Polypropylene (PP) tray laser coding | Macsa CO2 Laser
Polypropylene is a type of thermoplastic that, thanks to its strength and light weight properties, is increasingly used in various types of applications, especially in the food industry. In fact, polypropylene is a versatile and fully recyclable plastic, which means that it is being used as a substitute for other not-so-recyclable plastics. One such case is fresh fruit trays in supermarkets.
These types of transparent plastics are coded with CO2 systems that, although they do not generate a contrasting mark, make information highly visible due to the raised relief generated by melting part of the plastic.
However, when a fast marking is needed due to high production rates, the wavelength choice of the CO2 system is key in order to achieve an optimal result. It is important to mention that the absorption rate of polypropylene at a wavelength of 10.2 μm is four times higher than that of 10.6 μm, which is the standard wavelength of a CO2 laser.
With the SPA CF 30 P system, we can code the trays with 2 lines of text of 14 characters each at a rate of 60 m/min, while if we use the standard wavelength of the CB systems, the maximum speed would be 15 m/min, losing production capacity and efficiency.