Forest Sciences Commons^™

Influence Of Infrared Absorbing Anions On Paper Coating Structure, Sachitanand Karnakote

Masters Theses

Infrared units are widely used in paper coating drying to initiate evaporation and quickly reach solids immobilization point. Thermal efficiency of IR units can be improved by increasing absorption of coating color. Borate compounds have shown good IR absorption at wavelengths typical to commercial IR units.

The objective of this research was to evaluate the compatibility of selected borate-containing compounds with the primary components of the paper coatings like clays, carbonates, and some binders.

Coatings were prepared at 60% solids and viscosity and pH were adjusted to 900-1200 cp and 8.5-9.5 respectively. Dynamic stress and frequency sweeps were carried out …

The Relationship Between Single-Disk Refining Energy, Strength Properties, And Freeness For Softwood, Hardwood, And Recycled Stock, Ken Marker

Masters Theses

Statistical and graphical analysis techniques were applied to disc refining operations in order to understand the relationship between strength and drainage properties for a given stock. Two refining variables of refining energy and revolutionary velocity were varied during the experiment. The calculated variable of refining intensity was used to represent these refining variables. The relationship between the refining energy, strength, and drainage properties for northern softwood, northern hardwood, and printing grade recycled stock was explored. Experimental pulp was obtained on a Beloit Jones Single-Disc refiner, and a handsheet study was used to develop the relationship with strength properties. Several empirical …

Particle Size Analysis Of Commercial Printing Inks And Their Press Stability And Printability, Andrea Frimova

Masters Theses

The particle size of commercially produced printing inks available for each of the printing processes, such as letterpress, lithography, flexography, rotogravure and screen-printing was completed. The study of their stability on the press, as well as the examination of the effect of particle size on printability and color balance was investigated. This was demonstrated on several gravure and flexo printing trials lasting for several hours.

Decrease of rotogravure inks particle size was most obvious in black, while the decrease of particle size in all other colors was rather similar. Differences in color, print density, and specular gloss measured on printed …

Development Of Water-Based Ink System For Braille Printing, Saurabh Varma

Masters Theses

The most commonly used system of writing by and for blind persons is called Braille, named after its French inventor, Louis Braille (1809-1952). Braille is comprised of a rectangular six-dot cell on its end, with up to 63 possible combinations using one or more of the six dots. Braille is the only reliable method of literacy for blind persons, because it enables them to read and write by touch¹.

Currently, Braille is printed by special embossers that serve as a printing press. These embossers create Braille output when it is attached appropriately to computers. The speed of these …

Uv-Vis Spectral Analysis Of Spot Colors, Radovan Sporka

Masters Theses

Press return inks represent a continuous problem in printing industry. The best way of utilizing them is to mix them into new colors. Efficiently to do so, it is necessary to determine their composition first. The spot color inks for product gravure were analyzed using Perkin Elmer Spectrometer LAMBDA 900. UV/VIS/NIR analysis of mixtures showed rather similar course of ink spectra in ultraviolet and near infrared region. Thus, the VIS range from 400 - 700 nm was used for further analysis. The unique course of spectral curves of each pigment in visible region enabled successful qualitative analysis of two- and …

Rheology Of Silica Based Inkjet Coatings And Their Filterability, Peeyush Tripathi

Masters Theses

Coating rheology has long been understood to be a key factor in the smooth operation and performance of a coater. As coaters run faster and formulations become more complex, the demands on a coating's rheology grow more stringent.

Silica based coating formulations present unique rheological challenges, thus providing the opportunity for coating formulators to improve their performance through rheological studies under various conditions of shear. Due to rheological restrictions (gelling), silica based coatings are generally applied at 25-26% solids which is very low as compared to calcium carbonate or clay based coating, at 68-70% solids. Consequently, any improvement in coatings …

Lateral Migration Of A Solid Particle In Shear Flow, Wutthapong Jiraporncharoen

Masters Theses

Lateral migration of solid particles in shear flow is observed in various industrial applications. Suspensions in a blade coater, a device used to apply coating pigment to a base paper to improve paper properties, is an example. Particle hydrodynamics will affect the quality of coated paper and runnability of the coater especially when the speed of the coating machine is very high or the pigment concentration is increased.

Many factors will affect the particle migration. The wall repulsion or lubrication effect forces the particle away from a wall to the channel center. The inertial effects are increased by increasing the …

Enzymatic Deinking Of Flexographic Water-Based Inks, Somporn Chaiarrekij

Masters Theses

Introduction

In recent times, environmental concerns have led to the development of water-based flexographic and rotogravure inks. One of the major concerns for water-based inks is their deinkability. Wash deinking of flexographic water-based ink is much more effective than flotation deinking; however, it has two major disadvantages. It consumes large amounts of water and gives a lower yield than flotation due to the loss of fines and fillers in the effluent (1).

