UV coatings for wood

Light, as we all know, is an electromagnetic phenomenon. It is only one component of the continuous group of radiation ranging from radio waves to gamma rays, namely a small part of the so-called electromagnetic spectrum. Within the electromagnetic spectrum, only a tiny portion belongs to the visible spectrum and another to the ultraviolet spectrum. The visible spectrum is the group of wavelengths to which the human eye is sensitive and that are at the basis of the perception of colours. As a general rule, the visible spectrum lies between 380 and 780 nanometres. The smaller wavelength corresponds to the chromatic range of blue-violet, while the longer wavelength corresponds to the range of reds.
The portion of rays involved in the polymerisation of coatings is in the ultraviolet spectrum. Ultraviolet is the name given to a zone of the spectrum of electromagnetic rays with a wavelength of between 100 and 400 nanometres (nm), situated between the visible spectrum and the X rays. In fact, some substances strongly absorb UV, emitting other rays of a longer wavelength, generally in the visible range. In the curing of coatings, the UV radiation is absorbed by special substances called photoinitiators, which absorb the energy of the ultraviolet rays, setting off a chain reaction inside the coating, thus allowing for very rapid polymerisation.

The first coatings featuring UV drying properties made their appearance in 1965, and were intended purely for the filling of chipboard panels. For approximately 15 years, this new coating technology for wooden items was underestimated by the professionals in this sector and by the manufacturers of raw materials for coatings.
This is presumably due to:
- poor functional and aesthetic performance levels;
- impossible use for furniture topcoats;
- shortage of suitable resins and photoinitiators;
- expensive nature, of both the coatings themselves as well as the coating application systems and UV curing technology.
In light of the above, many operators declared that these new technologies had no future in the wood sector: let us not forget that the majority of furniture producers were of limited size, small craftsmen in mostly family-run businesses. The current UV technology has contributed to the recent innovations in the furniture sector, and now we benefit from technologically advanced industries that are on a par with all other sectors.
SAYERLACK, a leading company producing coatings for wood, dedicates a good portion of its resources to research into new products and new solutions, developing and trying to predict future market trends, taking into account that now more than ever the study of new products has to respect the ecology of the environment and human safety.
The main advantages of using UV curable coatings are:
- High production speeds;
- Savings in terms of space;
- Coatings with extended or unlimited pot life;
- Acrylic paints generally ready to use;
- Low or non-existent solvent emissions into the air;
- Items ready to be packaged at the end of the production cycle.