A Study on Feasibity of Secondary Recycled Fibers for Binderless Board Manufacturing

Abstract

The fiber length distributions and relative ratios (%) on furnish of recovered newspaper pulps are determined. However, the weight percentage of long fiber- and short fiber fractions (fines) was calculated approximately 46.9% and 43.3% in secondary pulp mixture, respectively.  These could be well sign of heterogenous fiber types and distribution of fiber length in various mesh fractions in pulp furnish. The highest internal bond (IB) value of 0.29 N/mm² was found for those in medium density (582 kg/m³) board sample followed by 0.16 N/mm² (I) and 0.15 N/mm² (D) samples. Moreover, regardless of experimental conditions only J type panel, which is the highest density (768 kg/m³) among study, give a bending strength value of 3.05 N/mm².  It has already well established that strength feature is usually correlate relative bonding area, the surface activation and fiber flexibility, which originates from the fiber properties. However, recycling stages could be made shortened fibers and creating fines. These impact on lowering strength with creating poor surface accessibility for bonding. It has realized a poor compatibility between secondary waste newspaper fibers in boards matrix structure. This is due to non-fibrous heterogeneous elements in furnish and these interfere fiber-fiber bonding to develop appropriate strength in board structure.  A cleaning procedure of these nonfibrous additives could be improved strength developments of panels. It is also realized that without any synthetic and/or natural adhesive usage, it is very difficult to get a well strength on these panel products which made from recovered newspaper fibers.