日本成人不卡一区二区-日韩欧美自拍在线观看-男人对女人下部猛插免费视频-欧美色香蕉一区二区三区-国产国产午夜福利视频在线观看-99国内精品一区二区三区-五月激情六月综合婷婷-亚洲欧美综合图一图二-亚洲国产欧美日韩在线人成

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.