Prototype Mold for Injection Molding – Rapid Tooling

custom plastic parts, injection molding solutions, Low-Volume Manufacturing

Prototype mold plays a vital role in the injection molding process, allowing the rapid and efficient production of prototype parts. Sungplastic provides two injection molding service options—prototyping and on-demand manufacturing. Each option has its own advantages depending on your project needs. If you need a small number of custom parts and need rapid development in a short period of time, then our prototyping option will be more suitable for you.
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What is Prototype Mold?

A prototype mold, also known as prototype tooling, is a specialized mold used in the injection molding process to produce prototype parts for testing, verification and design improvement purposes. Prototype molds are specially designed for the economical and rapid production of samples, prototypes and small series. They play a vital role in accelerating product development cycles, allowing manufacturers to evaluate the feasibility, functionality and performance of their designs before moving forward with mass production.
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Different Types of Prototype Molds

There are several types of prototype molds used in the manufacturing industry.

  • 1.Aluminum Prototype Molds: These molds are made from aluminum alloys and are known for their excellent thermal conductivity and durability. They are often used for low to medium volume production runs and can provide faster turnaround times compared to other mold materials.
  • 2.Rapid Tooling: Rapid tooling involves the use of various techniques such as silicone molds, epoxy molds, or composite molds to create prototype parts. These molds are typically made using additive manufacturing (3D printing) or subtractive manufacturing (CNC machining) methods. Rapid tooling allows for quick and cost-effective production of prototype parts with relatively lower tooling costs.
  • 3.3D-Printed Molds: With advancements in additive manufacturing, 3D-printed molds have gained popularity for producing prototype parts. These molds are created using 3D printing techniques, such as stereolithography (SLA) or selective laser sintering (SLS), and are suitable for small-scale production or low-volume runs. 3D-printed molds offer flexibility in design iterations and can be produced rapidly.
  • 4.Soft Tooling: Soft tooling, also known as bridge tooling or semi-production tooling, involves the use of softer materials like silicone or urethane to create prototype molds. Soft tooling provides a cost-effective solution for producing prototype parts with relatively shorter lead times.
  • 5.Hybrid Molds: Hybrid molds combine different materials and manufacturing techniques to create prototype parts. For instance, a mold may have aluminum inserts for critical features or cavities while incorporating 3D-printed components for less critical areas. Hybrid molds offer a balance between durability, complexity, and cost-effectiveness.

Each type of prototype mold has its own advantages and considerations, such as cost, lead time, durability, and production volume. The selection of the appropriate prototype mold type depends on factors such as project requirements, budget constraints, desired turnaround time, and the complexity of the part design.

Materials Used in Prototype Molds Manufacturing

Various materials are used in prototype molds manufacturing, depending on factors such as the intended application, production volume, budget, and desired mold properties. The choice of material for prototype molds manufacturing can impact factors like mold durability, part quality, and overall cost. Here are some common materials used in prototype molds manufacturing:

  • 1.Aluminum: Aluminum alloys, such as 6061 or 7075, are widely used in prototype molds manufacturing. Aluminum molds offer good thermal conductivity, which aids in efficient cooling and faster cycle times. They are relatively lightweight, durable, and can withstand high temperatures. Aluminum molds are suitable for low to medium production volumes and provide excellent dimensional stability.
  • 2.Steel: Various grades of steel, including P20, H13, and S7, are commonly used in prototype molds manufacturing. Steel molds are highly durable and can withstand high production volumes and demanding manufacturing conditions. They offer excellent dimensional accuracy, heat resistance, and long tool life. Steel molds are suitable for high-volume production and can handle a wide range of materials.
  • 3.3D-Printed Polymers: With advancements in additive manufacturing, 3D-printed polymers are increasingly used for prototype molds manufacturing. Materials such as photopolymer resins (e.g., SLA or DLP), thermoplastics (e.g., ABS or nylon), or powdered materials (e.g., SLS or MJF) can be used to create 3D-printed molds. These molds are cost-effective, allow for complex geometries, and offer rapid production of prototype parts.
  • 4.Silicone: Silicone is commonly used for creating soft or flexible prototype molds. It is suitable for casting low-temperature materials or materials that require flexibility, such as polyurethane or rubber. Silicone molds are relatively easy to work with, offer good dimensional accuracy, and allow for quick mold turnaround times.
  • 5.Epoxy: Epoxy molds are used for low-volume production or prototype parts that require high detail and surface finish. Epoxy molds offer good dimensional stability, can withstand high temperatures, and are suitable for casting materials like polyurethane or epoxy resins.

Selecting the right material for prototype molds depend on factors such as production volume, part complexity, desired surface finish, budget, and expected tool life.
Consult Sungplastic mold manufacturing experts, we will provide you with the most suitable materials and services for your products.

