Thesis (Ph. D.)--Institute of Paper Chemistry, 1937. / Includes bibliographical references (leaves 155-159).

No description available.

No description available.

The wicking properties of multi-ply paper samples with dissimilar plies were investigated. These materials exhibit wicking performance in excess of either of their individual plies. Samples were produced from a ply of softwood pulp and a ply of hardwood pulp of equal caliper and basis weight. The softwood sample possessed a larger average pore size, a fact verified via porometry. Samples of a single ply were also produced for comparison. The samples were tested using both upward and downward gravimetric wicking tests. There was no saturation gradient observed, however there was a variation in the degree of bulk expansion during wicking. Capillary pressure and permeability for the various sample types were determined from the results of these tests and compared. It is shown that the wicking performance of the two ply sample is comparable to that of a theoretical material with the capillary pressure of the hardwood ply but the permeability of the softwood ply. Wicking in two-ply samples was also observed in an NMR apparatus. This was used to determine that the hardwood ply leads during wicking, and observe the rate of saturation as well as bulk expansion. A third type of experiment tracked the transport of dyed water from one ply to the other, establishing the direction of fluid transport during wicking to be from the softwood ply to the hardwood ply. The theory is proposed, based on these results, that wicking in this type of material consists of a smaller pored leading ply that draws water from a more permeable larger pored material that acts as a moving reservoir.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1936. / Bibliography: leaves 114-117.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1948. / Bibliography: leaves 84-86.

Thesis (Ph. D.)--Institute of Paper Chemistry, 1953. / Bibliography: leaves 112-117.

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Patterson, Timothy; Committee Member: Aidun, Cyrus; Committee Member: Banerjee, Sujit

No description available.

In the flow distribution section of a paper machine, known as the head box, water is injected into the fiber suspension (stock) flow through a tee-mixer for more uniform production. This dilution process has two important requirements that must be fulfilled: (1) sufficient mixing so that the dilution flow spreads across the suspension flow and (2) that the injection flow rate not be so large to significantly alter the local head box flow rate. The objective of this research was to find a combination of velocity ratio and tee mixer geometry that lead to the injection flow being well mixed into the stock flow, but at the same time, the injection should not cause the total flow rate to change by more than 1%. Velocity ratios of 0.25, 0.75, 1.33, 1.5 and 2.25 were examined for four different cases of tee mixer geometries using the CFD software Fluent. Two of the cases had added contractions located near the injection point, while the other two cases had a more standard geometry with no added complexities. The pressure drop across the injection point was also measured. Mixing was qualitatively measured by simulating the injection of a passive tracer into the dilution flow. All of the results indicated that the case where the contraction was located after the injection showed the most promising results with quality mixing and lower flow rates. The cases without added contractions showed poor mixing for lower velocity ratios, and for higher velocity ratios, the flow rates were too large. The cases with contractions showed similar mixing, but the outlet flow rates produced were lower when the contraction was located after the injection instead of before it. A velocity ratio of 0.25-0.75 for the mixers with contractions produced acceptable flow rates and sufficient mixing. The simulations also showed that the static pressure for the contraction cases were nearly identical throughout the majority of the pipe. For both contraction cases the pressure drop across the injection increased with increasing injection flow rate. When the contraction was located before the injection, a pressure drop of 16% was calculated. A pressure drop of 18% to 20% across the injection resulted when the contraction was located after the injection.