The Challenge: Why Plastic Marking Is Different
Metal is straightforward — almost any fiber laser will mark it. Plastic is a different beast entirely. Here’s why:
Polymers absorb different wavelengths differently. The chemical bonds in ABS respond to UV light but are relatively transparent to CO2 wavelengths. Polyethylene is the opposite. There’s no universal “plastic laser.”
Heat sensitivity varies wildly. Polycarbonate softens at 147°C. PEEK withstands 343°C. A CO2 laser that produces clean marks on PEEK might melt polycarbonate into an unreadable blob.
Color change mechanisms differ. Some plastics carbonize (turn dark) when heated. Others foam (turn light). Some barely react at all. The mark you get depends on both the laser type and the specific polymer formulation — including additives, fillers, and pigments.
Additives change everything. Two ABS parts from different suppliers may mark completely differently because one contains laser-sensitive additives and the other doesn’t. This is why testing is non-negotiable.
Want to see how UV and CO2 compare on your specific plastic? [Request a free sample marking →]
