Appl. Sci. 2025 , 15 , 9160
9of 14
3.3. Physical Properties of Paper Figures 9 and 10 compare the effects of beating and refining on the tensile and burst strength of SwBKP and HwBKP. The data indicate that the refiner, equipped with an ultra- fine bar plate, facilitates faster development of both tensile and burst strength compared to the beater.
( a )
( b )
Figure 9. ( a ) Comparison of tensile strength of paper through beating and refining time; ( b ) compari- son of tensile strength of paper through freeness.
( a )
( b )
Figure 10. ( a ) Comparison of burst strength of paper through beating and refining time; ( b ) compari- son of burst strength of paper through freeness. At equivalent freeness levels, both SwBKP and HwBKP processed through the re- finer exhibited greater tensile and burst strength than those processed through the beater. This can be attributed to the refiner’s precise and intense mechanical action, which en- hances fiber bonding by promoting both internal and external fibrillation without excessive fiber cutting [24,27,31]. The increased fiber bonding potential leads to improved strength properties, as more flexible and fibrillated fibers form stronger inter-fiber bonds [32]. In contrast, the beater’s broader grooves and longer bars result in less effective fiber bonding and a higher likelihood of fiber shortening, which negatively impacts strength characteristics [28,29]. The less controlled and less uniform mechanical action of the Valley beater can also lead to uneven fiber treatment, further reducing the overall development of strength properties. The Valley beater, although widely used in laboratory settings to predict refining outcomes, has inherent limitations in replicating the precise effects of industrial refining. The scale and mechanical precision of the Valley beater differ significantly from those of industrial disk refiners, resulting in discrepancies in fiber modification and, consequently,
Made with FlippingBook interactive PDF creator