single cavity vs multi cavity injection mold

When planning custom injection mold projects, choosing between single cavity and multi cavity molds is a key decision that affects production output, unit cost, product consistency and overall project budget. Many buyers struggle to select the most cost-effective mold structure for low-volume prototyping, mid-batch trial production and mass production.



1. What is Single Cavity & Multi Cavity Injection Mold

Single Cavity Mold: One mold produces only one plastic part per injection cycle. It features simple structure, low manufacturing difficulty and easy mold adjustment. It is the standard choice for new product development and low-volume orders.
Multi Cavity Mold: One mold contains 2, 4, 8, 16 or more cavities, producing multiple identical parts in one cycle. It greatly improves hourly output and is designed for stable mass production demands.
 
2. Core Comparison: Cost, Output, Yield & Stability

2.1 Mold Cost & Investment

Single Cavity Mold: Lower upfront mold cost, simple processing, shorter lead time. It requires less steel material and fewer auxiliary structures, which effectively reduces initial investment for new projects.
Multi Cavity Mold: Higher mold manufacturing cost. It requires precise cavity balance, complex runner system and higher-precision machining. The more cavities, the higher the mold development cost.

2.2 Production Output & Efficiency

Single Cavity Mold: Low cycle output, suitable for small batch production. It cannot meet delivery requirements for large and urgent orders.
Multi Cavity Mold: Multiplied production efficiency. For example, a 4-cavity mold produces 4 times more parts per hour than a single cavity mold, greatly shortening mass production cycle and improving order delivery speed.

2.3 Product Yield & Consistency

Single Cavity Mold: Highest stability and yield rate. Independent filling and cooling, no unbalanced cavity pressure. Dimensional tolerance and surface quality are easy to control, ideal for high-precision plastic parts.
Multi Cavity Mold: Higher technical requirements. If the runner balance is unreasonable, it may cause inconsistent filling, size deviation and uneven surface among different cavities. Professional mold design and processing are required to guarantee uniformity.

2.4 Maintenance & Adjustment

Single Cavity Mold: Easy mold testing, simple parameter adjustment, low daily maintenance cost, convenient for rapid modification and iteration.
Multi Cavity Mold: Complicated testing and tuning. Once one cavity is damaged or defective, the whole production batch will be affected, and mold repair is more difficult.

3. How to Choose: Single Cavity or Multi Cavity Mold

Choose Single Cavity Mold If:
- New product development, frequent design changes
- Low monthly demand, small batch trial production
- High precision, strict tolerance and appearance requirements
- Limited mold budget

Choose Multi Cavity Mold If:
- Mature product with stable structure and no frequent changes
- Large monthly order volume and mass production demand
- Cost-sensitive for unit plastic part price
- Long-term stable OEM/ODM orders

4. Conclusion

Single cavity injection molds feature low cost, high stability and flexible iteration, which are suitable for R&D and small-batch projects. Multi cavity injection molds focus on high efficiency and low unit cost, perfectly matching large-scale mass production. Reasonable injection mold cavity configuration can balance mold investment, production efficiency and long-term manufacturing cost.
We provide professional custom plastic mold services, including single-cavity and multi-cavity mold design, customized cavity quantity optimization, and one-stop injection molding production solutions according to your demand volume and quality standards.