Chapter 2 - The UV Curing Process

Abstract

The ultraviolet (UV) curing process is predominantly determined by the desired application of a coating. The intended end-product governs the substrate to be coated. The targeted properties like high-gloss appearance, abrasion resistance, color effects, hardness, flexibility, and resistance against chemicals or scratches have to be provided by the chemical formulation consisting of base resins, diluents, photoinitiators, and various additives. An appropriate selection of the components has to be done to enable an effective curing process; for instance, in coatings containing pigments or UV light stabilizers, the spectral absorbance of the photoinitiator has to be adjusted to a spectral region where the pigments or UV absorbers are fairly transparent. This fine tuning is necessary to match the characteristics of the lamp system with the chemistry of the coating to provide an economic curing process. Besides the physical properties of the cured material to be obtained, the economics of the coating process is the most important variable that decides the type of coating used. Thus, to calculate the total costs of a coating process, not only materials costs but the whole process design and the equipment set-up have to be considered to compare different coating processes with each other.