Date of Award
Bachelor of Science
Paper Science and Engineering
The initial recycling of thermomechanical pulp leads to the flattening and increased flexibility of the fibers. Further recycling of the pulp leads to the unraveling of the fibers. The treatment of the fibers increases the bond potential of fibers while it decreases the fiber strength. Recycling of the fibers also leads to shortening of the fibers. The overall effect of recycling is the degradation of the finished product.
By varying the short fiber ratio the papers strength, physical, and optical properties can be directly affected. The strength properties dependent on bond potential are increased by adding short fiber and recycling. Strength properties dependent on bond potential are increased by adding short fiber recycling. Strength properties dependent on the fiber strength are inversely affected, therefore decreased. The exception being the Z-direction strength properties which are slightly increased with short fiber addition. Physical properties, such as density and porosity, are increased as the fibers are recycled and short fiber is added. Varying the fiber ratios can not offset the effects of recycling on the optical properties. Overall, fractionation can be utilized to duplicate virgin paper in terms of strength and physical properties.
Felker, Michael J., "The Optimization of a Recycled Thermomechanical Paper Using Fractionation" (1997). Paper Engineering Senior Theses. 104.