We use both 3D printing and injection moulding at BEC, often on the same project. The two get framed as competitors, but they do different jobs.

The skill is knowing where one ends and the other begins, because using the wrong process at the wrong stage wastes both time and money.

Read on to learn what each process achieves, where they overlap, and the point at which it makes commercial sense to move from a 3D printer to a mould tool.

What Is Plastic Injection Moulding?

Injection moulding works by injecting molten plastic into a closed metal mould under pressure. The plastic cools, sets, and is ejected as a finished part, and the cycle repeats.

The mould tool is the key. It’s designed and cut first, and it carries the main upfront cost. Once it exists, it produces identical parts quickly, at a low cost per unit, in any volume. That’s what makes injection moulding the standard for high-volume production.

What Is 3D Printing (Additive Manufacturing)?

3D printing, or additive manufacturing, builds a part by laying down thin layers of material and fusing them together. There’s no tooling involved, so a design goes straight from CAD file to physical part.

That makes it quick and cheap to start. A part can be printed, assessed, adjusted in CAD, and reprinted within hours. The downside comes at volume, where printing each part individually becomes slow and expensive next to moulding.

What Are the Key Differences Between Injection Moulding and 3D Printing?

The main difference is how each process handles cost and volume.

3D printing has almost no setup cost but a steady cost per part, whether you make one or a thousand. Injection moulding is the opposite. The tooling costs more upfront, but once it’s paid for, the cost per part is low and continues to fall as volume rises.

A few other differences worth knowing:

  • A moulding cycle takes seconds, where a print takes minutes or hours
  • Moulding uses the full range of engineering thermoplastics, printing a narrower selection
  • Moulded parts are consistent and clean, while printed parts can show layer lines
  • Moulded parts have uniform strength throughout, printed parts less so

What Are the Similarities Between Injection Moulding and 3D Printing?

The two have more in common than people expect:

  • Both turn a CAD design into a physical plastic part
  • Both rely on accurate 3D data to work from
  • Both use thermoplastics, with several materials common to each
  • Both sit within the same product development process

They also work well together. A design tested on a 3D printer moves into injection moulding once it’s finalised, using much of the same digital groundwork.

In practice, they’re consecutive steps rather than competing technologies.

When Is Injection Moulding the Better Choice?

Injection moulding wins as soon as volume is involved. Once you need consistent, identical parts in higher quantities, the economics favour it.

The tooling cost is offset by the low cost per part, so the more you produce, the cheaper each one becomes. It’s also the better choice for parts that need a specific engineering-grade material, tight tolerances, structural strength, or a high-quality finish off the line. Any product heading to market in volume ends up here.

When Is 3D Printing the Better Choice?

3D printing is best early on, while a design is still changing. It’s the fastest, cheapest way to produce a physical part, test it, and refine it before committing to tooling.

It also suits:

  • One-off prototypes and design iterations
  • Very low volumes that can’t justify tooling
  • Jigs, fixtures, and assembly aids for the production line
  • Reverse-engineering or replacing legacy parts with no CAD

For small manufacturers drawn by low start-up costs, printing is often the natural first step. The limit is economic. As volumes climb, printing each part individually becomes too slow and too costly.

Can You Use Both Processes in the Same Project?

Yes, and most projects benefit from doing exactly that. The two solve different problems at different stages, so using them together gives you the strengths of each.

In practice, you prove and refine the design through 3D printing, where changes are quick and cheap, then move to injection moulding once it’s locked down and volume increases.

Printing also supports moulding projects by producing jigs, fixtures, and assembly aids.

How Does BEC Use Both 3D Printing and Injection Moulding to Support Product Development?

We run both processes under one roof in New Milton, using each where it adds the most value. Our 3D printing and scanning service handles early development, and our injection moulding takes over for production.

  • Our Fusion F410 3D printer produces prototypes in minutes using thermoplastics such as ABS, PLA, PET, nylon, and polypropylene.
  • Printing a prototype can reduce prototyping costs by up to 80% compared with traditional moulding and lets a design be tested and refined before any tooling is cut.
  • When a client comes to us with a physical part but no CAD, our Einscan Pro HD scanner reverse-engineers it into accurate CAD data in minutes, ready to develop into a mould tool.
  • When the design is right and the volumes justify it, the same project moves into plastic injection moulding for consistent, high-quality parts at scale.

With design, tooling, and moulding on one site, that transition is straightforward, and the same team carries the project from first prototype to full production.

Getting the Balance Right

The manufacturers who get the most out of both processes are the ones who stop seeing them as either/or.

3D printing earns its keep while a design is still evolving, when the freedom to change something cheaply is worth more than anything else. Injection moulding takes over once the design is settled and the numbers start to climb, when consistency and cost per part matter more than flexibility.

Used in that order, the two complement each other neatly. If you’d like a steer on where your own project sits, get in touch and we’ll talk it through.