‘Plastics’ refer to materials with widely differing chemical compositions, which in turn means differing outcomes for the processes applied to them, including laser marking. Indeed, among plastics we can distinguish between polycarbonate, polyamide, polyester, PE, PET, ABS, and many others. These influence the choice of laser in terms of required wavelength.
By way of example, PET requires a specific short wavelength (9.3 μm) obtainable with CO2 laser markers. A laser with a different wavelength would risk overheating the plastic, causing micro-holes and burns. Laser marking on this quasi-transparent plastic results in white characters that seem to float on the surface. From PET bottles to thin film materials, laser markings with the correct parameters are always clear and sharp.
The different laser sources and the extensive specialization of modern laser technology currently allow us to mark all types of plastics, although the reactions due to color pigments and other additives vary widely.
Laser marking is preferable to other technologies for placing codes, logos, and designs on plastic components. Compared to ink-jet, laser marking does not have the problem of ink adhesion, dark substrate contrast, or finish complexity.
This is because the laser removes or modifies the surface of the plastic material, or modifies its color, creating a contrast.
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Discover all the information about Laser Marking on Plastics
Among the different processes that lasers can perform on plastics, some occur more often than others. Based on the requirements of the manufacturer and the type of product, we can meet different needs.
Carbonization, which creates very dark markings on very bright surfaces. When an area receives continuous high energy, the macromolecules of the element around the base material are charred and turn black.
Color change, i.e. change of color from dark to light or vice versa. Using a laser for plastic irradiation ensures minimal damage to the component during marking.
Selective ablation: in this case, the laser removes a surface layer of the material
The most popular lasers for plastic applications are the well-known UV laser, the FlyPeak green wave laser from LASIT, and the traditional green light laser with a fiber optic source. In most cases we recommend using a MOPA laser, meaning with variable pulse: thanks to the pulse duration control, this laser ensures maximum performance on more difficult applications.
Laser technicians carry out tests to determine which laser is best suited to achieve the desired result on specific plastics. The initial parameters used are usually those listed below. Starting from the results of the first tests, it is possible to identify the parameters best suited to the specific processing desired.
In most cases, forcing a marking can be counterproductive and decrease the final contrast, so it is better to start with 1 repetition and gradually increase from there.
Below, we have identified the three most common plastic materials in our experience, describing their characteristics and the best parameters to mark them. For full reports and further details, we recommend that you download the Guide.
This material, if not additivated, can be marked fairly well with an Infrared FiberFly laser, well with an Infrared FiberFly laser, well with a FlyAIR Green Wave green light laser and perfectly with a UV FlyUV laser. The latter provides a Photochemical reaction of the material, achieving a high, constant and absolutely indelible contrast, leaving the surface smooth to the touch.
Good contrast can be achieved with the Infrared FiberFly laser. The MOPA version is recommended to increase contrast.
Good contrast can be achieved with the Infrared FiberFly laser. The MOPA version is recommended to increase contrast.
Controlling the heat input is a key factor in achieving quality laser marking on plastics.
The pulse of the FlyPeak laser always remains below 10 ns throughout the range (at 20 kHz = 3.5 ns), which allows us to cool down the marking compared to traditional nanosecond lasers, including fiber lasers, and consequently increase the quality of the process and the result.
The FlyPeak laser marker uses a DPSS (diode pumped solid state) system, which combines a high peak power with a much shorter pulse duration than the solid-state lasers on the market, while maintaining the average power unchanged: no laser currently on the market offers the same performance levels.
The most notable features of this laser marker are:
FLYPEAK is ideal for marking all types of plastic, ensuring high peak power and a shorter pulse duration compared to other lasers in the same category.
The best-performing laser on plastics for aesthetic marking, especially appreciated in the medical and home appliance industries.
Ideal for marking organic materials, such as wood, fabrics, gems, and transparent objects on which other lasers don’t work.
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LASIT Laser markers are designed on the specific needs of the client, from the mechanical system to the software. In 30 years, we have developed Traceability and Aesthetic laser marking solutions for metal and plastic applications.
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