Life Sciences Commons^™

The Effects Of Recycling On Fiber Characteristics, Michael B. Bekes

Paper Engineering Senior Theses

Recent trends in recycling indicate that future use will increase. This increase will bring a demand for the secondary fiber. Many technical questions have to be answered before recycling becomes an economical process. One of these questions is how the recycling process affects fiber characteristics. This thesis will deal specifically with this question.

"Controlled Overdrying: Effects On Some Physical Properties Of Fine Paper", John T. Collins

Paper Engineering Senior Theses

The purpose of this study was to determine the effects of certain drying variables on some physical strength properties when these variables were controlled to bring about overdrying conditions. The variables under study were contact time on the dryer can (% moisture) and different percentage hardwood-softwood compositions. From the study it was discovered that overdrying actually increases tensile values but mullen and tear values did indeed decrease.

The object of the following report was to see if there was a decrease, if any, in certain physical properties and to what degree. If overdrying a sheet actually decreases the physical properties …

The Effect Of Pigments In The Flotation De-Inking Of Newsprint, Harold M. Cody

Paper Engineering Senior Theses

This study was performed to determine the effect of the addition of pigments in the flotation de-inking of newsprint. It has been proposed that pigments aid in the flotation and removal of ink. Two pigments were investigated: talc and diatomaceous earth.

The addition of talc caused the brightness of the sheets to drop because the talc became heavily concentrated with ink. The addition of diatomaceous earth to the cell had no effect upon the flotation and removal of the ink. Therefore the addition of pigments to improve ink flotation and removal cannot be justified.

Variables Affecting The Drainage Test, Jeffrey S. Honour

Paper Engineering Senior Theses

Certain variables affecting the Canadian Standard Freeness Test were investigated. Variables investigated included the zeta potential, pH, chemical type, and concentration. Chemicals used were NaCl, CaCl, AlCl , and SnCl, 5H₂O on the acid side. Chemicals used on the alkaline side included KCl, K₂S₄ and K₂HPO_4.. pH values were 4.5, 5.5, 6.5, 7.5, 8.5, and 9.5. Concentrations used were 1 x 10^-3M, 3 x 10^-3M, 5 x 10^-3M, 7 x 10^-3M, 9 x 10^-3M, 1.1 X 10^-2M, 1.3 x …

An Evaluation Of Permanence Using Wet And Dry Accelerated Aging, Patricia M. Kern

Paper Engineering Senior Theses

Evaluation of a series of paper samples aged using wet and dry accelerated methods showed that there is a definite difference between the two methods.

Electrometric pH and folding endurance provided the best indication of the deterioaration of the paper properties upon aging.

The Effect Of Auxiliary Dispersants On The Dispersion And Properties Of Coating Made With Domestic Clays, Carroll A. Brandt

Paper Engineering Senior Theses

Polymeric organic dispersants are now being used to replace all or part of the inorganic dispersants currently is use for pigmented coatings. They are generally recommended for hard-to-disperse or for special applications where unusual coating requirements must be obtained.

This study showed the effect of some of these auxiliary dispersants when used with tetrasodium pyrephosphate (TSPP) to disperse domestic clay.

The results of this study showed that the most effective type of dispersants for this application are the acrylic-based polymers. The lignosulfate derivative and styrene maleic anhydride did not look as good as the acrylic-based polymers. When used in coatings …

Three Stage Bleaching Of Recycled Fibers Containing 30% Groundwood, Ronald J. Buck

Paper Engineering Senior Theses

A three stage bleaching sequence for a mixture of recycled chemical and groundwood fibers was investigated for maximum brightness increase. The three stages consisted of a reducing or color stripping stage, an oxidizing stage, and last a mild alkaline extraction. The variables in this thesis and pH conditions in each stage and bleaching agent concentrations of each stage. At more alkaline pH's and higher concentrations of hydrogen peroxide there was the greatest increase in brightness. The was no observed effect of altering the concentration of the reducing agent.

