Date of Award


Degree Name

Bachelor of Science


Paper Science and Engineering

First Advisor

Dr. Brian Scheller


The main idea behind this thesis is to work with recycled paper because this is the latest trend due to the environment. Therefore, after checking into an aspect that has little research completed, the idea of the effects of chemical contaminants on sizing of paper, AKD in particular, was developed. To allow for expansion on this thesis topic, another student will be looking at the effect of chemical contaminants on sizing of the recycled paper.

The experiment contained water-borne chemical contaminants and fiber-borne chemical contaminants. Four different chemical contaminants were used including retention aid, defoamer, biocide, and wet strength. The water-borne chemical contaminants were added with the sizing and made into handsheets on the Noble and Wood. The fiber-borne chemical contaminants were added to the pulp, and washed and dried. Then the contaminated pulp was redispersed, sizing agent added and made into handsheets. The tests conducted were Hercules size test and contact angle.

The results for the water-borne chemical contaminants mostly followed the expected results. The retention aid helped the sizing while the defoamer, biocide, and wet strength hindered the sizing. For the fiber-borne chemical contaminants, the retention aid, defoamer, biocide, and wet strength all increased the sizing above the control level. The contact angle determined that small amounts of AKD give high contact angles, showing full sizing. Plus, the water-borne chemical contaminants had high contact angles for the high HST values, and the fiber-borne chemical contaminants gave high contact angle for the low HST values.

The objective behind this thesis was to determine if the chemical contaminants would adhere to the fiber before the AKD was added, and therefore help or hinder the sizing effect.