Influence Of Starch Molecular Weight And Sodium Alginate On Silicone Holdout For Release Papers, Peter Suchy

Masters Theses

This research was focused on determining the influence of applying one type of potato starch of various molecular weights on silicone holdout. Also, combinations of potato starch with a rheology modifier, sodium alginate, of low, medium, and high molecular weight were studied. The base paper employed was a commercially available paper generally used to manufacture release papers.

Sizing with low molecular weight potato starch is more effective for silicone holdout than sizing with high molecular weight potato starch. This study showed that the paper sized with low molecular weight potato starch has a smoother surface, lower permeability, and a smaller …

Hot Melt Inks For Rotogravure-Formulation, Print Ability And Rheology, James Atkinson

Masters Theses

A new generation of phase change, or hot melt ink will be formulated. This ink was solid at ambient temperature and liquid at the moment of printing. Inks will be formulated on the basis of polyethylene and Ethyl Vinylacetate chemistry. Inks were printed using a Meyer rod for screening printability study. Selection of the best formulations will be done on the basis of reflective density, specular gloss, mottle, and rub resistance. Screened inks having best properties were printed on the Moser laboratory sheetfed proofing press. More detailed printability analysis was done after Moser printing, including dot structure analysis, tone gradation, …

Assessing Silicone Holdout For Release Papers, Rudolf Haraga

Masters Theses

Silicone coating is widely used on papers that require low surface tension. Such papers are called release papers and are used in label, food, and packaging applications. Before silicone coating is applied, the base paper undergoes sizing procedures to smooth the surface and to cover voids present in the surface of the paper substrate. After the base paper is properly sized, it is silicone coated. This makes the surface of the base paper have a low surface energy. Therefore, when a second adhesive paper is applied to the base paper, the second adhesive paper can be easily recovered from the …

Reducing Decomposition Time In Landfills By An Aerobic Process, Cameron Clark

Paper Engineering Senior Theses

This experiment was performed to determine if sludge produced by the paper industry could be composted faster by promoting the aerobic degradation process. To perform this experiment, I chose a sludge produced by a virgin pulp mill. Once I collected sludge, it was dewatered to a moisture content of sixty-five percent or less. As soon as the sludge was dewatered, I set up four separate composting systems, three of which were run under aerobic conditions and one that was run under anaerobic conditions. The anaerobic conditions only had sludge and plastic for its bulking agent. In the aerobic systems there …

The Effect Of Hot Storage On High Yield Pulp, Jeffrey D. Hampton

Paper Engineering Senior Theses

In order to comply with new environmental regulations, the Menasha Corporation's Paperboard Division installed a 150 ton capacity blow tank and non-condensable gas collection system at the Otsego, MI mill. Concerns over the potential changes in pulp quality resulting from the hot storage time created a need for this study.

The objectives of the study were to determine the effects of hot storage under alkaline conditions on the refinability, fiber characteristics, and brightness of a semichemical mixed hardwood pulp. An experiment was designed to duplicate in the laboratory the internal conditions of the blow tank. Pulp was then stored at …

Analysis Of Crepe Blade Vibration, Mark J. Peterson

Paper Engineering Senior Theses

The goal of this project was to take the first step in analyzing this vibration. This meant setting up measuring equipment and analyzing basic blade vibrations.

In this experiment, a laboratory coater (Dow coater at Western Michigan University) was used instead of a tissue machine because it was readily available and easy to control and modify. An accelerometer was used to measure the vibration of a blade on the coater. A computer using Labview was used for data acquisition. Trials at various speeds were run with a piece of tape on the coater roll to cause and distinguish vibration at …

Alternate Models Of Centrifugal Cleaners For The Paper Industry, Eric Bauer

Paper Engineering Senior Theses

Clean pulp is essential to the optimum operation of any paper machine. The hydrocyclone is the most space, energy and cost efficient method to remove both heavy and light contaminants from a papermaking slurry. The efficiency of a hydrocyclone cleaner increases as the amount of removed contaminants increases. An efficient hydrocyclone allows the least amount of usable fiber to be lost in the cleaning process. Bradley devised a mathematical model to measure the efficiency of a hydrocyclone, and it is still the accepted model today. Several problems may exist with the Bradley Model as it applies to paper making slurries. …

Lignosulfonate As A Strength Additive For Non-Wood Paperboard, Francisco L. Martin

