What Does Composite Repair Mean?
Composite repair is an ISO- and ASTM-qualified repair technology used to repair defects in composite materials. Composite repairing rectifies defects in a wide range of equipment such as large diameter pipelines, high pressure piping systems, bends, flanges, valves, gaskets, fittings, pressurized vessels and tanks, saddles, main body connections, supports, nozzles and tees.
Corrosionpedia Explains Composite Repair
Composite materials are used in a wide range of industries including aerospace, marine, automotive and other industrial and manufacturing processes.
The types of composite repairs include the following:
- Cosmetic – In this repair method, surface restoration is performed with the help of non-structural and superficial filler until a permanent repair is made. The structure does not regain any strength and cosmetic repairs are used only where strength is unimportant. Due to high shrinkage, cosmetic repairs may start to crack after a relatively short time.
- Resin injection – This repair is appropriate where delamination is restricted to only one ply. This repair also does not help in regaining any strength; however this repair is quick and cheap. Resin injection helps to slow the delamination spread and is used only as a temporary repair method.
- Semi structural plug/patch – This repair helps to regain strength in the defect area of a composite material. A mechanically fastened plug (i.e., core plug) and patch repair can be especially effective where thick solid laminates are used, since they take bolt loads well.
- Structural mechanically fastened doubler - Full structural repairs using bolted doublers can be used in heavily loaded solid laminates. This is often the only practical means to repair such structures. A doubler is a localized area of extra layers of reinforcement, usually to provide stiffness or strength for fastening, or other abrupt load transfers, such as repairs.
- Structural flush repair - This repair restores the material's full structural properties by forming a joint between the prepared repair area and the repair patch. A repair patch is made by replacing each ply of the composite laminate that was removed from the damaged area. The size of the repair patch should exactly fit the repair area, except for a final cosmetic or sanding layer, which is often slightly larger to allow for sanding down to achieve a smooth and/or cosmetic surface.