Wood Science and Pulp, Paper Technology Commons^™

Strength Properties Of Steam Exploded Laser Printed Papers, Dhamodharan Srinivasan

Masters Theses

The mam objective of this study was to investigate the effect of steam explosion pulping on the strength properties of recycled fibers. The properties considered were zerospan tensile strength, tensile breaking length, tensile stretch, tensile energy absorption, scott bond and pentosan content. This study also examined the important operating parameters that affect the properties. Laser printed waste paper was pulped by the steam explosion process. The experiments were statistically modeled to cover the various process variables. Chemical addition, residence time, pressure, and dispersant level were varied during the steam explosion experiments. Chemical addition was kept at four levels and other …

The Factors Influencing Electrographic Toner Flotation, Udaykumar Ratilal Raval

Masters Theses

Conventional deinking is the process of removing the ink from usable paper fiber. Electrographic toners are hydrophobic in nature because they have negligible negative charge. A study of the effect of fundamental properties leading to electrographic toner flotation in presence of free fibers has not been reported.

Flotation deinking of fused "sharp" toner fraction below 300 micron in the presence of free fibers was performed in the Hallimond tube. Cationic (Dodecyltrimethyl ammonium bromide - DTAB) and anionic (Sodium dodecyl sulfate - SDS) surfactants having similar molecular weights were used at two concentration levels and two pH levels. The effect of …

The Effects Of Fines, Drying Intensity And Recycling On Pulp And Paper Properties, Chiranjiv K. Singh

Masters Theses

The effects of fines level, drying intensity and recycling on pulp and paper properties of bleached softwood kraft were evaluated graphically and statistically.

Fiber fines (100-mesh) were mixed in proportions of 0, 10, 20, 40% with the long fiber fraction. These pulps were tested for fiber length distribution. Handsheets prepared from these pulps were dried at low (air dry) and high (220°F, 4.25 min) drying intensities. These handsheets were recycled and new handsheets were dried at the above drying levels.

Water retention values increased with increasing level of fines for virgin pulp. Recycling resulted in a 20% decrease in water …

The Effect Of Manganese Peroxidase On Peroxide Bleaching Of High Yield Pulps, Cyril Vusani Simelane

Masters Theses

The main objective of this study was to investigate the effect of adding a pretreatment stage in conventional hydrogen peroxide bleaching of high yield pulps. To achieve this, three main variables considered crucial in the effectiveness of manganese peroxidase on the oxidation of lignin substructures, were chosen to evaluate the effect of this enzyme on high yield pulps. The responses to evaluate this effect were brightness, brightness reversion, pulp viscosity, and yield. Other properties included opacity, scattering and absorption coefficients, and the Hunter Lab values.

The pulps were bleached using two sequences Q(MnP), and Q(MnP)QP, to assess the effect of …

The Effect Of Age And Recycling On Paper Quality, Zhuang Wu

Masters Theses

The effects of recycling paper that has undergone aging for different periods on paper and fiber properties like strength, weighted average fiber length, and water retention value were investigated in this study. Old Newspapers (ONP) with different periods of natural aging (between 1 to 10 months) were recycled repeatedly for up to six times. Another goal was the study of aging effects on paper properties using accelerated aging at high temperatures (105±2) °C. Four different aging times (24, 48, 72, and 144 hours) were employed.

The results showed that naturally aged ONP loses little in strength properties up to 7 …

The Effect Of Wet End Operations On Sizing Loss In Alkaline Papers, Suresh B. Cherukuri

Masters Theses

Changes in wet end of alkaline papermaking affect the size development as well as sizing loss. These changes include pH, alkalinity and type of filler used. Precipitated and ground varieties of carbonate fillers and the alkalinity associated with · them are believed to be the causes for the gradual sizing loss in alkaline papers due the accelerated hydrolysis reaction of sizing chemicals at higher alkalinity.

Precipitated and ground calcium carbonate fillers are used as fillers and compared to non carbonate filler such as kaolin clay for their response to size development and sizing loss at lower and higher alkalinity ranges …

Reverse Osmosis Treatment Of Deinking Effluents, Lei Zhao

Masters Theses

The application of the reverse osmosis process for treatment of preclarified deinking effluent was studied for its efficiency and capacity to remove the total suspended and dissolved solids. Seven coagulants and flocculents were studied in the pretreatment to determine the best coagulant. Two variables, temperature and coagulant dose, were studied to determine the optimum conditions. For the reverse osmosis treatment, two types of thin film composite membranes, sea water and brackish water were used in the research. A set of orthogonal experiments and regression analyses were conducted to study the effects of pressure, temperature, feed concentration, and feed pH on …

Effects Of Polymers On Pressure Water Retention And Binder Migration Of Aqueous Coatings, Arvind M. Singhal

Masters Theses

The effects of the molecular properties (degree of polymerization and degree of substitution) of water soluble polymers (containing carboxyl and hydroxyl groups on cellulosic backbone) on water retention under pressure and subsequent binder migration of coating colors are documented. It is concluded that no single mechanism can explain either water retention or binder migration. The dominant mechanisms of water penetration under dynamic pressure pulse are different from the mechanisms of water absorption under static pressure.

