Functional coating developments for the digital manufacturing age

Abstract

Sihl in Bern has developed for two decades inkjet receptive coatings enabling images to bond with media surfaces and deliver high quality prints. This has contributed to the growth of digital art reproduction, poster and advertising to name just a few applications. As progress were achieved with inks - better, cheaper, faster drying – demands on matching coating performances kept researchers busy. These were days when everything had to be coated before printing, with price being a second level consideration. Good things never last forever: progress of inks enables decent to good output on several types of uncoated media. Graphic industry suffers worldwide from lower appetite for print, and tends to accept “good enough” quality in order to cut costs. Manufacturing and 3D printing emerge as the new “hot place to be” for ambitious developers. Luckily, wide-format printer users are often quite creative and try to add value beyond colour deposition to their activities. Sihl had noticed already some interest for coated materials with enhanced functionalities (water-resistance, fire-resistance, hardened surfaces). We did take some conventional coating contracts, to discover that this was a well-established and rather mature market. The market opportunities seemed to be at the junction between digital imaging and coating, and a different set of tools were needed to unlock these new markets. Sihl invested thus into coating line enhancements, adding a station dedicated to the deposition of thick functional materials, so that one pass functional + receptive imaging layer deposition could be achieved at high speed. Foam deposition is among the first practical developments: Sihl can apply foam layers, with adjusted thickness, softness, printability features on film and non-woven media. The resulting products are of great interest for indoor architects looking for decorative and noise control features. Longer term, as inkjet devices reach speed and width similar to coating machines, it becomes conceivable to have single-pass on demand manufacturing of complex media or finished products, incorporating variable material deposition, functionality addition and imaging.