How To Save Injection Molding Cost By Multiple Cavity Mold

When you have a project, then you may need plastic injection molded parts. The first thing you need to do is find a plastic mold company to make mold & molded parts, but before starting this, I think you need to check injection molding cost and mold cost in advance for your investment budget. Multi-cavity injection molding will be one of the best ways to save unit production cost.

Like other things, there is no one solution that is suitable for all of the projects. Below are some suggestions on how to save injection molding cost. There are both advantages and disadvantages; by reading this, you could choose the one based on your project requirements.

What is multi cavity injection molding

Multi-cavity injection molding is typically used when high-volume production of identical parts is needed. It allows for the efficient production of multiple parts in a single cycle, which can significantly increase production rates and reduce the cost per part. Additionally, using a multi-cavity mold can also help to reduce the overall cost of the mold itself.

Multiple cavity mold means the number of cavities greater than one, which means that it has more than one part in an injection mold. It is usually professional to say cavity, One cavity or two cavities, for example, 8 cavity mold, means one molding cycle to mold 8 parts with the 99% same part feature, dimension, shape, size, etc.

Some examples of products that may be produced using multi-cavity injection molding include automotive parts, electronic components, toys, and household items. It is also commonly used in the production of medical devices, personal care products, and packaging.

24 multiple cavity mold

When do we need Multiple Cavity Mold?

There are some factors to consider before starting to make your plastic mold.
1, the size of the plasatic product,
2. The number of the plastic products requirement
3. The size of the machine; if you only buy plastic molded parts, then you do not need to care about this point; your plastic molding supplier will handle this for you.

If the size of the product is small, such as the computer keyboard button, usually make 24 or 48 Multiple Cavity Mold, you must say why not make 30 or 40? This is because of the balance mold layout and material filling balance, especially when you use cold runner mold. So normally multi-cavity mold is 4, 8, 16, 24, 48, and 96 cavities are better options.

When we make multiple cavity mold and the cavities are more than 24, we normally suggest making hot runner mold, one part per hot drop. Of course, this will be a high cost for the injection mold. In that case, we suggest at least using six hot runners transferring to the cold runner, which means four cavities per hot drop. This could save the cycle time and keep the best quality of injection molding parts.

The advantages of Multiple Cavity Mold

The reason we make multi-cavity molds is simple: we need to save production unit cost for each plastic molded part. Multi-cavity molds have several advantages over single-cavity molds in injection molding:

Increased production efficiency: By producing multiple identical parts in a single cycle, Multiple Cavity Mold can significantly increase production rates and reduce the overall production time.
Reduced cost per part: Multiple cavity molds can produce multiple identical parts at a lower cost per part than single cavity molds.
Reduced tooling costs: Since multi-cavity molds require only one tool, the overall cost of the mold is typically lower than that of multiple single-cavity molds.
Better consistency: By producing multiple identical parts in a single cycle, multi-cavity molds can improve the consistency of the final product, reducing the need for rework or scrap.
Reduced labor costs: Multi-cavity molds require less labor to operate than multiple single-cavity molds, as the operator only needs to monitor one machine.
Reduced material consumption: By producing multiple parts in a single cycle, multi-cavity molds can also reduce the amount of raw material required to produce the final product.
Improve part quality: Due to the consistency in the process and the precision of the machinery, multi-cavity molds can produce parts with tighter tolerances and a better surface finish.

The disadvantages of multi cavity mold

We all know that all of the customers prefer the multiple cavity mold since this can save lots of production cost, but there are other factors you need to think about before making a decision, because making plastic mold is not cheaper; making multi-cavity mold is more expensive than single cavity mold, sometimes double or even three times more expensive than single cavity or two-cavity mold.

For example, if you make 24 cavity mold, then you at least need 6 hot runner drops for the mold; the pure hot runner cost is around USD 5400 (YUDO brand); if you use a China local brand of hot runner, you still need USD 3000, and this cost some times is enough to make 2 cavities of cold runner mold. Since there are many cavities in one mold, the mold manufacturing cost is higher than the less cavity mold as well; this is another cost, so the total cost is two or three times more.

