Views: 0 Author: Site Editor Publish Time: 2025-04-25 Origin: Site
The cavity number refers to the number of identical cavities (or part impressions) in an injection mold. For example:
Single-cavity mold (1 cavity) → Produces one part per cycle.
Multi-cavity mold (e.g., 2, 4, 8, or 16 cavities) → Produces multiple identical parts per cycle.
The choice of cavity number directly affects production speed, cost efficiency, and part quality.
Selecting the right cavity number involves balancing multiple factors:
High-volume orders benefit from multi-cavity molds (faster cycle times).
Low-volume or prototype production may use single-cavity molds for cost efficiency.
Clamping force must be sufficient to hold the injection mold closed during injection.
Shot size (injection volume) must accommodate the total material needed for all cavities.
Platen size must fit the injection mold dimensions.
Larger or complex parts may require fewer cavities due to space constraints.
Small, simple parts (e.g., bottle caps, connectors) are ideal for high-cavity molds.
Multi-cavity molds are more expensive to design and manufacture.
Maintenance and repair costs increase with cavity count.
Uneven filling or cooling can cause defects (warping, sink marks, dimensional variations).
Balanced runner systems are crucial for uniform filling in multi-cavity molds.
| Aspect | Single-Cavity Mold | Multi-Cavity Mold |
|---|---|---|
| Production Speed | Low (1 part/cycle) | High (multiple parts/cycle) |
| Unit Cost | Higher (less efficient) | Lower (economies of scale) |
| Mold Cost | Lower | Higher (complex design) |
| Quality Control | Easier to manage | Requires precise balancing |
| Best For | Prototypes, large parts | Mass production, small parts |
To ensure high-quality production, multi-cavity molds must address:
Naturally balanced runners ensure equal flow to all cavities.
Artificial balancing (using flow restrictors) may be needed for complex layouts.
Each cavity must cool at the same rate to prevent warping or shrinkage differences.
Conformal cooling channels can improve efficiency.
All cavities must eject parts simultaneously to avoid damage or misalignment.
High-wear-resistant steel (e.g., H13, P20) is often required for durability.
Tight tolerances are necessary to maintain consistency across cavities.
Modular Molds: Interchangeable inserts allow flexible cavity adjustments.
Smart Molding: Sensors monitor cavity pressure and temperature in real-time.
Additive Manufacturing: 3D-printed conformal cooling improves multi-cavity efficiency.
Choosing the right cavity number is a strategic decision that impacts cost, efficiency, and part quality. While multi-cavity molds offer higher productivity, they require careful design and balancing. Single-cavity molds remain valuable for low-volume or precision applications.
By analyzing production needs, machine capabilities, and part specifications, manufacturers can optimize cavity selection for the best return on investment (ROI).
