The preferred finishing process

During the last thirty years powder coating has become the preferred finishing process for number of substrates within the construction industry.

The particular growth of the use of aluminium has attracted many organisations to establish powder coating companies, especially when the capital required to set up can be relatively small. Ultimately the industry has now become split between those companies who continually invest in process equipment, personnel and quality procedures, ie Approved Applicators, and those companies that provide a basic coating service without any technical support whatsoever.

The nature of the construction industry is such that whilst the architect and main contractor may have an appreciation for the importance of using approved applicators, as work is subcontracted this key requirement is lost. This often results in product being coated by companies without the necessary pre-treatment or technical knowledge. Cost will always be a significant factor in decision making but often it is no more expensive to use approved applicators, and in some cases considerably cheaper when things go wrong.

Approval Status

Prior to any company seeking approval status they are required to have ISO 9001: 2015 registration.

This quality management system is an internationally recognised standard that must be maintained and is subject to annual audits. Companies with this accreditation must be systematic in their approach to all internal systems. Purchasing through to order processing and maintenance are monitored whilst customer satisfaction is achieved through performance measurements and management reviews.

The British Standard coating specifications that must be achieved are BS 6496:1984 and BS EN 12206-1:2004 for aluminium. The standards for galvanized steel are BS 6497:1984 and BS EN 13438:2005.

Approved applicator status

Approved applicator status is only awarded by the major powder manufacturers following an assessment of the technical competence of the company which will include.

The above items are indicative of some of the lengths to which, and the importance attached to, the technical competence and management control required of the coating company. These processes must be recorded in detail and made available to the powder manufacturers. Once satisfied, approved status will be awarded. Regular auditing of at least one visit per year means applicators must retain these quality procedures to keep their status.

The chemical pre-treatment process employed must be monitored through daily chemical analysis.

The use of deionised water is essential and the conductivity levels must be controlled.All ovens will have their temperature profiles measured using a data logger every shift.

A sampling regime must be in place to measure the salt spray and mechanical resistance of coated panels and pre-treatment coating weight.

Measurement equipment such as gloss meters and thickness testers must be externally calibrated.