Prototype Injection Molding: 7 Materials Commonly Used by Design Firms

injection molding services

Many industrial designers, inventors, manufacturers, and other professionals look for the best manufacturing process to meet market demand quickly. This is where prototype injection molding enters the picture.

What is prototype injection molding?

Identifying the optimal number of prototypes for validation and testing can help speed up the new product development process. Working with an injection molding design service on your product is a helpful first step in product development. After the design for the injection mold has been created, there are injection molding and casting services to meet all manufacturing requirements. For the past few decades, 3D printing has become almost synonymous with rapid prototyping, increasing its notoriety as a feasible alternative for manufacturing.

The remarkable improvements to materials, finishing, sintering, and printing processes have opened doors to exciting opportunities that were once deemed impossible. An excellent example is the capacity to 3D print injection mold tools for short-run production and prototyping projects. The relatively new application is gaining momentum among tool makers, contract manufacturers, and product developers because of its unique advantages.

RELATED: How to Design a Virtual Prototype for Your New Concept

People familiar with conventional IM or injection molding for production purposes know its inherent benefits. Aluminum tools, for instance, can produce parts in thousands, while steel tools continue to be the most efficient method for mass production that you can find today.

PCB enclosure plastic case design – injection molding

But the process doesn’t yield the finest results all the time, and tooling errors can turn into economic problems very quickly. Thankfully, prototype injection molding using 3D printed tools has now become a practical bridge to production tools that make it worth considering. First, learning the cost and time differences between the various prototyping methods is essential. Prototype injection mold tooling using 3D printing benefits engineers and designers because it is a fast and affordable way to avoid making mistakes. For instance, aluminum can be costly and tricky to tweak after the mold is delivered, becoming a financial and logistical nightmare.

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How is prototype injection molding used?

As mentioned earlier, prototype injection molding is a bridge-to-production method that enhances product validation and minimizes risks before mass manufacturing. Injection molding design services are available for companies to help create a viable prototype. Using injection molding to prototype is a beneficial option because of several reasons:


Product development relies on external and internal feedback to make the necessary improvements. The access to a small batch of the different product parts with prototype injection molding tooling allows remote engineering teams and beta customers instant access to the product. It is ideal for improving international organizations with several facilities or customer relationships. Since there is no scarcity of parts, there will be no unnecessary hold-ups or delays.

Functional testing

Prototype injection molding is also a cost-efficient method for engineers to shoot the end-use materials for product evaluation and testing. 3D-printed mold tools, for example, are reinforced with ceramic fiber. These are also strong enough for injection with various types of thermoplastics, such as polycarbonate, Ultem, nylon 66, and more. The engineering team can also produce more than 20 prototypes representing the final product ready to be processed and tested.

Unexpected challenges

Whether you like it or not, no prototype or design is flawless right from the get-go. If you are wondering what is more problematic between wasted money and wasted time regarding your new product development lifecycle, the answer is both. However, taking on a prototype injection molding process can offer solutions to production issues that often pop up later in the game. It eliminates expensive redesigns and even production mishaps.

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Materials that design firms use for prototyping and why

Choosing a suitable material is the first and most crucial step in your prototyping process. While hundreds of different materials are used for prototyping, only one will be considered the best option for your product. A reliable design firm, and injection mold design professional, can make your decision-making easier. The design firm should present you with a comprehensive list of advanced prototyping materials to help turn your prototypes into reality.

The injection mold design company must also have a team of experienced engineers with a deep and extensive understanding of the different prototyping materials. They will also give you some helpful advice regarding your one-of-a-kind product design that is exclusively yours and yours alone. Working with a reliable injection mold design firm means getting better advice you won’t find anywhere else. 3D printing design services employ industry leaders who have already worked with many types of prototyping materials. With the help of their experience, they can provide you with seven kinds of materials that they often offer to their clients and are known for their value for money and remarkable flexibility. The downsides of each material are also added to help you with your decision-making.

