low-volume injection molding

Low-Volume Injection Molding: Advantages, Applications and Alternatives

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Low-volume injection molding is one of the main advantages of on-demand manufacturing. As a low-volume injection molding company, Zhongde offers a multitude of advantages that have transformed the way businesses approach production. As we delve deeper into the world of low-volume injection molding, we will uncover its many advantages and applications. Whether you’re seeking cost-effective alternatives, rapid prototyping solutions, or the bridge between initial concepts and full-scale production, low-volume injection molding holds the key to unlocking new possibilities.

What is Low-Volume Injection Molding?

Low-volume injection molding, also called small run injection molding, is a specialized manufacturing process that stands as a testament to the adaptability and efficiency of modern production techniques. At its core, it involves the creation of plastic or polymer parts in quantities that are significantly smaller than those associated with high-volume production methods. This approach has gained prominence for its ability to deliver cost-effective solutions, rapid prototyping capabilities, and unparalleled flexibility in part design.

Zhongde is a company that provides low volume injection molding services, typically, our low-volume runs range from a few hundred to a few thousand units. This marked departure from the high-volume approach enables businesses to optimize their production processes and expenditures, especially when precision and customization are paramount.

Advantages of Low-Volume Injection Molding

  • Less Expensive Molds: Low-volume production molds made of materials like aluminum or soft/semi-hardened steels offer substantial cost savings. These savings come from both the lower material costs and reduced machining expenses. Compared with steel molds which cost from $2000 to $100000+, the low-volume injection molds are very cost effective.
  • Shorter Lead Times: The aluminum mold is easy and speedy to shape. This speedy mold production translates to shorter lead times from the beginning of mold-making to the start of injection molding. Faster mold creation also accelerates the overall time it takes to bring your injection-molded products to market. While Steel molds usually need 4-8 weeks.
  • Reduced Production Costs: Compared to using hardened steel molds, low-volume injection molding with aluminum molds allows for the production of more parts in the same amount of time. Because aluminum has greater thermal conductivity than steel. This increased production efficiency translates to lower production costs per part, making it a cost-effective choice.

Disadvantages of Low-Volume Injection Molding

  • Limited Volumes: One of the limitations of small run injection molding is its name itself—it’s designed for smaller quantities. If initial demand estimations are inaccurate and you later need to transition from low-volume to high-volume injection molding, it can result in higher costs. Switching to high-volume production often requires new tooling and molds, which can be a substantial additional expense.
  • Reduced Mold Life: The materials used for low-volume injection molds, such as aluminum or softer metals, have limitations when it comes to mold life. These molds are not as durable as those made from hardened steel. Over time, the wear and tear on these molds can lead to a reduced lifespan, which may necessitate mold replacement, adding to maintenance costs.
  • Design Constraints: Low-volume molds made from softer metals have certain design constraints. They may not achieve the same level of tight tolerances and fine surface finishes as molds made from hardened steel. This limitation can impact the precision and quality of the produced parts, which could be a concern for projects with strict design requirements.

Key Considerations of Low-Volume Injection Molding

Choose the Right Material for the Project

Different materials offer distinct properties, including strength, flexibility, temperature resistance, and durability. Selecting the appropriate material for low volume plastic injection molding  is a pivotal decision. Consider the unique requirements of the project and collaborate closely with material suppliers and mold designers to make the ideal choice. This ensures that your part performs optimally, both in terms of functionality and cost-efficiency.

Plastic Material Selection Guide for Your Manufacturing Process

Finesse a Part’s Finish

Achieving the desired surface finish is crucial, as it can impact both aesthetics and functionality. Work closely with mold designers to finesse the part’s finish, considering factors like texture, gloss, and any specific requirements for your application.