Prototype Mold Manufacturing Process

The prototype mold manufacturing process involves creating molds that are used for producing prototype parts or products before mass production.

  • 1.Design and Engineering:
  • Begin with a detailed design of the prototype part or product using computer-aided design (CAD) software.
    Create a 3D model of the part, ensuring accurate dimensions and specifications.

  • 2. Material Selection:
  • Choose the appropriate mold material based on factors such as the type of material to be molded, the expected production volume, and the desired prototype mold life.

  • 3. Mold Design:
  • Use the CAD software to design the mold based on the product’s CAD model. Consider factors such as parting lines, draft angles, gating system, and ejection mechanism. The mold design should ensure proper filling, cooling, and ejection of the prototype.

  • 4. Mold Fabrication:
  • Once the mold design is finalized, the fabrication process begins. It typically involves the following steps:
    a. CNC Machining: Use computer-controlled machines to carve out the mold cavities and create the desired shape from the chosen mold material. CNC (Computer Numerical Control) machines provide high precision and accuracy.
    b. Electro-Discharge Machining (EDM): In some cases, EDM is used to create intricate features or complex geometries in the mold. EDM involves the use of electrical discharges to erode the material and shape the mold.
    c. Polishing and Finishing: After the machining processes, the mold cavities are polished and finished to ensure smooth surfaces, which will result in better prototype quality.

  • 5. Assembly and Testing:
  • Assemble the mold components, including the cavity and core inserts, ejector pins, cooling channels, and any other necessary elements. Conduct thorough testing to ensure proper fit, alignment, and functionality of the mold.

  • 6. Refinement and Iteration:
  • Analyze the prototype parts and gather feedback on design, tolerances, and functionality.
    Make necessary adjustments to the mold design or manufacturing process based on the test results.

  • 7.Additional Steps (Optional):
  • Depending on the complexity and requirements, additional processes like overmolding, insert molding, or secondary operations might be integrated into the prototype mold manufacturing process.

  • 8.Finalization:
  • Once the prototype parts meet the desired specifications and performance criteria, finalize the prototype mold design.

  • 9.Documentation and Transition:
  • Document the prototype mold design, including assembly drawings, part specifications, and manufacturing guidelines.
    Transition to mass production tooling, if applicable, using the lessons learned from the prototype mold manufacturing process.

Keep in mind that the specific steps and techniques can vary based on the type of mold, the manufacturing technologies available, and the requirements of the prototype parts. Additionally, advancements in additive manufacturing (3D printing) have introduced new possibilities for rapid and cost-effective prototype mold manufacturing.

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Advantages of Injection Prototype Molds

Injection prototype molds offer several advantages in the product development process. Here are some key benefits:

  • 1.Accelerated Product Development: Injection prototype molds enable rapid production of prototype parts, allowing for faster iteration and refinement of product designs. It helps reduce time-to-market and gain a competitive advantage.
  • 2.Time savings: The tooling process is greatly accelerated and your first “right material” part can be produced in less time, typically between 2-4 weeks. Depending on the complexity of the cavity, it is 20%-40% faster than machines and 5-10 times faster than steel series mold polishing. This is an interesting solution for speed.
  • 3.Design Validation and Testing: Injection prototype molds allow for functional testing and validation of product designs before investing in expensive production tooling. This helps ensure that the final product meets performance requirements, functionality, and user expectations.
  • 4.Risk Reduction: By producing prototype parts using injection molds, manufacturers can identify and mitigate potential risks associated with part design, material selection, and manufacturing processes.
  • 5.Scalability and Benefit from Series Parts: Once the design is finalized and validated using injection prototype molds, it can easily be scaled up to mass production using production tooling. The mold remains your property and you can use it to produce fragmented small series of plastic parts. Overmolding and insert molding are also possible with this prototype mold.
  • 6. Suitable for low-volume production: Ideal for projects that require a small number of high-quality parts. Great for quantities up to 10,000-50,000 depending on the tool used.

Limitation of Injection Prototype Molds

While injection prototype molds offer numerous advantages, they also have some limitations that should be considered. Here are a few limitations associated with it:

  • 1.Limited Material Selection: Injection prototype molds may have limitations in terms of the range of materials that can be used. Some high-temperature or specialty materials may not be suitable for use in prototype molds.
  • 2.Surface Finish Limitations: It may not provide the same level of surface finish as production tooling. The surface quality of the prototype parts may have slight imperfections or variations that may not accurately represent the final product’s aesthetics or texture.
  • 3.Reduced mold life: Compared to production molds, prototype molds are often made of less durable materials, such as aluminum or 3D printing polymers.
  • 4.Possibility of Dimensional Variations: Due to the use of less rigid materials in prototype molds, production parts have a higher potential for dimensional variation than production molds. This variation may affect the accuracy and consistency of prototype parts.
  • 5.Limited volumes: Due to factors such as reduced mold life, increased cycle times, and limited durability of the mold material, they are more suitable for low to medium volumes.
  • 6. Most expensive prototyping technology: While creating a prototype mold is generally more cost-effective than manufacturing a production mold, it is important to note that prototype molds can still be an expensive prototyping technology. The cost of equipment and skilled labor, as well as the cost of injected materials is higher compared to other prototyping methods.