It is proposed that the molecular properties affect the rate of consolidation of the coating layer and thus greatly affect the water penetration under a …

The Effects Of Repulping Variables On Deinking Of Flexographic Inks, Sylvia Ciampa

Masters Theses

The effects of repulping variables (pH, surfactant concentration, time, and temperature) on deinking paper printed with flexographic ink were studied. A series of alcohol ethoxylate surfactants was evaluated. The one with HLB= 11.8 was selected for the majority of the study.

pH was the variable that presented the greatest effect on repulping and deinking. The brightness after repulping and the final brightness after deinking was significantly higher at pH 5 than at pH 9.

Paper was repulped for 15, 25, and 40 minutes respectively. Highest brightness after repulping and highest gain in brightness by flotation was observed after 15 minutes …

The Interaction Of Coated Paper Surfaces And Water- And Solvent-Based Rotogravure Printing Inks, Tanja M. Gnad

Masters Theses

The print quality of 24 different coating formulations was studied when printing with both water- and solvent-based rotogravure ink. Coating was done on a Cylindrical Laboratory Coater (CLC). The coated paper samples were supercalendered to achieve a smooth surface which is necessary when printing with rotogravure. The supercalendered coated paper samples where tested for optical and surface properties and also printed with water-based and solvent-based ink on a Moser Gravure Proof Press. The print quality of the printed samples was quantified by image analysis. The results showed that fine ground calcium carbonate gave the lowest percent bridging between ink dots, …

Physical And Optical Properties Of Steam Exploded Laser Printed Paper, Arvind Kumar Sharma

Masters Theses

The main objective of this study was to investigate the effects of steam explosion on the optical properties of recycled fibers, i.e., brightness, opacity, scattering and absorption coefficients, and to find out whether explosive discharge caused fiber damage and affected fiber bonding ability.

Laser printed paper was pulped by the steam explosion process. Addition of two different chemicals, residence time, pressure, and dispersant level were varied during the steam explosion experiments. All factors were kept at two levels.

Full factorial design and regression analysis were applied to determine the effect of different factors on steam explosion pulp. The data indicate …

Rheology Of Coating Colors Containing Water-Soluble Polymers And Their Effect On The Runnability Of The Clc Blade Coater, Harish K. Narasimhamurthy

Masters Theses

Four different classes of commercial rheology modifiers (thickeners) e.g., Polyacrylate (PA), Associative Cellulosic Thickener (ACT), Associative Synthetic Thickener (AST) and CMC were used in a simplified coating formulation to study their effects on rheological and viscoelastic properties of the coating colors. An attempt was also made to study their effect on runnability using the Cylindrical Laboratory Coater (CLC). A series of coatings were prepared using number one clay and styrene-butadiene latex. The thickeners were added to these at several levels. The coatings were evaluated for rheological and viscoelastic properties. The coatings were also applied onto paper using the CLC at …

Effect Of Poly Acrylate Addition On Coating Color Rheology, Water Retention And Coating Performance, Shambhu Nath

Masters Theses

Five polyacrylate samples were used to study their effects on coating color rheology, water holding and runnability. The Cylindrical Laboratory Coater was used to apply the coatings and study the runnability of the coating colors. The healing tendencies of the coatings were studied by inducing a scratch under the blade. The higher acid level and degree of crosslinking of the polyacrylate gave higher viscosity and the higher acid level also gave higher water retention. Coating colors containing polyacrylates were less prone to dilatancy at high shear. The addition of polyacrylate reduced the healing of coating colors, but for the same …

Effects Of Alkaline Internal Sizing On Rotogravure Print Quality Using Waterbased Inks, Michael L. Busche

Masters Theses

The effect of alkaline internal sizing in improving paper smoothness and ink gloss in waterbased rotogravure printing was investigated. Papers were internally sized with alkyl ketene dimer (AKD) under alkaline conditions from slack-sized to hard-sized. Papers were printed with waterbased inks on a web gravure press. A major problem with waterbased inks is increased surface roughening of paper and a low ink gloss. Temporal surface roughening was reduced by increased AKD internal sizing with a concomitant significant increase of up to 400% in ink gloss. Surface properties were correlated with print quality. The print quality improved with increased hydrophobicity of …

The Effect Of Viscosity In Beveled Blade Coating, Salih Cebe

Masters Theses

The objective of this study was to investigate the effects of several types of coating viscosity on coat weight development during the beveled blade coating process. In this study, the effects of several types of coating viscosity were experimentally investigated at the applicator roll, before and underneath the blade. Coating color viscosities were changed through two methods. The first method involved changing the temperature of coating color at constant carboxymethylcellulose (CMC) concentration, while the second method consisted of varying the CMC concentration in coating formula at constant coating temperature.