Higher initial cost: The initial cost of a multi-cavity mold can be higher than that of a single cavity mold, especially for complex designs.
Greater complexity: Multi-cavity molds are more complex than single-cavity molds and require more precise machining and design. This can lead to longer lead times for tooling and an increased risk of defects.
Higher maintenance costs: Due to the complexity of the mold and the increased number of moving parts, multi-cavity molds may require more maintenance and repairs than single-cavity molds.
Greater risk of defects: With multiple cavities, the risk of defects is greater, as a problem in one cavity can affect multiple parts.
Increased cycle time: Multi-cavity molds have longer cycle times than single-cavity molds as the machine has to fill multiple cavities at once.
Greater potential for warpage: multi-cavity molds have to be designed to account for the potential warpage that can occur during the cooling phase of the injection molding process.
Increased risk of sink marks: As the material cools, it will shrink. If the mold design is not optimized for multi-cavity, sink marks may appear on the surface of the parts.
Increased risk of flash: flash is the excess material that is extruded from the mold. Multi-cavity molds can be more prone to flash than single-cavity molds, as the pressure and flow rate of the material are increased to fill multiple cavities.

When do you need multiple cavity mold

There is some simple suggestion: when do you need to make single cavity mold (may have 2 cavities at the fist) and when should you make multi-cavity mold, like 8 cavity mold, 16 cavity mold, or more? When you are sure that you will need the plastic parts more than one million or at least 0.5 million, then going to 8 or more mold cavities will surely save cost for you.

You may need to pay more for plastic mold manufacturing, but compared to the production cost you are going to save, this injection mold cost is insignificant because you will save 10 times more than this injection mold cost.

If you are not sure how many plastic molding parts are needed at the first, or if this is depending on your business market, then we suggest using the 2 cavity mold at first, because this can save the plastic mold cost for you in advance. After you open your market and the requirement of injection molded parts increases, you can still save injection molding cost by making new multiple cavity mold.

You use the existing mold to produce the parts at the same time and make a new multi-cavity mold; this will not have a delay as well. After the multiple cavity mold is finished, you only need to run this multi-cavity mold, but if the quantity requirements are not so high, then you use the current molds to produce, so you still have good profits with less investment (compare to make multi-cavity mold at the beginning).

When do you need single cavity mold

A single-cavity mold is a type of mold used in the injection molding process. It consists of a single cavity or impression that forms the desired shape of the plastic part. This type of mold is used when the production volume is low or when the part design is complex and requires more attention to detail.

Advantages of using a single-cavity mold include:

Flexibility: Single-cavity molds allow for more flexibility in terms of part design and material selection. Each cavity can be customized to meet specific requirements.
Precision: With only one cavity to focus on, manufacturers can pay more attention to detail and ensure higher precision in the molding process. This is particularly important for intricate or complex part designs.
Cost-effective for low volume production: Single-cavity molds are cost-effective for low volume production runs. They have lower initial tooling costs compared to multi-cavity molds and are more suitable when the production quantity is small.
Material compatibility: Single-cavity molds are ideal when different materials or processes are required for each part. This allows for the production of diverse parts with varying material properties.

A single-cavity mold is typically needed when you require a small quantity of parts or when the part design is complex and requires more time and precision to manufacture. It is also used when the part size is large and cannot be accommodated in a multi-cavity mold. Additionally, a single-cavity mold may be preferred when the cost of manufacturing multiple cavities is not justifiable or when the part design requires different materials or processes for each cavity.

What do you think? By reading above, I assume you have an idea on how to save injection molding costs for your project.

If you have any project in hand that needs to make injection mold for your business, you are welcome to contact us. We will give you some good suggestions and ideas to help you spend minimum investment on plastic mold cost and open your market rapidly.

Sincere Tech is one of the top 10 mold manufacturers in China and offers custom plastic molds, injection molding manufacturing, die casting,prototypese, machining, and many moreservices. As one of the best injection mold suppliers in China, we pride ourselves on our commitment to excellence.

Below are a few of the services we offer:

Rapid Prototyping: We offer rapid prototyping services to quickly transform your concepts into live parts, allowing for iterative design improvements and accelerated product development. Please go to the rapid prototyping service page to know more.
Precision CNC Machining: Our advanced tooling equipment enables us to make high-quality plastic molds and machining components with tight tolerances, ensuring consistency and precision in your injection-molded products. Please go to the precision CNC machining page to know more.
Overmolding: We specialize in overmolding, which allows for the combination of multiple materials or components, resulting in enhanced functionality, aesthetics, and durability.
Insert Molding: Our expertise in insert molding enables us to securely encapsulate inserts within the molded parts, facilitating efficient assembly and enhancing product performance.
Two-Shot Molding: With two-shot molding, we can produce complex, multi-material components in a single operation, reducing assembly requirements and enhancing design possibilities.
Value-Added Services: In addition to injection molding, we offer a range of value-added services, including product assembly, packaging, and logistics support, streamlining your supply chain and reducing costs.
Product assembly Service: We offer all in one service from part design, production, until delivery, if you need products assembly service in China, we will be one the best options for you.

Not limited to below but more services we offer, welcome to contact us for your custom injection molding needs (no matter multiple cavity mold or single cavity mold).