Despite these limitations, injection prototype molds are still a valuable tool in the product development process. It is important to carefully evaluate project requirements and consider their limitations to ensure that they meet the goals and constraints of a specific product development process.

Prototype Injection Molding Considerations

We endeavour to meet the needs and desires of our customers. However, there are several key aspects to consider when developing a prototype mould, and the following analysis can help you determine whether the injection moulding prototype process is suitable for your product.

  • 1.Tool Life: The tool life of prototype molds is typically shorter compared to molds made of more durable materials. They typically use softer materials that are more likely to wear and deteriorate over time..
  • 2.Material Selection: The choice of mold material is crucial. It should be compatible with the intended production materials and provide the necessary properties. Consider the material’s ability to withstand the injection molding process and the intended production volumes.
  • 3.Tooling Considerations: Prototype molds are typically temporary, so the tooling approach should be cost-effective and efficient. Consider factors such as the mold fabrication method (CNC machining, 3D printing, etc.), lead time, and budget constraints.
  • 4.Mold Classes: Class 105 & 104 molds are the most suitable for prototyping molding runs and are typically made of Aluminum or Mild Steel.
  • 5.Mold Texturing & Polishing: While it is possible to perform texturing and polishing on prototype molds, it’s important to consider that the effects of these processes may not last as long due to the use of softer tooling materials. Typically we recommend B to D SPI finishes for it.

The types of Prototype Molding Processes

Some common prototype molding processes include:

  • 1.Injection molding: Molten material is injected into the mold cavity under high pressure.
  • 2.Blow molding: Air pressure is used to inflate a hollow tube of molten material within the mold, creating the desired shape.
  • 3.Casting: Liquid material, such as metal or resin, is poured into the mold and allowed to solidify.
  • 4.Thermoforming: A sheet of thermoplastic material is heated and formed over a mold to create the desired shape.
  • 5.Compression molding: A preheated material is placed into the mold cavity and compressed under high pressure and temperature.

Best Practices for Successful Prototype Mold Development

To ensure a successful prototype mold development process, it’s important to follow some best practices. Here are some key practices to consider:

  • 1.Design for Manufacturability: Design the prototype and mold with manufacturability in mind. Consider factors such as parting lines, draft angles, gating system, ejection mechanism, and cooling channels. Optimize the design to facilitate smooth and efficient mold fabrication, production, and part quality.
  • 2.Quality Materials and Components: Select high-quality materials and components for the mold construction. This ensures durability, longevity, and consistent performance of the mold during the prototype production process. Skimping on quality can lead to issues such as premature wear, dimensional inaccuracies, or poor part quality.
  • 3.Testing and Validation: Conduct comprehensive testing and validation of the prototype mold before proceeding with production. This includes testing the mold’s functionality, fit, alignment, and performance using appropriate prototype materials. Identify any issues or areas for improvement and make the necessary adjustments.
  • 4.Documentation and Record-Keeping: Maintain detailed documentation throughout the prototype mold development process. This includes CAD models, design revisions, test results, and any modifications made to the mold. Proper documentation helps track progress, facilitates troubleshooting, and provides valuable information for future reference.

These are just a small part of the practice, Sungplastic will increase the chances of successful prototype molds development by following these best practices, resulting in high-quality prototypes and efficient production processes.

Application of Prototype Mold

Prototype molds have a wide range of applications across various industries. They are used to create prototype parts and products for testing, validation, and design refinement before moving on to full-scale production. Here are some common applications of it:

  • 1.Product Development and Design Validation: They are extensively used in product development to create prototypes of new products.
  • 2.Proof-of-Concept Models: Prototype molds enable the creation of proof-of-concept models that demonstrate the feasibility and functionality of a new product idea.
  • 3.Market Testing and User Feedback: They are used to produce prototypes for market testing and gathering user feedback. This helps in refining the product design and ensuring it meets the needs and expectations of the target market.
  • 4.Trade Shows and Marketing Demonstrations: They are utilized to create prototypes that can be showcased at trade shows, exhibitions, and marketing demonstrations.
  • 5.Training and Education: They find applications in educational institutions and training facilities. They are used to teach students and professionals about the principles of mold design, injection molding processes, and manufacturing techniques.
  • 6.Customization and Personalization: In industries such as consumer electronics and consumer goods, prototype molds enable the creation of customized or personalized products, allowing manufacturers to quickly adapt to individual customer preferences.
  • 7.Medical and Healthcare: Prototype molds play a vital role in developing medical devices, prosthetics, and healthcare products. They allow for testing the fit and comfort of medical equipment and implants.
  • 8.Architectural and Industrial Design: Architects and industrial designers use prototype molds to create scaled-down models of buildings, structures, and industrial equipment. This aids in visualizing and refining the design before construction or production.