Coating viscosity had an influencing effect both on the amount of …

The Slip Velocity Of Coating Formulations Using The High-Shear Viscometer, Daniel Parker Krieger

Masters Theses

When using a cup and bob viscometer, it has long been recognized that errors in the viscosity measurement can arise from several factors, among them slip. Slip is a phenomenon which occurs when there are slipping layers in the fluid under shear, causing a non-uniform velocity gradient to be generated across the gap of the cup and bob viscometer. A layer of fluid at either the bob or cup wall moves faster than the adjoining layers, causing the slipping effect. This leads to a low viscosity calculation for the fluid.

In this study, experiments with coating formulations were conducted using …

Fountain Solution Ph And Conductivity Changes Caused By Paper Extractables During Offset Printing, Douglas E. Cox

Masters Theses

Economical and environmental issues are causing papermakers to change from the traditional acid papermaking process to neutral and alkaline papermaking processes. Also, offset printers are changing from traditional acid type fountain solutions, with or without alcohol, to: (a) neutral, (b) alkaline, and (c) acid with alcohol substitute type fountain solutions. The interaction between these new papermaking variables and fountain solutions and their effect on printability needs to be investigated.

The pH, conductivity, and contact angle changes of five different offset printing fountain solutions were monitored during offset printing press trials on acid, neutral and alkaline basestocks.

The results indicate that …

A Pilot Plant Evaluation Of Selected Hardwood Pulps For Supercalendered Grade B Paper, Devendra Kumar Srivastava

Masters Theses

The proliferation of wood free printing and writing papers suggests the evaluation of hardwood kraft and chemithermomechanical pulps for the manufacture of uncoated rotogravure paper. In this study 100% aspen kraft, 100% eucalyptus kraft, and 50% aspen chemithermomechanical with 50% kraft pulps were used to produce rotogravure paper on as 32" trim Fourdriner paper machine under alkaline papermaking condition.

The machine runnability was smooth using 100% hardwood furnish for the production of rotogravure paper. The paper produced was found suitable for supercalender grade B applications, such as Sunday magazines, inserts, and flyers. The tensile index and tear index values were …

A Study Of Alkaline Sodium Sulfite Pretreatment Of Spruce During Thermomechanical Pulping, Nagaraju Dendukuri

Masters Theses

A review of literature relating sodium sulfite pretreatment during thermomechanical pulping to pulp physical properties revealed many contradictions. Thermomechanical pulping variables were studied for their effect on pulp physical properties. An improvement in pulp physical properties was observed above 1% sodium sulfite treatment. Regression analysis and analysis of variance showed that there was a significant effect of sodium sulfite on the reduction of shive content, pulp brightness, and tear index. Fiber length, tensile, burst, and density were not found to be significantly affected by the amount of sodium sulfite. Sodium sulfite treatment during thermomechanical pulping showed a negative relationship with …

Microencapsulation As An Alternative To Emulsification For Preparing As A For Use In Papermaking, William J. Corriveau

Masters Theses

The sizing chemical ASA is emulsified to make i t compatible with the papermaking process. Unfortunately, emulsified ASA is chemically reactive with water at the elevated temperatures found in papermaking systems. As an alternative, encapsulated ASA was made and investigated for its stability towards water at elevated temperatures.

A handsheet procedure was developed to analyze emulsified and encapsulated ASA. It was concluded that the procedure gave statistically reproducible results. Investigations with the procedure revealed important variables concerning the laboratory and m ill application of ASA. Evidence indicated that retention of ASA was critical to sizing development.

Encapsulated ASA made for …

Pulping Of Rubber Wood For Pulp And Paper, George Paulose

Masters Theses

No abstract provided.

A Study Of The Effect Of Fiber Length Distribution On The Tear Strength Of A Synthetic Fiber Sheet, Kit Funderburk

Masters Theses

No abstract provided.

A Survey Of Management Opinions Of Noise In The Pulp And Paper Industry, Carola Trittin

Masters Theses

Introduction

The pulp and paper industry is the fifth largest in the United States, dollar-wise, and is also the third fastest growing industry in the United States (1). There are between 375,000 and 400,000 people employed directly in the pulp and paper mills in the United States and Canada. A nation-wide survey on the importance of noise in this industry is needed to help clarify the effects, if any, that noise has upon its employees.

By definition, noise is non-harmonious sound. When the subject of noise is mentioned, many suggestions are given on places where such a study should be …