PLSM.7160 - Plastics Engineering: Injection Molding
Program Overview
Seminar Overview
This seminar provides comprehensive information about the injection molding process, and covers both the underlying engineering principles as well as their application in the molding environment. Classroom lectures cover the basics of the injection molding process and provide practical analyses that yield results and can be applied in the molding shop.
Injection molding workshops supplement the class material to provide experience with actual machine operation and practical molding techniques. Machine start-up, operation and shutdown procedures are demonstrated. Molding trials that show the relationships between processing variables and part quality are conducted.
Workshop emphasis is on practical setup procedures that optimize molding cycle and product requirements. Troubleshooting techniques and solutions to practical molding problems are also addressed.
Audience
This course is appropriate for sales managers, account managers, sales and applications engineers, new product development specialists, product marketing professionals, product designers and engineers, industrial designers and industrial engineers, mechanical engineers, materials purchasing managers, manufacturing personnel and technicians, plant managers, production supervisors, quality assurance and quality control personnel, and anyone involved in plastic part or mold procurement.
Content
OVERVIEW OF THE INJECTION MOLDING PROCESS
- Molding behavior of thermoplastics; molding functions: plastication and injection, forming and solidification; machine and mold operations; machine sequence; process sequence and variables: plastication, injection, packing and holding, cooling
PLASTICS MATERIALS AND THEIR MOLDING REQUIREMENTS
- Molecular structure: polymer types, amorphous vs. crystalline; thermal characteristics: transitions and energy requirements; flow characteristics: non-Newtonian effects
PLASTIC MELTING, FILLING, HOLDING AND COOLING
- Processing mechanisms: feeding, melting and mixing; screw problems and solutions; special screw options: mixing, multi-stage
- Isothermal cavity filling: filling modes, filling problems; thermal effects: flow length, orientation, stresses; runner and gate flows; flow balancing; pressure requirements: pressure traces; packing/holding and cooling-heat transfer effects; pvT applications
ELEMENTS OF INJECTION MOLDS
- Mold types and configurations: 2-plate, 3-plate, stack, etc.; ejection systems; cooling systems; thermal systems/hot runners
INJECTION MOLDING MACHINERY
- Injection units: variants and options; clamp systems: toggle, hydraulic, hydromechanical; hydraulic/electrical systems; energy saving features; specialized machines: multicomponent, coinjection, gas-assist, etc.
PROCESS SETUP AND TROUBLESHOOTING
- Scientific and decoupled molding concepts; troubleshooting; cycle-time minimization and yield
PROCESS MONITORING AND CONTROL
- Machine and mold sensors; proportional and servo valves; closed-loop control; velocity and temperature profiling; statistical process monitoring
Workshops
Attendees will use both electric and hydraulic molding machines, and non-instrumented and instrumented molds.
About the Facilitator
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.