Forest Sciences Commons^™

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 …

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 …

Mathematical Model Of Paper Discoloration By Ink Particles, Zbigniew W. Slotwinski

Masters Theses

The goal of this experiment is to investigate how changes in the size and number of ink particles will affect the final brightness of the filter pad.

It was assumed that any differences in brightness of the used Millipore filters were due to change in the average particle size, given the same mass of ink solids on each filter. However, such simplified interpretation of image analysis proved to be inadequate to solve this complex problem.

The correlation between the particle area, number of particles, and brightness drop was established using an algorithm based on the particle area and the square …

The Effect Of A Sheet Tension Controller On The Productivity Of A Papermachine, Timothy J. Rummel

Honors Theses

This thesis proposal outlines a project in which the efficiency of a papermachine is increased by controlling the tension through the dryer section. The controlled tension is expected to reduce wet end breaks and to decrease the steam demand of the dryer section. The experiment will be run by placing a laser positioning sensor above the open draw of a papermachine and monitoring the position of the draw until an optimum height of the paper has been determined. Then an automatic drive controller will be connected to the wet end drive to maintain a constant draw height and the machine …

Chemically Enhanced Wet Pressing, Timothy Mishark

Paper Engineering Senior Theses

The problem of energy consumption is one of the largest confronting the paper industry today. One of the largest areas where this energy consumption occurs is the dryer section on the paper machine. If a legitimate way to reduce the load to the dryer section was developed, it would greatly benefit the paper industries financial situation. Some of the methods that have been used to reduce dryer load include; increasing the pressure in the press section, heating the press rolls in the press section, and applying chemicals to the felts which help inhibit rewetting. The latter item is what this …

The Effects Of Using Silicate And Borate In The Peroxide Bleaching Of Mechanical Pulp, Corey A. Bishop

Paper Engineering Senior Theses

In the peroxide bleaching process, sodium silicate is currently being used to control metal ions present in the pulp; these metal ions catalyze the decomposition of hydrogen peroxide, reducing the efficiency of the process. However, the addition of sodium silicate can cause scaling the fouling of equipment, wires, and felts. This, in turn, causes expensive downtime for scale removal. This experimental work involved replacing sodium silicate with a non-scale forming borate. This study determined if borate can replace silicate as a stabilizer in the peroxide bleaching process with equivalent bleach response. Rates of bleaching reactions were also determined in various …

The Effects Of Cationic Additives On Ink-Jet Coating Formulations, Sean Frank

Paper Engineering Senior Theses

The recent popularity of ink jet printers has led to the invention of an entire new line of paper coatings. These formulations often require cationic additives to achieve proper print quality. The effect of these cationic additives and their interaction with latexes is studied. This project investigated whether a high solids ink jet coating applied via blade coating can give satisfactory print quality, and the extent of interactions among latex and cationic additives (delete). The experimental design consisted of two different base formulations that were varied by addition levels of polyvinylpyrollidone (PVP), silica, latex, and cationic polymer. These formulations were …

The Effects Of Directional Drying On Binder Migration, Bruce Johnston

Paper Engineering Senior Theses

Binder migration or the nonuniform distribution of binder is a coating problem for many printing grades of coated paper. Binder migration causes mottle, dusting, non-porous coating and other problems in printing paper. Also, many coating dryers have extra capacity that cannot be utilized. The extra capacity goes wasted because at higher drying rates unacceptable binder migration would result.

If binder migration could be controlled, coated paper with better printing characteristics could be produced at higher speeds. This would result in a better product operating at higher speeds and a more satisfactory product to the printers.

