The Different Types of Injection Molds
Heating, automotive, medical, and electronics manufacturing demand these acute levels of precision and durability. Injection molds are also commonly used to create complicated and strong parts sections.
It is, therefore, necessary to familiarize oneself with the various types of injection molds to ensure that only the right types are applied to obtain the best outcomes concerning costs, cycle times, and end part quality.
What will you learn in this blog?
This blog will explain the general types of injection molds and the need to produce different kinds of materials. So, let’s get started.
4 Types of Injection Mold Classification
The injection mold has to be chosen as it defines the rate and cost at which the final product will be produced while also dictating its quality. Depending on the row of utilization, injection molds are mainly divided into four main groups:
Based on Feeding System:
The first method of categorizing injection molds is based on the feeding or runner system. The feeding system is the gate, sprues, and runners that convey the molten plastic from the nozzle to the mold cavity. Here’s a closer look at the types of injection molds under this category:
Hot Runner Injection Mold:
Hot runner systems utilize heated runners to maintain the plastic’s openness inside the manifold plate so that the material does not solidify; this shortens the production time. These molds are ideal for a large number of intricate parts, but they are rather expensive to establish and maintain.
Figure 2: Hot runner mold
Cold Runner Injection Mold:
Cold runner systems have unheated runners that must be replaced between cycles. They are easy to wash and maintain and permit rapid material and color switching. However, they create more scrapes, and the arrangement of runners for regrinding can modify the material characteristics.
Insulated Runner Molds:
Hot runner configuration and insulated runner molds involve using heaters to surround the runners, melting the plastic, and making it flow identically to hot runner systems without needing controllers. They are cheap and facilitate easy substitution of the materials to be printed; however, they can only accommodate certain materials, not high-grade plastics.
Based on the Number of Cavities
When classifying injection molds based on the number of parts they produce per cycle, there are three main types to consider: When sorting injection molds according to the part complexity made in a single cycle, there are three principal categories to distinguish.
Single Cavity Injection Mold
A single-cavity mold makes a single part or product per shot in injection molding. This, of course, may lead to lower production rates; however, tooling costs are lower, and thus, the process is easily justified as ideal for lower quantities. Several single-cavity molds are employed in manufacturing because even if a single-cavity mold develops a problem, many more molds can still be used for continuous manufacturing.
Multi-Cavity Injection Mold
With multi-cavity molds, several parts of the same design can be made in a single injection cycle. Indeed, the cost of these molds is slightly higher than that of single cavity molds; nevertheless, they are highly suitable for mass production. Thus, they help produce various components simultaneously and at a cheaper unit cost.
Family Injection Mold
Family molds, such as multi-cavity molds, can produce several parts in a cycle but are made to produce different parts simultaneously. For instance, a family mold may turn out both the right and left-hand parts simultaneously.
Yes, the family molds may be slightly more costly than the individual molds. However, they can bring down the overall cost of production since several parts can be made in one mold.
However, they are primarily appropriate for parts with similar material and color, and additional molds are needed if the material or color is different.
If you want to learn more about multi-cavity vs. family injection molds, click here.
Based on Mold Plate
There are also different categories of injection molds based on the number of operations they utilize and the number of plates. In part production, these plates form the whole mold cavity and are very important. Here’s a breakdown of the main types based on the mold plate structure:
Two Plate Injection Mold
The two-plate mold is considered to be the most popular one as well as the least expensive one. It consists of two main plates: the core plate and the cavity plate, where the former meets the latter at what is known as the parting line.
This part design ensures that the gate, runner, and parting line are located anywhere, allowing the mold to be compatible with any runner system. Otherwise, it is more suitable for single cavity molds because its structure is usually simple, and the tooling costs are down.
Three Plate Injection Mold
The three-plate molds include another plate called the stripper plate to produce two parting lines. The additional plate positions the runner system away from the molded part, and the runners do not need to be removed or recycled by hand.
This arrangement helps reduce time, but it also raises the total tooling expense since special cutting is needed. This type of mold is coupled with the cold runner system, while the hot runner system does not require such a mold.
Stack Injection Mold
Stack-type molds have several plates arranged in parallel, in pairs at least, but more usually in three or even four tiers. This design also helps generate parts in the shortest time possible by reducing the clamp tonnage per cycle. As a result of their structural design, stack molds are costly to make.
However, they are relatively cheaper to use in the long run. They can also be designed with the capacity to process several materials at once, and for this reason, the machines can be used extensively.
Conclusion-the Different Types of Injection Molds
It is crucial to know the types of injection molds since they can influence your production line and its costs. In terms of the injection molded part results, it is desirable to get the most optimal solution. From feeding systems with hot and cold runner molds to the number of cavities and the mold plates, they all possess their merits and use depending on the situation.
The suitable mold should allow efficiency in the production process, reduce waste, and increase the quality of the end product.
Go4 Mould manufactures and supplies injection molds and molding services that cater to the varied requirements of different industries. Whether you need a simple, all-purpose single-cavity mold, a multi-cavity one, or even a complicated stack mold, we guarantee you get the best solution. You are welcome to contact us to learn how we can assist with the molding projects and how we can help you obtain the optimized molding outputs.
