Metal is used to package an enormous range of different products. For some products the internal face of the metal container can be left uncoated, for others a thin coating is required to provide a barrier between the product and the metal.
Metal packaging offers many benefits as a packaging material. It is a 100% barrier to oxygen, light, microbes, and environmental contamination which makes it perfect for packaging a wide range of products safely over extended periods of time.
For example, it provides excellent long term ambient storage of food and drink with the benefit of a minimal reduction in nutritional value, flavour or quality over the whole of the storage period.
This ability to provide the long term availability of safe, nutritious wholesome food supply is hugely important given that according to the Food and Agriculture Organisation of the United Nations “Roughly one third of the food produced in the world for human consumption every year (approximately 1.3 billion tonnes) gets lost or wasted”.
For this to be achieved container integrity is essential. However, some products, including some foods are aggressive to metal, and therefore a high performance internal protective coating is vital to protect both the food and the container and to ensure the full shelf life of the product is realised.
Internal Coatings are mostly a combination of resins, cross linkers, additives, pigments, and catalysts and are applied in a carrier then dried and cross-linked in oven at around 200°C.
This results in a very high molecular weight impervious film of between 5 and 20 microns thick that gives the package the excellent characteristics required for long term safe storage of its contents.