I first had an interview on campus, which was pretty basic. It was done with 2 individuals from Operations. The entire interview was situation questions "Tell me about a time when you..." with no real curveballs. They want you to show leadership ability, manufacturing experience, and most of all an ability to work in a team environment.
From there I was invited to East Hanover for their second & final round of interviews. The day consisted of 3 interviews with teams of 2 people. The people were all very friendly, kind and professional. Only one difficult interview questions highlighted below. Most of the interviews were just going over your resume/experiences and accomplishments. You also have time to ask the interviewers any questions you want.
The most difficult part of the process is the Case Study. They put us in teams of 3 and gave us about 80 minutes to work through a solution to a complex problem and make a presentation about it. Ours was something along the lines of: The company is switching over its computer system - step by step describe the plan to implement this and all its effects. We presented later in the day and got essentially grilled - but it was not as bad as it could have been. I certainly learned a lot from the process.