This creates contact due to plastic, viscoelastic, and elastic deformation of the fiber surfaces.
The degree of molecular contact between the fiber surfaces initially depends on the surface roughness - smooth surfaces permit a high degree of contact.
This bonding is fully reversible, which makes paper an easily recyclable material.
Upon immersion in water with concomitant stirring, paper disintegrates into its component fibers, the resulting suspension can be reused in the papermaking process.
The fibers in paper bond to each other by six different mechanisms: interdiffusion, mechanical interlocking, capillary forces, Coulomb forces, hydrogen bonding and Van der Waals forces.
Reviews on fiber-fiber bonding and its mechanisms are given by numerous authors. paper, depends on the strength of these component fibers and the strength of the bond between these fibers.Interdiffusion refers to the migration of these molecules, usually polymers, from one fiber into the other.Interdiffusion is believed to be a key mechanism of fiber-fiber bonding.Thus the area of molecular contact is the most important factor determining the inter-fiber bond strength because it is a multiplier to the bonding obtained by inter-molecular mechanisms.A previous study provides details on the area in molecular contact of fiber-fiber bonds.In contrast to general believe which favors hydrogen bonding Van der Waals bonds play the most important role according to our model.Comparison with experimentally derived bond energies support the presented model.The fiber surfaces, consisting of cellulose, hemicelluloses and lignin in varying compositions, form stable bonds thus creating a composite material with remarkable strength per square meter.The salient feature of papermaking is that the fibers bond to each other without any glue or adhesive material added to the suspension.Here we show the first approach to quantify the bonding energies contributed by the individual bonding mechanisms.We calculated the impact of the following mechanisms necessary for paper formation: mechanical interlocking, interdiffusion, capillary bridges, hydrogen bonding, Van der Waals forces, and Coulomb forces on the bonding energy.