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ABSTRACT OF THE DISSERTATIONTheory and Applications of NMR to Problems in Material Science and Analytical ChemistrybyArun AgarwalDoctor of Philosophy, Graduate Program in ChemistryUniversity of California, Riverside, August, 2010Dr. Leonard J Mueller, Chairperson Recent developments in NMR spectroscopy have seen an increase in its application for the study of structure and dynamics in the field of material science. NMR can be used as a complementary technique to X-ray diffraction and other structure probing techniques such as AFM and STM in the study of complex systems. Due to its non-invasive nature, measurements can be made on samples without altering their structural or functional properties. In this thesis three different application of solid-state NMR will be highlighted. First, the butyl-substituted spiro-biphenalenyl radical will be studied. This molecule is a member of a new class of organic conductors which posses the highest conductivity of any neutral organic molecular solid via a magnetic phase transition. 13C chemical shift measurements allow us to track the transition between the diamagnetic and paramagnetic states, which we find builds in as a gradual increase in the spin-density at the aromatic sites and a decrease in the electron spin-spin coupling between adjacent radicals. Our model suggests that the electron is not delocalized over the entire molecule, but is in fast exchange between the phenalenyl rings. Next, the photophysics of photomechanically responsive molecular crystal nanostructures based on anthracene esters is studied using solid-state NMR. A detailed study of these materials provides significant insight into the molecular-level dynamics that give rise to the micron-scale response of the nanorods. This work provides insight into how solid-state photochemistry within nanostructured molecular crystals can give rise to novel photomechanical behavior on micron lengthscales. Finally, the last chapter discusses several examples of analytical applications of NMR. A combined approach of using solid as well as solution state NMR spectroscopy to study the stereo-chemical and functional properties of industrially useful compounds has been presented. The approach taken has the potential to be used for a wide variety of industrial applications.

Densitometric and gravimetric methods are employed to measure the percent of ink trapped in a wet-on-wet transfer. This study seeks to discover the relationship of the two methods and if there is a significant difference between the percent gravimetric and percent apparent trapping. An IGT Printability tester (Model-A2) with two printing discs is used to apply ink onto paper. When using the gravimetric method the amount of ink on the disc and ink transferred onto paper are weighed with an analytical balance. The author then calculates the percent ink trapping. When using the densitometric methods densities are measured by polarizing and non-polarizing reflection densitometers which are used to generate data to determine percent trapping. The author also applies an antilogarithm trapping formula to determine percent trapping. The experimental factors studied here are the three tack levels of both ink layers, which are defined as low, medium, and high; the three different types of paper, which are newsprint, uncoated paper, and coated paper; and the four measurement methods. These methods are gravimetric, apparent, polarizing apparent, and antilogarithm trapping. The study results reveal that there is significant difference between the four measurement methods. The regression analysis establishes the relationship equations between percent gravimetric and apparant trapping. All of the equations are rejected because they lack accuracy in predicting percent gravimetric trapping using percent apparent trapping. Improved equations for percent trapping on newsprint, uncoated paper, and coated paper are presented. These equations estimate the percent gravimetric trapping on the basis of densitometric data but they are complex, and therefore only useful in the laboratory at this time. The author also determines percent gravimetric trapping using densities in terms of the exponential function and establishes prediction equations of percent trapping for each type of experimental paper. Further study will be needed to develop equations useful to the printing industry.

For many years the printing industry, specifically sheetfed offset and letterpress printers, have been dealing with the problem of chemical ghosting. Traditionally it has been, a problem associated with drying oil inks. More recent research concludes that ghosting is also affected by the permeability of an adjacent substrate. This thesis examines paper coating constituents, their degree of concentration, and what influence they play- with regards to ghosting. A quickset drying oil ink has been found which when subjected to the proper laboratory conditions will display a high degree of colored ghosting. The thesis indicates the method of creating ghosting and a method of measurement. A procedure for making paper samples with various percentages of coating constituents is outlined. Experimentation has shown ghosting to be affected by the absorbency and ink hold out of the paper coating. This effect is increased at low absorption levels but diminishes as absorption is increased. In addition, comprehensive background information is included to assist the reader to become more enlightened to the true nature of this problem. The list of subjects surveyed include the definition of ghosting, the mechanisms involved, associated variables, and a summary of all pertinent literature.

