3D printing is widely used in prototyping and production of parts, especially in handling complex geometric shapes and reducing assembly. However, injection molding remains the preferred service for mass production of cost-effective parts. Although 3D printing is popular in prototyping, it has higher costs when scaling up and still has certain limitations compared to injection molding. When choosing manufacturing services, factors such as cost, complexity, and production scale need to be considered.
In this article, we’ll delve into the costs of both technologies, including everything from material costs, equipment costs, production time, and maintenance, to help you make more informed decisions.
Is 3D printing cheaper than injection molding?
When producing more than 1000 parts, injection molding is generally more cost-effective than 3D printing. The primary cost in injection molding is the creation of molds, and as the production quantity increases, the unit cost significantly decreases. The cost of mold manufacturing depends on factors such as product size, material, and complexity, averaging around $11,000.
In contrast, 3D printing has a relatively stable unit cost that does not decrease with increasing production quantity. While the initial costs for mold and first run may be higher, injection molding becomes more cost-effective per unit than 3D printing when producing the second batch of parts. 3D printing is suitable for small batches, rapid manufacturing, or projects requiring frequent modifications, while injection molding is ideal for large-scale production and projects with high-resolution requirements. The choice between the two methods depends on project needs and production scale.
Understand Injection Molding Cost and How to Estimate It
3D printing vs injection molding: cost comparison
There are some key differences in cost between 3D printing and injection molding:
1.Cost drivers
3D printing:
The costs associated with 3D printing primarily include printing materials, equipment maintenance, and energy consumption. For example, a medical device company utilizing SLA technology (the purchase cost of a high-quality SLA 3D printer can range from tens of thousands to several hundred thousand dollars) to print a complex medical device prototype. The material cost for printing is approximately $150, and the equipment operating cost is $20 per hour. Total costs also include maintenance and post-processing, but these depend on the required surface finish and precision.
Injection molding:
The injection molding cost lies in the manufacturing of injection molds. The cost of producing an injection mold can be as high as $50,000, but the mold’s lifespan for production can reach several million cycles. Assuming the production of 100,000 parts, the allocated cost of mold manufacturing is only $0.50 per part. The unit cost of injection molding significantly decreases in large-scale production, typically becoming competitive when the production quantity exceeds 1,000 parts.
2.Applicable production scale
3D printing:
3D printing is suitable for small batches, prototyping, and personalized production, but its costs tend to be higher for large-scale production. Typically, if the production quantity is less than 500, the overall cost of 3D printing may be more competitive.
Injection molding:
Injection molding is capable of producing millions of identical plastic components, such as plastic body parts for vehicles. Injection molding is commonly employed for mass production. The unit cost of injection molding significantly decreases with an increase in production quantity, typically gaining cost advantages when producing over 1,000 parts. The high production capacity of injection molding makes it an ideal choice for large-scale production.
3.Manufacturing cycle
3D printing:
3D printing is a relatively slow process that involves stacking materials layer by layer. For example, using SLA technology to print medical models with a diameter of 10 centimeters and a height of 5 centimeters may take an average printing time of 4 to 6 hours. For larger or more complex components, this time may be further extended. The manufacturing cycle of 3D printing is mainly influenced by technology, part size, and complexity. However, its flexibility in prototyping and small-scale production, as well as its advantages in customized design, make it an indispensable choice in specific application scenarios.
Injection molding:
For projects that require large-scale production and rapid delivery, injection molding has a superior production speed. The cycle of injection molding is usually from a few seconds to a few minutes, suitable for large-scale production.
4.Material selection
3D printing:
In 3D printing, material selection has a significant impact on overall cost. For example, when using SLA technology to produce the parts required for medical models, the cost is usually between $50 to $200 per kilogram. This depends on the type of photosensitive resin used, and the cost of high-performance resins may exceed $150/kg, while common PLA materials may decrease to $20/kg. Although 3D printing has advantages in providing design flexibility and manufacturing complex geometric structures, its material costs are relatively high, especially in large-scale production, which may lead to an overall increase in project costs.
Injection molding:
In contrast, the material selection for injection molding is more diverse, but it is more competitive in terms of overall cost. The average material cost for producing plastic parts required for household appliance casings using injection molding is usually between $1-5 per kilogram. For example, the cost of ABS plastic may be around $2 per kilogram, while the cost of more specialized engineering plastics such as PA6 may exceed $5 per kilogram. In large-scale production, the material cost of injection molding is relatively low, making it an economical choice, especially for projects with large production quantities and high consistency requirements.
Materials Guide
Advantages and disadvantages of 3D printing and injection molding
3D printing and injection molding are two common manufacturing technologies, each with its unique advantages and disadvantages. Here are their main differences:
Advantages of 3D Printing:
Capability to Manufacture Complex Shapes: 3D printing technology can produce parts with intricate shapes and internal structures that are challenging to achieve with traditional manufacturing methods.
