In traditional UV curing process, photo initiators are mixed into the varnish. Photo initiators are of considerable importance as they absorb UV radiation and generate radicals, which initiate UV polymerisation and thus the curing process by converting the C=C double bond.
The low availability of photo initiators poses a challenge for the ink and varnish industry. The reason for the restriction of photo initiators is increased environmental regulation in China, the main production country for photo initiators and their raw materials. Within the framework of the REACH regulation (REACH stands for Registration, Evaluation, Authorisation and Restriction of Chemicals), it is conceivable that certain photo initiator types could be reclassified and therefore no longer available in future. In addition, photo initiators have the potential for odours and migration. As a result, UV processes are excluded for applications or can only be implemented with great effort.
The increased performance in the UV-C up to 280 nm was achieved by the following measures:
Our FREEcure is not only suitable for 100% UV systems, but also for water borne UV systems. When formulating the UV systems, the following aspects were taken into account: