Cold plasma-assisted paper recycling

The aim of this study is to modify the surface of a commercial paper, using the cold plasma treatment in order to increase its hydrophilic character, thus minimizing the disintegration time and/or the energy consumption, needed to recycle cellulose fibers and obtain a homogeneous suspension. Plasma treatment was applied for different exposure times, under optimal experimental conditions of ground pressure and power. The treated paper samples were characterized by contact angle measurements. The plasma treated samples were disintegrated using a series of different number of rotations (rpm) and the resulting fiber suspensions were used to prepare laboratory hand sheets using a conventional sheet forming. Before paper making, the morphological characteristics of the fibers were evaluated by a MorFi analyser. The effect of plasma treatment on the quality of recycling was evaluated measuring the first-order entropy of the sheet formation. These results show that for similar entropy values, disintegration time for the reference samples is longer than for the treated samples. X-ray photoelectron spectroscopy (XPS) showed that the surface of the treated samples underwent strong oxidation, which is probably responsible for easy recycling of the paper samples.

► Application of plasma treatment in paper recycling.
► New contribution for paper recovered industry.
► Use of an eco-friendly technique.
► Contribution to reduce energy consumption in disintegration process.