Injection molding is a widely used technology for producing multiple parts and components for various applications. How much does injection molding cost? This question is important in determining whether the process is suitable for your manufacturing project.
This article examines the cost of injection molding and the factors that influence it. You will also learn more about the production volumes of injection molding types and how you can reduce the cost of injection molding. Let's start.
What do injection molding costs depend on?
In general, injection molding does not involve fixed costs for each application. The cost of custom injection molding ranges from thousands to hundreds of thousands. Below are common factors that affect injection molding costs.
1. Cost of molding tools
Manufacturing the mold and mold base for products is expensive, although molding equipment is a one-time investment. Furthermore, the process of making the molds determines the cost. Standard mold manufacturing techniques include CNC machining, electrical discharge machining and 3D printing.
CNC processing
The CNC machining process is suitable for producing aluminum or steel metal molds. For example, CNC machines use cutting tools to remove material from an aluminum block and create an aluminum mold. Furthermore, this machining method produces aluminum molds with high precision.
EDM (Electroerosion)
Electrical discharge machining (EDM) is an assisted technique for producing shapes with complex and precise characteristics. The metal part is melted by electrical discharge and molded into the desired size and shape. Although EDM offers excellent precision, it is only compatible with metal molds.
3D printing
3D printing is one of the fastest ways to create molds for plastic injection molding projects. This method uses a 3D printer and does not necessarily require an experienced operator. Therefore, labor and mold costs are saved. However, the dimensions of 3D printed components are often limited due to the size of the 3D printer's build platform. Likewise, printed forms are more likely to shrink.
2. Equipment costs
The injection molding process requires special equipment. However, the size and complexity of the machine determines the cost, ranging from small to large machines. Therefore, it would be helpful to consider the following types of injection molding machines and their impact on injection molding costs.
Electric injection machines
Electric injection molding machines use an electric servo motor to control the machine during injection molding. They consume less energy, have low operating and maintenance costs, and are accurate and easy to use. However, their initial investment costs are high and they require regular maintenance.
Hydraulic injection machines
These hydraulic injection molding machines perform injection molding operations using a hydraulic pump. They are generally long-lasting, offer very consistent yield and injection performance, and are inexpensive to purchase. However, they can be inaccurate and consume excessive energy.
Hybrid injection machines
Hybrid injection machines combine the properties of electric and hydraulic injection machines. They use a servo motor and a hydraulic pump to distribute the oil needed to create the hydraulic pressure that forms the component in the machine.
These machines offer high precision, repeatability and energy efficiency. Furthermore, their acquisition costs are high and maintenance is expensive because they use electric motors and hydraulic pumps.
However, to avoid the high cost of an injection molding machine, it may make more sense to outsource the work to injection molding service providers instead of purchasing a machine.
3. Cost of plastic resins and additives
Plastic injection molding is compatible with a wide range of plastic resins with varying availability, price, application and properties. Typical examples of plastic injection molding materials include PC, ABS, PU, PP and PE.
The cost of plastic pellets used in the plastic injection molding process ranges from $1 to $5 per kg. However, the final cost of the injection molded material depends on the quantity used and the desired design.
4. Cost of injection molded parts
Molding variables such as design, size, and volume of the injection molded components often determine the cost of the injection molding tool. You can significantly optimize the cost of your project by understanding how these variables affect the cost of your plastic injection molding project.
Part complexity
To make complex parts, you need to create a shape of consistent complexity using manufacturing methods like 3D printing, CNC machining, or EDM machining. You also need more material to fill the mold and make complex parts. This consequently increases the cost of the injection molding material. At the same time, complex parts may take longer to produce as additional steps may be required in the production process.
Part size
More injection molding material is required to produce large molded parts, which increases the cost of injection molded components. Similarly, when processing large parts, it would be better to use the right injection molding machine and make the right size mold.
Undercuts
In general, recesses in injection molding make it difficult and, in some cases, impossible to mold parts. Eliminate them if possible. If you have difficulty getting them out, try sliding plugs through the cores or changing the parting line and draft angles to make the mold easier to make.
Finish and appearance
Unnecessary features that do not add significant value to your final products increase the cost of plastic injection molding. For example, textured surfaces may simply not be necessary. This also applies to additional cosmetic functions such as pearl blasting or high-gloss polishing. Keep in mind that excess features may also require more mold cavities, further increasing costs.
5. Labor and other services
Most processes related to injection molding are automated and controlled by software systems. However, typical injection molding labor costs include:
- Establish costs : Each phase of the injection molding process has specific injection molding machine setup requirements and configurations. For example, when creating the molds, it is necessary to make some adjustments to the tools, which is time-consuming due to the technical knowledge and precision required.
- Repair costs : Plastic injection molding is a mechanical process that requires several types of equipment. Injection molded components may break or wear out more easily. Therefore, costs may arise for repair and maintenance operations.
- Operator costs : Even though injection molding machines are automated, you need an operator to monitor the process. Therefore, operator costs are a crucial factor in labor costs.
Injection molding costs for different production quantities
Different production quantities are also a significant factor in injection molding costs. Furthermore, production volume affects the amount of raw materials used in injection molding, the required complexity of the machine, and the properties of the injection mold such as durability, strength, and other properties. Here are typical injection molding types with production quantities:
Small quantity injection molding production
Small-volume plastic molding involves producing parts of between a few hundred and a few thousand. Manufacturers often make the molds themselves and carry out the molding process themselves, without necessarily using sophisticated machines. Therefore, manufacturers produce molds using 3D printed polymer resin or rapid tooling as they are cost-effective and do not require a long production cycle.
