How to Calculate Number of Cavity in Injection Molding?

What is Cavity in Injection Molding?

In injection molding, a cavity is a hollow space or void within a mold that is filled with molten plastic resin to produce a specific shape or part. The cavity is typically designed to match the desired shape of the final product, and it may have various features such as ribs, bosses, and threads that are used to enhance the functionality of the part.

During the injection molding process, the molten plastic resin is injected into the cavity under high pressure, where it cools and solidifies to form the final part. The design and construction of the cavity is critical to ensuring that the part is produced accurately and efficiently, and that it meets the required specifications for strength, durability, and appearance.

How to Calculate Number of Cavity in Injection Molding?

The calculation of the number of cavities in injection molding depends on several factors such as the size and complexity of the part being produced, the size of the injection molding machine, and the desired production rate.

Here are the steps to calculate the number of cavities:

Determine the size of the injection molding machine that will be used for the production. This will give you the maximum mold base size that can be accommodated.

Determine the size of the part being produced. This will help you determine the mold base size required.

Determine the desired production rate, which is usually measured in parts per hour.

Calculate the projected cycle time for each part. This is the amount of time required to complete one cycle of the injection molding process for one part.

Calculate the total production time required by multiplying the projected cycle time by the desired production rate.

Calculate the number of cavities required by dividing the total production time by the total time required to produce one part in a single cavity mold.

For example, if the total production time required is 10 hours, and the total time required to produce one part in a single cavity mold is 1 minute, then the number of cavities required would be 600 (10 hours x 60 minutes per hour / 1 minute per part per cavity).

Keep in mind that the number of cavities that can be used in a mold will also depend on other factors such as the material being used and the part design. It is important to work with an experienced injection molding professional to ensure that the mold design is optimized for production efficiency and quality.