According to a recent article from The Swedish Research Council, published in Phys Org, it states that new research reveals mechanisms of stiffening paper pulp, could lead to improved recyclability.
The article states that "One of the problems with paper recycling is that the fibers stiffen during the dewatering and drying processes, also known as hornification. The same thing happens to dishcloths, for example, they stiffen over time. New research can now explain the mechanisms of hornification, knowledge that will enable us to recycle paper fibers many more times compared to the current limit of between five and seven times."
The article goes on to state that "Through our studies, we now know at what level of dryness the hornification process begins, already at a dry content of 20 percent, says Björn Sjöstrand, Docent in Chemical Engineering from The Swedish Research Council.
We also know at what temperatures hornification begins, already at temperatures as low as 40° C, but the biggest changes are seen at temperatures above 100° C. The solvent also plays a role; if we replace the water in the paper pulp with other solvents, it reduces the hornification. This implies that the hydrogen bonds that form in the water environment contribute to the hornification of the fibers."
You can read the full report published in the journal Cellulose by clicking here.
Helen Roush is Executive Vice President of Paperitalo Publications.
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