It is critical to optimize the drying process for high-quality coatings. Let us look at the six points to consider:   

Substrate and dryer  

The type of substrate has a significant influence on the dryer choice and configuration. Indeed, whatever material is used - paper, aluminum, film or other - it is the substrate that counts. It is also important to note that the thickness range and the tensile strength determine the ideal tape tension. Temperature and resistance to changes in heat dictate the choice of the dryer technology itself.  

Thickness and solids  

Infrared technology has many uses. It is used to preheat the substrate before it is put into the convection dryer. This technology is also used for thin coating applications. Convection and flotation dryers are mainly used for heating coatings and substrates on both sides. Therefore, they are more versatile thanks to their added flexibility, especially for thicker coatings.  

Coatings and viscosity  

Under the specific NFPA 86 guidelines, it is important to consider safety measures, such as purging and LFL monitoring, when dealing with solvent-based coatings, among others. Moreover, this may alter the material’s visual appearance as convection dryers are highly efficient and generate rapid airflow, impacting the coating surface. This is particularly the case for low-viscosity coatings and optical-quality products.  

Energy and baking  

You must consider availability and cost to make an informed choice about what energy to use - natural gas, electricity or other. Regarding baking, the convection dryer allows precise times for hardening the coatings while maintaining a stable temperature.  

 
Three dryer types  

The different dryer types all offer considerable advantages.  Convection dryers transfer heat and will dry products evenly thanks to their high-speed airflow. They adapt to a wide range of substrates.  Flotation dryers are more suitable for delicate substrates and heat-sensitive coatings. Why is this? Because they have a combination of heated air and flotation that dries the coatings while supporting the substrate, eliminating all contact with the roller. Finally, infrared dryers use electromagnetic waves to create heat. They evaporate water fast and efficiently by transferring energy into the coating. However, heat distribution can be uneven, and penetration is generally limited in thicker materials.  

Pyradia assesses all factors to recommend the most suitable dryer for your needs. The company offers digital simulation services, enabling you to test your structures and products. Therefore, you will know exactly what dryer is best to use, whether convection, flotation, infrared or a combination of all these options!  

For any requests for information for selecting your dryer, contact them today.