Lithography is the most common printing process. However, very little is known about the theory of lithography. Pressroom practices have evolved more out of experience than on the basis of any theory. The objective of this paper is to develop a mathematical model for the non-image area of the offset lithographic plate. A model of this kind would provide a rationalization for the observed behavior in lithographic process. The study concentrates on the various materials and the phenomena involved. Properties of aluminum oxide surface and gum arabic that make them suitable for the process have been presented. Rheological properties of ink have been discussed to show their effect on the print quality. Most importantly the subject of surface energetics has been used to explain the interfacial behavior of the three phases involved - ink, fountain solution and plate surface. The study of the interfacial behavior helps in arriving at the final model. There are several phenomena taking place in making lithography work. Adsorption of gum arabic, wetting of the plate by fountain solution and film splitting at the nip exit are explained and the interrelationship between them derived. Surface energetic equations and Griffith's free energy for fracture have been used to present the final model for the system. The model as proposed in this paper gives a deeper insight into the lithographic process and helps- in understanding the reasons for the printing aberrations. There is a need to model other aspects of the process and design methods to test them so as to help in development of better equipment and standard practices for lithography.

It has been known that apparent trapping percentages caused by changing printing sequence (or printing order) affect the color appearance of the overprint areas. However, no other studies in the past were done in a standard color measurement system- that is the CIE system. This thesis was conducted in order to learn how the selected printing sequences yellow- magenta-cyan-black, black-cyan-magenta-yellow, yellow-magenta-cyan-black, and cyan-magenta-yellow-black- of a monotack process ink yield the color gamuts on the CIE LAB color space. Since the two sequences: yellow-magenta-cyan-black and cyan-magenta-yellow-black, were recommended to be adopted as standard sequences for SWOP inks, this reseach attempted to prove that these sequences printed by a web-offset press yielded the similar color gamut on the CIE LAB color space. How the abovementioned selected printing sequences affected the changes in the apparent trapping percentages were also studied. The color differences between the color patches printed by changing printing orders and those of the ideal inks were calculated and compared with one another in order to find out whether the overprint colors visually differed from one another or not. Moreover, how the trapping changed the color appearance of the print from what was expected in terms of hue angles and chroma shifts were studied. Last but not least, the colorimetric trapping percentages were also studied. It can be concluded from the findings that the changes of ink sequence of the monotack ink in the web-offset printing caused the wet-trapping percentages change. Thus caused the hue angle and chroma shifts which resulted in different color gamuts. It was proved that the two sequences yellow-magenta-cyan-black and cyan-magenta-yellow-black did not have the similar color gamut on the CIE LAB color space; they produced visually different green. The relationships between ink trapping percentages and visually different color appearance in this study can be explained as follows. It is found that the trapping of yellow over magenta did not yield different color appearances from the trapping of magenta over yellow. The trapping of cyan over yellow yielded different color appearances from the trapping of yellow over cyan, but the trapping of cyan over magenta did not yield different color appearances from the trapping of magenta over cyan. The densitometric apparent trapping percentages calculated from the Preucil's equation failed to explain the relationships between the red trapping and the color difference of the red printed patches from the red ideal ink. The colorimetric trapping percentages using the Preucil’s concept was proved invalid. Larger sample sizes and other ink sequences are recommended for the next study.

Several studies and investigations have been conducted to test the new Toray plate. The studies revealed that the new plate eliminated many of the problems that used to hinder the progress and development of the driographic plate system. The two major problems with this plate were short run lengths and toning in the non-image areas. This study investigates toning problems in negative working Toray plates. Toning is a term that refers to the non-image areas of the driographic plate that are accepting ink. Previous studies have shown that ink tack and flow do not affect toning in any way. However, printing speed, nip pressure, printing density and ink temperature were found to have some effect on toning. To investigate the effect that different percentages of oil in the ink has on toning in the non-image areas of Toray negative working plates, this study uses five ink samples, each containing a different percentage of oil, and measures with a densitometer the density of toning in the non-image areas. The hypothesis tested in this study states that the amount of toning in the non-image areas of negative Toray plates increases as the amount of oil contained in the ink increases. Upon analyzing the data collected, it was found that when using the special driographic ink no scumming occured. However, the hypothesis proved to stand true because it was found that a strong positive relationship exists between the amount of oil contained in the driographic ink and the amount of toning in the non-image areas of negative Toray plates.

