Date of Award

4-2008

Degree Name

Master of Science

Department

Chemical and Paper Engineering

Department

Paper Engineering, Chemical Engineering and Imaging

First Advisor

Dr. John Cameron

Second Advisor

Dr. Said Abubakr

Third Advisor

Dr. Andrew Kline

Access Setting

Masters Thesis-Open Access

Abstract

The objective of this research is to study the effect of high temperature on paper drying rates and properties of both virgin pulp and recycled paper. Process variables as shell temperature, moisture content, refining, basis weight and fiber recycling can affect the drying rate and paper properties. In addition, high surface temperature can affect the heat transfer rates from the dryer shell to the paper. The Gas Heated Paper Dryer (GHPD) is a high temperature dryer where internal shell temperature can reach 300° C, which significantly increases the drying rate. However, there are many concerns about the effect of this high temperature on paper properties especially paper curl and paper strength.

In this research, a laboratory drying system that simulates paper drying at elevated temperatures was used to dry different handsheets. The heat transfer coefficient was found to be constant in the constant rate drying zone and in the first following rate zone, but decreased with an increase in shell temperature in the second following rate zone. This result provided information that optimizes the location of the high temperature dryer. At the ideal location, the heat transfer and drying rates are maximized with minimum effects on sheet properties. Sheet curl was found to be a function of recycling and the drying temperature.

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