Composite film for coating steel pipe and method of manufacturing same

A composite film for surface protection and reinforcement of a steel member, the composite film comprising:

• a first film layer attached to a surface of a steel member;
• a second film layer positioned on the first film layer;
• and
• a mesh film layer having a mesh structure and positioned on the second film layer,
• wherein the first film layer is made from a first polymer mixture comprising 50 to 85 wt % of a linear low density polyethylene (LLDPE) 12 to 45 wt % of maleic anhydride, and 2 to 5 wt % of masterbatch,
• the second film layer is made from a second polymer mixture comprising a linear low density polyethylene (LLDPE),
• the mesh film layer is formed by weaving synthetic resin yarns containing a high density polyethylene (HDPE) and 0.12 to 1.42 wt % of an inorganic filler,
• the mesh film layer is partially embedded into the second film layer during a heat compression process when the composite film is manufactured, and
• the inorganic filler of the mesh film layer is a stone powder having an average particle size of 10 to 90 μm.