These are just a few examples of the applications of prototype molds. Essentially, it acts as a bridge between design and mass production. The versatility and flexibility of prototype molds make them valuable tools in the early stages of product development.
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Future Trends in Prototype Mold Technology


The field of prototype mold technology is constantly evolving, driven by advancements in materials, manufacturing processes, and digital technologies. Here are some future trends that are expected to shape the landscape of prototype mold technology:

  • 1.Additive Manufacturing (3D Printing): Additive manufacturing, particularly 3D printing, is revolutionizing the prototype mold industry. It offers faster and more cost-effective ways to produce complex mold geometries, reducing the need for traditional machining processes.
  • 2.Integration of Sensors and IoT: The integration of sensors and Internet of Things (IoT) technologies within prototype molds will enable real-time monitoring and data collection during the production process.
  • 3.Simulation and Virtual Prototyping: Advances in simulation software and virtual prototyping tools will allow designers and engineers to simulate the mold filling process, optimize mold design parameters, and predict part quality before physically producing the mold.
  • 4.Hybrid Manufacturing Processes: Hybrid manufacturing processes, combining additive manufacturing with traditional machining techniques, will become more prevalent in prototype mold technology. These processes leverage the strengths of both methods, enabling the creation of complex mold geometries through 3D printing and achieving high surface finish and precision through subsequent machining operations.
  • 5.Automation and Robotics: Automation and robotics will play a larger role in prototype mold manufacturing, improving efficiency, precision, and repeatability. Robotic systems can handle tasks such as mold assembly, material loading, and part ejection, reducing human labor and increasing productivity. Automation also enables lights-out manufacturing, where the mold production process can run continuously without human intervention.

These future trends in prototype mold technology have the potential to improve the speed, efficiency, and quality of prototype mold development, enabling faster product innovation, reducing costs, and accelerating time to market.

Prototype Molding Service With Sungplastic

At Sungplastic, we provide a range of services such as CNC machining or 3D printing of prototype parts. We would like to take our customers’ prototyping needs to the next level and help them bridge the gap between initial prototypes and full production runs of proven products.
Our prototyping services cover many fields. Manufacture parts with the same quality you expect with the technology, materials and finishing options that Sungplastic offers in plastic injection molding services. Our engineers will work closely with you to understand your project’s unique requirements and help you make informed decisions to optimize for lowest cost and fastest lead time.
Please contact us immediately, we will provide you with satisfactory prototype plastic customization services.

FAQ:About Prototype Molding

  • Q: How does prototype molding differ from production molding?
  • A: Prototype molding focuses on creating small quantities of prototypes for testing and validation purposes, while production molding involves the mass production of final products. Prototype molds are usually less expensive and quicker to produce than production molds, but they may have a shorter lifespan due to differences in material and manufacturing requirements. Production molds are designed for longer-term use and are built to withstand high-volume manufacturing processes.

  • Q: How long does it typically take for Sungplastic to complete prototype molds?
  • A: At Sungplastic, the typical timeframe for completing prototype molds is 3-7 days, assuming a standard level of complexity. However, more intricate molds may necessitate additional time for design and fabrication. But we will try our best to provide the prototype mold in the fastest time.

  • Q: In addition to prototype mold customization, does Sungplastic provide other plastic customization services?
  • A: Yes, Sungplastic provides other plastic customization services, including production mold design and fabrication, injection molding, product development and design assistance, material selection and consulting, secondary operations and finishing, and quality assurance and testing.

About Sungplastic

About Sungplastic

Sungplastic is a plastic product manufacturer with rich experience in injection molding. According to the different product development requirements, we flexibly adjust the manufacturing process to achieve high quality, high efficiency and more economical.

We offer a variety of manufacturing services: Rapid Prototyping, Tool Making, Injection Molding, Product Design and Development, CNC Machining and Metal Stamping. You can choose from a variety of plastics, silicone rubber, or metal for your product. Regardless of mass production or small batch customization, Sungplastic has always been committed to providing assured, efficient and more economical one-stop processing services for your projects.

Contact us for a free quote and project review.

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