What to do with 500 empty spools?
Our print service is running at full speed — and with that comes a small but persistent problem: empty filament spools. We care about the future of our children, so simply throwing them away felt wrong. But what to do when hundreds of them start piling up in the basement, threatening to spread under people’s desks?
You know the mantra: reduce, reuse, recycle. The spools are intact, making them ideal for reuse. But it can be easier said than done. Let’s examine the case, including its pros and cons, and what we ultimately did.
The travel of a spool
The spool is used for the thread of filament or printing material. Therefore, it plays a crucial role in feeding the 3D printer, and when it is empty, it is no longer useful unless it can be reused for the next load of filament.
Part of our production solutions involves the material; we always go the extra mile to ensure consistent quality in the materials we use and supply. The material is tested and certified, and quality is proven in dedicated production facilities in Europe. To reuse the spools, we need to return them to that facility.
However, we hadn’t yet decided on what to do. The fact is that at one point, we counted more than 500 empty spools stacked in the basement. They were multiplying faster than we could deal with them. Something had to be done.
Recycling or reusing?
- Option A: the quick, local solution. Drive them 3 km to the local recycling center—cheap, low effort, and environmentally sound.
- Option B: the complicated solution. Order pallets and boxes, pack everything up, and ship the spools to our production partner in Europe for reuse. This process involves high labor, high cost, and long-distance transport.
What does the CO2 calculation tell us?
Admittedly, this is not a scientific calculation, and we will not take it as the final truth. But based on common industry emission factors, the calculation looks like this:
CO2 calculation in simple terms
- Number of spools: 500
- Weight per spool: 0.6 kg
- Total weight shipped: ~300 kg
Transport footprint
- Distance: 2,600 km by truck
- Emissions: ~75 kg co2 for the whole shipment
Making one new plastic spool:
- ~1,5 kg co2
- For 500 spools: 750 kg co2
Net result
- By reusing instead of making new: ~675 kg co2 saved, even after transport
That is interesting – in the CO2 calculation, the transport cost is still better than making new ones. In this calculation, we base our number on conventional (fuel/diesel) road freight emission factors.
The big dilemma and the joker
But it is not a no-brainer. A brand-new spool is cheaper than reusing one. That’s the reality of global plastic production today. But if we only look at price, we ignore the bigger cost — the one paid by the planet. Our choice to reuse spools isn’t about saving money; it’s about aligning our actions with our values. Sometimes, the responsible option may appear expensive on a spreadsheet but pays off in terms of trust, credibility, and long-term impact.
And there may also be a joker … While reuse may seem like extra effort today, it could soon become a business advantage as sustainability reporting becomes the standard.
By choosing respooling instead of producing new spools, we significantly reduce CO2 emissions. In a traditional setup, producing 500 new polypropylene spools would emit around ~750 kg CO2. With respooling, the footprint is limited to cleaning and transport, in the range of ~75 kg CO2. Totally represents a saving of roughly ~675 kg of CO2.
For customers with ESG reporting obligations, this falls under scope 3 (purchased goods and upstream transport) and can be included as a measurable contribution to reducing their indirect emissions.
Final thoughts
The truth is, there’s no perfect solution.
We should note that mechanical recycling would still reduce emissions compared with making virgin spools: our estimate shows recycling the 500 spools would cut roughly ~380 kg CO2. The catch is that recycling puts the plastic back into the general material stream, while we would still need new spools for our own use. Because the spools are intact and can be respooled by our production partner, the reuse route delivers the largest climate benefit in our case — and that’s why we chose it.
Reuse beats recycling in terms of CO2, but it requires more money and effort. Recycling is simpler and cheaper, but it discards the value that remains in the spools.
In the end, we chose reuse — not because it made the best business case, but because it aligned with our values and because we believe it is the responsible thing to do. It was our way of reducing waste, lowering CO2, and showing that even small choices add up when you look at the bigger sustainability picture.
And here’s the bigger perspective: while we’re not yet required to report under ESG frameworks, many of our customers are. Circular practices like this can directly support their ESG goals, turning an everyday choice into a measurable advantage.
What if transport changes?
The CO2 numbers we’ve shared are based on conventional diesel trucks. If we used electric trucks or rail transport, the footprint of shipping the spools would drop by roughly 60 kg CO2 in our case. That would make reuse even more clearly the best option, and shows how future improvements in transport and energy efficiency can amplify the benefits of circular practices.
Still, the dilemma remains: should companies incur extra costs for the sake of lower CO2 emissions, even when customers may not notice? And what happens when transport, energy sources, or recycling technology improve?
We don’t have all the answers, but we believe in starting the conversation. And for the spools, we believe reuse is the future. What’s next? Perhaps redesigning them to make shipping easier — or even making them refillable.
