PLASTIC TUBES FOR HEAT EXCHANGERS AND METHOD FOR MANUFACTURING PLASTIC TUBES FOR HEAT EXCHANGERS AND USE OF PLASTIC TUBES FOR HEAT EXCHANGERS

摘要

A plastic tube (1) containing graphite filler material in an amount of 40 to 90 weight % of the total mass of the plastic tube and having tube walls with a wall thickness equal to or larger than 0,75 mm is disclosed, wherein the graphite filler material consists of a mixture of a first graphite powder essentially consisting of platelets, strands or fibres and a second graphite powder essentially consisting of spherical particles and the amount of the second graphite powder is selected to be within a range of 0 to 50 weight % of the total mass of the graphite filler material, 50% or more of the graphite platelets, strands or fibres of the first graphite powder in a region with a distance of at least 0,1 mm from the tube wall surfaces are oriented in a range of 45 to 90° relative to the longitudinal direction (z) of the plastic tube, and the outer surface (2) of the tube wall has been subject to a surface activation increasing the surface energy by flame treatment.