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  1. Composite structures

Composite structures are non-metallic and are known for their excellent dimensional stability. These materials can be carbon or glass-reinforced, and the carbon structure can even have the same strength as steel. The tooling costs of composite structures can also be low. But the main concern is that carbon fiber is pricier than glass. A minor failure can also be catastrophic, and parts usually have just a single good surface, with pricier tooling being the only exception.

  1. Mass Cast Epoxy

Mass cast epoxy is a thermosetting polymer poured into a cast and then allowed to harden. The material is durable, hard, and water-resistant and can be molded into almost any shape. However, mass cast epoxy tends to shrink during curing, making changes can be tricky, and constraints in thickness limit the material.

Epoxy injection mold
  1. Metals

Steel and aluminum are standard material options for prototyping. Metals are known for being precise, well-finished, and strong. The only issue is that using metals tends to be labor-intensive, and these are also usually done in subtractive manufacturing processes that can produce high amounts of waste. Common parts only have a single good surface, with more expensive tooling being the only exception.

  1. Silicones

Silicones are oxygen and silica compounds that come in various forms, which include liquid or solid rubbers and resins. These materials can range from hard and stiff to very flexible and soft. Silicones are also waterproof, resistant to temperatures, easily colored or decorated, and have virtually no creep. No shrinkage occurs during molding. However, silicones are very soft elastomers that tend to be tacky. The materials also have high CLTE.

RELATED: Selecting Materials for 3D Printing Your New Product or Prototype

  1. Thermoplastics

Thermoplastics are a type of plastic that can be melted down, and 3D printed or molded into specific shapes. These materials are durable and recyclable with a wide array of properties. You can also remold thermoplastics several times. They also offer quick molding times for lower costs with well-established automated processes. Unfortunately, thermoplastics have high tooling costs and tend to melt under high heat.

  1. Urethane resins

Urethane resins are thermosetting polymers often poured into molds to produce prototypes. This material is known for its versatility, as it can be tough, stiff, or elastic, and it is also durable for flexibility and abrasion. The only concern is that urethane resin might leave a rough finish since it is impressionable.

  1. Wood

Plywood is among the few wood-based materials used for prototyping. Wood is cost-effective and flexible, and both hardwoods and softwoods can be used. The material is also easy to refine. But wood can also be labor-intensive and may not be as dimensionally stable as the other materials.

RELATED: Injection Molding Tips for Cost-Effective Prototypes and Mass-Manufacturing by a Mold Design Firm

Importance of choosing a suitable material for prototyping

Your choice of material used for prototyping can affect the quality of your prototypes because of several reasons. Here are some considerations to remember:

* Aesthetic versatility

Check if the material is available in different colors and if the color can be changed by adding powders and other pigmentation.

Plastic chair – injection molding

* Comparison to your projected production material

If your prototype uses a different material from what you plan to use for production, check if it has the same response to your process. For example, ensure that both materials quickly fill the injection mold and their cooling times are the same.

* Cost

Determine if you use the most reasonably priced option for your non-production grade piece.

* Environmental issues

Confirm if you can recycle your prototypes or reclaim them otherwise.

* Fidelity to your original digital or CAD drawing file

Check if the material is conducive to high accuracy in rapid prototyping or 3D printing.

* Functionality

Check functionality with durability, hardness, material flexibility, and others. If preferred, confirm if the material can also copy the planned functionality of the final product.

* Suitability for chosen prototype process

As mentioned earlier, determine if you are using the suitable material that is compatible or available for the prototype process you chose. For example, is your resin or plastic available for 3D printing in spool form? Working with a suitable material can significantly affect the prototype injection molding process. Find the best material for your prototyping injection molding needs for the best results.

How Cad Crowd can assist

Cad Crowd offers services from the initial product concept and design to prototype design services, patenting, 3D printing services, injection molding and casting services, and manufacturing. Regardless of the size of your project, our injection mold design experts are here to help bring your vision to life. Contact us for a free quote today.