The objective of this thesis …

The Effects Of Multiple Recycles On Wheat Straw Fibers, Jeffrey S. Greaves

Paper Engineering Senior Theses

Ever since the late 1960' s, the concern for finding suitable replacements to wood fibers within a paper making medium has been one of the focuses for the industry. At the current time, there are only a limited amount of mills that actually utilize non-wood fibers in order to satisfy the demand for paper within developing countries. Much of the use of non-wood fibers stems from the fact that there are only limited amounts of suitable woody raw materials available to sustain their paper industry. Also, areas that dispose of their agricultural resdiues by burning the remaining stalks is starting …

An Evaluation Of Never-Dried Pulp At Multiple Freeness Levels, Timothy Clifford Liverance

Paper Engineering Senior Theses

Recycled paper is a viable and economical source of useful wood fiber for paper manufacture. Two of the largest contributors to today's paper waste stream are Mixed-Office Waste (Softwood Kraft Pulp) and Newsprint (Stone Groundwood Pulp). When paper is recycled the fibers are unavoidably, and irreversibly damaged. This damage is caused by Hornification (irreversible effect of re-drying fibers) and from the morphological changes on the fiber surface and structure from repeated re-slurring. The combination of these effects will affect the actual strength of the fiber, the bonding potential of the fiber and the freeness of the pulp (drainage rate equivalent). …

The Recycling Of Vacuum Formed Products And The Effect On Use Characteristics, Robert J. Miles

Paper Engineering Senior Theses

Vacuum formed products, commonly called molded pulp, are a superb alternative to expanded polystyrene (Styrofoam) in many current packaging applications. This movement from the petroleum based products of the past to innovative new wood fiber based packaging is due to many reasons including economic benefit, environmental stigma, and/or legislative intervention. The current dilemma is dealing with the inherent fiber characteristics, contaminants, and product composition of molded pulp products. As more of these products appear in secondary waste streams, there is a need for information pertaining these parameters. Unfortunately, very little technical information is available due to the high level of …

The Use Of Borax To Inhibit The Brightness Reversion Of Bleached Ctmp, Chad J. Longcore

Paper Engineering Senior Theses

This thesis evaluated the ability of Borax to inhibit the yellowing process of paper that was made from bleached chemithermomechanical pulp (BCTMP). Paper made from BCTMP has a tendency to lose brightness (photoyellow) when exposed to ultra violet (UV) light. The light initiates a series of chemical reactions to take place that results in the formation of yellow ketone and quinone products. A combination of boric acid and borax was applied to the surface of the paper to interfere with these chemical reactions and prevent the formation of the yellow products that cause photoyellowing. The effectiveness of these additives was …

Eliminating Coating Flakes With Ultrasound, Ryan Zarbaugh

Paper Engineering Senior Theses

As paper mills took to reuse as much internal waste as possible, problems in the system can be introduced. The buildup of deposits or fluctuations of chemicals can occur when more broke is introduced. In mills that add a layer of coating to the paper problems associated with the coating can be introduced. At Champion International in Hamilton, Ohio, a heavy layer of coating added to the sheet introduces the problem of coating flakes to the system.

It was hypothesized that the use of the ultrasonic cavitation mechanism should be able to break the flakes apart and reduce the overall …

A Comparison Between Two Phase System And Single Phase System In Stiff Beveled Blade Coating By Measuring The Blade Forces, Ravi Mohan

Masters Theses

The effect of pigment particle interactions in a two-phase system on blade force is investigated. Three coating colors of 0%, 40% , and 55% solids, of the same high shear viscosity and density, were tested for blade force, blade run-in relationship. The Cylindrical Laboratory Coater was used to blade coat the coating on a polyester film. Blade deflection was measured by placing a probe in direct contact with the back side of the blade. A calibration plot between blade force and blade deflection was then used to determine the actual blade forces. A statistical analysis of the data reveals that …

Effect Of Precalendering On Surface And Printing Properties Of Coated Sheets, Hariharan Venkata-Chinnaswamy

Masters Theses

This study focuses on the effect of different types of precalendering on coated woodfree paper for surface and printing properties as well as coat weight distribution and binder migration.