A Study Of The Effects Of Ionic Charge And Molecular Weight Of Polymers On Wet-Web Strength, Charles Kelso

Paper Engineering Senior Theses

Improved machine speeds in the production of paper have increased the number of wet-end breaks due to wet-webs that are unable to withstand the increased stresses at increased rates of production. Lyne and Gallay layed the cornerstone on which most of today"s knowledge of wet-web strength is built. This research attempted to expand on this knowledge by determining whether chemicals could be employed to improve wet-web strength.

The results of this experiment indicates that cationic polymers do improve wet-web strength at levels of addition of 160 lbs/ton of pulp and 1600 lbs/ton of pulp. This indicates that cationic polymers are …

The Use Of Direct Measurement To Evaluate Wet Press Draws And Their Effect On Paper Properties, Jeffrey A. Johnson

Paper Engineering Senior Theses

Previous laboratory investigations of the effects of paper machine draw tension on paper properties have been qualitative in nature. It is the object of this study to deal with quantitative values in examining the wet press area of the paper machine. Typically, by increasing draw tension machine direction tensile is improved, while elongation and cross direction tensile degrade. The establishment of known responses in paper properties to exact units in web tension would allow a control system to operate this draw area at optimum conditions. A cantilever beam force transducer was used to directly measure web tension at specific draw …

The Effects Of Various Adhesives And Adhesive Levels On The Scattering Coefficient Of Pigmented Coatings: An Attempt To Predict Scattering Coefficients, Andrew R. Knoll

Paper Engineering Senior Theses

The object of this study was to determine the effect of various levels of different adhesives on the scattering coefficients of a coating. Once the relationship of the adhesive effect on the scattering coefficient was determined an equation was to be developed to predict the optical properties of the coated sheet. This study shows that there is an increase in scattering coefficient from 5 to 10pph adhesive and after 10pph a steady decrease in the scattering coefficient as more adhesive is added. The increase is theorized to be due to flocculation of fines within the coating and the decrease due …

A Study Of Bentonite As An Additive For Starch Size Press Treatment, C. Ted Romer

Paper Engineering Senior Theses

The size press has been examined in the past for its application for coating or pre-coating. Bentonite has been found to be a rheology modifier and also has been found to form a film on paper. Bentonite has been found to improve holdout and printing properties as well. In this study, bentonite was applied in small quantities on a pilot machine size press and the paper thus produced was examined for any improvements in coating, physical, and optical properties. Testing showed that bentonite had the greatest effect on porosity and pick strength, in that porosity decreased with increasing bentonite and …

The Influence Of Base Sheet Moisture On Size Press Pick-Up, Karen S. Ross

Paper Engineering Senior Theses

An investigation was conducted to determine the relationship, if any, between base moisture before the size press and actual size pick-up. While size press operation is subject to the effects of many variables, existing literature indicated that maximum pick-up would be realized at twenty percent moisture, while the acceptable on-machine moisture range is five to twelve percent before the size press.

A machine trial was conducted on the pilot fourdrinier at Western Michigan University, wherein the coat weight was monitored as a function of pre-size press moisture. This study revealed that higher coat weights would be realized at increased adhesive …

Development Of A Testing Procedure For Gloss Ink Holdout, Steven M. Cunningham

Paper Engineering Senior Theses

There is currently no standard acceptable method used to evaluate gloss ink holdout. Four methods are investigated to evaluate holdout. Heat seat ink is used to reduce absorption effects. The K&N ink smear test and the Vanceometer absorption tester are both discounted as inappropriate tests since they look at absorption alone and have widely varied results. The IGT printability tester is an improvement because it involves another major influence to holdout, printing pressure, but does not hold the ink film thickness constant. The Vandercook Proof Press procedure is judged the most valuable since it takes into account printing pressure and …

The Repulpability Of Coated Broke Containing Latexes And Its Effects On A Rosin-Alum Sizing System, Walter Cordell Iii

Paper Engineering Senior Theses

It is the purpose of this thesis to attempt to evaluate the repulpability of coated papers that contain latex as a binder, and also to evaluate the effects of an alum-rosin sizing system on the latex particles, as well as any bundles of fibers or fibers and coating.

