Polyester Powder Coated Aluminium
In most cases all windows and doors will be painted in a chosen finish using the polyester powder coating process.
Aluminium which is powder coated has finely divided polyester powders which are given a polarised electric charge from a high voltage generator. The particles, being similarly charged repel each other and seek an earth (the article to be coated). The coated components are heated to 200°C for 10 minutes causing the powder to melt, flow and chemically react to form a continuous film which is firmly anchored to the substrate. Electrostatic coating, as the process is known, provides good coverage as the powder tends to ‘wrap-around’ the profile. Colours should be chosen from the extensive RAL or BS colour ranges and are available in matt, satin or high gloss finishes.
Aluminium, even when thoroughly cleaned, does not present an ideal surface for painting. Extrusions emerging from the die at about 500oC immediately oxidise on contact with the air. The oxides of the alloying elements (magnesium, silicon, copper, manganese, etc.), swarf and extrusion ‘fines’ (mechanical linishing can be offered as an additional service), damage caused during handling and organic materials (dirt and oils) must all be removed to ensure adequate paint adhesion. This cleaning process is an essential part or polyester powder coating and must in all cases be applied by a qualified company meeting the current British Standards.
Products from a reputable supplier should all meet both RAL and Syntha Pulvin Finishes, complying with BS6496 and 6497 across the full range of colours. The paint guarantees offered for powder coated finishes are:
Syntha Pulvin 15 years for Syntha Pulvin Gloss and Satin
25 years for Syntha Pulvin Plus
RAL & BS 25 years for Gloss Satin or Matt.
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