... abrasion resistance 3.Widely used in the drainage of railway,highway ,tunnel HDPE double-wall corrugated pipe using HDPE as main material, and adds ... various plastic additives,then by twin-screw extrusion, a pipe formed which consist of ... ×1mm≤30×3mm surface should be homogeneous ,and the inner wall should be smooth , no burr. HDPE double-wall corrugated pipe