Recycling is the best way to deal with 3D printed plastic, but not all plastics are recyclable, and those that are, aren’t always widely recycled. This puts barriers in the way of sustainable additive manufacturing.
The plastic crisis is one of the most significant challenges facing our planet. Our reliance on plastics is too great to give it up, and our insatiable appetite means that 380 million metric tons of plastic are produced yearly.
While 3D printing is not a leading cause of global plastic waste by volume, we must recognise that it contributes.
Whether it’s waste like support material and plastic shavings from post-processing or functional parts that reach the end of their life, plastic from 3D printing must go somewhere – preferably not a landfill or into an incinerator.
Unrecycled plastic is typically incinerated, resulting in carbon emissions, or it is sent to a landfill – even if it has been recycled several times before.
Recycling is the best way to deal with 3D printed plastic, but four boxes need ticking to ensure 3D printed plastic gets recycled:
- That the plastic is recyclable.
- That the plastic is easily recycled.
- That waste is sent to proper recycling facilities.
- That the recycling facilities can process the waste.
Simply put, 3D printed plastic recycling has a few essential ingredients.
The first step to assuring recyclability is specifying a recyclable plastic.
It’s crucial to know that thermoplastics are Type 7 plastics, so you cannot put them into a recycling bin. However, when sent to the correct facilities, recyclable plastics do get recycled and turned into other products.
In the correct facilities, the following plastics are recyclable:
- Polycarbonate (PC)
- HIPS (support material)
Specifying a recyclable thermoplastic will give your 3D-printed parts and waste the best chance of being turned into other products.
Thermoset plastics, such as those printed by SLA 3D printers, are the most difficult to recycle (and most can’t be recycled at all). This is because they cannot be melted again without breaking down the molecular structure.
Ease of recyclability
Just because plastic is recyclable doesn’t mean it is economical, thus creating the main problem with plastic recycling.
Some plastics are difficult to melt down without breaking molecular bonds, and most have only a limited number of melt cycles before breaking down entirely.
Additionally, it is rare for plastics to be correctly sorted before arrival at facilities. No machine in the world can sort through tonnes of plastic waste and differentiate 3D-printed ABS, PC, and PET-G from non-recyclable waste.
The bottom line is that there is too much competition with virgin plastics, with virgin plastics often working out cheaper to produce.
This means most plastic waste is not recycled, even if it is recyclable.
Sending waste to proper facilities
Let’s assume 3D-printed plastic waste is sent to the proper facilities. If that’s the case, there’s a strong possibility it will be recycled.
You should bag and label 3D-printed plastic waste and discuss recycling with the facility before shipping it off so that you have a paper trail.
The trouble is that there aren’t enough recycling facilities in the UK to keep up with demand, so less than 10% of plastic is recycled.
Hard plastics like ABS, PC, PET-G, and PEEK are also energy intensive to recycle, and with the energy crisis, this means it is getting costly.
The result is the UK sends around two-thirds of plastic overseas for recycling. Sadly, we have no control over whether it gets recycled outside our borders, and shipping also increases plastic’s carbon footprint.
The bottom line is that 3D-printed plastic waste must be sent to specialised facilities with governance and processes to assure recycling rates. You must ensure your waste is not sent overseas to ensure it gets recycled.
How to make 3D printing more sustainable
There are several ways you can make additive manufacturing more sustainable:
- Choose recyclable and biodegradable thermoplastics.
- Collect waste and sort it for recycling.
- Reduce print failures by knowing the most common 3D printing problems.
- Design more sustainably to reduce material waste. Use new geometries and infills to reduce support structure.
- Make models thinner to reduce material consumption. You can use new infill patterns and more dimensionally stable materials to retain strength.
- Use CAD/3D modelling software with AI to create efficient build paths to reduce material consumption and waste.
- Store moisture-sensitive materials like PLA, ABS, PVA, and nylon in a humidity-controlled environment.
- Consider metal 3D printing for solid parts. The Markforged Metal X prints steels, copper, and Inconel, which are easily recycled.
Several thermoplastics/3D printing filaments are recyclable, but that doesn’t mean they are easily and widely recycled.
The current state of plastic recycling means that most waste is not recycled, and the UK sends most of its plastic waste overseas.
Besides buying a recycling facility, there is no way to guarantee the recycling of 3D-printed waste. However, you can seek assurances from recycling plants and ensure that all waste is sorted and ends up in the right place.
It is also crucial to build sustainability into additive manufacturing with efficient design to reduce material consumption and waste. This will also save you money and speed up print times, helping make 3D printing more economical.
Find out more
To find out more about the recyclability of 3D printed plastics, please get in touch with the team at 01765 694 007, email email@example.com, or you can