| 摘要 |
The present invention relates to a drainpipe to uneven process both side surfaces of an extruding profile and to form a joining coating layer for improving bonding strength between reinforcement connecting members and, more specifically, to a drainpipe to unevenly process both side surfaces of an extruding profile and to form a joining coating layer for improving bonding strength between reinforcement connecting members to form an uneven projection and an gear type uneven groove continuously from the both side surfaces of the profile by installing a side surface molding apparatus on the front in an extrusion process of extruding the profile formed with one hollow hole in the profile formed with a cross reinforcing bar in which a plurality of hollow holes is formed. |
