Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 590

Full-Text Articles in Life Sciences

Determining Differences In Quality Between The Gravure And Flexographic Process On Films, Pete Welther Apr 2004

Determining Differences In Quality Between The Gravure And Flexographic Process On Films, Pete Welther

Paper Engineering Senior Theses

Quality is the goal of every printing company. Every day printing companies spend money trying to find ways to improve the quality of their product. Type of paper, ink, and even the types of printing processes are all characteristics looked at when determining the quality of a printed product.

In today's printing industry, there are two printing processes that have arguably jumped to the front in terms of the highest quality printing ability. The flexographic process and the gravure process have both risen to meet the standards of high quality. The gravure process has always been at the top. For …


Reducing Decomposition Time In Landfills By An Aerobic Process, Cameron Clark Apr 2001

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 Apr 2001

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 Jan 2001

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 Dec 2000

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 Dec 2000

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 …


Chemically Enhanced Wet Pressing, Timothy Mishark May 1998

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 Apr 1998

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 Use Of Borax To Inhibit The Brightness Reversion Of Bleached Ctmp, Chad J. Longcore Apr 1998

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 …


The Recycling Of Vacuum Formed Products And The Effect On Use Characteristics, Robert J. Miles Apr 1998

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 Effects Of Cationic Additives On Ink-Jet Coating Formulations, Sean Frank Apr 1998

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 …


An Evaluation Of Never-Dried Pulp At Multiple Freeness Levels, Timothy Clifford Liverance Apr 1998

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). …


Eliminating Coating Flakes With Ultrasound, Ryan Zarbaugh Apr 1998

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 …


The Effects Of Directional Drying On Binder Migration, Bruce Johnston Apr 1998

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 Apr 1998

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 …


The Effects Of Potato, Corn And Wheat Starch On The Rheological Properties Of Pigmented Paper Coatings, Brian G. Hart Feb 1998

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 Dec 1997

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 Dec 1997

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 Dec 1997

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 …


The Effect Of Antioxidant Addition On Lightfastness Of Color Ink Jet Printing, Jennifer M. Siuda Dec 1997

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 Dec 1997

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 …


Cationic Polymeric Microparticle Retention Systems And Fines Retention, Derek Maddox Dec 1997

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 Effects Of Repeated Recycle On Paper Strength, William T. Byrd Apr 1997

The Effects Of Repeated Recycle On Paper Strength, William T. Byrd

Paper Engineering Senior Theses

As society stresses the need to recycle to reduce the amount of waste sent to our municipality landfills every year, the effect of secondary fiber on the papers that we produce becomes greater and greater. One of the largest effects that these fibers have is to change the strength properties in the sheets which contain them. Most studies have shown a decrease in the tensile strength of paper as fibers pass repeatedly through a series of recycle. The reason of this tendency is believed to be a loss of bonding potential between fibers as they become shorter and stiffer through …


A Study Of The Use Of Borates In Semi-Chemical Pulping, Dan Hebner Apr 1997

A Study Of The Use Of Borates In Semi-Chemical Pulping, Dan Hebner

Paper Engineering Senior Theses

The purpose of this project was to identify sodium metaborate as a pulping chemical in semi-chemical pulping with soda ash. The experimental design included four digester cooks with 0%, 10%, 20%, and 40% addition of.the borate compound. The resulting yields were 81. 3 %, 79. 2%, 77.4 %, and 7 4. 5% respectively. Therefore, under the definition of pulping, sodium metaborate was considered a pulping chemical. The pulps were mechanically refined. The resulting screened rejects increased with increasing borate addition. Handsheets were made and tested for strength and optical properties. The tensile and mull en strengths of the handsheets increased …


The Effect Of Deinking Variables On Flotation Deinking Of Electrographic Toners, Joel E. Jacobs Apr 1997

The Effect Of Deinking Variables On Flotation Deinking Of Electrographic Toners, Joel E. Jacobs

Paper Engineering Senior Theses

Concern for the environment has grown dramatically over the last two decades. In response to this concern, flotation deinking has become a popular way to recycle paper, reduce waste, and achieve a relatively white pulp without cutting down more trees and operating a bleach plant. However, the inks are becoming more and more difficult to deink. With the rise of photocopiers and laser printers the amount of electrographic toner in recycled paper has increased dramatically. Therefore, research on how best to remove these inks from paper is required.

