PLLS 0001 - Designing Plastic Parts & Selecting Materials for Injection Molding
Course Description
Gain a fundamental overview of plastic part design for the process of injection molding. This course is ideal for engineers and designers who are accustomed to working with metals but are faced with metal-to-plastic conversions.
The course begins with an overview of plastic material fundamentals, injection mold basics, injection molding equipment and injection molding process parameters. before shifting It then explores design for manufacturability (DFM) considerations for plastic parts, including gating scheme, mold shrinkage and warpage issues, draft angles and undercut release.
A significant portion of the course is dedicated to plastic material selection and the mechanical performance of plastic materials, including creep and stress relaxation behavior. The course ends with an overview of prototyping techniques and common assembly techniques for injection-molded plastic parts.
Included Course Materials:
Participants in this course receive an electronic textbook copy of “Plastic Part Design for Injection Molding,” 2nd ed. by the instructor Robert Malloy included with registration.
Course Outline/Topics
Thermoplastic Material Fundamentals
- Brief History of Plastics
- Molecular Weight and MW Distribution
- Repeat Unit Chemical Structure
- Morphology and Crystallinity
- Common Additives for Plastics
- Material Property Data Sheets
- Melt Flow Rate and Melt Viscosity
- Regrind and Recycling Considerations
The Injection Molding Process
- Injection Molding Cycle
- Injection Molding Machinery Overview
- The Injection Unit
- Reciprocating Screw
- Mold Clamping System and Clamp Tonnage
- Ejection System
Types of Injection Molds
- Standard vs. Custom Mold Bases
- Two Plate Molds
- Three Plate Molds
- Hot Runner Molds
Design for Manufacturing (DFM) Considerations
- Mold Cavity Filling
- Non-Isothermal Filling and Orientation
- Gating Scheme
- Runner System Design Considerations
- Molding Process Simulations
- Flow Leaders and Restrictors
- Weld and Knit-lines
- Cooling, Shrinkage and Warpage Issues
- Cooling Time Estimations
- Molded Part Tolerance
- Material Supplier Shrinkage Data
- Design for Part Ejection/De-molding
Other Nonstandard Injection Molding Processes
- Multi-shot Molding
- Insert Molding
- Co-Injection Molding
- Gas Assist Molding
- Structural Foam Molding
- Metal Injection Molding
Plastic Material Selection Methods
- Classical Plastic Material Selection Process
- Plastic Material Databases
- Alternative Material Selection Methodologies
Mechanical Property Behavior
- Short Term Stress-Strain Behavior
- Long Term Stress-Strain Behavior
Prototyping Options for Plastic Parts
- Subtractive Machining of Prototypes
- Additive Rapid Prototypes
- Cast Prototypes
- Injection Molded Prototypes
Assembly Methods for Injection Molded Plastic Parts
- Design for Assembly
- Mechanical Fasteners
- Snap Fit Assembly
- Press Fit Assembly
- Thermal and Solvent Welding
- Adhesive Bonding
Design for Enhanced Recyclability
Benefits and Learning Outcomes
- Recognize how to select an appropriate plastic material grade for a new application
- Understand the manufacturing limitations associated with the thermoplastic injection molding process
- Eliminate common design errors that can lead to added tooling costs and molding defects
Notes
Customized Corporate Training. Bring our courses to your team. We can tailor the curriculum and delivery to meet the specific needs of your organization. For more information, go to our Customized Corporate Training page or email sce-customized@uwm.edu.
Prerequisites
Some knowledge of plastic materials, injection molding and engineering principles is useful but not required. Basics of these principles are introduced within the course.
Who Should Attend
Engineers and designers with limited experience working with plastic materials. This includes designers who are accustomed to working with metals and are faced with metal to plastic conversions.
Testimonials
Hear from past participant Natalie Gamez
"The instructor was the best one I’ve ever had for a seminar or training class. I’m definitely going to come back to UW-Milwaukee for future classes."
- Mary J. Glander, Task Force Tips
"Fantastic plastics overview class for understanding all the fundamentals of injection molding. Gives you to ability to get up to speed really quickly on plastics without coming from a background of understanding these topics."
- November 2024 Participant
"I wish I would have come to this training as soon as I started working with plastic parts instead of 3 years after, all the basics in a nutshell so we can understand how to better deal with plastics, highly recommended!"
- November 2024 Participant
Instructors
Partners & Professional Credits
- Professional Development Hours 14.0 PDHs