Novelis Painted Products

A unit of Novelis Inc., the world leader in aluminum rolling.

Locations Contact us
Search

About Aluminium

About Aluminium > Pre-Painted Aluminium > Production Process

Production Process

State-of-the-art pre-treatment and coating technology (Coil-Coating)

Coil Coating – a technology that is unique in its approach to the environment and scarce resources. The pre-treatment and coating stages of this process guarantee an efficient use of chemicals and paints and thus help to protect our environment.

Novelis‘ wet paint coating facilities use a technique by which - according to configuration - up to four paint layers and coating on front and reverse sides (also with strippable protective film) can be applied.

During the stove enamelling, the solvent vapour is collected, burned off and thus used to heat the ovens. This reduces the need for additional heating and minimises emissions to well below the legal thresholds.

All coatings are adjusted to the application desired involving two major groups: decorative and functional surfaces. Typical paint system requirements are formability, scratch-resistance, appearance, weatherability, printability, etc. To meet these requirements, various paint systems are used - from 1- to 4-layer systems / primers, polyester, polyurethan and PVdF paints.

Tension levelling

Tension levelling at the beginning of the manufacturing process guarantees an absolutely flat product.

Cleaning of strips through cascade spraying

Environmentally friendly cascade cleaning.
Perfect cleaning, removal of oxides, dirt and lubricants.
During the cascade cleaning process, the aluminium strip is cleaned in alternate directions within different zones. Cleaning is thus much more efficient than conventional technologies and water can be re-used, thereby cutting consumption levels.

Pre-treatment - for optimum paint adhesion

Coating is applied using a roll process

Minimal chemical usage
No wastes
Optimises adhesion of coating for optimum corrosion protection

Pre-treatment is the key of the coil-coating process. The pre-treatment is needed to increase the corrosion resistance and to ensure paint adhesion. During pre-treatment a conversion layer is chemically built up on the surface of the aluminium strip. Novelis is using the most efficient no-rinse technology.

Absolutely uniform coating using roller coating
Eliminates over-spraying
Coating dosage is rationalised through minimised layer thickness
Eliminates wastes

Coil Coating

The paint is applied using rollers. All paint systems are geared to match the requirements of the application. There are essentially two different types of coating - decorative and functional. Typical requirements are formability, scratch resistance, appearance, weather resistance, printability etc.

To achieve different results, 1- to 4-layer paint systems are used, e.g. acrylic primer, polyester, PUR, or PVdF. The reverse side always has a protective lacquer (if nothing else is required).

Curing

Depending on the paint system, the curing temperature lies between 200 and 300°C. It is a key advantage that Novelis has more than 30 years experience in coil coating. In order to protect the environment as well as possible, the solvent vapour is used to heat the oven without gases escaping from the closed system.

Solvent-based lacquer
Temperature 200 to 300 °C
Fan extraction of solvents
Solvent vapour is burned-off and used to heat the ovens

Coil coating and heat curing

Continuous quality control criteria monitored during the production:

Colour
Paint thickness
Gloss
Paint hardness
Paint adhesion
Formability

Quality Control
By means of a computerised process involving highly sensitive electronic measuring devices, our paint quality is constantly controlled. Also, the quality criteria determined for each product are examined, e.g. colour uniformity, coating thickness, gloss, paint hardness, paint adhesion and forming characteristics.

Layering structure

Lamination of protective film
A protective film is applied to most of Novelis‘s products. This film helps you to simplify the handling of Signicolor sheets. The films differ depending on the particular product and often carry additional information such as coating direction and brand details. The films are environmentally friendly and are easy to recycle.

Further processing

The coated aluminium coil will be wind up and is ready for further processing.

Strips painted are stored for processing
Customer specified individual cut sizes of coils for sheets or strips
Packaging the finished product