Date of Award
Bachelor of Science
Pulp and Paper Technology
Dr. Stephen Kukolich
Many of the fundamental sheet properties are inter-related with the fiber orientation of the sheet. Until recently, this sheet was made of a Fourdrinier machine and the relationships were thoroughly studied. The advent of the Verti-Forma has opened up a new field of study. The objective of this thesis was to compare the fiber orientation in the two-wire Verti-Forma with the conventional Fourdrinier using the Instron tensile tester.
Test samples were acquired from the pilot Fourdrinier at Western Michigan University, a Fourdrinier at Allied Paper Company, and the Verti-Forms also at Allied. Full and split sheet halves were tested for elongation, ITEA, and tensile at angles of 0°, 30°, 60°, and 90°.
The Verti-Forma reduced the two-sized effect of the conventional Fourdrinier. The average percentage differences of the test values of both the top and bottom sides of the Verti-Forma sheet for TEA, tensile, and elongation were lower than the percentage differences of both Fourdriniers. Full sheet tensiles showed that the overall fiber alignment wasn't changed by the Verti-Forma, the only change was in the alignment of the individual sides. The bottom side of the Verti-Forma was slightly stronger than the topside.
The differences in the Fourdriniers wee mainly due to machine speed. The Fourdrinier with the higher speed had more fiber alignment in both the full sheet and split-sheet halves. This gave higher degree of two-sidedness.
The fiber counting procedure, the basic method for determining fiber orientation, proved to be unsuccessful for this study. The fiber axial direction could not be determined accurately.
Kiffe, Paul J., "A Comparison of Fiber Orientation on Fourdrinier and Verti-Forma Paper Machines Using the Instron Tensile Tester" (1970). Paper Engineering Senior Theses. 250.