| Student and Faculty Print Research Center |
| Updated: May, 2005 |
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Many classes
in the Clemson University Department of Graphic Communications require
students to take charge of their education and conduct research
on topics of their own selection. This site will be updated frequently
with student papers written on a wide range of graphic communication
related topics. Please note that these papers are the work of Clemson
University students and do not necessarily represent the views of
the faculty or Clemson University. No part of these papers may be
published without express written consent of the author or a Department
representative. If you would like to publish or obtain a full copy
of student research, please e-mail jsperry@clemson.edu
for instructions.
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Index |
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| TAGA
Student Chapter Published Research |
Radio Frequency Identification Technology: An Investigation of Process Benchmarks
Author: Jay Sperry
PDF: http://graphics.clemson.edu/ITC/research/RFIDTechnology.pdf
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Abstract:
The use of conductive inks in Radio Frequency Identification (RFID) technology provides flexographic printers the resources and opportunities to contribute to the production of RFID components. This paper evaluates how specific variables within the flexographic package printing industry relate to printability and functionality of silverbased conductive inks. Variables researched included film and paper substrates, drying parameters, ink film thickness, rubber and photopolymer plate types and print design. Process benchmarks for the flexographic printing of conductive inks were established through conclusions based on research findings. |
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The Effects of Ink Viscosity of Water-Based Inks on Print Quality in Flexographic Printing
Author: Beth Cook
PDF: http://graphics.clemson.edu/ITC/research/InkViscosity.pdf
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Abstract:
Ink viscosity of water-based inks is an important factor in the flexographic printing process. The following research was performed in order to determine the effects of ink viscosity on print quality. Print quality is achieved when measurements, such as density, print contrast, color, and dot gain fall within a range of target values in addition to a subjective evaluation of the printed piece. The outcomes of these measurements are dependent upon the ink’s viscosity, the independent variable. This research project involved printing at various ink viscosities to determine if and how this will affect the quality of print. Upon completion of this research project, it can be concluded that viscosity does in fact have an effect on print quality. The change in viscosity causes noticeable variations in density, print contrast, color values and dot gain. |
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Product Resistance Testing: An Analysis of L*a*b* value readings of water-based flexographic inks printed on coated and uncoated substrates when subjected to common household chemicals.
PDF: http://graphics.clemson.edu/ITC/research/ProductResistanceTests.pdf
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Abstract:
Have you ever spilled some of your household cleaning solution on the package labeling only to have the ink smear? This is a problem addressed through this research project.
The affects of various materials found in common household products, such as acids, water, and oil were tested on printed substrates including coated and uncoated paper. All of these tests were printed with flexographic ink, since flexographic ink is most commonly used in printing product labels. Three different colors of flexo ink (black, cyan, and magenta) were also printed. It was determined that testing yellow would not be practical because most companies would never print a label with just yellow ink. The L*a*b* values of the inks on each substrate were read before and after exposure to the materials and then compared. The most resistant substrate and ink color were determined by seeing which had the least difference in L*a*b* values before and after exposure to the materials. Using the press to lay down the ink rather than a hand held proofer ensured consistent ink density. This project determined which color ink and which substrate was the most resistant overall to the household chemicals.
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“The Gravure Effect” and Metallic Ink Reflectance
Authors: Blake Cannon, Blair Hunnicutt, Robert Povelones
PDF: http://graphics.clemson.edu/ITC/research/GravureEffect.pdf
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Abstract:
There are many problems with the printability of metallic inks. One of the most prevalent problems with metallic inks is uneven or mottled areas in a solid area. This is usually due to inadequate amounts of ink being transferred to the substrate. This could lead to a number of undesired effects in the final printed piece such as unattractive print, customer’s disappointment, end-buyer’s lost attention, and many more. This disadvantage can be eliminated by simply transferring more ink to the substrate. One way to do this is through the gravure effect. The gravure effect is a phenomenon that occurs mainly in flexography where a 98 or 99% dot transfers more ink to the substrate than a 100% solid. This occurs because the large dots on the flexographic plate have little voids between them that actually end up carrying ink. Therefore, they act like a gravure cylinder and actually transfer more ink than a 100% solid since both the dots and the cells are able to hold ink. This will allow printers to print more uniform, consistent metallic solids since the gravure effect allows them to lay down more ink on the substrate.
This research project examined the printability and press behavior of metallic inks, with the focus on narrow-web flexography. This study observed how the ink delivers to the substrate, using different anilox roll specifications. Then there were suggestions on how to improve the process of printing metallic inks. This will help printers in the industry print uniform areas of solid metallic ink while utilizing the gravure effect to print a more consistent end product.
