The processing of the laser die-cutting/scoring machine was mainly discussed in the previous articles ,and now we will continue to talk about some basic principles of the laser scribing/scoring machine in the flexible packaging layer cutting process.

Plastic film layer, metal film layer and paper have different absorption performance and radioactivity in the wavelength range (9.4~11μm) 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 a typical wavelength of 10.6μm. After absorbing the laser beam, a part of the plastic film is heated and completely melted. However, 10.6μm is not workable for a few plastic films such as OPP, PE and LLPE . The aluminum foil layer does not absorb all the wavelengths by the low-power CO2 laser and is completely reflected.


According to the desired layer cutting structure, the laser die-cutting/scoring machine can cut in line with the packaging material. As long as the correct laser wavelength is used, the layer can be scored from the correct film surface. The following examples illustrate the basic principles of laser layer cutting of composite films.

①PET-AL-PE: This is a typical laminated films for food packaging, such as coffee packaging bags. The selective absorption of CO2 laser (10.6μm) by the material can use the mechanically supported PET layer to completely vaporize in very small parts. It will affect other layers, and the reflection effect of the aluminum foil layer helps to use the laser more effectively.

②OPP-PE: This is laminated packaging material commonly used for laundry powder packaging. Because PP has stronger absorption capacity for laser beams than PE, you can choose to cut the PP layer without affecting other layers.In this case, the laser beam can be injected from any side of the film, that is, the laser beam is allowed to penetrate the PE layer first, and then melt through the PP layer.

Choose the right wavelength is quite important , it better to be tested and find the best solutions .