Full small-batch mold production typically takes exactly three days to produce finished parts. For example, let's assume the following parameters for a run of 100 to 200 pieces:
- Number of pieces: 100 – 1,000
- Mold Cost: $100 – $1,000
- Raw material cost per piece: 0.5 USD
- Total cost of materials: $50 – $500
- Labor cost per part: $3 – $30
- Total labor cost: $300-$3,000
- Total injection molding process cost: $450 – $4,500
- Cost per piece: $4.5
Medium volume injection molding production
When injection molding medium quantities, quantities are generally between five thousand and ten thousand molded parts. This type of production requires pre-hardened steel or aluminum molds. You can outsource mold making and molding processes for this production scale.
However, let's assume the following cost calculation for injection molded parts with quantity of 5,000 to 10,000. They are the same parts made from thermoplastic materials such as polypropylene.
- Number of pieces: 5,000 – 10,000
- Mold Cost: $2,500 – $5,000
- Raw material cost per piece: 0.5 USD
- Total cost of materials: $2,500 – $5,000
- Labor cost per part: $2
- Total labor cost: $10,000 – $20,000
- Total injection molding process cost: $15,000 – $30,000
- Cost per piece: $3
Large quantity injection molding production
When producing injection molds in large quantities, hundreds of thousands of molded parts are produced. Due to their long service life, steel molds are often required in this process. High-volume projects also require sophisticated machinery, which increases the cost of injection molding. However, when producing in large quantities, the distribution of costs per piece is greater, ensuring lower costs per piece.
For example, let's say we mold 100,000 to 300,000 parts of the same type in ABS.
- Number of parts: 100,000 – 300,000
- Mold Cost: $25,000 – $75,000
- Raw material cost per piece: US$0.5
- Total materials cost: $50,000 – $150,000
- Labor cost per part: $1
- Total labor cost: $100,000 – $300,000
- Total injection molding process cost: $175,000 – $525,000
- Cost per piece: $1.75
However, it is obvious that the injection molding price per part is significantly reduced when producing large quantities. Large volume projects therefore offer the best cost advantage in terms of injection molding costs.
How can injection molding costs be reduced?
As mentioned above, the easiest trick to reduce unit price is to increase the quantity of parts, as the initial cost of machining and mold design can be used for more parts. Additionally, you can also try the following ways to reduce your injection molding cost and get the best results for your project.
Using DfM analysis
DFM (Design for Manufacturing) in injection molding is about producing a part within the budget set by the customer and fulfilling the intended purpose. DFM analysts often consider multiple factors based on technology, art and science to determine the most efficient design. Therefore, the cost of injection molding is significantly reduced.
Simplifying Design Features
Due to the complex properties of your products, plastic injection molding may require the use of complex shapes and additional steps. Therefore, it would be better to remove unnecessary features to reduce the price of injection molding. At the same time, you can save more money by removing any features that merely add cosmetic finishes.
Universal shapes rather than special shapes
If you don't need a custom format, you can use the universal format. These molds are often cheaper than custom molds and can still produce high-quality parts.
Additionally, if you need a custom mold, you should always create a CAD model before starting the manufacturing process. This helps to optimize designs and identify potential problems such as steep tilt angles, unnecessary wall thicknesses, complex shapes, etc.
Choose the right injection molding material
The cost of the preferred material for your parts often influences the overall cost of the injection molding process. If possible, use cheaper materials such as ABS or polypropylene. This helps keep production costs as low as possible.
Try betting forms
Injection molding and insert overmolding are effective technologies that save costs in the long run. For example, insert molding eliminates the need to add threads to plastic to attach to metal parts, making the process economical.
Minimize the number of voids in the mold
The more cavities a mold has, the higher the cost. Therefore, it is important to keep the number of cavities in the mold as low as possible.
One way to reduce the number of voids is to optimize your part design using mold flow analysis. Using a mold flow analysis, you can identify areas where voids can be eliminated without affecting the function or aesthetics of the part.
Self-adjusting parts
Manufacturing self-adjusting parts is one of the most reliable methods to save injection molding costs and simplify design. These parts are those that lock together when rotated 180 degrees. These pieces are ideal because you can use a single half mold to make the entire piece. This reduces molding costs and halves the size of the injection mold.
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Concluding
Injection molding is one of the most commonly used manufacturing processes for various products today. However, by understanding and estimating injection molding costs, you can significantly optimize the manufacturing process. This article will discuss the different variables you need to know to understand the cost of injection molding and how to take advantage of it. Therefore, it is helpful to understand the cost differences in injection molding tooling and mold costs.
Common questions
Is injection molding expensive?
There is no simple, clear answer to this. In general, however, it can be said that although injection molding can be expensive, this is not always the case. Factors such as production volume and complexity of the parts to be manufactured play a key role in ultimately determining injection molding costs. When similar items are manufactured in large quantities with tight tolerances, injection molding proves to be a cost-effective process.
How much does injection molding cost?
The cost can range from a few hundred to hundreds of thousands of dollars. Think about the many possible uses of injection molding. There is a virtually unlimited range of products made from it. In this scenario, it is difficult to provide an exact figure for the cost of injection molding.
Is injection molding compatible with materials other than plastic?
Although manufacturers typically use injection molding to mass produce thousands of identical parts using thermoplastic and thermosetting polymers, materials such as metals and elastomers are also compatible materials.
