Number and type of cavities in an injection mold has an impact on manufactured part quality, mold cost and production rate. In this article we will discuss single cavity, multi cavity and family mold. That will help you in the selection of the best injection mold for your plastic part.
Single cavity injection mold consists of one cavity. Therefore one component is produced per injection cycle. For small production volume plastic parts, single cavity injection moulds are recommended.
Advantages of Single Cavity Injection Mould
Single cavity mold has the following advantages:
- Low mold manufacturing cost compared to multi cavity injection mold.
- Single cavity molds are easy to design and manufacture.
- Molder and tool manufacturer gets more control over the injection molding process. This helps in improving injection molded plastic part quality.
- Sometimes two single cavity molds are preferred instead of one two cavity mold. Because in breakdown conditions, one injection mold can still run.
Disadvantages of Single Cavity Injection Mold
Single cavity mold has following disadvantages:
- Low productivity.
- High unit part manufacturing cost.
Multi Cavity Mold
Multi cavity mold consists of more than one cavity. Therefore multiple parts are manufactured per injection cycle. In multi cavity injection mold, initial investment cost is very high but this higher tool cost can be compensated by lower unit part molding cost.
Advantages of Multi Cavity Injection Mold
Multi cavity injection mold has following advantages:
- Reduced unit part manufacturing cost.
- Higher productivity.
Disadvantages of Multi Cavity Injection Mold
Multi-cavity injection molds have following disadvantages:
- Higher mold manufacturing cost compared to single cavity injection mold.
- Higher tonnage machine is required to run a multi-cavity injection mould.
- Longer mold manufacturing lead time.
A Family mold consist of two or more core and cavities for different parts. Therefore two or more different components are molded in one injection cycle. In this way Family mold reduces overall tool manufacturing cost, by molding two different parts using one injection mold.
Advantages of Family Molds
Family mold has following advantages:
- Lower tool manufacturing cost.
- Two or more components are produced in one injection cycle. Therefore productivity increases.
Disadvantages of Family Mold
Family moulds have following disadvantages:
- Molten plastic flow balancing in different geometry part cavities is a challenging task. It can result in various injection molding defects.
- Family mold produces different parts in the same material in one injection cycle. Therefore it is recommended to use family mold for the same material and color parts.
To sum up, A single cavity mold produces a single component per injection cycle and a multi cavity mold produces multiple components per injection cycle. Whereas in family mold multiple different components are produced in one injection cycle. Click this Link! to know various ways to reduce injection mold price.
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