Cryogenic separation is based on the ability of cryogenic fluids, such as liquid nitrogen, to reach temperatures low enough to embrittle the paint on the substrates, making it easier to remove.

The underlying concept is simple: the paint-coated substrate is immersed in low-temperature cryogenic fluid, so that contact with the liquid gas causes the paint to contract suddenly, while the substrate is only affected by the cold afterwards, with a less significant contraction. Consequently, due to the different rates of shrinkage, the paint cracks and separates from the substrate.

However, in order to achieve perfect removal, a slight mechanical action is necessary at the end of the operation. In cryogenic paint stripping systems, the various stages of the operating cycle are performed automatically:

• The substrate is immersed in a tank filled with cryogenic fluid so that the paint coating becomes brittle and cracks.
• A shot blasting machine mechanically removes paint flakes, which are completely detached and collected in special containers, separated from the grit.
• A water-based release agent is applied to protect the substrate and simplify subsequent painting, where necessary.

This cryogenic technology represents an environmentally friendly alternative to standard techniques such as thermal and chemical paint stripping.