Laser Die Cutting Machine - Flexible Packaging Layer Cutting Process You Never Knew (Part 2)

Layer cutting process of laser die cutting machine mainly talked about the shortcomings of the original processing method in the previous article, and here we will continue to talk about some basic principles of laser scribing machine in flexible packaging layer cutting processing.

Plastic film layer, metal film layer and paper show different absorption and radiation properties in the wavelength range (9.4~11渭m) generated by CO2 laser. Most plastic materials in the packaging industry, such as PET, PS, PC, PVC and OPA, can absorb laser beams very effectively at the typical wavelength of 10.6渭m. After absorbing the laser beam, the plastic film is locally heated and completely melted. However, a few plastic films such as OPP, PE and LLPE completely pass the 10.6渭m laser wavelength. The aluminum foil layer does not absorb any wavelength emitted by the low-power CO2 laser and reflects it completely.

Let the laser die-cutting machine cut the packaging material according to the desired layer cutting structure. Just use the correct laser wavelength and cut the layer from the correct film surface. The following example illustrates the basic principle of laser layer cutting of composite films.

鈶燩ET-AL-PE: This is a typical composite material for food packaging, such as coffee packaging bags. The selective absorption of the material to the CO2 laser (10.6渭m) can use the mechanically supported PET layer to completely vaporize in a very small local area without affecting other layers. The reflection effect of the aluminum foil layer helps to use the laser more effectively.

鈶PP-PE: This is a composite packaging material commonly used for washing powder packaging. Since PP has a stronger ability to absorb laser beams than PE, when cutting layers, you can choose to cut the PP layer without affecting other layers; in this case, the laser beam can be shot from any side of the film, that is, it is also allowed to penetrate the PE layer first, and then melt through the PP layer.