It has been found that SBR latex will break up with the greatest difficulty, probably due to its added stability imparted by the carboxyl group attached to it. The PVAC and acrylic latexes break up much easier than the SBR under the same conditions, with the acrylic breaking up more readily than …

A Comparison Of Unbleached Pulps From Cherry Heartwood And Sapwood, Craig Bethke

Paper Engineering Senior Theses

The purpose of the project was to evaluate pulps made from cherry heartwood and sapwood.

The amount of heartwood a tree has is an individual trait of the tree rather than a function of geography or environment. Tree breeders can, through selection, reduce or increase the amount of heartwood if it is economically justifiable.

Three cherry logs with 50-50 heartwood to sapwood ratio were barked and chipped at S.D. Warren Company in Muskegon. The chips were separated, heartwood from sapwood, by the color difference.

The chips were cooked using 20% active alkali, 6 to 1 liquor ratio, for 1.5 hours …

The Effects Of Polymer Molecular Weight On Colloidal Retention And The Bridging Mechanism, Joseph A. Bergeron

Paper Engineering Senior Theses

A review of retention is presented. Included are discussions concerning retention mechanisms, variables which affect retention, variables affected by retention and various retention aids. A detailed experimental procedures involving the use of the dynamic retention/drainage jar is included along with several modifications of the apparatus.

The purpose of the experimental work was to study the effects of polymer molecular weight on retention and the bridging mechanism. Two cationic retention aids of low and high molecular weight along with two non-ionic "bridging agent" retention aids were employed. Various combinations of these chemicals were studied at different levels of addition and under …

The Effect Of Carbon Black On Tr Moisture Measurements And Beta Ray Basis Weight Measurements, William A. Beck

Paper Engineering Senior Theses

Computer control of paper industry processes is becoming a very significant segment of the industry. Of major importance is on-line measurement and control of moisture and basis weight in the web, those two parameters affect practically every other sheet characteristics. Accurate closed loop control is essential to keeping the product within customer-demanded specifications.

Board mills in particular utilize large quantities of waste paper, with the rate of usage expected to increase from 20.5 percent in 1970 to 26 percent by 1985. The concentration of contaminants will increase at a similar rate. One such contaminant, carbon black, will reduce the effectiveness …

Cooking Variables In Recycling Newsprint, Herbert W. Fergison Jr.

Paper Engineering Senior Theses

The purpose of this paper was to compare the effect of some cooking variables on the brightness of the final sheet and the yield per cook in recycling newsprint. The cooking variables examined were: the kind of cooking chemical, the amount of cooking chemical, and the cooking temperature. The cooking variables, that were held constant, were pressure, time, agitation, and consistency of the cooks. The newsprint was cooked in an apparatus similar to a hydrapulper. The brightness decreased with both increased temperature and increased percent addition of chemicals. The yield decreased with both, increased temperature and increased percent addition of …

Thermal Conductivity Measurements Of Wet Paper, Keith S. Kearcher

Paper Engineering Senior Theses

The thermal conductivity of wet paper mats was studied as a function of moisture content and porosity. The conductivity measurements were conducted with a steady-state hot plate apparatus. Results show the relationship of conductivity and moisture content to be non-linear in an increasing fashion. Large variability in results obtained is largely attributed to experimental apparatus design and engineering. Solid cellulose conductivities were calculated using experimental results and the average value was found to be 0.317 ± 0.188 BTU/hr-ft-°F. Close correlation of data using different pulp furnishes indicate type of furnish is not a major variable in conductivity determinations.

