Session: 02-01-01: Product and Process Design 1

Paper Number: 166053

Design of a Lab-Scale Molded Pulp Machine 

As traditional materials for the molded pulp manufacturing process become less common, the need for alternative feedstocks increases, and there is a need to conveniently test these materials. Molded pulp manufacturing uses a slurry of fibers formed into a solid product using a vacuum mold. Traditionally, this pulp is made of recycled materials such as used newspapers to create products such as egg cartons, drink holders, and specialized packaging inserts. However, recent shifts in consumer behavior and an increase in demand for molded pulp products have led to difficulties in sourcing these traditional materials. For these reasons, novel materials such as hemp hurd and food process byproducts are desired to meet the demand for these products. However, there has been limited research in testing the viability and properties of molded pulp products using these materials. Current molded pulp machines are large and require large amounts of slurry in order to function, which makes testing novel materials expensive and inconvenient. To facilitate efficient testing of novel materials, a lab-scale molded pulp machine is needed. A machine was created to test novel pulps, offering researchers the adaptability and convenience needed for lab-scale testing. This machine enables small-batch production of molded pulp products, supports interchangeable molds of various shapes and sizes, and features adjustable processing parameters. With this machine, researchers can efficiently test a variety of novel slurries and molds to determine their viability in the molded pulp process. The machine has been used in collaboration with food science researchers at Oregon State University to evaluate various concentrations and varieties of a slurry made from a mixture of hemp hurd and cardboard, and the mixture’s ability to create sustainable plant pots. The design of the machine prioritises the ease of use for researchers while forming molded pulp products quickly and repeatedly. The machine includes a mixing tank, a common wet/dry five-gallon shop vacuum, a water recirculation pump, a core and cavity mold, and a touch screen PLC user interface. Molded pulp products as large as 10 inches in diameter and 5 inches deep can be made with the correct mold. The machine has a small footprint, allowing for multiple such machines to be placed together to allow for concurrent testing of multiple materials and molds. The machine is also mobile, allowing for easy relocation or movement in a lab environment. The machine is programmed to allow researchers to control several critical parameters of the molding process, such as forming time, drying time, and pressing time, all from a touch screen interface. These features allow researchers a simple way to test several forming parameters easily. Using this machine, consistent molded pulp products were successfully created using novel materials. To test the ability of the machine, a sample production of pots was created. The pots were formed using a hemp hurd and cardboard slurry. They measured approximately 5.5 inches in diameter and 4 inches tall, with a wall thickness of approximately 0.0625 inches. These pots had consistent qualities such as wall thickness and strength. Strength of the pots was found by measuring the force required to crush the pots. These results show the ability of the lab-scale molded pulp machine to form products comparable to industrial machines, and to efficiently test novel materials for their use in molded pulp manufacturing.

Presenting Author: John Parmigiani Oregon State University

Presenting Author Biography: Professor John Parmigiani has long and varied experience in engineering. Academic training began with metals-machining and vehicle mechanics courses prior to college and continued with B.S. and M.S. degrees in mechanical engineering from the Pennsylvania State University, and a Ph.D in mechanical engineering from the University of Michigan. Professional experience includes 10 years as a practicing engineer in industry with several Pennsylvania manufacturing firms. He is a licensed professional engineer in the states of Oregon, Pennsylvania, and Washington. His current position is as an associate professor in the School of Mechanical, Industrial, and Manufacturing Engineering at Oregon State University. His work there focuses on working with entrepreneurs and regional companies to create novel mechanical devices and equipment. He has a particular interest in creating prototype products.

Authors:

Lucas Dassonville Oregon State University
Samuel Austin Oregon State University
Xiaofang Bai Oregon State University
Jooyeoun Jung Oregon State University
John P. Parmigiani Oregon State University