to melt, and the nitrogen blows out the slits, and inappropriate chemical reactions are avoided.
- Excessive Heat: If the laser beam is too powerful or the cutting speed is too slow, it can overheat the material, causing it to burn.
- Inadequate Air Assist: Air assist is a feature that blows air directly onto the cutting area. Without it, smoke and debris can accumulate around the cut, leading to burnt edges.
- Material Type: Certain materials, like wood or acrylic, are more prone to burning than metals due to their composition.
- Improper Focus: If the laser beam is not focused correctly, the cut becomes less precise, causing heat buildup and burnt edges.
4.Use Air Assist
One of the most effective ways to prevent burnt edges is to use air assist.
- Removes debris: It also removes debris and dust from the cutting path, allowing the laser to work more efficiently.
- Prevents heat buildup: By blowing away smoke and molten material, air assist keeps the cutting area cool and prevents the material from burning.
5.Choose the Right Material
Certain materials are more susceptible to burnt edges than others. Wood, acrylic, and plastics tend to burn more easily, while metals like stainless steel and aluminum are more resistant to burning.
- Wood: Use a lower laser power and a faster cutting speed to avoid excessive burning. Also, try masking the wood with painter’s tape to reduce scorch marks.
- Acrylic: Acrylic can burn easily at the edges, so consider using lower power and high-speed settings. Using air assist is especially important for acrylic to prevent overheating.
- Metal: Metal materials are less prone to burning, but using the correct gas assist (such as nitrogen or oxygen) can improve the cut and prevent slag buildup.
6. Optimize Focus and Lens Settings
The focus of your laser beam is crucial in preventing burnt edges. An unfocused beam spreads the energy over a wider area, leading to excess heat and potential burning.
- Focus the laser beam correctly: Always ensure the laser beam is properly focused on the surface of the material. For thicker materials, you may need to adjust the focus point to optimize cutting performance.
- Clean your lens: A dirty or damaged lens can scatter the laser beam, reducing the precision and causing inconsistent cuts. Regularly clean the lens to maintain the cutting quality.
7.Experiment with Cutting Techniques
- Multiple passes: Instead of trying to cut all the way through in a single pass, try multiple passes at lower power. This allows the laser to cut through the material without generating excessive heat.
- Use protective coatings: For wood and acrylic, you can use a protective coating or masking tape on the material’s surface to shield it from direct heat and reduce the chance of burns.
- Proper ventilation: Ensure your workspace is well-ventilated, especially if you’re cutting materials that emit fumes, such as plastics. Proper ventilation helps remove the fumes, reducing the risk of burning and improving air quality.
Conclusion:
By adjusting the laser power, cutting speed, and focusing the laser properly, you can significantly reduce or eliminate burnt edges in your laser cutting projects. Additionally, using air assist, experimenting with multiple passes, and choosing the right material will further help you achieve clean, precise cuts.
With these tips in mind, you can confidently cut through a variety of materials without the worry of unwanted burns, delivering high-quality, professional results every time.
FAQ
Why do laser cuts have burnt edges?
Burnt edges are caused by excessive heat from the laser beam, improper focus, or low cutting speed. To avoid this, adjust the laser settings and use air assist to cool the cutting area.
Can I prevent burnt edges when cutting acrylic?
Yes! Use lower power, higher speed settings, and make sure to use air assist. Consider masking the acrylic with tape to reduce burning.
Does air assist really help with burnt edges?
Yes, air assist blows away smoke and debris, keeping the cutting area cool, preventing heat buildup, and reducing burnt edges.
How can I achieve a cleaner cut on wood?
Use a lower power setting and a faster cutting speed. Additionally, masking the wood surface with painter’s tape can help prevent burning.
By following these steps and tips, you can minimize the chances of burnt edges and improve the quality of your laser cutting projects.