Reduced Material Waste: 3D printing is an additive manufacturing technology, using only the material required to create the part, helping to minimize material waste and costs.
Customization: 3D printing allows for the production of customized products tailored to the specific needs of customers, catering to the increasing demand for personalized products.
Small Batch Production: 3D printing is well-suited for small-batch production, as it eliminates the need for expensive molds or tools, enabling quick production of a limited quantity of products.
Disadvantages of 3D Printing:
Cost: While the cost of 3D printing is gradually decreasing, it remains more expensive than traditional processing techniques like injection molding.
Production Time: The production time for 3D printing is relatively longer, especially for large parts.
Material Limitations: The range of materials available for 3D printing is currently limited, which may not meet all application requirements.
Advantages of Injection Molding:
Cost-Effectiveness: Injection molding is a mass production technology, capable of producing large quantities of products in a short time, leading to reduced per-unit costs.
High Output: It is a mature manufacturing technology that can quickly and efficiently produce large volumes of products.
Wide Material Selection: Injection molding can utilize a variety of plastic materials, meeting diverse application needs.
Disadvantages of Injection Molding:
Challenges in Producing Customized Products: Injection molding typically requires molds, making it impractical or costly for customized or small-batch production.
Material Waste: Injection molding generates a significant amount of waste and leftover material, leading to material wastage and increased costs.
Long Production Cycle: Injection molding involves the use of molds and machinery, contributing to longer production cycles.
In conclusion, 3D printing and injection molding each have their strengths and weaknesses. The choice between the two technologies depends on specific production needs and application scenarios. In some cases, a combination of these technologies may yield the best results.
Injection moulding vs 3d printing: Which one to choose?
The choice between injection molding or 3D printing depends on multiple factors, including production requirements, product characteristics, cost budgeting, and the advantages and disadvantages of the manufacturing process. Here are some key factors to compare the two technologies and help you make wise choices:
Production scale
Injection molding: suitable for large-scale production, especially when a large number of identical parts are required. Injection molding machines can efficiently produce large quantities of products in a short period of time.
3D printing: more suitable for small batch production, prototyping, or personalized products. 3D printing is suitable for flexible production needs, but the production speed is relatively slow.
Manufacturing costs
Injection molding: In large-scale production, the cost of each component is usually lower. However, mold manufacturing may require a high initial investment.
3D printing: In small-scale or prototype production, 3D printing can be more competitive because there is no need to manufacture molds, but the cost of raw materials is relatively high.
Manufacturing speed
Injection molding: With fast production speed, it is suitable for high-yield demands. Each injection molding cycle is relatively short, which can quickly meet market demand.
3D printing: The production speed is relatively slow, especially for complex structures or large parts. Suitable for scenarios with low production speed requirements.
Design flexibility
Injection molding: Design changes usually require modifying the mold, which may increase time and cost. Suitable for stable product design.
3D printing: Provides greater design flexibility and facilitates rapid design iterations. Suitable for products that require frequent design modifications or personalization.
Material selection
Injection molding: can use a variety of traditional plastic and metal materials, with a wide range of applications.
3D printing: There are relatively few material options, but new materials are constantly emerging. Suitable for specific applications such as high strength, high temperature, or special chemical environments.
Manufacturing complexity
Injection molding: suitable for manufacturing relatively simple parts, and may require multi-step production for complex structures.
3D printing: capable of manufacturing complex geometric structures and internal spaces, suitable for parts with high complexity requirements.
Conclusion
- High volume production: Choose injection molding.
- Low-volume manufacturing: choose 3D printing.
- The design is complex and requires fast delivery: choose 3D printing.
- Requirements frequently change or customize: choose 3D printing.
- Focus on strength and consistency: Injection molding may be more suitable.
The final choice will depend on your specific needs and priorities. In some cases, it may be best to use a mixture of these two technologies to get the most out of each.
Will 3d printing replace injection moulding?
3D printing and injection molding are considered complementary manufacturing technologies rather than direct substitution relationships. Although 3D printing performs well in areas such as prototyping, injection molding still dominates in most industrial plastic component production because it can more easily control costs and ensure quality, while also being suitable for large-scale production.
Injection molding faces the challenges of high manufacturing mold design costs and long lead times, while 3D printing has shown unique advantages in areas such as prototype production and customized products in the medical industry. Therefore, it is more appropriate to consider them as complementary processes. By simultaneously applying these two technologies, the pre production cycle can be shortened, preparing for large-scale production.
Conclusion
Overall, 3D printing and injection molding each have their unique advantages and challenges. Balancing these factors in manufacturing decisions and making wise choices based on product characteristics, market demand, and cost budgets will help ensure the success and economic benefits of the production process.
FAQ
Yes, there are many metal 3D printing technologies, such as SLS and DMLS, capable of manufacturing metal components, suitable for industries like aerospace and healthcare.
Yes, both technologies can complement each other. For example, using 3D printing to create custom molds and then mass-producing through injection molding.
