Date of Award
Bachelor of Science
Paper Science and Engineering
Extensive work has been done on the physical properties of paper with recycling, however not much has been researched on the surface properties of paper. This thesis was intended to give more information on this fairly untouched area. An extra dimension was added with the inclusion of virgin fibers. Two loops were designed, one using the conventional 100% recycled fibers and the other, with an addition of virgin pulp. 100% never dried kraft hardwood, refined at 300 CSF, was used. All handsheets were made on the Nobel and Wood handsheet-maker and repeated reslushing was performed on the British Disintegrator. No additives, fillers, or sizing agents were used at any point, thus, recycling was only subjected to: slushing, sheet making, wet-pressing and drying. Calendering was also performed. The principal effect of recycling was the loss of the fiber bonding ability, noticeably in the first recycle for opacity and porosity (100% recycle). The addition of virgin fibers was interestingly seen to improve the brightness with recycling. This phenomena (an increase in brightness with the addition of virgin fibers in comparison to the original brightness) has to be further investigated. Calendering with its compacting and polishing action, decreased the opacity and increased the smoothness. Roughness and gloss did not show a significant change with recycling but with calendering a more smoother and glossier sheet was obtained, as expected.
Sidhu, Jasvinder Singh, "The Effect of Repeated Recycling at Different Levels of Addition (Virgin and Recycled Fiber) on the Surface Characteristic of Paper Before and After Calendering" (1994). Paper Engineering Senior Theses. 491.