Though paper is a extra environmentally pleasant packaging materials than plastic, it’s usually contaminated with components, corresponding to adhesives used to create a safe seal. That complicates the recycling course of and reduces the standard of recycled paper. Now, German researchers at 4 Fraunhofer institutes have developed an alternate course of that may seal paper packaging with out glue or plastic utilizing a carbon monoxide laser.
The brand new system, at the moment known as the Papure venture, leverages the experience of the Fraunhofer institutes, every of which focuses on areas corresponding to polymer analysis, engineering and packaging, and laser beam applied sciences. Step one of the brand new sealing course of entails analyzing the chemical composition and morphology of assorted paper sorts utilizing strategies corresponding to scanning electron microscopy and X-ray photoelectron spectroscopy to find out if they are often sealed with out an additive. The quantities of components corresponding to hemicellulose, cellulose, lignin, talc, and calcium carbonate within the paper can have an effect on the energy of the ultimate packaging’s seals.
As soon as a paper sort is authorized, it’s irradiated with a CO laser in a managed course of that quickly heats its floor, changing the lignin, hemicellulose, and cellulose into short-chain compounds. From there, what researchers name “fusible cleavage merchandise” stay on the paper’s floor and act like a pure glue, creating a decent seal when warmth and strain are utilized. The researchers are nonetheless fine-tuning the varied parameters of the Papure venture, together with laser depth and paper seam design, to maximise bond energy. However in present testing, they’ve discovered {that a} 2cm seal that’s simply 3mm large is powerful sufficient to assist a 44-pound load.
The researchers have already constructed a “laboratory-scale modular paper processing manufacturing unit” able to producing a flat, four-sided paper bag design that’s generally used immediately by corporations like Lego. They’re additionally working to streamline and shrink the design of the laser and sealing modules and to combine measurement methods that may assess the standard of the seals being produced and routinely regulate numerous settings to make sure they’re assembly a selected bond energy goal. By the top of September, their purpose is for the pilot machine to supply 10 packages per minute.
