Aalberts surface technologies Kirkby

Aalberts Surface Technologies Ltd is a leading supplier to Aerospace, Defence and Automotive OEMs and manufacturers across Europe and across the globe based in Kirkby-in-Ashfield near Nottingham in the UK. The division formerly known as Acorn Surface technology has been a leading name in the area of surface coating technology for over 40 years. Hard anodising is at the core of the business, but the range of coatings and treatments has been expanded by including sulphuric and chromic anodising, Aerospace-standard wet paint processes, IVD aluminium vacuum coating, PTFE and lubricated coatings, Chromate and Non-Chromate Conversion coatings, and NDT (Penetrant Flaw Detection).

With the merger of Aalberts surface treatment Tamworth Ltd in 2014 we enhanced our portfolio. This increased our portfolio of coating processes based on fluoropolymers, metals, plastics, ceramics, nanostructures, and powder coatings to optimize traction properties, corrosion protection, non-stick properties, and resistance to wear.

The range of applications for components with engineered surface coatings is ever increasing, some current examples of end markets include: Aerospace, Defence, Marine, Automotive, Oil and Gas, Renewable Energy, Electronic, Space, Communications, Machine Tools, Motor Sport, Converting, Printing, Packaging, Textile, Chemical, Food, Non-Woven. Hydraulic and Pneumatic Systems.

Our research shows that IVD aluminium vacuum coating is widely identified as the high-quality alternative to the use of cadmium for corrosion protection, because it combines limited levels of added layer and comparably low life costs with a satisfying duration of protection.

In terms of accelerated corrosion tests IVD aluminium exceeds the performance of cadmium: 25 to 50ums of aluminium (a class 1 type II coating) will pass the standard 672 hours salt spray test and typically exceed 1,000 hours. Thinner coatings, that can be specified for close tolerance or threaded parts, will easily exceed the specified 336 hours for comparative cadmium coatings.

Hard anodizing produces a relatively dense, thick oxide layer. As a result, the film tends to be darker in appearance although the final colour is largely dependent on the alloying constituents (elements) of the base material and, in its natural state, can be anything from light green/gold to dark grey/charcoal.

Hard anodizing has become a very important technique where weight saving (e.g. by replacing aluminium with steel) combined with good corrosion protection and wear resistance are required. Furthermore, unsealed anodic coatings can absorb and retain oil when used on sliding surfaces for cylinders and pistons etc., providing longer lasting lubrication.

We have a close working relationship with Whitford, who manufacture fluoropolymer coatings under the Xylan® brand, and with Chemours, who manufacture the Teflon® range of coatings. This ensures we are kept abreast of the latest developments in coating technology.

It is a common misconception that Xylan® or Teflon® is an individual, specific coating. In fact, they are brand names which cover a huge range of fluoropolymer coating systems. A fluoropolymer has a Fluorine atom in it – hence the F in PTFE for example. The system may consist of a single layer, two layers or even three or more layers. The coatings themselves are based on different resins, such as PAI (polyamide-imide), PPS (polyphenylene sulphide), epoxy and polyurethane.

In addition to resins and fluoropolymers, the coating systems have additives, pigments and fillers to achieve specific properties: corrosion protection, abrasion resistance, electrical conductivity / resistance, lubricity, aesthetics, non-stick, thickness, colour. The ratios of these various ingredients are varied to achieve different results. All of this is carried out by the coating manufacturers.