Paper Engineering Senior Theses

Recycle mills that use old corrugated cardboard (OCC) in their furnish experience difficulties in maintaining the quality of the paperboard produced. Recycle mills using the OCC collect their OCC from many parts of the world. Countries such as China and Japan use rice fibers in the production of corrugated cardboard. Other countries use straw as a fiber source. The end result is that OCC in the United States contains a portion of non-wood fibers as well as the typical wood fibers. Paperboard containing these non-wood fibers typically has lower strength properties than paperboard produced from pure wood fibers. Literature suggests …

The Influence Of Base Sheet Sizing On The Print Quality Of Matte Coated Ink Jet Papers, Saurabh K. Halwawala

Masters Theses

The most recent developments in ink-jet papers have been related to coating aμd pigment technology. Silica is the preferred pigment for matte coated ink-jet papers. Besides being expensive, the high surface area and porosity of this pigment limits the percentage coating solids to less than 30-35%, which increases production cost due to higher dryer loads. Thus, a need exists to develop a new generation of pigments. The objective of this research was to evaluate the effect of base sheet absorbency on the surface, as well as print properties of matte coated ink-jet papers using a new pigment capable of being …

Effect Of Size Level And Fiber Coarseness On Ink-Jet Printability Of Size Press Coated Paper, Falguni Mehta

Masters Theses

In recent years, matte coated paper has enjoyed wide spread usage for ink-jet applications. The coating performance is strongly influenced by base sheet properties including fiber coarseness and base sheet absorbency. Base sheet absorbency, which is elevated in terms of internal sizing, is a crucial property of ink-jet paper.

The objective of this research was to evaluate the influence of size level and fiber coarseness on ink-jet print qualities. A secondary objective was to examine the size reversion phenomena and to quantify the effect of size level, pigmented coating, and fiber coarseness on size reversion.

The results showed that the …

Development Of A Photoinitiator Blend For Uv Cured Inks And Coatings, Madhu Bansal

Masters Theses

The purpose of this study is to develop a new standard blend of photoinitiators, having properties of low odor, high solubility, faster curing, and being efficient for pigmented as well as for clear systems. In the process, we expect to understand the behavior of mixtures of photoinitiators and their resulting UV spectra. An important first step is to prepare different blend with different photoinitiator and characterize them on cure basis. Curing properties were studied by the KMnO₄ yellow stain density test. The absorption range in the UV spectra was measured for each Photoinitiator with methanol and acrylate as background …

An Investigation Into The Influence Of Common Fillers On Color Reversion Of Bctmp Pulp, Joseph N. Mikowski

Masters Theses

Recent advances in the pulping and bleaching of high-yield pulps, particularly bleached thermomechanical pulp, have made these pulps suitable replacements for bleached kraft pulps. Unfortunately, these high-yield pulps are not appropriate for making high-grade papers because of their tendency to yellow. Extensive efforts have been made to reduce the yellowing, but none of the methods that have been investigated have been at once both practical and economical.

This study investigated the ability of common pigments used in the paper industry to reduce the extent of yellowing of an 80/20 blend of bleached chemithermomechanical and bleached softwood kraft pulp. The effectiveness …

Borax As Internal Stock Additive In Papermaking, Nejib S. Yousef

Masters Theses

The effect of borax on strength property of paper has been investigated in different ways. The use of borax either improved the physical properties or assisted in the reduction of refining energy to significant level.

The study of borax in the presence of precipitated and ground calcium carbonate was accomplished by using white water recycling. In the absence of retention aids, recycling of white was a necessary condition for the retention of ash content. As the ash content increased the strength property decreased. But the presence of borax slowed down the detrimental effect of fillers.

Sizing development progressively improved especially …

Effect Of Calendaring On Flexographic Print Ability Of Linerboard, William P. Woods

Masters Theses

Today's corrugated board end user demands a higher quality than ever. Retailing techniques are moving toward so-called ''value-added packaging," which consists of high quality printed packaging that works to sell the product from the shelf. To preserve'its dominance in the corrugated market, the flexographic printing industry must find new ways to cost effectively satisfy the new demands.

One possibility is the use of an additional calendering step to give the linerboard better printability. This study evaluated two different types of calenders: the shoe (extended nip) calender and the hot/soft nip calender (Appendix A). The test material was commercially produced linerboard, …

Fundamental Study Of The Coating And Basesheet Influences On Gloss In Relationship To Coated Inkjet Papers, Raja Ramakrishnan

Masters Theses

The use of fumed metallic oxides for glossy ink jet media offers alternatives to expensive cast coated and extruded film methods. Fumed metallic oxide pigments provide a high internal porosity and packing porosity that enable the rapid diffusion of liquid inks into the coating layer. Their small particle size (0.1-0.3μm), enable the development of gloss. However, calendering is needed to develop gloss values in the range of cast coated and extruded film grades.