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Effect of Yule Nielson factor and Cellular Neugebauer model on gray
balance prediction
Author: Vinod Panangat
PDF: http://graphics.clemson.edu/ITC/research/gray_balance_prediction.pdf
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Abstract:
The determination of gray balance largely depends on printing test
targets. A theoretical approach to gray balance determination is
proposed in this paper. This paper is an extension of the research
paper ìGray balance determination by using Neugebauer equation and
Kubelka Munk Equation, Vinod Panangat,2003î. Experimenting with
different Yule Nielson factor ëní values, the accuracy of the prediction
of dot percentage using the Kubelka Munk equations, is tested. It
is interesting to note that the predictability decreases with the
increase in the ëní value. A Yule Nielson factor of one is found
to be the best fit for the prediction of dot percentages using Kubelka
munk equations. A ëní value of one basically reverts back to the
simple Neugebauer equation in its original form. The Cellular Neugebauer
model (using 9 cells) is also tested. The cellular approach provides
the best prediction value in magenta and yellow, but fails poorly
with cyan. The cellular approach however produced dot percentages,
which were difficult to apprehend. The research study improved the
predictability by a maximum of 6%, when compared to the earlier
research.
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A Comparison of Print Quality using Digital Cyrel Fast and Digital
Cyrel Solvent Wash
Authors: Kaete Hoyt, Jennifer McClain, Jade Hamilton and Melanie
Edwards
PDF: http://graphics.clemson.edu/ITC/research/print_quality_fast_vs_solvent.pdf
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Abstract:
Print quality is the cumulative factor that printers aim to achieve
in all printing processes. In this research project, print quality
of two different plates, one being DuPont's Cyrel FAST and the other
being DuPont's Cyrel digital plates, were analyzed and compared
to see if the plate composition and/or plate processing has an effect
on print quality during press runs. Print quality consists of many
factors involved in printing. Tests similar to this research project
have most likely been performed by DuPont, but often times industry
uses other, less biased, outside research to back up their own.
This study could help printers determine which plate material would
be better for their particular process. The FAST system saves time,
but the question is whether that hinders the final quality of print.
The main issues involved in determining print quality involve dot
gain, print contrast, density, and tonal range. Ink density determines
how much light is absorbed by the ink and how much is reflected.
This determines how humans will perceive the color printed on the
substrate. Density is the direct determinant of print contrast and
dot gain, so it is essential to find the appropriate density to
ensure the best looking print. Print contrast is a means of determining
the optimum amount of ink laid onto a substrate that will give the
darkest shadow areas while at the same time keeping the 75% range
open. Print contrast is directly related to the tonal range that
can be created. Tonal range is the range of tints that run from
0% to 100%. The goal is to see a transition from each tint patch
to the next. It is likely that dots below a certain percentage will
not hold on the plate and dots above a certain percentage will fill
in and create solid ink coverage. A further fill in is contributed
to dot gain. Dot gain is a problem that exists in all areas of the
printing process. When ink is combined with pressure, heat, and
human error, there will be a gain in the dot size when the plate
contacts the substrate. The struggle exists in the industry to control
dot gain and not let the dot gain control the process. With this
study, we found any differences, good or bad, that may exist in
the two plates tested.
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Gravure: Color Reproduction and Engraving Technology
Author: Kevin Bourquin
PDF: http://graphics.clemson.edu/ITC/research/gravure_color_and_engraving.pdf
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Abstract:
The gravure industry has held a large share of the printing market
since its beginnings over a century ago. Gravure is a simple process
that is capable of producing the highest quality product at extremely
fast speeds for exceptionally long runs. It has proven itself among
the five major printing processes for providing excellent color
and ink density on a variety of substrates. Recently, the gravure
industry has grown due to many technical advancements of the process.
These include shorter engraving times, increased press speeds as
well as sizes and enhanced cell formations. Process color is becoming
common in an abundance of printed material. For gravure, this means
its time to show off its capabilities. Even though this may sound
easy, it has actually become a complicated science of physics and
chemistry. Color management has taken the printing industry by storm.
It has become an essential part of any printerís color reproduction
process to ensure success. It revolves around process control, capability,
predictability and repeatability. In order to be successful it is
important to master the process. When the worlds of gravure and
color reproduction collide, there is the chance for supreme dominance
or bitter defeat. Reproducing a characterization target on an output
device to predict color space and tone reproduction is a major component
of color management. When characterizing a gravure press, the speed,
wiping of the doctor blade, and target orientation to web direction
may affect the reproduction. This could influence the reproduction
and produce less than optimal results. Along with its high quality
production of color, gravure is also known for rough edged type.
Industry advancements have made an impact on these two areas as
well as others. A new electromechanical engraving technology, Super
E, allows cells to be formed to ensure a smooth ink transfer from
cylinder to substrate. This technology has the potential to affect
the engraving process for future color reproductions.
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Digital Flexographic Plate Technology: A comparison of solvent processed
and thermal processed plates
Author: Megan A. Chase
PDF:
http://graphics.clemson.edu/ITC/research/comparison_solvent_and_thermal.pdf
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Abstract:
Is there a difference in print quality between solvent processed
flexographic plates and thermal processed flexographic plates when
using the described evaluation method? Hopefully, this study can
contribute some information to help so that decisions can be made
as whether there is a significant difference between the two plate
types to make the investment in a thermal process system.
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