Surging technical competence
One of the changes that led to the development of UPM Confidio was brand owners responding to growing pressure to move from fossil-based to packaging materials based on renewable resources. This demand has, in turn, been driving industry-wide growth in the number of commercially available chemicals, increased knowledge and improvement in heat sealability and barrier performance.
“There have previously been some heat sealability functionality trials at Jämsänkoski that didn’t go so well, but this new approach has vastly different chemistry compared to our one-sided coated products. While some barrier properties are difficult to control on the factory side, we have constant measurements in the lab and control on the machine line to ensure that the quality is what is needed. We must always fulfil everything promised in terms of barrier properties,” stresses Lahtomäki.
Over the last few years, there has also been a surge in technical competence related to packaging end-use and barrier property measurements at UPM Specialty Papers, the majority of which were drawn upon during the development period of Confidio. “The exchange of information and communication between R&D and the factory has been quite intense. New methods to check heat sealability have been developed both in Lappeenranta and at the Jämsänkoski factory, so that has been a learning curve for both sides,” explains Saukkonen.
Along with monthly development meetings, there was at least one person from R&D present during all the factory trials together with the mill personnel. Even though this was challenging during the pandemic, it was maintained because it was a valuable way to exchange information. Researchers could also see first-hand how the barrier coating behaved differently from the pilot in the factory.
Lahtomäki says, “When you are testing formulas or chemicals in the laboratory or during the pilot, and those are working fine, it doesn’t necessarily mean that it will function at the mill scale. A lot of things you wouldn’t imagine can have an effect such as the recyclability of the structure, meaning how it disintegrates or can be repulped. Mill circulation waters are different to those used in R&D operations, plus there are also dissolved and colloidal substances (DCS), which are difficult to mimic on a lab scale.”