A HDPE geomembrane smooth is very low permeability synthetic membrane liner or barrier with smooth surface. It can be used solely or with any geotechnical engineering related material so as to control fluid (or gas) migration in a human-made project, structure, or system. The manufacturing of HDPE geomembrane smooth begins with the production of the raw materials, which mainly include the HDPE polymer resin, and various additives such as carbon black, antioxidants, anti-aging agent, UV absorber, and other adjuvant. The HDPE resin and additives ratio is 97.5:2.5.