top of page

What Are Multiple Cavity Molds?


Multiple cavity molds produce numerous copies of a plastic part simultaneously. Instead of making one part per cycle, multiple cavity molds allow for producing several parts in a single injection molding cycle.


Multiple cavity molds produce numerous copies of a plastic part simultaneously. Instead of making one part per cycle, multiple cavity molds allow for producing several parts in a single injection molding cycle.


These multiple cavity molds are used in consumer goods, automotive, medical, pharmaceutical, and electronics industries.


Multiple Cavity Mold Life Cycle


Here’s how a multiple-cavity mold works:


  1. Design: The mold has multiple identical or different-shaped cavities arranged in a layout that optimizes space and facilitates efficient cooling.


  2. Injection: During injection, molten plastic is injected into the mold cavity under high pressure. The material flows through runners and gates into each cavity, filling them to form the desired shape of the part.

  3. Cooling: The mold is cooled so that the plastic can solidify. Efficient cooling ensures that each part solidifies uniformly and quickly, allowing for faster cycle times.

  4. Ejection: Once the parts have solidified, the mold opens, and ejector pins push the parts out of the cavities.


Advantages of Multiple Cavity Molding


Multiple cavity molds are designed to produce various identical parts in a single molding cycle, offering several advantages, including:


Increased Productivity


The primary advantage of multiple-cavity molding is the ability to produce multiple parts simultaneously, increasing production throughput and efficiency compared to single-cavity molds. This parallel production reduces cycle times and allows manufacturers to meet high-volume demands rapidly.


Cost Savings


Despite the higher initial tooling cost, multiple cavity molding achieves economies of scale by spreading the cost over more parts produced per cycle. This results in lower unit costs as production volumes increase, making them economical for high-volume manufacturing.


Consistency


All cavities in multiple cavity molding experience the same conditions simultaneously, ensuring consistent part quality and minimizing part-to-part variations. This uniformity is crucial in industries where precision and consistency are needed.


Energy Efficiency


Multiple cavity molding optimizes energy use by producing parts in a single cycle, reducing the injection molding process’s overall energy consumption and carbon footprint. This aligns with sustainable manufacturing practices and environmental regulations.


Challenges of Multiple Cavity Molds


There are also challenges associated with multiple cavity molds. They include:


Uniform Material Distribution


Ensuring that the molten plastic material flows evenly and fills all cavities simultaneously during the injection molding process can be a challenge. Factors like injection flow rate, material properties, and process conditions can affect the flow pattern and core material penetration, leading to inconsistencies across cavities.


Cavity Balancing


A balanced filling of all cavities is crucial to producing consistent parts. Asymmetrical designs or variations in the runner system can cause uneven filling, resulting in defects like short shots or uneven packing pressure.


Higher Initial Costs


Multiple cavity molding has higher upfront costs due to the complexity of creating numerous identical cavities with precise tolerances. The initial investment can be significant, although higher production rates and economies of scale offset it.


Tooling Complexity


Multiple cavity molds require intricate designs with balanced runner systems, cooling channels, and venting to ensure proper cavity filling. This increases tooling costs and complexity compared to single cavity molds.

bottom of page