The number of cavities refers to the number of cavities in a mold that can simultaneously mold the same or different products, which directly determines the product output in a single production cycle. For example, "2 cavities" means molding 2 identical products at a time, and "2*40" means that 2 different products can be produced, each with 40 cavities.
When our manufacturers receive inquiries from customers, we will first confirm the product requirements with the customers, including core parameters such as product size, material (plastic, silicone, metal, etc.), order quantity and annual output, surface treatment (mirror/etching, etc.). There are also special requirements: such as medical/food grade certification, high temperature resistance (>200℃) or corrosion resistance (acid and alkali environment) characteristics. Next, we will calculate the mold development cost (including steel selection, hole number design), unit production cost and delivery time based on the product characteristics, and provide customers with a quotation. After the customer accepts
the price, we will provide customers with DFM (manufacturability design analysis).
For mold selection, please refer to our other article
Size and structure: Small and simple products are more likely to increase the number of mold cavities (such as 12-16 cavities are commonly used in mobile phone lenses), while large or complex products may need to reduce the number of cavities to reduce the complexity of the mold structure.
Precision and surface requirements: Products with high precision or special surface treatment (such as mirror polishing) may need to reduce the number of cavities to ensure quality.
Output demand: Products with high annual output are usually expected to increase the number of cavities to shorten the production cycle and reduce the cost per piece.
Mold cost: The more cavities, the higher the mold cost, but the cost allocated to a single product is lower, and the initial investment and long-term benefits need to be weighed.
Runner and cooling system: Multi-cavity molds need to optimize the runner layout to achieve balanced filling and avoid deformation due to uneven cooling.
Core pulling and slider structure: Products with complex structures such as undercuts may need to reduce the number of cavities to simplify the design of the mold action mechanism.
Injection molding machine capacity: Limited by injection volume, clamping force and mold size, the number of cavities needs to be adjusted according to equipment parameters.
Material properties: Plastics with poor fluidity (such as PC) may limit the increase in the number of cavities to avoid insufficient filling.
Multi-variety adaptation: Adopt a detachable modular mold design (such as the split structure of the staircase mold), and realize the sharing of mold cavities for multiple products by replacing some components, balancing efficiency and flexibility.