The purpose of this study was to address, through colorimetric analysis, color variation as it relates to the efficiency of trapping. A developing awareness of colorimetric analysis in the graphic arts, as well as the realization of some of the limitations of densitometry when applied to color analysis provided impetus for such a study.

A major problem in the printing of newsprint by flexography with water-based inks is the filling-in of halftones. Drying of the ink and rewettability, the ability of the fresh ink to wet the dried ink, appear to be primary in the understanding of the filling-in problems. Quantification and qualification of critical factors are essential in resolving this problem. In this study black water based flexographic news inks from different manufacturers were compared in terms of their drying and rewettability characteristics. The change in weight with time and contact angle measurements are the response parameters considered. Proper care has been exercised to maintain constancy of parameters while conducting the experiments. Four samples of black ink were analyzed in this study. The critical balance-weight differential-gravimetric method was adopted to determine the drying rates and the sessile drop method was used for finding the contact angle. This study has yielded information which will enable a better understanding of the drying properties of the inks. More important, the contact angle will serve as the determinant of the fresh ink's ability to wet the dry ink.

Driography is a planographic printing process. A driographic printing plate differs from a conventional offset lithographic plate in that water is not required to keep the non-image area clean of ink during printing. Water, or fountain solution, is not required during printing because a silicone rubber coating which repels ink is used for the non-image area of a driographic plate. The first driographic plate was introduced in the early 1970's by the 3M Company. The plate was a positive working printing plate and has since been discontinued. Driography has since been researched by a number of companies but only one is presently marketing a driographic plate. The Toray Company, a Japanese based firm, is producing a negative working driographic printing plate. The purpose of this study is to research Toray's negative working driographic printing plate. It is hypothesized that as ink tack decreases, toning in the non-image area will increase. In this experiment, ink tack was monitored at the point of impression using a thermocouple device. The thermocouple was used to measure ink temperature on an inking form roller. Temperature/tack curves were developed and used to convert ink temperatures to tack readings. The actual experiment was performed on a duplicator offset printing press. A second technique using ink tack-reducer to alter ink tack was performed as an alternative test to support the initial method results.During the course of the study a number of variables could have altered the test results. These variables were monitored and kept constant during testing. The variable which affected test results most dramatically was the oil content in the ink. It was concluded that the amount of oil content in an ink had more influence on the degree of toning than ink tack did as originally hypothesized.

Product end use dictates the materials used to produce a printed piece. If flexographic printers are purchasing ink for a packaging carton job, they don't choose a scuff prone ink. The same should be true for printers producing letterheads for subsequent use in electrophotographic equipment . Electrophotography is an image transfer process that uses the principles of electrostatics. An Ektaprint 200 copier/duplicator charges the surface of a sheet exposing an image area, develops that image, affixes toner to that image and then mechanically traps the toner to the surface of the substrate using heat and/or pressure. When a litho graphically printed letterhead is subject to the heat of a fuser roller, it can cause the ink to resoften and subsequently transfer to the next sheets passing through the copier, an undesirable effect. This experiment tested various ink/paper/drying combinations to determine whether or not specific print conditions affect the transfer of lithographic ink during electrophotographic imprinting. A test form was designed to include all the images typically printed on a letterhead. Each test sample was first printed under controlled conditions and then run through an Ektaprint 200 copier/duplicator. Visual assessment was used to evaluate test samples. The presence 2 or absence of image transfer determined whether or not the null' hypothesis was rejected. A Wilcoxon sign test was used to determine whether or not a test sample could be evaluated. A level of .05 significance was obtained in two cases. These samples were excluded from the results. Densitometric readings were taken to determine the severity of the lithographic image transfer. Various ink and paper characteristics were evaluated using descriptive statistics . Twenty-one print conditions exhibited no visual image transfer when processed in the Ektaprint 200. These ink/ paper/drying conditions could guide printers of letter- heads which are to be subsequently processed in electrophotographic equipment.

