This New Laser Can Glue Paper Without Any Adhesives and It’s a Bigger Deal Than You’d Think
A laser reshapes paper at the molecular level, creating bonds strong enough to hold 20 kg—without a drop of glue.

Paper bags are often touted as a greener alternative to plastic because paper is natural and recyclable. But there’s a sticky secret hiding in the seams: most paper packaging is held together by synthetic glues and adhesives that aren’t that eco-friendly. While the paper itself can be broken down and reborn as a new box, those adhesives act like a contaminant in the system.

In some cases, they even force paper to be downcycled or discarded altogether. So while paper looks like a clean alternative to plastic, its reliance on glue has been an unsolved flaw.

Now, researchers in Germany are trying to remove this flaw entirely—not by finding a better adhesive, but by eliminating it altogether. Their solution uses lasers to turn paper into its own glue.

The research is a part of the project, called PAPURE, which is being developed by multiple institutes under the Fraunhofer Society (a research organization in Germany). Instead of adding new materials to fix the problem, the team started by looking closely at what’s already inside the paper and how that can be used.

Paper isn’t a uniform sheet—it’s a mix of natural polymers like cellulose, hemicellulose, and lignin, along with fillers such as talc and calcium carbonate. These ingredients vary widely depending on how the paper is made, and this variation turns out to be crucial.

This is because some compositions can form strong bonds when treated correctly, while others fail. In short, these determine how well the paper can bond with the adhesive.

To figure this out, researchers analyzed around three dozen types of paper using high-resolution imaging and chemical techniques. This allowed them to map both the structure and the chemistry of each sample.

The more they did this, the more they noticed a pattern. Papers with too many inorganic fillers struggled to form strong seals, while thicker papers with a balanced mix of natural components performed better.

https://www.zmescience.com/science/news-science/laser-makes-paper-stick-to-itself-without-glue/