Inert gas curing

Inert gas curing

Under normal atmospheric conditions, oxygen reacts with photoinitiators in the ink after they are exposed to UV light. This renders some of them inactive and limits the extent of polymerisation that can occur. The coating is then poorly cured or the process is forced to run much slower. This is where inert gas curing comes into play.

Curing under an inert atmosphere eliminates oxygen and significantly increases the rate and extent of cross-linking. Curing speeds are greatly improved, migration of harmful materials is reduced and the finished product odour is better.

• Allows curing of low migration inks for food-grade applications
• Improves the curing speed of all free radical inks
• Enables curing of free radical silicone coatings
• Reduces ink odour

GEW’s inert gas curing chambers can be custom integrated for many different applications and machines. Whether a web runs straight through the UV unit or is supported on a roller, our unique design ensures the minimum usage of inert gas whilst maintaining adjustable oxygen levels to below 50ppm. Sensors constantly monitor the level of oxygen inside the curing chamber and the RHINO system can maintain the desired oxygen level automatically via closed-loop control.

Typical system components:

1. UV lamphead
2. Inert gas curing chamber
3. Oxygen analyser
4. Inert gas control box
5. Multi-point UV monitors (optional)
6. HMI touchscreen
7. RHINO Power electronics
8. Inert gas feed