UV curing technology is using light to cure a chemical substrate. Light is made up of a wide spectrum of electromagnetic radiation, with different wavelength regions corresponding to different amounts of energy, such as infrared, visible, and ultraviolet (UV). As the wavelength of light decreases (and the frequency increases), the energy it carries increases. Therefore, as shown in the diagram below, (gamma) and X rays carry much more energy than radio waves.
Every chemical reaction requires a minimum amount of energy applied to it before it can start off; this is called the activation energy. The different amounts of energy provided by the different wavelengths of light are able to trigger and activate different chemical reactions, acting as their activation energy. UV light, which carries a relatively high amount of energy, can be used to start chemical reactions which have a high activation energy. Microwaves, which carry a relatively low amount of energy, can be used to start chemical reactions which have a low activation energy.
Curing, a chemical process during which an adhesive and its substrate toughen and harden into a cross-linked product, can be initiated or accelerated through the use of light. Different adhesives require different activation energies for their curing process. Adhesives that can be heat-cured are initiated by infrared radiation; UV curing adhesives are initiated by ultraviolet radiation; and so on.