Dot gain is the enlargement which takes place in a dot from the time the dot is captured or generated on the film until it is printed. Dot gain can cause many problems, including color variation and loss of contrast, and if uncontrolled is one of the main contributors to waste in offset lithography. Of the many factors influencing dot gain, inks have been found to be a major contributor. One property recommended for further investigation is ink viscosity, which is the resistance to flow of an ink. The purpose of this study was to investigate the effect of ink viscosity on dot gain in offset lithography. It was found that as ink viscosity increases, dot gain will decrease, and if ink viscosity is optimized, dot gain will be optimized. Experimentation was done on a single color, single impression sheet-fed lithographic press, with five inks of different viscosities. Results of this experiment show that ink viscosity is significant in affecting the amount of dot gain that occurs. Inks with 15 and 20 percent solvent added, which were less than 1000 poise viscosity, were found cause the significant difference. Other factors found to be significant were screen ruling and paper absorbency. The Yates Method of Analysis of Variance and graphing were used to analyze the data.

In order to establish limits which are representative of the allowable variation in solid ink density (SID) of the single process colors, as determined by the allowable variability of their overprints, a study was conducted utilizing fourteen (14) experienced color observers selected from printing companies in the Greater Rochester area. Printed color patches, at the 70% tint level of cyan, magenta, yellow, red (M+Y) , green (Y+C) , blue (M+C) and three-color overprints (Y+M+C) , were shown to observers, individually. In each group, the observer was asked to accept or reject the patch when compared to the reference standard in that group. The solid ink density of the process color or colors, which created the patch, were measured to determine the allowable variation in SID for the single colors, two and three-color over prints . The findings indicate that there is greater allow able variation when comparing single colors alone than when comparing their overprints. The standard deviations (S), ranges (R) and (R) average ranges of the allow able variation in SID for the colors utilized were: (See Thesis for Table). These findings and others would indicate that present standards, usually assigned to good quality color printing, such as -0.05, are unrealistic and unnecessary. The ranges allowed by these experienced color observers were as much as 0.42. Other significant findings show that magenta-reds are preferred to yellow-reds and that overall, increases in the magenta solid ink density were allowed more than increases in the cyan SID. There is conclusive evidence to show that these observers accepted greater variation in lightness than in hue and therefore would not accept as much hue change as lightness change. There is further evidence to indicate that it is important to monitor the hue change in the three-color overprints and near neutral colors, since these observers failed to accept comparatively small changes in SID in this region. It is, therefore, appropriate that the pressman vary SID on the press to maintain consistency in the overprints. In conclusion, it may be stated that densitometric values have been established which represent the allowable variation in SID of the single colors. These values are representative of the levels of the process colors on the press and could be applied towards a more effective method of controlling process color printing at the press.

In 1958, Preucil suggested an equation to calculate ink trap based on measurements of a printed sheet with a densitometer. Preucil's equation was based on the additivity rule and the proportional rule. However, these rules do not hold in all cases. Several alternative equations have been suggested. This study intends to examine the effectiveness of three ink trap equations using densitometry by means of comparing the calculated values to those measured by the gravimetric method. An attempt is also made to estimate the value of maximum printable density, Dm, in Hamilton's equation. The theoretical basis of each equation is briefly introduced. The causes attributing to the failure of additivity and proportionality are discussed as well. Also reviewed are several methods for measuring ink trap, such as colorimetric, spectrophotometric, and magnetic methods, and factors involved in the efficiency of ink trapping. In the experiment, two newsprint and one coated paper were printed with cyan, magenta, and yellow ink in a simulated wet-on-wet condition on the IGT printability tester. Each ink had a specific tack. The second-down inks were transferred on the first ink layers with low, medium, and high thickness. The percent ink trapping on printed strips were then calculated by both the densitometric methods and the gravimetric method. The factors causing poor trapping and back-trap in the experiment are discussed. Preucil's equation was found to correspond better with gravimetric trap values than Brunner's equation. However, both under estimated ink trap in the majority of the tested conditions. As the ink trap measured gravimetrically increased, the discrepancy of ink trap calculated by Preucil's equation increased. This applied to Brunner's equation as well, but not obviously to Hamilton's equation. Hamilton's equation proved to reduce the differences between gravimetric ink trap and densitometric ink trap significantly. A Dm value of 1.59 for newsprint A, 1.99 for newsprint B, and 2.5 for coated paper resulted in the greatest accuracy over the conditions tested. When the Dm value approaches infinity, Hamilton's equation becomes the equivalent of Preucil's equation. The experiment suggests that a range of Dm values between 1.5 and 2.5 was suitable for the tested conditions. For future research, a larger selection of various types of papers and inks are needed to specify a Dm value for general conditions. It might also be useful to specify a theoretical maximum printable density for general conditions, with which the maximum printable density of a given paper can be compared. Thus, the reproduction quality of the paper can be predicted before the printing is conducted. Since the effects of back-trap and ink contamination influence the accuracy of Hamilton's equation in this experiment, studies for compensating this inaccuracy are suggested.