The effects of pH, surfactant concentration, surfactant charge, and toner charge on …


The Effect Of Varying Drying Temperatures On The Recyclability Of Thermomechanical Pulps, Jeffry J. Collegnon Apr 1997

The Effect Of Varying Drying Temperatures On The Recyclability Of Thermomechanical Pulps, Jeffry J. Collegnon

Paper Engineering Senior Theses

There has been conflicting data regarding the effects of recycling on pulps. Strength properties go down for chemical pulps after being recycled, but the strength properties go up for mechanical pulps after recycling. The objective of the thesis will be to study the effects of varying the drying temperature on the recycled fiber properties of thermomechanical pulp.

A never-dried thermomechanical pulp furnish was obtained, from which three samples were separated out. Pulp sample one was air dried at approximately 77°F, sample two was dried at a temperature of 155°F, and the third sample was dried at a temperature of 250°F. …


The Optimization Of A Recycled Thermomechanical Paper Using Fractionation, Michael J. Felker Apr 1997

The Optimization Of A Recycled Thermomechanical Paper Using Fractionation, Michael J. Felker

Paper Engineering Senior Theses

The initial recycling of thermomechanical pulp leads to the flattening and increased flexibility of the fibers. Further recycling of the pulp leads to the unraveling of the fibers. The treatment of the fibers increases the bond potential of fibers while it decreases the fiber strength. Recycling of the fibers also leads to shortening of the fibers. The overall effect of recycling is the degradation of the finished product.

By varying the short fiber ratio the papers strength, physical, and optical properties can be directly affected. The strength properties dependent on bond potential are increased by adding short fiber and recycling. …


The Effects Of Recycling Of Mechanical Pulps, Bill D. Draze Apr 1997

The Effects Of Recycling Of Mechanical Pulps, Bill D. Draze

Paper Engineering Senior Theses

The recycle movement is now bigger than ever, with more reasons than ever. Recycling has the potential to save the world's landfills millions of cubic feet per year of precious space, as well as preserve our natural supply of virgin timbers. The recycling effort has sparked many questions over the years for papermakers. One big question is "how will repeated beating of fibers affect recycling potential?, and how will the effects differ between chemical and mechanical pulps"?

Chemical pulps have been found to lose strength from recycling. By becoming stiffer, chemically pulped fibers lose critical bonding area and flexibility, whereas, …


The Effects Of Recycling On The Hygroexpansivity Of Thermomechanical Pulp, Derek M. Depuydt Apr 1997

The Effects Of Recycling On The Hygroexpansivity Of Thermomechanical Pulp, Derek M. Depuydt

Paper Engineering Senior Theses

The objectives of this thesis were 1) to determine the effects of recycling and increased drying temperature on the hygroexpansivity of the fibers and 2) to investigate the role of beating on the hygroexpansivity of the fibers.

A never-dried thermomechanical pulp was obtained and separated into three samples. Handsheets were produced, dried, and placed in a conditioning room. Sample one was air dried (77°F), sample two was dried at 155°F and sample three was dried at 250°F, respectively. Five handsheet samples at each varying temperature were taken and the hygroexpansivity was tested and calculated for each sheet using the equation …


The Effect Of Silica Surface Area On Microparticle Retention Systems, Jason P. Hoffmann Apr 1997

The Effect Of Silica Surface Area On Microparticle Retention Systems, Jason P. Hoffmann

Paper Engineering Senior Theses

Retention of fines and fillers has always been a concern in the paper industry. There has been many different types of retention aids in the past, but they lack performance under the vigorous conditions in today's paper mills. High shear forces associated with high speed paper of recycled materials into the mill brought along with it high fines content and a lot of anionic trash which readily reacts with cationic polymers. Consequently, the dosage must be increased which can lead to poor formation and increased chemical cost. A new retention aid was needed to combat these problems. Microparticle retention systems …