Low-Volume Injection Molding: What You Need to Know

Low-volume injection molding is the best option if you are looking to make parts in quantities of 100,000 or fewer. It’s used for mass-producing identical parts before committing to a long-term molding setup, whereas other parts may never need to be produced in higher volumes. This form of molding is one of the most common processes for manufacturing plastics today. At Rex Plastics, we focus on quality assurance to make sure manufacturers receive the highest quality plastic parts.

Low-Volume Injection Molding vs. Traditional Injection Molding

One of the key differences between low-volume injection molding and traditional injection molding is the speed of production. Traditional injection molding is slower than low-volume injection molding. Traditional injection molding also has more complexity to the mold designs which can increase the time needed to make the parts. Because of this, there are many key advantages for choosing low-volume injection molding over traditional methods.

Advantages of Low-Volume Injection Molding

Some key advantages for low-volume injection molding include:

• Mold Cost: In many cases, low-volume manufacturing has lower overhead costs. Also, low-volume molds are usually cut from high-quality aluminum, which is easier to make and modify than other types of metals.

• Quick Production: Low-volume injection molding usually takes 1-3 days whereas mid-volume takes 3-4 weeks and high-volume injection molding takes 4-8 weeks. This quick production of parts allows for a faster fulfillment for orders in markets where time is crucial.
• Inventory Management: If a company orders parts and receives more than their inventory can manage, this can cause issues for a company’s bottom line. Requiring more storage space, waste of inventory due to disposal of unsold products, and lower productivity. Low-volume injection molding can help regulate your inventory by giving you a range of products closer to your required quantities.

Disadvantages of Low-Volume Injection Molding 

While there are great advantages to choosing this type of molding there are some disadvantages too.

• Net Cost of Tooling: While cheaper by itself, the net cost of tooling will be higher if they later transition to medium or high volume molding. As opposed to beginning with a more durable option right away.
• Shorter Product Life: The cost savings aren’t always worthwhile for the sacrifice in durability. We advise against aluminum tooling unless product life is 20000 parts or fewer, and there are many qualifiers that go with that pertaining to part design.
• Design Constraints: Low-volume tooling, usually aluminum, has more design constraints because of the durability issues aluminum has. A design that would easily work in a steel mold may cause an aluminum mold to wear out prematurely.

Does small series injection molding make sense for my project?

Low-volume injection molding is ideal for these types of projects:

• Prototypes – If your company is looking to quickly produce prototypes to test for form, function, and production method achievability before final design, low-volume injection molding is the way to go.
• Low-volume production runs – If your project doesn’t require hundreds of thousands of parts, but still needs injection molding, low-volume injection molding will be the most cost-effective choice.
• Testing for market and or pilot production – If you are creating a piece for testing or as a pilot for your product, then low-volume injection molding is ideal for bridging the gap between small testing production runs and full production. Low-volume injection molding can be used to start creating products while the large scale production tooling is still being finalized.

Small quantity production with Rex Plastics

At Rex Plastics we specialize in startup services, plastic injection molding, prototyping and more. We are a proud USA company that sources our materials locally whenever possible. We believe in the importance of giving back to our community and making sure that not only our employees are happy, but our customers feel valued. Let us know about your next project and find out how we can help!