This investigation sought to determine if a quicksetting type lithographic ink printed into the bind edge of an adhesive bound product influences adhesion at the spine in a negative manner. The testing system included four (4) paper lots; two (2) coated and two (2) uncoated, five (5) ink levels; 0.0 to 2.2 (10 percent) solid ink density, and three (3) testing times. Two (2) methods were chosen to test variables. The first was considered a traditional, practical method of binding book blocks which included selected test units that were later pulled from the block. The second method sought to simulate the adhesive bind condition through lamination of a test unit, hotmelt and an internally strong base paper. Although a quick test of this sort would be valuable from a production quality control viewpoint, further experimentation and analysis indentified this configuration as not being a valid predictor for the pagepull test, at this time. Based upon the results gathered from this investigation using a pagepull technique, the statement tying a quicksetting type lithographic ink to a loss of adhesion at the spine of an adhesive bound product can not be supported.

The Walker and Fetsko ink transfer equation is the most used ink transfer equation to predict the ink and paper behavior on the ink transfer step in the printing process. All previous studies have shown that this equation is mostly applicable in the three major printing processes, letterpress, lithography and gravure. A study by Schaeffer, Fisch and Zettlemoyer reported extensive measurements for several oil-base ink and paper combination over a range of proof-press printing conditions. Yuri Bery did a series of studies for modifying the Walker and Fetsko equation in gravure inks for Weyerhaeuser Company. All the studies showed that although generally the Walker and Fetsko ink transfer equation can be applied to all three major printing processes, there are always some modifications needed for different rheological characteristics and printing conditions . The trends for the lithographic process is toward Web Offset printing. The components of Web Offset ink is quite different from conventional sheetfed lithographic ink in the pigment and vehicle used. This paper is to find out if the Walker and Fetsko ink transfer equation can be also applied to the Web Offset ink. By investigating the effect of viscosity - one of the most important characteristics in rheology of ink - on the transfer parameters, the ink transfer mechanism model can be examined to see whether it is the same for oil base ink as for the heat-set Web Offset ink. The result of this experiment showed there is a significant different absorption behavior between coated paper and uncoated paper. This difference is effecting the applicability of the Walker and Fetsko ink transfer equation in this particular type of ink and paper combination.

