Plastic Part Design for Injection Molding (July 2026)

Date & Time

The date and times for this seminar are Tuesday, July 7 - Friday, July 10 (4 days) from 8:30am-5:00pm (This includes breaks. Light breakfast, lunch and snack will be provided with no additional charge during breaks). 

Overview

This seminar is offered to engineers and designers involved in the design of injection molded plastic parts. The course provides a fundamental overview of the many factors associated with plastic parts that will be produced using the injection molding process. In order to design a high-quality injection molded part, the designer must select an appropriate plastic material formulation, develop a functional design, and work within the manufacturing limitations associated with the mold design and injection molding process. This course will cover the fundamentals of plastic materials behavior and selection, engineering design, manufacturing (moldability) considerations, prototyping, stress analysis and assembly methods. The timely subject of design for enhanced recyclability will also be discussed, as will design developments related to new injection molding technologies.

Content

Introduction

• Plastic material fundamentals and review of the injection molding process.

Fundamentals of Mold Design

• Mold types; gates and runners; ejection considerations

Manufacturing-Related Design Considerations for Molded Plastic Parts

• Mold filling considerations, shrinkage and warpage of molded parts, mold cooling considerations

Design Guidelines

• Uniform wall thickness; factors affecting wall thickness; parting lines; tolerances

Mechanical Behavior of Plastic Materials

• Short term stress-strain behavior, creep and stress relaxation, structural design of molded plastic parts, fatigue performance, impact performance, plastic materials databases

Design for Enhanced Recyclability

• Design-related issues that enhance or hinder the recyclability of thermoplastic products

Case Study for a New Product

• Steps involved in the development of a new part (including materials selection)

Prototype Part Production

• Machine prototypes; rapid prototyping techniques; cast prototypes; molded prototypes, and rapid tooling techniques

Assembly of Plastic Parts

• Selection of an assembly method; press fit assembly, snap fit assembly, mechanical fasteners, thermal welding techniques for thermoplastics, adhesive bonding and solvent bonding

Fundamental Design Considerations for 'Other' Injection Molding Processes

• Structural foam, gas assist, multi-shot molding, multi-layer, metal injection molding

Lab Content

• Design analysis and prototyping lab
• Injection molding lab

About the Instructor

Dr. Stephen Johnston came to UMass Lowell in 2003 to pursue his M.S. degree and subsequently his Ph.D. in Plastics Engineering. His expertise is in the area of instrumentation, analysis, and simulation of the injection molding process. Dr. Johnston has worked at Lord Corp., Moldflow Corp., Bausch & Lomb Inc., and does research and consulting for numerous other companies. In the fall of 2007, he started teaching courses at UMass Lowell. His course offerings focus on mold design, product design and processing.

Other seminars taught by Dr. Johnston: Injection Molding

Additional Notes

Email notifications

Upon registering, you will receive an automated confirmation email from Canvas Catalog with an email address of notifications@instructure.com. Please ensure that you are able to receive emails from this address, and please remember to check your junk and/or spam folders. This email address is unmonitored.

Additional notifications and important information regarding this seminar may be sent from Corporate_Education@uml.edu and/or other University email addresses ending in @uml.edu. Please contact Corporate_Education@uml.edu if questions or concerns arise regarding this seminar.

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Location

This is an in-person seminar held at UMass Lowell's North Campus in Lowell, Massachusetts.