The selection of injection mold type depends on plastic part design, budget, and production volumes. During new product development, manufacturers always ask: What type of injection mold is required?
- Single cavity, multi-cavity, or family mold.
- Hot runner or cold runner mold
- Two–plate or three–plate mold.
Accordingly, manufacturers provide tool estimates. Manufacturers can also suggest ways to reduce mold prices. In this article, we will discuss two–plate and three–plate mold, their construction, advantages, and disadvantages.
Two-Plate Mold
Two-plate molds are the most commonly used type of injection molds. They consist of one parting plane where the mold splits. In a multi-cavity two-plate mold, runner and gate must be in the parting plane to ensure runner and gate ejection when mold split.
Advantages of Two-Plate Mold
- Simple and low-cost design.
- Less lead time
- Lower cycle time compared to three plate mold.
Disadvantages of Two Plate Mold
- The parting line must align with the gate in a multi-cavity two plate injection mold.
- In multi-cavity injection mold, Molten plastic flow balancing is a challenging task.
Three-Plate Mold
Three plate injection mold consists of two parting planes and mold splits into three sections. Therefore runners and components can be located on different parting planes. In three plate molds, the runner is ejected separately to the molded part. Therefore automatic de-gating is possible.
Its application includes the positioning of the runner system in different planes to injection location and automatic de-gating.
Advantages of three plate injection mold
- Flexibility in gating location.
- Low-cost alternative to hot runner mold.
- Eliminate gate removal operation.
Disadvantages of three-plate mold
- Higher injection time due to the ejection of the runner system.
- More complex tool design.
- High injection pressure is required.
- High material wastage.
To sum up, two plate molds are the most commonly used injection moulds. It consists of one parting plane and mold splits into two halves, whereas three plate injection mold consists of two parting planes and mold splits into three sections.
Two plate mold is a low-cost solution, whereas three plate mold can be an alternative to hot runner mold.
We will keep adding more information on two plate and three plate mold. Add your suggestions, comments, or questions on the difference between two plate and three plate injection molds in the comment box.
I am Tool Room engineer and working as senior faculty member of DELHI INSTITUTE OF TOOL ENGINEERING.
I WISH TO LEARN MORE IN TOOLING INDUSTRY
Application of three plate mould plz answer sir fastly
Three Plate molds are used for auto de-gating and to get flexibility in runner positioning
Tell use in different kinds of things
mai petrochemical ka engineer hun mujhe moulding ke bare me btao