3-Layer Polyolefin Coatings
In our multi-layer polyethylene / polypropylene (PE / PP) systems, robust polyolefin coatings are applied to a fusion bonded epoxy (FBE) primer. The coatings produced in this way display high electrical resistance. Used in conjunction with cathodic protection, pipes achieve service life well in excess of standard specifications.
Multi-layer Pe and PP coatings develop their full anti-corrosion effect at thicknesses of as low as 1 mm. However, the coating thicknesses specified in standards are higher, usually in line with pipe diameter so as to provide additional protection against mechanical damage due to compressive and shear forces during transport and installation.
Where stress and strain is particularly severe, even thicker coatings are used.
PE is the standard solution, while PP allows higher service temperatures and provides better mechanical properties in terms of indentation and impact resistance. Coatings can be designed to deal with service temperatures of up to 120°C. The materials used and the various layer thicknesses within the coating system are important factors.
FBE PRIMER: 1st layer – Epoxy powder spray-applied with electrostatic guns in typical thickness of 80 – 250 μm.
COPOLYMER ADHESIVE: 2nd layer – Copolymer bonding layer extruded in typical thickness of 250 μm.
POLYETHYLENE: 3rd layer – Outer polyethylene layer extruded in typical thickness of 1.2 – 3.5 mm, possible increase to over 10 mm. service temperature up to 80 °C.
POLYPROPYLENE: 3rd layer – Outer polypropylene layer extruded in typical thickness of 1.2 – 3.5 mm, possible increase to over 10 mm. service temperature up to 120 °C.
Fusion Bonded Epoxy Coating
FBE coatings are thermoplastically hardening layers of epoxy resin applied to steel pipes using an electrostatic process, and which protects them against corrosion.
FBE can be applied at service temperatures of up to 110 °C; the typical thickness is 350 to 450 micrometres. For increased resitance to mechanical loads, additional layers of special epoxy can be applied. This is known as dual FBE coating or abrasion-resistant overlay (ARO).
FBE DUAL LAYER: 1st layer – Corrosion protection epoxy powder spray-applied with electrostatic guns in typical thickness of 250 – 275 μm.
FBE DUAL LAYER: 2nd layer – Mechanical protection epoxy powder spray-applied with electrostatic guns in typical thickness of 375 – 625 μm.
FBE MONO LAYER: Epoxy powder spray-applied with electrostatic guns in typical thickness of 350 – 450 μm.