Aluminium Finishing- At Presto we take responsibility for all aspects of your project from submission of drawing to on time delivery of your components with a pristine finish.

We offer a range of finishes and the application of the product usually determines the choice of finish.  For visible parts where appearance is key aluminium lends itself to stylish finishes such as anodising.  Durability is often a deciding factor particularly when parts are for outdoor use.  When parts will not be visible and are for indoor use they can have a range of cost effective treatments such as Surtec 650, Alochrom or Irridite.  Whatever your requirements we work with you to find the best solution for your component.

Below are a selection of finishes we offer:-

 Anodising

Anodising can only be carried out on aluminium and it is the most frequently requested finish by our customers.  It is an electrochemical process that converts the metal surface into a decorative, durable corrosion-resistant anodic oxide finish and can be dyed in a variety of colours and finishes.

Anodising is accomplished by immersing the aluminium into an acid electrolyte bath and passing an electric current through the medium.  A cathode is mounted to the inside of the anodising tank; the aluminium acts as an anode so that oxygen ions are released from the electrolyte to combine with the aluminium atoms at the surface of the part.  In brief, anodising is a matter of highly controlled oxidation which is an enhancement of a naturally occurring phenomenon.

Benefits of Anodising include:-

Durability – Most anodised products have a long life span so the finish needs to be durable.  Anodising is a reacted finish that is integrated with the underlying aluminium for total bonding and unmatched adhesion.  The anodised surface is very hard and as a result preserves and extends the life of the aluminium product.  Anodised aluminium is resistant to corrosion and well suited to a wide range of applications.

Colour Stability – The sealing process used in anodising results in your anodised part looking factory new for years.  Anodised surfaces provide good stability to ultraviolet rays, do not chip or peel and are easily replicated.

Ease of Maintenance – Scars and wear and tear from handling, installation, frequent cleaning and usage are virtually non-existent.  It is generally sufficient to clean anodised surfaces with mild soap and water to maintain the original finish although a mild abrasive cleaner can be used for more stubborn stains.

Aesthetics – Anodising offers a wide variety of colour and texture alternatives and allows the aluminium to maintain its metallic appearance.

Cost – A low initial finishing cost combined with minimal maintenance costs makes anodising excellent long term value.

Health and Safety – As the anodising process is a reinforcement of a naturally occurring oxide process, it is non-hazardous and does not produce any harmful or dangerous by-products.

Anodising Pre-Treatments

• Bead Blasting

Bead blasting is the process of removing surface deposits on metal by applying fine beads at high pressure using compressed air without damaging the surface.  It is a popular choice of finish with our customers and we have invested in new Bead Blasting and Graining equipment.

Machined aluminium parts end up with lines, swirls and etching on the surface as a result of the machining process.  To prevent these imperfections from translating through a coating or anodising the surface is always made uniform by bead blasting prior to applying the chosen finish.

The benefits of Bead Blasting include:-

Uniform Finish –A perfectly clean uniform finish is achieved on all shapes of component including 3D and curved.

Styling Options – By varying the bead size the surface finish can be altered to suit individual customer requirements.  The graining can be made coarser or finer and the finish matte or bright.

• Graining

Graining is the process of polishing ‘grit lines’ onto the surface that are uniform and directional in appearance.   It is achieved by polishing the surface with an abrasive grit belt.  The finish achieved will depend upon the coarseness of the grit used.  Graining followed by clear anodising will result in a natural finish.  This finish is particularly popular for trims and badges.

Industrial Paint Finishes 

There are two systems of industrial paint finishes for aluminium finishing; wet painting and powder coating. Both of these systems will offer a durable and corrosion proof coating, but the application of the component will determine which system is used.

• Wet Paint

Generally speaking wet painting is used where a durable high quality finish is required on visible surfaces that the end user comes into contact with. For example applications can range from machined front panels for high end audio equipment through to car bodywork. Finishes are wide and varied and range from high gloss through to matte, and there is also the ability to have soft feel rubberised and suede textures incorporated.