Influence Of Overdrying On Dimensional Stability And Certain Strength Properties Of Paper, Shun K. Ma

Paper Engineering Senior Theses

In the past, the consequences of overdrying have been examined with the drying theory. This study was designed to look at the effects of overdrying on handsheets. Comparison of the dimensional change and strength properties was made between two sets of handsheets, one conditioned in the humidity room and the other overdried at 90°C for four hours. The handsheets used in this experiment were made from five types of furnishes: Hardwood Kraft, Softwood Kraft, Hardwood Kraft and Softwood Kraft combination, and two different percentages of TiO₂ added to Softwood Kraft. The dimensional stability was measured by the Neenah Expansimeter. …

The Use Of Dry Strength Additives To Improve Curling Resistance In A Sheet Of Paper, Stephen D. Olsen

Paper Engineering Senior Theses

The purpose of the following report was to look at the possibility of using dry strength resins to help reduce curling tendencies in a sheet of paper.

The use of dry strength additives greatly increased the strength characteristics of a sheet of paper. The increase was so great it allowed: substituting softwood fibers with hardwood fibers and/or using a higher freeness and still retain the same strength characteristics. The results of these changes would give a sheet of paper reduced curling tendencies. The changes could also result in power reductions, material savings, and/or improved formation for producing the sheet of …

A Study Of Dual Polymer Retention Aids For The Retention On Titanium Dioxide Using The Dynamic Drainage Jar, Minidrinier, And Handsheets, David E. Null

Paper Engineering Senior Theses

Two types of dual polymer retention aid systems, a low molecular weight, high charge density, cationic polyamine with a high molecular weight, low charge density, cationic polyacrylamide, and the same polyamine with a high molecular weight, highly charged anionic polyacrylamide, were studied using the Dynamic Drainage Jar, the Minidrinier, and handsheets. Both systems gave higher retention than could be achieved using any of the retention aids alone, however, formation was a problem. Contact time and shear were shown to be important variables. All three testing methods were useful, the Dynamic Drainage Jar having an advantage due to its flexibility.

The Effects Of Anthraquinone On Kraft Pulping, Allison K. Noble

Paper Engineering Senior Theses

Popel chips were cooked in Kraft liquor modified by anthraquinone (AQ). Ten trials with varying levels of AQ, white liquor and cooking time were completed. It was found that the percent yield decreased by as much as 10 points as the level of AQ was increased. But the Kappa number decreased by only 2 points at the maximum AQ level; therefore, at a consistant Kappa number, the percent yield for the unmodified Kraft pulp would be greater than the modified pulp. Overall pulp strength increased significantly with the addition of 0.05% AQ, as was evidenced by the improvement of strength …

The Effects Of Temperature On Hot Melt Removal, Thomas J. Westerback

Paper Engineering Senior Theses

This experiment attempted to reveal the role temperature plays on the removal of hot melt adhesive from corrugated medium.

Three repulping trials were conducted· on stock containing a previous applied EVA base hotmelt. The trials were conducted at the following temperatures: 160°F, 100°F and 40°F. The stock was then screened and centrifical cleaned at varying temperatures.

Handsheets were made before and after each stage, and visually inspected for hot melt content. Trial 2A gave a final sheet with virtually no hot melt content.

Further lab work was conducted. At 160 ° the hot melt was found to tear into pieces. …

Zeta Potential And Its Affects On The Washing Stages Of Newsprint Deinking, Stephen J. Shelton

Paper Engineering Senior Theses

The use of zeta potential as a parameter in the washing stages of newsprint deinking is discussed. Previous research provided the temperature, time, and consistencies used in the hydropulper and washing stages. The research carried out tried to determine whether or not zeta potential can be used as a way of increasing the effectiveness of the washing stages. The research carried out tried to determine whether or not zeta potential can be used as a way of increasing the effectiveness of the washing stages. By varying the zeta potential with chemical additives it was found that very little correlation could …