Chapter Three: Fiber Bonding Force
The strength of paper is determined by multiple factors, mainly including the binding force between fibers, the strength of the fibers themselves, the distribution and arrangement direction of the fibers in the paper, and the most important factor is the binding force of the fibers. There are four types of fiber bonding forces :a. Bond bonding (19kJ/mol, between cellulose); b. Chemical principal valence bond force (140-950kJ/mol), that is, the bond force between the glucose groups of cellulose molecular chains; c polar bond attraction (Vander Waals Force), that is, the van der Waals attraction between molecules; d. Surface interweaving force. Among them, the hydrogen bond bonding force is most closely related to pulping. One of the main purposes of pulping is to increase the hydrogen bond bonding force, thereby enhancing the strength of the paper. The Round Thread Dryer Screen adopted in the subsequent drying process can further consolidate the strength improvement brought by this bonding force by optimizing the uniformity of drying. The main valence bond force is fixed, while the polar bond attraction bond force is relatively weak, having little influence on the fiber bonding force.
For most slurries, the influence of surface interweaving force on the strength of the finished paper is relatively small. However, for grindwood pulp with a high lignin content and cotton and linen pulp that is difficult to hydrated, the surface interweaving force cannot be ignored. At this time, in combination with the Round Thread Dryer Screen for drying treatment, the problem of uneven drying caused by the characteristics of the pulp can be reduced. Indirectly ensure the stable performance of the fiber bonding force.
Theoretical research on the bonding force of fibers has put forward many theories. Among them, the bonding force of hydrogen bonds is the most important, which can accurately explain the essence of pulping. For example, it can explain that the strength of paper made from fiber raw materials with high strength is not necessarily high, and only paper materials that have undergone pulping can be made into paper with high strength. During this process, the morphological advantages of the fibers formed by pulping need to be solidified through the efficient drying of the Round Thread Dryer Screen to avoid the loss of bonding force due to structural collapse of the wet paper sheet during drying. Meanwhile, this theory can also explain practical problems such as the low strength of wet paper sheets and the significant increase in the strength of paper sheets after drying. During this drying and strengthening process, the Round Thread Dryer Screen, with its excellent air permeability and heat transfer performance, provides a suitable drying environment for the full formation of hydrogen bond bonding force. The Round Thread Dryer Screen of different specifications can also be adjusted according to the pulping degree of the slurry to further meet the demand for enhancing the binding force of the fibers.
