International. Laura Kela from Finland's Centre for Technical Research (VTT) gave a presentation showing how pulp waste can provide ink binders.
Polymers based on hemicelluloses and wood resin oil have potential for use as ink binders. They originate from renewable non-food materials. In addition, it is possible to extract them from side streams of existing production processes, which would offer an eco-friendly option for inks.
Kela shows that hydroxyl groups in hemicelluloses allow polymers to be modified to improve properties such as water repellency. Even the manufacture of paste from other by-products can be used for this purpose. Water-based flexographic inks have been produced on the basis of hemicelluloses and pine rosin esters.
As the products are biodegradable and non-toxic, they can be of particular interest for packaging printing, where compostability arouses greater interest. The potential market for packaging inks is large as such, but much smaller than the amount of hemicellulose produced in paste.
