A Detailed Explanation of the Differences in Laser Marking Parameters for EPDM and Silicone Rubber

In the article, we compare and contrast the parameters of EPDM rubber and silicone rubber, and explain how to adjust the power, speed, and frequency to improve the quality of the marking and increase production efficiency.

Why should the parameters vary with the material?

Laser marking is not a one-size-fits-all technology. Although EPDM and silicone are both elastomers, their molecular structures and heat resistance are very different.EPDM has a higher carbon content than silicon and thus absorbs more of the laser's energy. Silicon is more sensitive, and if the temperature rises too much it can turn yellow or even burn.If parameters are not adjusted according to the characteristics of the material, the result may be blurred marks or even product damage.

Comparing the characteristics of the two materials.

The nature of EPDM rubber.

It can withstand temperatures of around 150 ℃, and has a hard, rough surface. It is best to use medium power with a fast speed when laser marking this material.For example, if you use a fiber laser with 20W of power and 800mm / s speed, you can get a clear mark without burning the edges.

Silicone's sensitive point.

If the temperature exceeds 200 ℃, the jade will "get upset" and become shiny.At this point, it is necessary to use low power (10-15W), low speed (500mm / s or less), and a high frequency pulse mode (50-80kHz). This can create fine text and avoid local overheating and bubbling.

Practical parameters setting guide.

Three steps to EPDM rubber.

1. Initial parameters: Fiber laser power 18 W, speed 1000 mm / s, frequency 20 kHz.

2. Adjusting the effect: If the edges are rough, lower the power to 15W; if the text is too light, raise it to 22W.

3. The secret of avoiding burning: Install an air compressor to blow air, which cools the metal and blows away the residue.

Parameters to avoid.

Start with a low power setting and gradually increase the power until you find the critical point.

Speed must be slow: Start at 300-400 mm / s and reduce for more complex patterns.

Frequency is key: below 40kHz leaves a burning mark, so it is recommended to keep above 60kHz.

- Auxiliary tools: A special film is used to minimize interference from reflected light.

It's common to see overturned vehicles on the road.

If your silicone label turns yellow, check the following: Is the power output over 15W? Is the heat dissipation fan working properly? Has the focal point shifted?If the EPDM appears to have uneven thickness, 90 % of the time this is because the material contains uneven fillers. Try adjusting the filling spacing from 0.05mm to 0.03mm.

Finally, a word of advice: Don't be lazy! The materials from different manufacturers or different batches may not perform in the same way, so it is better to test a small sample before changing materials than to do a rework.