Effect of shape and particle size of mechanical pulp fines on paper properties

The effects of different fines with different shape and size of mechanical Pulp on Paper Properties in two fractions was investigated. Fines was classified in two categories including fibrils and flakes, and then effect of these particles on pulp properties was studied. The fibril fraction was consist of fibrillar material, i.e., ribbons, fibrils, and thin lamella particles. The flake fraction consist of flake like material i.e., fiber wall fragments and thick lamella. An advanced image analysis method was used to characterize the properties of fibrils and flakes. The results indicate that the fibrils and flake fractions have distinct characteristics and effect on sheet properties. The fibrils strongly affected the strength properties, while the flakes improved light scattering. Generally, the smaller size Particles afforded higher sheet density and strength. Fines content and fibrillar material are very important parameters in mechanical pulping and can also affect quality controlling of mechanical pulp and papermaking.