轻一点我要你搞我小穴视频-日韩人妻中文字幕高清在线-精品一区精品二区国产-韩国毛片在线播放第8-亚洲天堂成人在线免费网站-日韩精品电影一二区-欧美日韩国产精品1卡-色综合91久久精品中文字幕-黄色无毒免费av网站

The color of plastic material laser marking is yellow, which mainly depends on the material itself, the model used and the adjusted parameters, such as PVC plastic, the color of carbon dioxide laser marking is yellow, oxidized or vaporized; if it is marked with fiber laser, it is black; In addition, because of the material itself, the parameters of the laser marking machine are not adjusted correctly, which will cause the printing to become yellow.