快递袋分类有快递胶袋，快递文件信封，气泡快递袋等。
Express bags are classified as express plastic bags, express document envelopes, bubble express bags, etc.
这次我们重点介绍下快递胶袋和快递袋制袋机。
This time we will focus on the express bags and express bagging machine.
1.快递胶袋材质：低密度聚乙烯（LDPE）通常说的PE，高密度聚乙烯（HDPE）通常说的PO，快递胶袋具有成本低，重量轻等优点。
1. Express plastic bag material: low density polyethylene (LDPE) commonly said PE, high density polyethylene (HDPE) commonly said PO, express plastic bag has the advantages of low cost, light weight and so on.
PE与PO在快递胶袋的区别：PE透明度、柔软度比较好，印刷颜色比较光亮；PO具有比较良好的机械性能；在国内快递袋一样都是使用PE作为主材料，而国外般都是使用PE、PO复合作作为快递袋的主材料。
The differences between PE and PO in express bags are as follows: PE is transparent, flexible, and the printing color is bright; PO has good mechanical properties; PE is used as the main material in domestic express bags, while PE and PO are used as the main material in foreign countries.
2. 我们国内的快递胶袋的款式，大概分为两种。 一种是普通的快递袋，应用比较广的快递品牌如，圆通快递，申通快递，韵达快递，天天快递等。 另外一种是带有透明运单袋的快递袋，如顺丰快递，DHL快递等。
2. There are two styles of express bags in our country. One is the ordinary express bag, which is widely used in express brands such as Yuantong Express, Shentong Express, Yunda Express and Tiantian Express. The other is the express bags with transparent waybill bags, such as Shunfeng Express and DHL Express.