Life Sciences Commons^™

Hydrogen Ion Concentration Of Sheet Making Water And Its Relationship To The Hygroexpansion Of Paper, James M. Rischar

Paper Engineering Senior Theses

The hygroexpansivity of paper is of particular importance in the paper industry. As paper dimensions become more critical, the problem of hygroexpansivity in paper necessarily becomes more critical. Since the hydrogen ion concentrations (pH) of papermaking water effects the use of fillers, dyes, size, and the quality of the final product, the relationship between hygroexpansivity of paper and the pH of papermaking water is, therefore, an important consideration. Fortunately, the experimental evidence from this project indicates that the pH has little effect upon the hygroexpansion of paper. But rather, this project found the sheet density to have a far greater …

Investigation Of Factors Influencing The Use Of Wet Strength Resin On Unwashed Nssc Pulp, James L. Latta

Paper Engineering Senior Theses

To improve the wet strength of paper, colloidal dispersions of thermosetting wet strength resins are added to the papermaking furnish. However, these resins show low efficiency when applyed to unwashed neutral sulfite semichemical corrugating medium. To determine the reason for this, experiments were made in which corrugating mill stock was made into handsheets using Paramel HE and Kymene 557 wet strength resins.

It was found that Kymene 557 gave poor wet strength when used at levels less than .67%, but that further addition brought increasingly larger gains. The wet strength attained with Paramel HE showed a rapid rise up to …

The Affect Of Fiber Length On Wet-Web Rheology, Jeff Lowe

Paper Engineering Senior Theses

A spruce bleached kraft pulp was cut to varying degrees in an attempt to determine the influence of fiber length on the rheological properties of the wet-web. The results indicated that greater fiber lengths increased wet-web strength properties. The rheological data implied surface tension as the basic mechanism of strength properties between 16% and 30% solids, and on this data the mechanism of wet-web behavior under stress was proposed.

The Effect Of Relative Sediment Volume On Sheet Properties Of Coated Paper, James A. Chalfin

Paper Engineering Senior Theses

The degree of dispersion of pigment has been claimed to be an important variable in the determination of sheet properties such as smoothness and gloss. The degree of dispersion of a pigment can be related to relative sediment volume (RSV) by comparison of the solid and void volumes of a clay slip. One school of thought suggests that there is a relation between RSV and coated sheet properties; this relation being, as RSV decreases, smoothness and gloss increase. It was decided that an attempt to relate RSV (degree of dispersion) to optical properties of coated paper could be valuable. Because …

Using Kelgin To Increase Heat Resistance And Strength Of The Sheet Of Paper Against Prolonged Heating, Jeffrey Atkinson

Paper Engineering Senior Theses

The purpose of this paper has been to examine what properties of sheet strength may be stabilized by the use of kelgin in a size press application and after a subsequent heating period.

A softwood kraft pulp was used because of the strength properties which it possesses. Alkaline sizing with Aquapel and Kymene was felt to be the best because of the alkaline p.H. range which was desired. The sheets were sized with solutions of Kelgin (M .V.) of varying concentrations and treated at 150 and 175 °C. The effects were studied using the M.I .T. Fold Test, the Instron …

The Effect Of Fiber Length On Tear Strength, Kit Funderburk

Paper Engineering Senior Theses

The purpose of this investigation was to study the effect that fiber length had on the tear strength. Of utmost importance to the results of this study was the elimination or controlling of variables which have appeared in all related studies to date. With this in mind, an experimental procedure was drawn up which would eliminate or control the variables. Long, whole fibers were isolated, formed into handsheets, and dried without having been pressed. The handsheets were then cut in order to reduce the fiber length. Cutting of the fibers was done with a paper cutter and was followed by …

Effect Of Dispersant On The Centrifugal Dewatering Of A High Ash Primary Clarifier Underflow, George J. Renner

Paper Engineering Senior Theses

The objective of this study was to determine the effect of dispersants on the centrifugal dewatering of a high ash, paper mill, primary clarifier underflow. By using dispersants a higher cake dryness and smaller sludge volume could save the paper industry money.

With this objective in mind, primary deinking sludge samples were defibered and evaluated as to the effect of a dispersant during centrifugal dewatering. The effect of fiber on the dispersants was determined by evaluating sludges with predetermined amounts of fiber fines added prior to centrifugation.

It was found that use of dispersants during centrifugal dewatering resulted in an …

The Effect Of Surface Tension And Viscosity On Wet-Web Strength, Wayne H. Nay

Paper Engineering Senior Theses

A study of the effects of surface tension and viscosity on wet-web strength shows that they are related. Hand sheets were made and pressed on the Noble and Wood Sheet Mold. Tests were run on sheets with solids varying from 18 to 28 percent. The Instron Tensile Tester gave more consistant results for wet-web testing than did the Brecht Tester. Carboxy propyl methyl cellulose, a cationic starch, oleic acid, and sodium hydroxide were used to vary the surface tension and viscosity of the entrained water in the web. It was found that as the surface tension was lowered, the wet-web …

A Study Of The Conductivity Of Several Conductive Polymers, Howard W. Renner

Paper Engineering Senior Theses

The purpose of this thesis is to compare the conductivities of several solutions now in use in producing electroconductive paper. The testing procedure involved the use of a Kiethyl 610 B electrometer with two aluminum discs for conductance through the sheet and two brass strips for conductance across the sheet. Attempts were made to improve the conductance of the solution by the addition of surface agents in the belief that this would lead to better dispersion and thus to better film continuity. No effective method was found to improve the conductivity of a solution of given concentration. Increasing the concentration …

The Effect Of Changing Dryer Temperature On The Gloss Characteristics Of Coated Paper, Dan Kaiser

Paper Engineering Senior Theses

The purpose of this study was to note the effect of varying drying temperatures on the gloss of papers coated with three different coating formulations. The three coatings studied contained Polyvinyl Acetate, a combination of styrene butadiene and casein, and a formula using casein and styrene butadiene as binders in conjunction with a fine particle size clay. Coating applications and drying were accomplished with a Keegan Laboratory Coater.

The results indicated that increasing drying temperatures decreased gloss, and that overdrying increased gloss.