The screen printing process has been the least understood and studied versus other imaging methods in the graphic arts industry. As equipment configurations improve and a continuous technological development and need for high quality output persists, this fascinating process becomes increasingly popular in several end-use applications. Such as in packaging, labeling, durable graphic films printing and even short run large format halftone graphics. There is a serious need for further deep scientific analysis of the process and its variables. One of the poorly investigated sides of the four color screen printing is the effect that ink placement has to the final color appearance of a halftone print. Several known factors can influence the color result of a screen printed image. Limitations inherent to screen printing allow for a smaller color gamut reproduction compared to other methods, but colors are reproduced vividly due to a uniform and high ink film thickness. The screen - equivalent to a printing plate - consists of a stretched porous fabric mounted on a carrier frame that is coated with a light sensitive emulsion (stencil) and subsequently exposed and hardened at the non image areas. The ink will flow through the screen mesh openings when pressure and hydraulic forces are applied by a squeegee blade system. The ink system can be cured or dried by various methods depending on its chemistry and composition. For the specific system investigated, UV curing units expose the wet ink film to high energy radiation for full polymerization. The different types of equipment configurations in screen printing are designed for various processing speeds, base material formats, ink systems of specific drying and curing characteristics and also for various end use applications. This study utilized a Kammann web screen printer with five color stations and UV curing capability for roll to roll one-pass multi color printing. This type of screen printing press is used for applications such as promotional labelling with high precision type and halftone reproduction. A popular film substrate is the polyolefin construction that delivers printability, water resistance, color strength and good process characteristics through roll to roll printing presses. The polyolefin material used for this study was supplied by Fasson Films and is constructed to give a consistent ink film deposit under the set parameters without any penetration, absorption or permeation of the ink system. The samples printed from the total graphics system were produced under the same conditions using in a period of a full working day the press, screens, ink systems and substrate, but only varying the order of the printed process colors yellow (Y), cyan (C) or process blue, magenta (M) or process red and black (K). The importance of ink sequence is determined by creating these prints under the same arrangement and evaluating the color result as it relates to the sequence followed. The purpose of this study was to determine the effect of the ink sequence to the final color appearance of fully dried /cured ink film as expressed by its hue and saturation characteristics. The ink sequence is treated as the sole variable and all other parameters remain constant. An image was designed specifically for this process containing solids, tints and an actual halftone icon. Data was collected by a densitometer and a spectrophotometer from the individual color patches. The representative sampling consists of selected prints throughout each ink sequence run and the measured mean values of all color patches are recorded, plotted, graphed and statistically analyzed. The Hexagon GATF diagram was used to show changes from run to run, densitometric data was also graphed for comparison critique and the CIE*L*a*b* color coordinates allowed mapping of the prints for comparison analysis and color difference [delta]E* study. The data is statistically analyzed and validated versus the null hypothesis using a single factor analysis of variance (ANOVA) and Scheffe comparisons. The final visual evaluation under standard lighting conditions per ASTM standards helps to support the results and conclusion. Experience from the field supports that the ink sequence affects the final color result assuming that all other system components remain equal. This study shows that the sequences' compared color is different and the ink sequence is a critical factor that should be analyzed further for the screen printing industry in order to help maintain color consistency and control. The hypotheses are supported by the study's results. The ink sequence influences the color's hue and saturation in four color halftone screen printing having distinct differences for every sequence that was produced during the printing run. The UV ink systems used, adhere and transfer better to the substrate instead of the ink layers. The placement of black is important for color control and trapping. If black is printed first down then the other inks trap well and a clean image is produced; if black is last, trapping is poor and consequently the color and image appearance. The target guide Nucleus Pattern Sequence Originator was ideal for color measurements and evaluation in screen printing; it is recommended for similar future research work. Densitometry and use of Hexagon diagrams is not very effective in screen printing. The use of colorimetry can show any color changes more accurately. It was also shown that the midtones are influenced the most form the change in ink sequence; especially important for trapping. Finally, two ( 2) of the ink sequences showed good results as concluded by the final evaluation. The MCYK delivered the best output in data and KMCY printed closest to the original proof.

This study proposed to determine the most appropriate place to measure variability in dot gain and solid ink density on a form using color control bars. The study developed a form that entailed three GATF/SWOP, 133 line color control bars placed strategically at the lead, middle and trail edges of the sheet. The test set specific density standards to control to, and while these densities were being controlled, samples were obtained that represented a typical press run. Each of the control bar set-ups was treated as a separate press run, allowing the press operator to change the set densities to the next control bar once the samples were pulled. Five samples were averaged to obtain one sample for that particular sample set. That sample represented one of thirty for one entire press run. Every sample's average density and dot gain was determined, as well as its accuracy, precision, and range. A one-way analysis of variance was used to determine difference between control bar data. Through the statistical tools listed above, the variability in each position of the control bars was determined. The results revealed that both the density and dot gain positions at the trail edge for cyan, black, magenta, and yellow were the most consistent, most precise, most accurate, as well as containing the smallest range of data. In conclusion, based on this study, the trail edge may be the most appropriate position on a form to consistently control a web offset press. The data that were obtained when the middle was being controlled also showed this to be a good location for the control of the press.

