Engineering Commons^™

The Relationship Between Rheology, Application Method, And Final Coating Structure, Basant Galal Dimetry

Electronic Theses and Dissertations

Paper is coated to improve the printability and the visual properties. The factors that determine the coating structure are important because the structure determines the physical, optical, and printing properties. This work focuses on determining a relationship between the rheological properties of the coating, the application method, and the final coating structure. Coatings with different polymers and pigments were characterized in terms of steady shear and viscoelastic properties. These coatings were applied onto plastic film and paper with a laboratory rod coater, a spray coater, and a high-speed blade coater. The final coating structure after drying was characterized in terms …

Influence Of Viscoelasticity On The Nano-Micromechanical Behavior Of Latex Films And Pigmented Coatings, Manish Giri

Electronic Theses and Dissertations

Nan0 to microscale deformation behavior of different carboxylated styrene-butadiene co- polymer Latexes were investigated using a commercial nanoindentation device. The latexes dif- fered primarily in their glass transition temperature (T_g). The bulk dynamic rheological properties, as determined from a rheometer, dictate the axismmetric deformation behavior of the latexes. Results from dynamic tests performed on latexes were analyzed using the theories in contact and fracture mechanics. Two theories of linear viscoelastic fracture mechanics (LVEFM) were employed to model the adhesion hysteresis (loading-unloading cycle) curves to obtain meaningful cohesive zone (fracture process zone) parameters and a stress intensity functional ( …

The Influence Of Fiber Swelling On Paper Wetting, Sedef Akinli-Kocak

Electronic Theses and Dissertations

The water uptake behavior of fibers, especially those at the surface of paper, influences printing and coating operations. The dynamic water uptake behavior of the surface fibers may determine the initial consolidation of the coating at the surface and the penetration of coating into the paper, but clear studies on this topic have not been reported in the literature. Four different fiber types and seven different paper sheets were investigated in the present study. The three different fiber types were prepared by carboxymethylation of softwood kraft pulp thereby producing pulps with different water uptake values. The fiber length and water …

Bubble Growth Behavior In Supersaturated Liquid Solutions, David Robert Cyr

Electronic Theses and Dissertations

The growth characteristics of gas bubbles in supersaturated liquid solutions were measured in preliminary experiments involving glass bottles followed by more controlled and systematic investigations using a custom designed experimental apparatus. It was proven that the presence of pre-existing gas was responsible for the bubble formation observed. Bubble growth occurred in very regular cyclical patterns at specific locations containing trapped gases. In the custom designed apparatus, liquids could be saturated with gases and supersaturated solutions made by depressurizing the system. Artificial capillaries, pre-seeded with air bubbles, behaved in a similar manner to naturally occurring sites containing pre-existing gases. The apparent …

The Influence Of Process Parameters On Filament Size Distribution, Saybil Nuray Ercan

Electronic Theses and Dissertations

Filaments are formed at the exit of rolling nips in some coating and printing operations. The filament size distribution can determine product quality such as gloss. The average filament size is linked to operational difficulties such as misting. The filament size distribution of various fluids and inks is characterized and compared to theoretical model. A high-speed video camera is used to visualize the exit of a rolling nip. The size distribution of the filaments is characterized with image analysis. A laboratory print tester is used with the high speed camera to characterize the size of the defects right after printing. …

Gloss Dynamics Of Inkjet Printers, Amol G. Shirke

Electronic Theses and Dissertations

Inkjet printing is a popular non-impact technology with widespread use in home and office applications. The basic principle involves propelling ink drops of different colors on a substrate. High quality images, near photographic quality, are now possible. The gloss of the printed substrate is an important quality attribute. Printed gloss depends on a number of characteristics of the media and the ink, but a good fundamental understanding is not available in the literature. The dependence of the gloss on the media and ink characteristics is reported in this work. The experimental results are compared with values predicted by a mathematical …

Micro-Probe For Physical And Chemical Surface Analysis, Joshua Mathews

Electronic Theses and Dissertations

Non-uniform porosity of paper and coated paper is important in printing and paper making industries. Current porosity measurements give results averaged over a large area. A new method is developed to determine local variations in porosity and surface chemistry. A measured volume of a probe liquid is applied to a hemispherical glass probe. The substrate of interest is brought into contact with the fluid drop. The resulting liquid bridge exerts a force on the probe due to surface tension forces. A video camera is used to visually correlate the physical phenomena with the force-time data. The force-time data is recorded …

The Viscoelastic Behavior Of Pigmented Latex Coating Films, Katharina Prall

Electronic Theses and Dissertations

The mechanical properties of paper coatings are essential for use performance of coated paper (e.g. calendering, printing degradation during printing operations, pick). This study investigates the microscopic and macroscopic mechanisms that determine the viscoelastic behavior of pigmented latex coating films. Pigmented coating layers were prepared with different microstructures. This was achieved by using different pigment types and shapes (polystyrene plastic pigment - spheres, precipitated calcium carbonate - rhombs, clay - plates), and changing pigment volume concentration (PVC). Two styrene-butadiene latices with different degree of carboxylation (acidic level 0.3% and 4.5%) were evaluated to determine effect of adhesion. The viscoelastic material …

Explorations, Vol. 3, No. 3, Tim Lyden, John Muth, James Leiby, Kevin Scully, Jayalakshmi "Jaya" Krishnagopalan, Ivar H. Stockel, Peter Wagner, Luanne L. Peters, Mark W. Anderson, Judy C. Gates, Cheryl Waltz, Paula Quatromoni, Douglas Kellogg, Kimberly Dagher, James Linehan

Explorations — A Journal of Research

Cover: Artwork by Marcia Spencer, University of Maine art student.

Articles include: "Characterization of Normal and Carcinogen Induced Neoplastic Cells of Teleost Origin," by Tim Lyden

"Attitutdes and Opinions of Maine Dairy Farmers," by John Muth and James Leiby

"Background: the quest for the eighteen month oyster," by Kevin Scully

"The Quest for the Eighteen Month Oyster," by Kevin Scully

"Measurement of Surface Tension of Kraft Black Liquor," by Jayalakshmi "Jaya" Krishnagopalan

"From the former student," by Jayalakshmi Krishnagopalan

"From the faculty advisor," by Ivar H. Stockel

"Aquatic Fungal Decomposers in Two Adjacent Maine Lakes of Different Acidity," by Peter …

An Investigation Of The Suitability Of Pinus And Chamaecyparis From Fukien Province, China For Pulp And Paper Manufacture, Tsung Ho Wang

Electronic Theses and Dissertations

No abstract provided.

A Study Of "Black Liquor" From Soda Pulp, Chen Chi Pan

Electronic Theses and Dissertations

At the present time, practically all of the soft easy bleaching pulps used for the manufacture of high class book, magazine, general printing and cheaper writing paper are made by the Soda Process. Although the sulphite and mechanical process and to a less extent the Sulphate Process predominate, the Soda Pulp is remarkably well adopted for producing Pulp Fibres from any kind of wood or other fibrous material, no matter how resistant to chemical attack it may be.

Up to 1876, black liquor was run to waste. But since the River Pollution Act, it is treated to recover the soda, …