Plastics, in one form or another, have been around since the 1800's, but after WWI the mass production of plastics catapulted this material into the forefront of our culture. One of the most ubiquitous materials in use today, plastics can be found in fields as diverse as food service and aerospace.
The prevalent use of plastics creates a huge demand for ways to permanently and clearly mark a large variety of plastic materials. Not all plastics react well to every marking method. For instance, styrene and many thermoforming plastics have a tendency to melt, or become soft and deformed, when laser engraved.
Choosing the right marking method can be fairly straightforward when the exact composition of the plastic to be marked is known. However, just because plastics are used in almost every industry doesn't mean that those who use them necessarily know the details of the particular plastics manufacturing process or composition. It is not uncommon for a customer to have a plastic part which needs to be marked without knowing the specific composition of the plastic itself.
There is a difference between marking plastics and engraving plastics. All plastics can be engraved with CO2 lasers. Engraving does not generally provide a contrasting color change and is frequently not crisp. When marking plastics with a fiber laser the goal is to create a contrasting mark on the surface of the plastic without engraving into it or melting it. Ideally, the marking results in a contrasting light colored mark on dark plastics and a contrasting dark colored mark on light plastics. Not all plastics are suitable for marking with fiber lasers.
When we need to discover a marking method to create a clear mark on an unknown plastic material there are a number of variables that we normally look at. Typically we experiment with optical settings such as focusing lenses and focused laser spot size and laser settings such as output power, marking speed and laser pulse frequency. Jimani Langolier Fiber Laser Marking Systems are available with both fixed and variable pulse width laser sources and, in some cases, shorter laser pulse widths provide superior results on plastics.
The goal when laser etching plastic parts with a fiber laser is to create a crisp, contrasting mark on the surface of the part. Sometimes the process of finding the right settings for marking a specific part can take some trial and error, but, if the plastic reacts to the output of a ytterbium fiber laser, suitable results can generally be achieved.
If your application calls for permanently marking plastics, then contact us to learn more about our custom job shop applications or to find the right marking system for your in-house needs.