Philadelphia — Rowdy the Riverhawk has helped a group of undergrads at University of Massachusetts Lowell learn valuable lessons about injection molding.
For a student project, five undergrads in the school's plastics engineering program designed and molded a Croc charm — officially called a Jibbitz, which is a decoration used with Crocs shoes — based on the UMass Lowell mascot.
"We wanted to show that plastics are more than a single-use material and also draw attention to the program to try and increase enrollment," Abigail Mastromonaco said March 5 at Antec 2025 in Philadelphia. The charm has been entered in SPE's Impact Injection Molding Performance Awards, which is a contest for students in plastics programs.
Other students who worked on the project were Daniela D'Alleva, Alex Rhodes, Sarah Ross and Ryan Tangney. Mastromonaco, D'Alleva and Rhodes presented the project at the conference.
The group went through a complete injection molding design process to make the charm. They made a two-shot, three cavity mold and did the molding work using a Milacron Roboshot machine.
The red piece and insert of the charm are made from ABS, while the blue part of the piece is polypropylene. The group made 3D printed prototypes before doing the molding work.
At the conference, the students reviewed things they would have done differently with the project if they could do it again. Rhodes said they would use thermoplastic polyurethane, a more flexible material, for the charm. They also would add more details to the design, he added.
D'Alleva said they would aim to reduce waste on the project by reducing runner volume and would use software to simulate the first shot as a way to more accurately predict cooling of the parts.