Precalendering enhanced the gloss and reduced the roughness of the coated paper at all coat weights. In the case of post-calendered papers, any differential effect achieved through various types of precalendering was recovered during post calendering. The final porosity values of precalendered and uncalendered sheets were more dependent on the coat weight at the high coat weights (10-18 g/m² ). At low coat weights the type of precalendering influences the …

The Effect Of Ink Jet Coating Rheology On Screening, Burak Aksoy

Masters Theses

Ink jet coating formulations are becoming of increasing importance due to rapid expansion in digital printing. These coatings have very specific ink absorption requirements, which are fulfilled by using polyvinyl alcohol and silica as binder and pigment, respectively. These coatings have unique rheological behavior and often have problems in industry during the filtering process. In this work, an attempt was made to relate filter blocking to the rheological behavior of the coating. A series of coatings were prepared and their rheological properties characterized. The solids content and pigment selection of the coating were altered in order to adjust the coating …

Direct Measurement Of The Water Retention Of Coatings Under Shear, Mohana Sundaram Thiagarajan

Masters Theses

Coating water loss is one of the most critical concerns in coated paper production. The objective of this study was to determine directly the water retention value under dynamic conditions. The effect of shear rate on water transfer was documented for a delaminated clay coating color. The results showed a small change in water transfer at low shear rates, compared to the static condition. But at higher shear rate, the water transfer increased significantly. The water transfer increased with time, reaching an asymptotic limit at 300 seconds. This indicates that at higher retention time, the water transfer rate is reduced …

The Effects Of Potato, Corn And Wheat Starch On The Rheological Properties Of Pigmented Paper Coatings, Brian G. Hart

Paper Engineering Senior Theses

The paper industry is one of the largest users of commercial starch in the world. Starch has many uses in the papermaking process, including coating operations. In coating, starch has two main purposes: to work as a binder and to give desired rheological properties to the pigmented paper coating. Research was done examine the effects of three different starches on the rheological properties of pigmented paper coatings. The three starches were com, wheat, and potato. These starches were modified using the enzyme conversion process. The converted starches were added to the coating formulas and then tested for high and low …

Optimizing Biocides To Control Microorganisms, Josh Taube

Paper Engineering Senior Theses

Microorganisms can cause many problems during the papermaking process. These problems include slime deposits, corrosion, felt plugging, holes, and additive contamination. An effective biocide program can reduce the numbers of microorganisms resulting in a reduction of these associated problems. This study focuses on the control of microorganisms on the paper machine and the relevant sources of water. Observation of the paper machine began with bleach being pumped into the headboxes, AES screen rotating shower water system and Bel-Bond showers. There was approximately 250 ml/min of bleach being pumped into each of these systems. The amount of bleach being pumped into …

Silica Gel: An Experiment In Surface Area, Scott Vermullen

Paper Engineering Senior Theses

Within the paper industry today, there are advancements in technology every year, every month, most likely every day as well. These new technologies work to obtain the same major goals. These goals include faster machine speeds for improved output. They-include less, pollution, and in fact are working towards a pollutant free system. And finally, product quality for today's high demanding consumer market.

To realize these goals, paper makers must effectively utilize the most amount of fiber and filler possible in their sheet. That is, they must bind up fines and filler within the sheet rather than sending it to the …

Md Ribbing Instability Of Air Knife Coating Application, Bradley W. Fadden

Paper Engineering Senior Theses

The coating application process is an area of great concern for most mills that produce a coated media. During the roll application of the coating onto the sheet, the fluid that is passed to the sheet from the roll, goes through a process known as film splitting. Film splitting is the mechanism for the transfer of the fluid from the application roll to the sheet. Instead of smoothly transferring onto the sheet, the film splits away from the roll and then onto the substrate. Without even transfer and leveling of the coating fluid, the splitting results in stripes or ribs …

Cationic Polymeric Microparticle Retention Systems And Fines Retention, Derek Maddox

Paper Engineering Senior Theses

A new cationic polymeric microparticle (CPMP), which is not yet commercialized, has been developed as a retention and flocculation aid. To study the effectiveness of this new cationic polymeric microparticle as a retention aid it was used in conjunction with both a cationic polyacrylamide (CPAM) and an anionic polyacrylamide (APAM). Laboratory evaluation involved using a Britt Dynamic Drainage Jar, two different furnishes and multiple retention system addition levels to test for fines retention. The two systems were then evaluated individually and compared.

