Forest Sciences Commons^™

Study Of Trisodium Borate Formation And Its Reaction With Green Liquor In Partial Autocausticizing, Pasupathy Rajan Subbaiyan

Masters Theses

This thesis investigates a new development of autocausticizing the green liquor with trisodium borate. Sodium metaborate (NaBO₂) reacts with the sodium carbonate (Na₂CO₃) in the char bed at 850°C in the recovery furnace to form trisodium borate (Na₃BO₃) which in tum, when dissolved in water produces sodium hydroxide (NaOH) regenerating sodium metaborate (NaBO₂). The main objective of this research is to study the formation of trisodium borate from the reaction of sodium metaborate with sodium carbonate at different molar ratios of carbonate to borate and to determine the …

Generating Icc Output Profiles For Different Substrates: Application To A Shinohara Offset Press & Several Printers, Kailashnath Jaganathrao Pohnerkar

Masters Theses

The International Color Consortium (ICC) was formed to undertake problems in achieving reliable and reproducible color throughout the reproduction process; the ICC Profile Specification offers solutions to color matching and quality. Problems with the ICC Profile relate to tools in the field, output devices, various substrates, profile calculation processes and color accuracy.

A color management system (CMS), developed by International Color Consortium, allows color transformation to be carried out by the operating system in conformity. ICC profiles describe the color range of a device and the way it distorts the color of an image. The profiling software is required to …

Effect Of Partial Borate Autocausticizing On Causticizing Rate And Equilibrium, Murugavel Anbalagan

Masters Theses

Borate autocausticizing can replace - total autocausticizing, or supplement the kraft lime cycle- partial autocausticizing. Partial autocausticizing is undergoing trials in several mills and has been recently commercialized in one mill. One common observation in the on-going trials is that the causticizing efficiency increases. The primary objectives of this research are to study the effect of metaborate on the causticizing rate, equilibrium and rate controlling parameters such as the temperature, concentration and sulfidity. The aim is to define the conditions that resulted in the increase of the causticizing efficiency.

The major findings of the research are that when the causticizing …

Borates As Infrared Drying Agents And Bulking Agents In Paper Coatings, Balarama K. Morla

Masters Theses

In the paper industry, the drying process is the second most energy consuming process after the pulping process; it accounts for around 35% of the total energy consumption. If energy consumption in the drying process can be reduced, the cost of paper production would be decreased considerably. The more recent and wide acceptance of the use of infrared energy for the drying of coated grades has led to many developments and improvements in materials and controls, making IR a practical and safe method for the paper industry. This process is mainly based on the absorption of infrared radiation by paper …

Determine The Effect Of Pulp And Paper Properties Such As Basis Weight, Degree Of Refining On The Drying Proportions Of Both Hardwood And Softwood, Vidit Kumar

Masters Theses

Paper drying is a very important unit operation and a highly energy intensive operation in the paper industry. Various studies have been made to discuss the effect of various variables on the drying behavior of the paper. Extensive efforts have been made to reduce the energy requirement in this operation.

This study tries to find the effect of basis weight, refining level on the drying behavior of the paper of both hardwood and softwood. The basis weight, the degree of refining and type of wood affects significantly the drying rate, the drying time and the contact coefficient between the paper …

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 …

Crt Versus Lcd Monitors For Soft Proofing: Quantitative And Visual Considerations, Veronika Chovancova

Masters Theses

Quantitative and visual considerations of accuracy of colors in images displayed on two types of monitors employing a soft proofing system were accomplished in this research work. Soft proofing proposes possible savings in material and time, which are essential issues of current digital and quick turn around workflow. The investigation focuses on the quantitative evaluation process of color monitor profiles along with the color quality of software used to achieve the created profiles. Specific tests are provided to look at the color quality of the monitors and output profiles in greater details. Also, a general comparison of the CRT and …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Hot Melt Inks For Rotogravure - Formulation, Printability 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, …

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 …

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 …

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 …

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 Calendering 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, …

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 …

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 …

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 …

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 …

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 …