Acid-resistant slings are almost all high-strength polypropylene slings used in China. Acid-resistant slings are made of heavy-duty webbing made of acid-resistant materials, which are sewn into the required flat white slings. The current high-strength polypropylene slings are affected by the width of the heavy-duty webbing webbing. The limitation is that it can only achieve a width of 500mm. The strength of polypropylene is 1/2 of that of polyester, so the strength is subject to certain restrictions. Most polyester manufacturers mistakenly believe that they are not acid-resistant. In fact, they have forgotten the fact that the suture of the acid-resistant sling used is Polyester, because the temperature resistance of polypropylene thread does not exceed 80 degrees, and the sewing needle often exceeds 100 degrees at high speeds, the polypropylene thread is easy to fuse after the high-speed extrusion of the sewing needle, and only high-strength polyester thread can be used as the sewing thread. If the polyester sewing thread is not acid-resistant, the acid-resistant sling will crack and break within a few days. The fact that there is no such phenomenon is enough to show that the polyester thread is acid-resistant. The polyester sling is the same width and thickness as the large-tonnage acid-resistant sling, and the strength is sufficient. Twice as much as polypropylene acid-resistant slings, polyester acid-resistant slings are more resistant to aging and can be placed for a longer time.