欧美日韩国产免费一区二三播放_三级成人熟女影院_日韩制服诱惑在线_男人天堂日韩精品

The QR codes on some products we have seen are engraved by laser marking machines. The principle of laser marking technology is to irradiate the surface of the workpiece with a high-energy laser beam, and instantly vaporize to form a two-dimensional code. The non-contact processing has little impact on the workpiece, and it can also be one object, one code, and the marking has longevity.