Waterless lithography is one of the printing processes that was developed around 1968. It has a strong impact in the current printing industry. Like other printing processes, waterless lithography has both advantages and disadvantages. It is said that waterless lithography can print with more consistency and less dot gain than conventional lithography. However, it has one significant disadvantage, currently there is only one waterless lithographic plate supplier in the industry. There is very little quantitative data describing the waterless lithographic process to support the arguments that waterless lithography prints with more consistency and less dot gain. There is even a report that conflicts with such arguments. Consequently, this research investigates waterless lithography to provide more quantitative data and a better understanding with its conventional counterpart. The purpose of this research was to compare a process capability index (consistency) in terms of solid ink density and the magnitude of dot gain between waterless lithography and conventional lithography. This research performed a series of test runs in an academic environment. The densities of the sample press sheets were measured and used to calculate dot gain. Several statistical methods were used to analyze data and compute process capability indices. From the data analysis, it was found that waterless lithography is only as good as, but not better than, conventional lithography in terms of process capability of solid ink density. Also, waterless lithography does not produce significantly less dot gain than conventional lithography.

The transfer of the image to the substrate in lithographic printing relies very much on the characteristics of the fountain solution. The quality or desensitization potential of the solution has always been determined by measurements of pH ; and by the more "recently" proposed method of electrochemical conductivity. The purpose of this study was to determine which of these techniques most suitably measured the efficiency of the solution. Since the fountain solutions were always changing during the press run, the response of pH and conductivity to changes in concentration were used as criteria for measuring their suitability. The effect on print quality variables were also used as a criterion. The design of the experiment was such that the concentration/conductivity was artificially changed by addition of sodium chloride and potassium citrate salts as well as gum based concentrate and alcohol. The investigation included the study of the physical and plate performance characteristics of the solutions at different concentrations. Relationships and comparisons were made on the properties of pH, conductivity, density, surface tension, viscosity, print sharpness, resolution, resistance to scum, contrast and the number of fogged patches that printed. Experimental work was conducted under controlled conditions and depended on the assumption that the conductance of the solution will be directly dependent on the concentration (and type) of materials and inversely related to the viscosity of the solutions. The pH was assumed to be independent of concentration and viscosity of the solutions. The results obtained were graphically and statistically analyzed. Equations that will permit the estimation of physical and print qualities were also obtained as a step towards accomplishing the objective of calibrating the fountain solutions . It is concluded that under some conditions conductivity is a more useful measurement technique than pH. The concentration of the components of the solution certainly has effect on print qualities. The significance of the effect is determined by the nature of the materials and the extent of their concentrations. Further results indicated that an organic salt shows more compatibility with the solutions than an inorganic salt. While the results called for modification of the definition of a fountain solution, there was no evidence to reject the experimental model. Although acidic fountain solutions were used, the result on conductivity and pH agreed with previous investigations and conclusions on alkaline fountain solutions.

This thesis is a study of Surland's Emulsification Method, and is intended to demonstrate the effect of change in emulsification rate curve with different types of fountain solution whose surface tension was varied. The surface tension of a fountain solution can be changed by the addition of isopropyl alcohol. Two inks were modified to produce the same tack reading but a different emulsification capacity. Using the Surland method the two inks and two fountain solutions generate four different emulsification rate curves and these four curves are tested for their effect on printed quality. The printing performance of an ink is judged by the ease with which an ink can obtain ink-water balance as well as the degree of freedom from printing problems such as "catching up" and plate scumming. The printed sheets are sampled and the data is analyzed statistically using solid ink density and dot gain as response variables. The RIT Symmetrical Scale was included in the printing form design to facilitate solid ink density measurement and dot gain calculation. Solid ink density and dot gain variations are calculated within each printing run. The addition of isopropul alcohol to a dampening solution not only reduces its surface tension and increase its wettability but it also suppresses an ink's continuous emulsification tendency. Ink and water balance is easily controlled when a printing ink is able to reach a state of equilibrim with dampening solution. On the basis of observation during the on press printing run it was found that a high percentage of isopropyl alcohol in a dampening solution can dissolve the blue toner from the black ink and requires an increase of ink feed to obtain the desired optical density. This study indicates the tendency of plate "catching up" can be associated with emulsification rate curves. The Pb type of emulsification rate curve can be so modified that press run will encounter fewer problems. Density variation within a press run is then more easily controlled.