PLSM.5260 - Plastics Engineering: Injection Mold Design
Program Overview
Seminar Overview
Injection mold designers are faced with the difficult task of designing a tool that will produce quality thermoplastic products at acceptable production rates. In addition, the tool must operate consistently over the long term with minimum maintenance requirements. Unfortunately, the injection mold is generally a complex piece of tooling, as it must incorporate many necessary functions.
This three-day seminar on Injection Mold Design should give those involved in the thermoplastics injection molding industry a strong fundamental understanding of tooling technology and the underlying engineering principles in the areas of melt flow, cooling, part ejection and mold structure.
In addition, the important topic of injection mold instrumentation is given special consideration as the use of mold pressure and temperature instrumentation is increasing rapidly. These variables have been shown to be extremely useful as a measure of process stability and part quality.
Laboratory workshops will provide participants with an opportunity to study the injection molding process using instrumented tooling. Students will also be exposed to some of the latest computer-aided mold design tools and techniques.
Content
PLASTIC MATERIALS BEHAVIOR
Flow properties of plastic melts; thermal behavior/properties; material shrinkage; test methods; filled/reinforced materials; use of material data in mold design
REVIEW OF THE INJECTION MOLDING PROCESS
Materials handling; plastication/melting; injection phase; packing and holding phases; cooling phase; part ejection; machine/mold interactions; machine controls
FUNDAMENTALS OF PLASTIC PRODUCT DESIGN
BASIC FUNCTIONS AND TYPES OF INJECTION MOLDS
Two-plate molds; three-plate molds; insulated/modified molds; hot runner molds; specialty molds
SPRUE BUSHINGS AND NOZZLES
Mold location; cold sprue designs; hot/insulated sprues; mounting and cooling of bushings
GATE LOCATION AND TYPE
Orientation effects/shrinkage; number of gates; weld lines; core deflection; types of gates
COLD RUNNER SYSTEMS
Cavity layout; balanced systems; pressure drops; runner balancing for family molds; runner cooling
COMPUTER-AIDED MOLD DESIGN
Mold filling; mold shrinkage
STRUCTURAL DESIGN OF INJECTION MOLDS
Deflection of cores and cavities; mold support system; clamp surface area
VENTING OF INJECTION MOLDS
CAVITY/CORE INSERT MOUNTING
PART EJECTION
Ejection techniques; engineering design of ejection systems; ejection of undercuts
MOLD COOLING AND HEATING
Cooling methods; cooling time calculations; fluid flow/heat transfer considerations
MOLD CLAMPING SYSTEMS
INJECTION MOLD INSTRUMENTATION
Mold pressure measurement; mold temperature measurement; parting line sensors
About the Facilitator
Steve Thibeault is the President of Poly-Ject Inc., a small custom injection molder and mold maker located in Amherst, NH. He has a Bachelor's Degree in Plastics Engineering from the University of Massachusetts Lowell. He has designed and built over 200 injection molds for products ranging from tight tolerance military connectors to sporting goods, medical devices and everything in between. He also does all of the part designs at Poly-Ject for a wide range of customers and applications.