Asee peer logo

Energy Savings In Injection Molded Plastic Manufacturing

Download Paper |


2004 Annual Conference


Salt Lake City, Utah

Publication Date

June 20, 2004

Start Date

June 20, 2004

End Date

June 23, 2004



Conference Session

Design Experiences in Energy Education

Page Count


Page Numbers

9.533.1 - 9.533.13



Permanent URL

Download Count


Request a correction

Paper Authors

author page

Thomas Wanke

author page

Stephen Williams

author page

Michael Scheuerell

author page

Glenn Wrate

Download Paper |

NOTE: The first page of text has been automatically extracted and included below in lieu of an abstract

Session 2433

Energy Savings in Injection-Molded Plastic Manufacturing

Stephen Williams, Glenn Wrate, Thomas Wanke, Michael Scheuerell Milwaukee School of Engineering Milwaukee, WI 53202


The results of a joint project between the Wisconsin Focus on Energy program, the Milwaukee School of Engineering (MSOE), and Plastic Molded Concepts, Incorporated to improve the injection-molded plastic manufacturing process are described.

Medium range (10 - 100 HP) motors are used to pump hydraulic fluid in injection-molded plastic processes. Hydraulic power required during one cycle of manufacturing a single part varies greatly. With a single speed motor driving a fixed displacement hydraulic pump, the electric power consumed over one cycle is constant and equal to at least the maximum required hydraulic power plus losses.

Energy savings are realized by reducing the speed of the motor via a variable frequency drive (VFD) during those times of the part cycle when less than maximum hydraulic power is required. Another energy saving alternative is to replace the fixed displacement hydraulic pump with a pressure compensated variable volume hydraulic pump.

Variable frequency drives are installed on a number of presses at Plastic Molded Concepts (PMC) in Eagle, Wisconsin. One of these presses is used as a test bed for this study. The test bed system at PMC is used to compare several different process technologies. A multidisciplinary team of students and faculty (ME and EE) conducted baseline energy studies and redesigned the process to include variable displacement hydraulic pumps or VFD technology.

Verified energy savings of the redesigned system with VFD technology are presented. Projected energy savings of the redesigned system with a variable displacement hydraulic pump are also presented. This paper includes a description of the manufacturing process, information on the instrumentation used for the energy studies, and a description of the redesign. Feedback from the student team involved in the baseline studies, redesign, and verification are offered.

Student Design Involvement

The Wisconsin Focus on Energy is a program funded by Wisconsin electric rate-payers to encourage energy efficiency and the use of renewable energy, enhance the environment, and ensure the future supply of energy for Wisconsin. University involvement in the program is a deliberate decision intended to expose engineering students to energy conservation concepts and techniques.

As a result of this decision, students at Milwaukee School of Engineering (MSOE) are participating in a number of Focus on Energy projects. The faculty at MSOE view the projects as

Wanke, T., & Williams, S., & Scheuerell, M., & Wrate, G. (2004, June), Energy Savings In Injection Molded Plastic Manufacturing Paper presented at 2004 Annual Conference, Salt Lake City, Utah. 10.18260/1-2--13933

ASEE holds the copyright on this document. It may be read by the public free of charge. Authors may archive their work on personal websites or in institutional repositories with the following citation: © 2004 American Society for Engineering Education. Other scholars may excerpt or quote from these materials with the same citation. When excerpting or quoting from Conference Proceedings, authors should, in addition to noting the ASEE copyright, list all the original authors and their institutions and name the host city of the conference. - Last updated April 1, 2015