1. Core Mold Types:

   • Injection Molds: The dominant type for high-volume production of complex, dimensionally precise parts (e.g., housings, containers, automotive components).

2. Injection Mold Structure & Operation:

   • Two-Plate Molds: Simplest design; core/cavity split into two plates; runners/scrap ejected with parts.

   • Three-Plate Molds: Adds a movable runner plate; allows automatic runner separation and center gating; more complex.

   • Hot Runner Molds: Eliminates solid runners using heated manifolds/nozzles; reduces waste and cycle time; higher cost/complexity.

   • Cold Runner Molds: Utilizes cooled runner channels (molded scrap).

3. Production Scale & Specialization:

   • Prototype Molds: Quick-turn, lower-cost molds (often aluminum) for design validation and low-volume pre-production.

   • Production Molds: High-precision, durable steel molds built for long-term, high-volume manufacturing.

   • Family Molds: Produce multiple different parts simultaneously in one mold cycle.

   • Multi-Cavity Molds: Contain multiple identical cavities to significantly increase output per cycle.

   • High-Cavitation Molds: Very high number of cavities (e.g., for small disposable parts like caps).

   • Insert Molds: Mold plastic around pre-placed inserts (metal, ceramic, other plastics).

   • Overmolds: Mold a second material over a pre-molded substrate.

   • Stack Molds: Effectively doubles cavities by stacking mold sets vertically.

4. Material & Construction:

   • Mold Base: Standardized frames (e.g., DME, HASCO) holding custom components.

   • Core & Cavity Inserts: Precision-machined blocks defining the part shape (hardened steel, aluminum, beryllium copper).

   • Mold Steels: Tool steels selected for hardness, polishability, corrosion resistance, and thermal properties (e.g., P20, H13, S136, 420SS).

   • Surface Treatments: Coatings (e.g., DLC, Ni-PTFE) or processes (nitriding) to enhance wear resistance, release, or corrosion protection.

5. Ejection & Gating Systems:

   • Ejection Mechanisms: Pins, sleeves, blades, lifters, stripper plates, air valves.

   • Gating Systems: Controls molten plastic entry (e.g., edge gate, tunnel/sub gate, pin point gate, valve gate).

Key Considerations for Mold Makers: Design for Manufacturability (DFM), precise cooling channel layout, venting design, steel selection for part/material, maintenance access, and robust ejection are paramount. The choice depends on part geometry, material, required tolerances, production volume, and cost targets.