How sustainable is injection moulding?

If you’re exploring manufacturing options for your plastic product line, sustainability is probably at the top of your list of priorities. If it is, injection moulding may well be the right choice for you.

As such, we’ve put together this article to explain how sustainable it is, and why what really matters is how you design your product, how the moulding is run and how the materials are sourced.

 

What makes injection moulding sustainable?

Optimised correctly, injection moulding can be one of the more resource-efficient manufacturing methods, because:

 

It produces minimal material waste

The injection moulding process involves ‘injecting’ only the precise amount of polymer needed to fill the mould. This means there’s much less scrap compared with subtractive processes such as CNC machining, drilling or milling. Modern mould designs and runner systems also usually allow leftover plastic to be recycled and reused in production. That means even less waste.

 

It supports recycled and alternative materials

Modern injection moulding can incorporate recycled or biodegradable plastics. That’s a significant boost to your sustainability because it lowers your reliance on virgin fossil-fuel polymers and helps keep plastics out of landfills.

 

It scales efficiently at high volumes

Once you’ve created a mould, you can use it to create thousands, or even millions, of identical parts with minimal variation. As a result, you should have fewer defective, wasted parts, and lose even less material during production. That’s a major sustainability advantage for large-scale manufacturing.

 

New machines are dramatically more energy efficient

Modern electric injection moulding machines use significantly less energy than older models. Of course, it depends on which specific units you’re comparing, but newer machines tend to cut energy use by about 30% to 45%. That means less of an impact on the environment.

 

Where injection moulding still faces sustainability challenges

No process is eco-friendly by default, and that includes injection moulding. When our clients request injection moulding, we work with them to navigate sustainability challenges and ensure the lowest possible environmental impact. Here are some of those challenges:

 

High energy demand

Although modern machines are much more energy efficient, injection moulding still consumes a lot of power. The process requires high temperatures and pressures, and these naturally demand significant amounts of power. The best way to minimise power use is to optimise how many units you produce. Use reliable forecast data to produce exactly how many you need, nothing more, and nothing less.

 

Plastic lifecycle impact

Although you can use more sustainable plastic options (recycled, biodegradable, etc.) in injection moulding, many are standard, non-biodegradable plastics. Of course, this raises concerns about your long-term environmental impact.

One way to minimise this impact is to choose recycled or recyclable materials and design your products so they can be reused or recycled after use. You could still use non-biodegradable plastics wherever necessary, but using fewer of them reduces your environmental impact.

 

How your design decisions can influence sustainability

With all that said, know that the design and production process in injection moulding can be varied to meet your sustainability goals. It’s not a ‘one-size-fits-all’ process. For example, you can work with your supplier to optimise your mould layouts and process parameters.

These design choices could lead to a significantly more efficient moulding process by:

 

• minimising scrap and rejects (and landfill use)
• reducing cycle times (and energy consumption)
• eliminating excess plastic such as flash or sprues
• extending your product’s lifespan
• cutting costs

 

In other words, sustainability starts at the design stage, not the factory floor.

 

Why you might choose injection moulding

Injection moulding is one of the most widely used manufacturing methods because it brings balance. With everything considered, you get better performance, cost and environmental sustainability than many alternatives. Some of the main benefits of injection moulding include high-volume, high-quality production, complex shapes and tight tolerances, predictable costs and lead times, and versatile material options. As such, injection moulding tends to be the most environmentally responsible choice when:

 

• you’re producing large volumes
• you specify recycled or low-impact polymers
• your design minimises waste and cycle time
• your supplier uses modern energy-efficient machines
• the process captures and reuses scrap

 

Thinking about injection moulding for your next product line?

Injection moulding isn’t inherently sustainable or unsustainable. It’s a high-efficiency manufacturing method. The environmental impact depends on how it’s implemented.

The best way to minimise your environmental impact during production, regardless of the method you choose, is to work with an experienced partner. They can help you optimise your design, materials and process from day one. Here at Talisman Group, that’s exactly what we do.

Our friendly team of experts is on hand to recommend the best ways to optimise your injection moulding production run, working side-by-side with your team for the best possible results.

Get in touch with us today to benefit from our wealth of experience and industry-leading facilities.