Calendering of coated sheet reduces production speed, adds additional handling and rewinding cost (if performed off-line) and reduces the bulk and porosity of the coating layer, consequently …

Effect Of Various Starch Sources On The Silicone Holdout Of Release Paper, Chandrasekaran Duraiswamy

Masters Theses

Siliconized papers are widely being used from food and packaging industry to pressure sensitive label industry and their use has increased considerably over the last decade. Surface and structural properties of the sheet influence the silicone hold out and release properties.

Surface sizing of the sheet is done prior to silicone coating. The objective of this research is to find their film forming capabilities, fluid hold out of various starches, and the effect of the various calendering process on the release properties was also studied.

No significant difference between the starch sources were observed, except for the modified com starch …

Use Of Boron Compounds To Reduce Phototyellowing Of Mechanical Pulps, Qilin Zhou

Masters Theses

Bleached chemithermomechanical pulps (BCTMP) are replacing chemical pulps such as bleached kraft pulp (BKP) in many paper grades. However, the loss of brightness that arises from exposure to light remains a significant impediment to the wider use of these pulps. Efforts have been made in reducing photoyellowing, but so far no universal, economical method has been found which converts high-yield pulp into a product with brightness stability comparable to that of a bleached chemical pulp.

This study evaluates the ability of sodium borate and/or boric acid to inhibit the yellowing process of paper that was made from BCTMP, with an …

Borax As A Strength Additive In Recycling, Siva Krishnagopal Devisetti

Masters Theses

The effect of multiple recycling on strength properties and fiber properties like strength of fiber, weighted average fiber length, fines percentage and water retention values were investigated in this study. Borax was used as a strength aid and swelling agent to improve the flexibility of fiber and strength of recycled paper. Bleached softwood kraft pulp was used to make the hand sheets and recycled repeatedly for up to four cycles. The main objectives were to evaluate the chemically treated pulp and untreated pulp at each stage of recycling, to study the effect of multiple recycling on strength properties of paper …

The Influence Of Fumed Metallic Oxides On Coating Structure And Their Relationships To Print Quality, Hyun-Kook Lee

Masters Theses

Aqueous-based coating for paper or paperboard applications use traditional coating pigments such as clay, calcium carbonate, and titanium dioxide. But, for matte coated ink jet papers, amorphous and gelled silicas are used due to their unique morphological properties, which are sponge-like in nature. The unique structure of these pigments provides an internal porosity and packing porosity which enables the rapid diffusion of liquid inks into the coating layer. The rapid uptake of the ink immobilizes the anionic dyes at the surface of the coating, allowing high optical print densities to be achieved.

The particle size of precipitated and gelled silicas …

Dimethyldioxirane In Tcf Bleaching Sequences, Nayereh Mahdavi

Masters Theses

The use of chlorine containing bleaching process creates various organic compounds such as chlorinated furan, dioxin, and AOX (adsorbable organic halogen). The human and aquatic life has been affected with the formation of these chlorinated organic compounds. EPA is proposing new regulations to impose discharge limits on the conventional pollutant materials of the bleaching effluents.

The objective of this research was to evaluate two TCF (Total Chlorine Free) bleaching sequences that use hydrogen peroxide and DMD on oxygen delignified hardwood kraft pulp. In one of the sequences, the DMD stage (A) was used prior to the hydrogen peroxide stage (P), …

Effects Of Temperature Control On Gravure Packaging Inks, Rodrigo Sosa

Masters Theses

It is well known that variations in ink temperature cause a variation in color density and viscosity. The viscosity of almost all liquids decreases with increasing temperature. In this research project, three different ink temperatures were selected to measure the effects of temperature control on solvent and ink consumption and on printability. Two colors were selected (magenta and cyan) and two heat exchangers were constructed to cool and/or heat the ink.

It was found that variations in ink temperature cause variation in solvent and ink consumption. As the temperature of the ink increases, solvent consumption and ink consumption increase, but …

The Effect Of Using Hemicellulase And Oxidase Successively As Pre-Bleaching Agents For Hardwood Kraft Pulp, Bryan R. Moore

Honors Theses

Environmental concerns have applied pressure on the paper industry to change many erstwhile processes that have traditionally remained unchallenged. One process in particular is pulp bleaching. Elemental chlorine, while effective in bleaching pulp and low in capital cost, is a major environmental threat because of the toxic chlorinated compounds and other dioxins that are generated in mill effluents. With increasing technology and demand, there has been much research devoted to the development of alternate bleaching sequences, whether Elemental Chlorine Free (ECF), which can use Chlorine Dioxide (ClO₂), or Totally Chlorine Free (TC). THe wide acceptance of these bleaching …