Laser marking machines are widely used in the field of plastic marking.
The principle of laser marking machine is to use high energy density of laser light to irradiate the surface of the material, so that the surface of the material is vaporized to reveal the deep material, or under the action of light radiation, the surface of the material produces a chemical reaction that can change the color, leaving permanent marking marks.
Polypropylene material is non-toxic and tasteless, has good processing performance, low density, light weight, high impact resistance, and can can resist a variety of acids and alkalis, organic solvent corrosion. These advantages make it the lightest general-purpose plastic, with a very wide range of applications in the industrial field.
Here we mainly introduce the influence of laser marking machine process parameters on the marking effect of polypropylene plastic.
Through experimental research on laser marking of polypropylene plastics, we found that:
1. Laser power, marking frequency, and marking speed are the main indicators that affect the laser marking effect of black polypropylene plastic. If the power is too high, the speed is too slow, and the frequency is too high, the surface of the polypropylene plastic will burn and turn yellow, the color of the font will be uneven, the surface flatness will decrease, and the border of the font will be unclear. If the power is too low, the marking strength will be insufficient and the color change will not be obvious. If the speed is too fast and the frequency is too low, the font will be blurred and uneven.
2. The marking line width, stack height and melting depth will indirectly reflect the marking effect. If the three are too large or too small, the marking effect will be adversely affected, and they should be controlled within a reasonable range in actual use.
3. For polypropylene plastic laser marking, the best process parameters are 8W laser power, 2.0m/s marking speed, and 20KHZ marking frequency. At this time, the line width is about 25μm, the stack height is about 25μm, The ideal depth is around 23 μm.