The coatings that give corrosion protection to large metal components, provide clear varnish on plastic products, and allow for colored décor on stone all require a drying process.
Infrared systems help ensure that the heating steps needed to dry these products are carried out as efficiently and uniformly as possible. Small, irregularly shaped stones or other bulk materials dry just as reliably with infrared heating technology as do large-surface metal parts, according to Heraeus Noblelight GmbH, headquartered in Hanau, Germany.
Metal plates must be heated homogenously over the entire surface to ensure coating quality. A precisely matched emitter arrangement in combination with the right control system will bring significant improvements, Heraeus says. An appropriate guidance system ensures the optimum alignment of stones or granules to the radiation, and bulk materials can be dried efficiently. No coating process is exactly the same, but lacquers and paints should always be dried as quickly as possible.
Many coatings set challenges that can't be met with standard heat sources, and the coating system defines the data framework. For example, water evaporates more slowly than do solvents, therefore infrared emitters dry water-based lacquers significantly faster because the emitters are optimally matched to the absorption properties of water.
Nano coatings to some extent require very high temperatures, which can be reliably delivered by infrared emitters. Powder coatings must be gelled very quickly, so infrared drying saves time and money because only the coating and surface are heated. The result is that the products are ready for further processing much more quickly after the heating stage.
Industry keeps pushing the limits, wanting to dry lacquers and coatings ever faster. However, at the same time, the drying must produce a top quality product using the minimum amount of energy. Energy reduction and material costs are important to end-users in their struggle to maintain or improve competitiveness. Often, companies find it more sensible and cost effective to optimize an existing system by adding infrared to it rather than introduce an entirely new system or set up a new plant, Heraeus says.
Infrared heating technology offers several benefits that optimize energy consumption in industrial heating processes:
- High heat transfer capacity.
- Contact-free heat transfer.
- High efficiency.
- Efficient energy transfer by using optimum
- Energy use confined to the working area
by matching emitters to product shape.
- Energy used only when required because of fast response times.