Date of Defense

4-15-2025

Date of Graduation

4-2025

Department

Chemical and Paper Engineering

First Advisor

James Springstead

Second Advisor

Jason Wang

Abstract

This study was born out of curiosity around the potential use of reject materials from the papermaking screening system for molded fiber product development. The team sought to explore the technical feasibility of this concept and develop a proposed design for mill implementation. The project supports the common papermaking objective of reducing fiber loss from the stock preparation process.

The project assessed first the technical feasibility through laboratory testing and trials. The team dedicated time to characterizing screen reject samples from local mills and running trials using the good fibers extracted from the samples. Molded fiber products were successfully created using this method and evaluated for strength and physical properties.

The second component of this project was creating a plan for the implementation of this concept into a paper mill. The engineering design for the addition of a fine screen, refiner, and molded fiber machine in addition to two tanks and the relevant pumps and piping for material transport were detailed and reported based on material and energy balances performed.

Implementation of this concept and its profitability is dependent on process specific variables including the type of paper product produced by the mill, overall production rate, and current landfilling costs. However, based on a general analysis using industry averages for these values, the proposed design is estimated to have an IRR of 35% over 2.5 years.

Another large barrier to the implementation of this design is the potential for a mill to be unable to install the equipment needed. A relatively large amount of real estate is needed for the installation of needed equipment so an alternate method of implementation was presented. Instead of building a molded fiber machine process on site, a facility may be able to ship their rejects to an existing molded fiber production facility where they would be screened for use on the machine. This would reduce the cost to the mill and provide viable fiber to molded fiber manufacturing facilities for lower cost. This solution provides an IRR of 34% over 2.5 years.

Aside from potential financial benefits from selling molded fiber products or screen rejects, depending on the method of implementation, this project offers significant environmental benefit. Rather than discarding viable fibers for papermaking to the landfill, they are recovered and reused, reducing the amount of new fiber needing to be harvested. Due to the recently developed competitive nature surrounding sustainability goals within the industry, the potential for this implementation could be relevant and helpful to many mills around the world.

This report outlines recommendations for further research, design, and implementation of the concept of recovering fiber from screen rejects for use in molded fiber products.

Comments

Co-authored with:

Tyler Coyne

Alex Hamann

Parker Langellier

Access Setting

Honors Thesis-Open Access

Additional Files
Presentation.pdf (1780 kB)
Defense Presentation
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