Marking technique
- Laser marking additives
- Laser marking concentrates
- Laser marking of thermoplastics
LASER MARKING OF POLYMERS
Traditional marking method
The traditional method of writing on plastics is printing with ink. The systems currently used for this purpose include pad printing, ink jet printing and stamping. All of these methods are firmly established, but they present some disadvantages with respect to flexibility and durability of the marking, and have a negative environmental impact.
Laser marking plastics
Laser marking of plastics has established itself as an accepted technology and is proving to be highly competitive in comparison to more traditional methods such as pad printing, inkjet printing, and hot foil stamping.
The ‘drivers’ for laser marking include:
- the increasing use of “tamper-proof” laser marking for better product traceability
- unique identity coding in relation to product lifetime recognition and liability
In addition, due to the flexibility of laser marking, it is the methodology of choice for part customization (many small series), part miniaturization, and complex geometries.
How laser marking works
Laser light is light of a single wavelength and high energy, which can interact with a substrate to provide it with a mark. The highest flexibility is obtained using galvanic mirrors for laser marking.
Here the marking is performed by beam manipulation, i.e., a pulsed laser beam is focused through two computer-controlled galvanic mirrors. In this way very fine patterns of high image quality can be written, as if it were a pen.
How our additives help
The basic precondition for marking is the absorption of the laser light by the polymer. Unfortunately, most polymers are (partly) transparent to the laser. The desired degree of absorption can be achieved by using additives or pigments, i.e., conventional laser additives absorb the laser light, transform the absorbed light into heat and carbonize the polymer matrix.
Conventional laser additives influence the color of the compound. As the quality of the mark depends on the carbonizing ability of the matrix, every formulation requires a specific solution for interaction with the laser light. Also, colorants affect the marking performance by interacting with the laser light. This implicates that a major drawback for laser marking is that every grade or color combination needs to be tuned for the applied laser system, which takes time and is a costly process. Moreover, the contrast of the obtained marks is often weak, the definition is poor and the images are not sufficiently vibrant and stable.
How color affects laser markings
However, conventional laser additives influence the color of the compound. As the quality of the mark depends on the carbonizing ability of the matrix, every formulation requires a specific solution for interaction with the laser light.
This means that a major drawback for laser marking is that for these polymers every grade or color combination needs to be tuned for the applied laser system, which takes time and is a costly process.
Moreover, the contrast of the obtained marks is often weak, the definition is poor and the images are not sufficiently vibrant and stable.
Dark markings with INCA® technology
With INCA®, laser marking no longer relies on carbonization of the polymer matrix and is therefore matrix-independent. This makes INCA® ideal for marking anything from circuit breakers to appliances, medical products, computer housings, cable coatings, bottles, closures and all manner of security cards at higher marking speeds, without adverse effect on other properties.