9NOVEMBER, 2021cure with exposure to UV light or Electron Beams (EB). Jointly referred to as radiation curing, the big advantage was instant curing and excellent coating properties. During the 80s the technology developed and started to be used on a commercial scale. As the awareness of solvents' effect on the environment increased, so did the popularity of radiation curing as a way of reducing the amounts of solvents used. This trend has not slowed down and the increase in adoption and type of applications has continued since, and so has the demand both in terms of performance and sustainability. Moving away from solventsAlthough UV curing in itself is already a very sustainable technology, certain applications still require the use of solvents or monomers (with risk of migration) to lower the viscosity for a satisfying result when applying the coating or ink. Recently, the idea emerged to combine UV technology with another sustainable technology: water based systems. These systems are generally either of a water soluble type (either through ionic dissociation or miscible compatibility with water) or of the PUD (polyurethane dispersion) type where droplets of a non-miscible phase are dispersed in water through the use of a dispersing agent. Beyond wood coating Initially the waterborne UV coatings have mainly been adopted by the wood coating industry. Here it was easy to see the advantages of combining benefits from high production rate (compared to non-UV) and high chemical resistance with low VOC. Essential properties in coatings for flooring and furniture. However, lately other applications have started to discover the potential of water based UV as well. Water based UV digital printing (inkjet inks) can benefit from the advantages of both water based (low viscosity and low VOC) as well as UV curing inks (fast cure, good resolution and chemical resistance). Development is moving forward quickly and it is likely that many more applications will soon evaluate the possibilities of using water based UV curing Water based UV coatings everywhere?We are all aware that our planet is facing certain challenges ahead. With a growing population and increased living standards, consumption and therefore resource management becomes more critical than ever. UV curing will not be an answer to all of these challenges but it can be one piece of the puzzle as an energy and resource efficient technology. Traditional solvent borne technologies require high-energy systems for drying, along with the release of VOC. UV curing can be done with the use of low energy LED lights for inks and coatings that are solvent free or, as we learned in this article, using only water as solvent. Choosing more sustainable technologies and alternatives enables you to not only protect your kitchen floor or book shelf with a high-performing coating, but also protect and recognize the limited resources of our planet. The Perstorp perspective Perstorp is one of the leading suppliers of polyol building blocks for UV/EB curing. These polyols are often key components in creating resins for high-performing UV curable inks and coatings. Several of these polyols are now also available as bio-attributed grades which enable even more sustainable solutions with significant reductions in the carbon footprint throughout the value chain.Focusing in on waterborne technologies like UV PUD, Perstorp does not only have polyols building blocks that can be part of the backbone of the structure, but also a range of dispersing agents. Perstorp Bis-MPATM and YmerTM for example allow for stable and easy to formulate water dispersions. With a long history and broad portfolio, we at Perstorp are more than happy to share our experience and understanding of the building blocks themselves but also on resin synthesis as well as formulation and evaluation.
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