Laser Marking Parameters and Code Readability

In response to the difficulties of adjusting the parameters of laser marking machines, the authors tested 20 commonly used materials to determine the best way to adjust the machine to ensure that barcodes can be read.The optimization scheme covers parameters for metal, plastic, and wood, helping users quickly improve the clarity of the markings and the success rate of scans, and solving the problem of setting parameters in production.

This is the core logic of adjusting laser marking machine parameters.

The settings of a laser marking machine directly affect the final result. There are three key points to consider: the properties of the material, the marking speed, and the laser power.For example, metal materials need higher power but the speed can be slower, while if the power is too high for plastics it will burn.It is recommended that beginners start by testing with a small range of parameters, and only after finding a balance point should they operate on a large scale.

The techniques of parameter fitting for different types of materials.

Tests showed that when the power is adjusted to 80-90 % and the speed controlled at 600-800 millimeters per second, the recognition rate for stainless steel and aluminum alloy can be more than 98 %.But for materials like acrylic or PVC, the edges will carbonize if the power is set above 70 %. In those cases, the cut is cleaner if the speed is set at 1000 mm / s.There is a little trick to this: for dark materials you should lower the frequency (20-30 kHz), and for light materials you should raise it (50 kHz or more). The contrast will be more obvious.

20 materials tested.

We did a lateral test with materials commonly used in factories and discovered two unexpected results. When metal parts with a coating are scanned under the same conditions, the success rate is about 15 % lower than for bare metal. And for plastic objects with a matte surface, the recognition rate can be significantly increased by tilting the marking angle 10-15 degrees.Part of the actual test data is as follows:

304 stainless steel: 85 % efficiency / 700 mm / sec → 99 out of 100 scans successful.

- PET (polyethylene terephthalate): 60 % power / 1200 mm / second → requires black ink.

- Solid wood: 40 % power, 400mm / sec. Recommended to apply a protective coating to prevent color from bleeding.

Solutions for when bar code recognition fails.

If you encounter a scanner that can't read the label, don't immediately send it back for reworking. First, use an alcohol wipe to gently clean the surface of the label. It turns out that 30 % of failures are caused by surface dust.If the lines in the barcode are broken, try adjusting the spacing between the lines from 0.05 mm to 0.03 mm.Once, a customer couldn't mark a certain part, and we discovered that it was because the air conditioners in the workshop were blowing directly on the part, causing temperature fluctuations. We added a cover to block the air, and the problem was solved.

Maintenance is a hidden plus.

Many people ignore the importance of lens cleaning in maintaining stability in the parameters. In fact, when the same machine was tested after the optical lens had been cleaned, the laser energy output under the same parameters was 8-12 % higher.We suggest that you use a lint-free cotton swab dipped in a special cleaning solution to clean the lens once a week, and that you maintain the humidity in the environment between 40 % and 60 %. In humid weather, moisture can interfere with the laser path.