0.02mm high-precision UV laser is more suitable for printing date on PE film PE film can be used as the inner layer of food bags, clothing bags, composite bags, and packaging for cosmetics, pickles and pastries. Because PE film is easily deformed by heat, it is necessary to use the ultraviolet laser which is the father of cold processing to mark the bar code or the production date on its surface . The wavelength of the UV laser is 355nm, the beam quality is good, the focused spot is small, and the processing heat-affected zone is small.