Flame spray coating of a barrier material

摘要

A polyolefin substrate is coated with a melted powder that forms a barrier layer. The barrier material may be applied directly to the polyolefin or onto a flame spray coated primer layer. Preferably the primer layer is either a thermoplastic with a specific elastic modulus or an acid modified polyolefin. The primer can be modified by boric or carboxylic acid. The barrier layer may itself be coated. The polyolefin substrate is HDPE and the barrier material is polyethylene vinyl alcohol. The material is used in multilayered fuel containers and pipes. These are shaped by co-extrusion followed by blow moulding or thermoforming. The coating is applied to the cutting face or a thin area.