Uniform Wall Thickness

Too thick can lead to cooling issues, while too thin can result in structural weaknesses. It’s important to consider the appropriate wall thickness to avoid issues like warping or sink marks during the cooling process. Ideally, wall thicknesses should typically stay within the range of 0.04 to 0.14 inches (1 to 3.5mm). Thicker walls can lead to cooling inconsistencies and potential defects, while thinner walls may result in structural weaknesses. Striking the right balance in wall thickness is essential for producing high-quality molded parts.

Injection Molding Wall Thickness Guideline: Maintain Uniform Wall Thickness of Injection Molded Plastic Parts

Rounded Edges and Corners

Incorporate rounded edges and corners whenever possible. Sharp angles can be challenging to mold and may lead to part defects.

Avoid Undercuts

Minimize or eliminate undercuts in your design, as they can complicate the ejection of the part from the mold.

Proper Draft Angles:

Draft angles are essential for ensuring that the molded part can be easily removed from the mold without damaging it. All vertical faces should have at least 0.5 degrees of draft, but if the part design allows, it’s preferable to have 2 to 3 degrees of draft. In some cases, complex surfaces may even require as much as 5 degrees of draft. These draft angles facilitate smooth ejection of the part from the mold, reducing the risk of defects and ensuring a successful molding process.

Enhancing Part Quality by Optimizing Injection Molding Draft Angle Design

Applications of Low-Volume Injection Molding

Rapid Prototyping

Low-volume injection molding is a vital tool in the realm of rapid prototyping. Designers and engineers can swiftly transform the concepts into tangible prototypes. It enables thorough testing, design tweaks, and refinements, ensuring that the final product meets or exceeds expectations. In today’s competitive market, being the first to market with a high-quality product is often the key to success, and low-volume molding plays a pivotal role in achieving that goal.

Low-Volume Parts Production

In the world of manufacturing, not every project calls for mass production. Sometimes, you need just a small batch of parts. This is where low-volume injection molding shines. Many niche products, limited production runs, and specialized components fall into this category. Whether you’re creating unique automotive parts, medical devices, or specialized electronic components, low-volume injection molding caters to the demand for precision and quality in smaller quantities. It’s cost-effective and efficient, making it an ideal choice for projects where quantity isn’t the primary focus.

On-Demand Injection Molding

The modern manufacturing landscape demands adaptability and efficiency. Enter low-volume injection molding as the solution for on-demand manufacturing. Companies can order custom parts tailored to their exact specifications, whether it’s specific shapes, materials, or unique features. This flexibility minimizes excess inventory, streamlines production, and ultimately leads to significant cost savings.

Alternatives to Low-Volume Injection Molding

CNC Machining

CNC Machines can be highly automated and precise. CNC machining is an alternative to injection molding for lower part volumes, especially when parts have complex geometries. Multi-axis CNC machines are often required for intricate designs.

3D Printing

3D printing offers the advantage of creating parts with highly complex geometries that may not be achievable through other manufacturing methods. It’s especially popular for prototyping.


Thermoforming, particularly vacuum forming, is a viable option for thinner parts with simpler designs. It’s a cost-effective method for creating parts with larger surface areas.

Urethane Casting

Urethane casting can produce durable components that closely resemble injection molded parts without a significant tooling investment. This method is particularly valuable when you need robust prototypes or low-volume production.

Zhongde Urethane Casting

Zhongde makes all the molds in-house. And we have experienced engieers can accuratly analyze whether the product is suitable for cast molding or other manufacturing process.

Choosing the right manufacturing method depends on various factors, including the specific requirements of your project, cost considerations, material options, and production speed. Each alternative offers unique advantages and limitations, and the choice should align with your project’s goals and constraints.


Low-volume injection molding isn’t merely a modern manufacturing process; it’s a pathway to innovation, cost-effectiveness, and quality. It empowers businesses to bring their ideas to life swiftly, respond to market demands, and deliver products that meet the highest standards. As you start your manufacturing projects, consider the immense potential of low-volume injection molding.

Choose A Reliable Manufacturer for Your New Project!

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