Plastics Workshops and Seminars
Runner & Gating Design
Instructors: David Rose and David Hoffman
**Each participant will receive a copy of the 281 page, full-color book: “Runner & Gating Design Handbook – Tools for Successful Injection Molding” – a $129.95 value.
WHO SHOULD ATTEND:
This one-day seminar would benefit mold designers/engineers, tool makers, process technicians, and plastic engineers. Engineering and process managers could also benefit from gaining a better appreciation of the complex issues that go into designing a proper melt-delivery system and its effects on the overall process window, mold efficiencies, and part quality.
EDUCATIONAL GOALS:
This seminar takes the task of designing or specifying melt delivery systems from an art to a science. The seminar will cover both hot and cold runner systems (primary focus is cold runner systems), and can be directly applied by mold designers, tool makers, or mold engineers. The seminar will progress from a basic understanding of polymer flow to the critical design criteria required for a fully optimized runner and gating system. Also included is an in-depth discussion for determining the optimum runner sizes and configurations, along with techniques to determine the ideal number, location, and style of gate for a given part and resin. Real-world sample parts will be used and play an important role in demonstrating the fundamentals taught throughout the day.
SEMINAR OUTLINE:
1. Understanding Molds and Runner/Gating Options
- Cold runner 2-plate versus 3-plate molds and gating designs
- Hot runner systems (direct gate and hybrid systems) and gate tip designs
2. Determining Optimal Gate Location(s)
- Gate positions
- Filling and packing considerations
- Impact of wall thickness variations
- Orientation
- Effects on shrink and warp
- Filled versus non-filled materials
- Integral hinges and other filling challenges
3. Optimizing the Melt Delivery System
- Runner design options
- Geometrically balanced runner designs (“H”, “X”, and Radial runner designs)
- Ladder runner (fish-bone) designs
- Odd cavitation layouts
- Balancing the flow lengths
- Understanding flow rate balance
- Family molds
4. Runner Design Details
- Sizes and shapes
- Optimizing runner sizes
- Effect on filling, packing, and cooling
- Constant diameter versus stepped diameters
- Hand calculations versus mold-filling analysis
- Runner cross-section shapes
- Expense versus efficiency
- Effect of pressure drop
- Optimizing runner sizes
- Shear rate considerations
- Sprue-puller designs and runner ejection considerations
- Cold slug wells
5. Effect of Shear on Runner Balance
- Basics of plastic rheology
- Flow imbalances
- Intra-cavity
- Cavity-to-cavity
- Mold balance analysis
- Melt-rotation technologies