Recent testing has demonstrated that Ketjenflex® 8 greatly improves the adhesion of lamination inks to the substrate, says France-based Axcentive sarl. Sulfonamide-based specialty additives have been widely used in the inks industry for many years.
Laminated film packaging systems consist of several layers of films, ink and adhesive. Commonly the ink is reverse printed on a transparent PET top layer, as used in the simple system tested by Axcentive shown below. The ink used must be formulated to give optimum performance in the lamination system, and one important factor is adhesion to prevent delamination of ink from film or ink from adhesive.
Tests compared the lamination bond strength of a typical Nitrocellulose-Polyurethane ink containing various types of flexibilizing additive by measuring the 180° peel-off strength using an adapted tensile strength meter. The results, shown below, prove that Ketjenflex® is many times more effective at adhesion promotion than other common plasticizers, with tearing of the film instead of delamination observed in most test runs.
|Plasticizer used (equal addition)||Highest measured lamination bond strength of ink|
|Di-octyl Sebacate||150 g /m2|
|Di-octyl Adipate||120 g /m2|
|Ketjenflex® 8||FILM TEAR|
Ketjenflex® prevents delamination of the top layer from the base layers.
Toby Heppenstall, General Manager at Axcentive, commented on the results:
“We just prove here what many customers have known for years; nevertheless the data has been helpful in soliciting interest from new quarters. We even made a video of the test which was useful as a tangible demonstration of the benefit for inks formulators who were previously unfamiliar with Ketjenflex® technology”.
Axcentive says that the biggest opportunity lies in educating ink formulators in countries where the industry is still experiencing growth and open to innovation, particularly the Middle East, Latin America and the Indian subcontinent.