Date of Award
Bachelor of Science
Paper Science and Engineering
Wet strength resins are used to enhance the strength of the paper in the presence of water and high humidity. Paper makers have a difficult time breaking down the wet strength resins which are used to aid in this process. The ideal situation would be to have high wet strength and still be able to brake it down easily. Unfortunately wet strength paper keeps its integrity because of the chemistry involved in its preparation. The chemistry that protects the structure of the high wet strength paper will also defend it in the pulper. The problem that causes the main concern for the paper makers are the chemicals that are used in the break down of these products. Most of these chemicals are known to be harmful to the environment (ex. Chlorine, Ozone, and Hydrogen peroxide).
The wet strength resin Kymene 557, developed by Hercules Incorporated, used in most bottle carriers, was evaluated in this study. This was done by the use of two different chemicals (sodium hypochlorite and sodium hydrosulfite) in a laboratory study.
It was found that sodium hypochlorite functions as a valuable replacement of sodium hydrosulfite in the breakdown of bottle carriers. The combination of mechanical shear and sodium hypochlorite at 5.2% achieves the highest tensile strength. The use of sodium hypochlorite is also more economical due to lower chemical requirements and its low initial cost.
Khosravani, Mahsa, "Repulping Bottle Carriers" (1996). Paper Engineering Senior Theses. 174.