QiTech ACADEMY

How to make recycled filament from waste products such as failed 3D printing prototypes?

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Last updated: August 2026

Failed prints, support structures, and other filament scraps don’t have to go straight into the trash. In this how-to, we’ll show you how to turn scraps—sorted by type as much as possible—into new filament through shredding, drying, extruding, cooling, and winding. This is exactly how we recycle filament in practice—only with a bit more technology, depending on the quantity.

QiTech Shredder when shredding 3D printing scraps

Plastic Shredding

First, the material has to be shredded. We use our QiTech Shredder.

If you don't have access to a shredder, search the Precious Plastic map for workshops near you, buy new or used items at the Precious Plastic Bazaar —or get creative: a manual shredder, a paper shredder, or a scissors-and-blender combo. It sounds like something you'd find in the kitchen, but that's how we got started, too.

However, the more uniform the granules are, the smoother the material flow will be later on in the Extruder —and the better the conditions for producing high-quality filament. Angular flakes measuring around 3–5 mm are a good guideline. Large chunks get stuck in the hopper.

To the QiTech Shredder

Drying granulate

The next—and often overlooked—step is drying. Before extrusion, the pellets should be clean, dry, and as homogeneous as possible.

Moist material bubbles up in the Nozzle, the filament becomes porous, and you wonder why the print isn’t turning out right. Especially with leftover 3D printing material, you quickly realize that “PLA” isn’t always just PLA. That’s why it’s better to separate it properly beforehand, rather than wonder later why the filament is no good.

We have instructions for professionally drying granules —as well as for a more cost-effective but less efficient alternative using a homemade DryBox. We use the Digicolor Drywell for this, which is also available from us.

Overall, drying is pretty unspectacular. But you’ll definitely notice the difference if you skip it.

This Is How We Recycle in Darmstadt

Extrude

Next comes the main step: extrusion. Of course, you'll need a Extruder for this. You can build one yourself using the Precious Plastic blueprints or buy one online, for example at the Precious Plastic Bazaar.

We've been improving our " Extruder " for years and have learned that three things are especially important:

A suitable screw conveyor
Precise Temperature Measurement and Control
Easily replaceable nozzles

The more uniform the input material, the less the Extruder has to compensate. In our QiTech Extruder , the temperature zones and the mass pressure sensor help keep the process under control—if something does get stuck, it shuts down before the pressure causes major damage.

To the QiTech Extruder

Cooling Extruded Filament

When the hot filament comes out of the Extruder , it must cool down in a controlled manner before it reaches the spool .

For many setups, air cooling is sufficient—for example, using a tower fan or our QiTech Airpath, as the speed increases. If the cooling path is no longer sufficient at higher exhaust speeds, multiple Airpaths can also be arranged in series.

For even greater cooling performance, the QiTech Aquapath offers a water-cooling solution. Important: Your hardware must be compatible with water contact.

Overall, after cooling, the filament should still be firm enough to wind, but not so cool that it no longer lays neatly on the spool .

About Air Cooling About water cooling

Laser Measurement

In our production process, we still use laser measurement to ensure that the diameter isn't left to chance. This is more of an optional step, but it's important to us so that we can guarantee minimal deviations.

In addition, the data is then fed into our own QiTech Control software. If the filament becomes too thick or too thin, the feed rate during winding can be adjusted immediately.

About Laser Measurement

Winding Filament

Finally, you can wind the filament onto a spool so you can use it in your printer later. For this step, we'll use our QiTech Winder.

It pulls the filament in a controlled manner and distributes it evenly across the roll via the puller, traverse, and spool axis. The “F” in “filament guide” stands for precision. To ensure that no loosely wound spool is produced at the end, the filament should always remain under tension during this process. Our intelligent software handles this. Thanks to it, we don’t have five individual machines lined up next to each other, but rather a single, intelligent integrated system.

Go to QiTech Winder Learn more about our software

Printing

Now you can load the new filament into the printer. Have fun printing!

For your first experiments, you don't need the latest technology or every machine in our full filament line.

However, if you process materials on a regular basis, it’s worth coordinating the individual steps: Shredder(drying), Extruder(cooling), laser measurement, and Winder. The combination that works best for your material and volume depends on your specific application. If you have any questions or are interested in our machines, just drop us a line!

If you have any questions or are interested in our machines, just send us a message!

P.S.: You can also find filament and accessories in our Community Shop.

Go to the Community Shop

YOUR CONTACT PERSON

Do you have any questions or comments?

You can reach Milan at the number below via Whats-App or SMS. Of course you can also simply contact us by e-mail. Just as you like :)

info@qitech.de

Milan von dem Bussche, contact person at QiTech

Milan von dem BusscheTechnical Contact