Wet paint is commonly applied using a spray painting method, which involves utilising an air-pressurised spray gun. The air gun is made up of three main parts; the nozzle, paint basin and air compressor.  Paint is mixed with compressed air and when the trigger is activated a fine spray is released.  Usually a coating will be applied by hand, although the process can also be automated.

• Powder Coat

Powder-coating also provides a very hard wearing and durable coating.  It is ideal for products that are subject to intense handling or products that do not require such a high quality finish.  A multitude of coatings can be specified such as satin, gloss, metallic, iridescent and matte.

Powder coat application is based on the principle of opposite electric charges being attracted to one another.  Powder particles are electrostatically charged as a result of passing through a charged spray gun and are then attracted to an earthed component. The part is then thermally cured in an oven and the result is a high resistance finish.

Screen Printing

Screen printing is used in Aluminium finishing to print text and colour graphics onto almost any component for example control panels, nameplates for machines, serial and model numbers etc.  It results in a durable print that cannot be scratched off easily and is resistant to corrosion and extremes of temperature and weather.

Anoprinting

Anoprinting is generally used for demanding applications such as industrial environments. The process of anodising opens up the pores of the aluminium, a printed dye is then introduced into the porous surface layer. The pores are then sealed, trapping the ink into the surface. It changes the chemical composition of the aluminium, forming a hardened layer which provides protection from corrosion, and increases resistance to wear and abrasion. The surface appearance is resistant to marking from fingerprints and makes for a functional and decorative label.

Laser Engraving

Laser engraving is a process  that is suitable for aluminium finishing it’s where a high heat laser beam physically removes the surface of the material by causing it to vaporise and creates a cavity.  If the metal has been pre-treated or coated, the laser will engrave away this top coating to reveal the metal finish below.  Engraving can be used to customise or personalise parts and is particularly good for high wear parts.

Laser Etching

Etching is a process where a laser beam uses high heat to melt the surface and the melted material expands and causes a raised mark.  It can be done on anodised or bare aluminium.

Laser Marking

Laser marking uses a lower power beam than laser engraving and etching and leaves the surface material intact.  It is achieved by moving a low powered beam across the surface which causes oxidation under the surface turning the material black.  The precise and repeatable nature of lasers allow for fine detail marking on small components.  Laser marking is used for identifying products for example bar codes, serial numbers and regulatory symbols.

The options for aluminium finishing are endless so please do call us on 01865 883508 or e mail us at sales@prestoeng.co.uk to discuss your project.

For more information about Presto Engineering please visit our website here and if you would like to discuss a project with us please call us on 01865 883508 or e mail Julian at sales@prestoeng.co.uk.

The post Aluminium Finishing first appeared on Presto Engineering.

The post Aluminium Finishing appeared first on Presto Engineering.

“Here at presto, we have taken control of another step in the process by investing in new bead blasting and graining equipment to cater for your needs.”

The graining operations undertaken at Presto are applied under pressure by a linishing belt, providing a straight grain across a flat surface. Appearance of the grain can be varied based upon the coarseness of the belt used for the operation. See below an example of a part manufactured by presto using this technique on the top surface:

Alternatively, bead blasting can be used in a variety of scenarios, such as a flat, 3D or curved components with a consistent finish. It works by firing small beads at a component under high pressure, to give a consistent surface finish without damaging a part. Surface finish can be altered to suit your particular requirements, with both coarser/finer and brighter/duller appearances possible. An example of a beaded component can be seen below:

Carrying out these operations in house enables us to produce a consistently high standard of finish, whist also cutting lead times. Both of these attributes are in line with our philosophy of providing the highest standards of finish.

Feel free to contact Presto today with any queries you may have regarding the subject.

The post Bead blasting and Graining Aluminium first appeared on Presto Engineering.

The post Bead blasting and Graining Aluminium appeared first on Presto Engineering.