The reality of the workplace was transported to the classroom this semester for a group of mechanical engineering students at the University of Rochester. For their senior design project, the students undertook an ambitious collaboration with Rochester 100 Inc., a local manufacturer of heat-sealed vinyl products, to build an ultrasonic sheet plastic welding machine. "Applying ultrasonic welding to plastic sheet products is relatively new," says David Quesnel, professor of mechanical engineering. "It's not a small effort to design new technology and put it in the workplace. This was a large industrial project."
The students based their design on studies of existing machinery at Rochester 100 to make products from polypropylene instead of vinyl. Polypropylene is a newer technology that promises better and cheaper products. However, since it doesn't melt like vinyl, polypropylene must be welded together with ultrasonic vibrations instead of more conventional welding technology. With this stipulation, the students set out to design a smaller, more versatile piece of equipment that would better handle large, flat sheet materials and accept different die sets.
Christened PJ-99, the students' ultrasonic welding machine weighs 3,000 pounds and can produce 4,000 pounds of welding force. Rochester 100, which funded the project, will acquire the machine following graduation to make product samples such as identification card holders and passport sleeves. The company also hired one of the students who worked on the project.
"The magic of teaching is watching students take their education to the edge. Then they realize they can do it," Quesnel says. He ran the advanced mechanical design class like a company, with 38 students forming 13 sub-system teams. "It added a bit of realism to the class in terms of developing interpersonal skills and working in team environments."
One team was dedicated to meeting Occupational Safety and Health Administration requirements, while another group, dubbed the Tear-Out Team, designed a pneumatic robot to remove finished products from the machine. The students within each team acted as manufacturing engineers, senior design engineers and designers. Quesnel himself served as the corporate liaison for D'Vinyl, the name the students gave their fictitious company, to imply a ridding of vinyl from the company.
Although Quesnel arranged the funding with Rochester 100, the students designed the machine, ordered parts, and interacted with suppliers, vendors and machinists. The process of benchmarking an existing machine and then proceeding with their own design also introduced the students to intellectual property issues and rights concerning new technology, areas they will deal with in the industrial workplace.
"The most important thing of the class is that we worked on real engineering. We actually produced a product. I hope this might be a paradigm for working with local companies in the future," Quesnel says.