It was found that both the CPMP-APAM and CPMP-CPAM systems were beneficial in retaining both fiber and filler …

The Effect Of Antioxidant Addition On Lightfastness Of Color Ink Jet Printing, Jennifer M. Siuda

Paper Engineering Senior Theses

Fluorescent office lighting has been shown to fade ink jet colors. Fading of ink jet dyes is a problem when the shelf life of documents is important. For effective, low cost ink jet printing, the color quality of the printed paper must be maintained for a duration of time. Research in hot melt adhesives has shown a reduction of color loss associated with the use of antioxidants.

During this thesis, a coating formulation was tested with and without an antioxidant present. The antioxidants tested were alpha tocopherol I vitamin E, and sodium thiosulfate. The addition rate was varied at 2.65 …

Effect Of Borax On Drying And Strength Properties Of Paper, Melanie J. Robydek

Paper Engineering Senior Theses

Sodium tetraborate, the most common of the borate minerals, is a salt believed to promote crosslinking among cellulose and hemicellulose fibers. Samples of bleached Burgess hardwood pulp (45% maple, 25% birch, 15% beech, 15% poplar) obtained from Crown Vantage were treated with borax at three different levels: 0.5%, 1.0%, and 2.0%. The pulp was pre-soaked with borax at 10% consistency, for one hour, prior to refining in a PFI mill. The drying and strength properties of the paper produced from the control and treated pulps were tested according to standard TAPPI procedures and analyzed statistically. The addition of borax resulted …

The Effect Of Drying And Rewetting On Single Fiber Flexibility For Chemical And Mechanical Pulps, Mark E. Dulemba

Masters Theses

Over the years, various attempts have been made to develop methods to measure fiber flexibility. In the course of developing test methods for fiber flexibility, various studies have been performed that measure the flexibilities of different wood pulps.

In this study, never-dried individual thermomechanical pulp (TMP) and bleached kraft fibers were mounted on the tip of a glass tube submerged in water and deflected by water flow. The deflection of the individual fibers was measured using a microscope and image analysis software. The fibers were then dried, rewetted, and the deflection was measured_again. This drying and rewetting cycle was repeated …

The Repulping Of Wet-Strength Paperboard, Angelo N. Melchiorre

Masters Theses

Beverage carrier paperboard containing the polyamide wet-strength resin is one type of fiber that is presently landfilled. In this study, it was repulped at a 15% consistency and a pH of 10 at 150° F. in a z-bar mixer. Hydrogen peroxide (HP), ammonium perswulfate (AP), sodium persulfate (SP) and dimethyldioxirane (DMD) were used during repulping. The HP was added at 1.0%, 2.5% and 5.0%, based on O.D. weight of the fiber. The remaining chemicals were added at the same oxidation equivalent. During repulping, the pulp was screened using a Britt Jar to determine percent yield over time. Samples were taken …

Effect Of Wire Gauge, Web Speed, And Coating Solids On Leveling Of Streaks In Rod Coating, Mukhtar A. Khan

Masters Theses

The behavior of coatings and their study is becoming more important in proportion to additional use of coated paper. Good coating is key to enhance print quality. Blade coating is quite common, but rod coating is coming back for the advantages it has over blade coating. The process of rod coating is simpler and maintenance is easier. Coatings at low solids can be applied with ease and the impurities are washed away by rod rotation. The surface profile of coating is a potential concern, due to streaks in the machine direction. If the coating is immobilized before the streaks heal, …