“Adhesives are indispensable in packaging production: they reduce material requirements and enable lighter packaging, which is in line with the objectives of the new Packaging and Packaging Waste Regulation (PPWR). Although adhesives only make up a small proportion of total packaging, they have a significant impact on recycling processes, paper production and the CO2 footprint. The Sugra (“Sustainable Gluing with Renewable Adhesives”) project is dedicated to this topic: it is developing adhesives based on renewable raw materials that protect the recycling process and reduce the CO2 footprint. These adhesives meet the requirements of modern production techniques and promote sustainable production without compromising performance.
The basis of adhesives is starch: this natural raw material is already used intensively in natural and modified form. Starch plays a particularly important role in paper production and processing, as it increases the strength of paper and refines its surfaces. In corrugated cardboard production, starch is used to bond the layers together.
Starch-based adhesives are not new: they are already used in flexible paper packaging to bond layers. However, the starch adhesives currently available have clear limitations when it comes to bonding folding cartons and corrugated cardboard boxes, due to long setting times and low initial tack. After the pressing process, these packages often open again, as their higher bending stiffness compared to paper increases the tendency for the adhesive gap to crack. This can only be remedied by longer storage under pressure or greatly reduced production speed – both of which are uneconomical.
more at: https://twosides.info/UK/sustainable-adhesives-sugra-project-researches-environmentally-friendly-solutions-for-the-packaging-industry/