Do you have plastic waste? It might be your next product

Waste as a Challenge

The principle we’re interested in is actually quite simple:

company → waste → product

We take specific plastic waste as the starting material for designing a new application. This results in small, functional micro closed-loop systems designed for a specific client, a specific material, and a specific use.

So it’s not just about the material being “recycled.” What matters is where it comes from, what properties it has, and what new product actually makes sense to create from it.

The term “closed loop” is used very frequently today, sometimes even as a buzzword in debates about sustainability. In reality, however, it is not an automatic process. Plastic that has already gone through a production cycle changes its properties, and it is necessary to re-evaluate them.

That is why at Plastenco, we always start by examining the material flow itself:

• how stable the material’s composition is
• how it behaves during processing
• what its limitations are
• and for what type of product or architectural application it still makes sense

Only once we understand a specific waste stream can we propose what should be created from it. This is precisely where, in our view, product design meets materials research. It’s not just about what can be printed, but mainly about what makes sense to print—and from what.

Typically, we print using a single material, with the vision of taking products back and recycling them into a new generation of products.

One result of this approach is, for example, the Sediment project, which demonstrates what a design object born out of circular materials research can look like.

The material must “feed” the robot

Our research also includes robotic large-format 3D printing. However, this doesn’t work with just any plastic.

The robot requires relatively specific “nutrition”—the right type of plastic, the appropriate fraction, the shape of the granules or crushed material, and sufficiently stable material properties. That’s why, when working with recycled plastics, we don’t just ask whether the material is recyclable.

Its processability and long-term consistency are also crucial.

Incidentally, this is one of the reasons why the market for recycled plastics is so volatile. For actual production, it’s not enough that the material is available. It must maintain similar properties, purity, and visual characteristics over the long term. This is particularly critical for transparent plastics.

Shredded Material vs. Regranulate

In practice, we often have to choose between two material options:

Shredded material (mechanically shredded waste)

• shorter material cycle
• lower energy consumption
• closer to the original waste
• less stable during processing

Regranulate

• More consistent parameters
• More predictable behavior during extrusion
• more suitable for larger production runs
• higher cost and additional energy consumption

It is therefore not a simple choice between a “better” and a “worse” solution. We are looking for a balance between:

• print stability
• the appearance of the result
• cost
• energy consumption
• the actual degree of circularity

Materials Research in Practice

Currently, as part of the TAČR PlastIT research project, we are testing various types of plastic waste and their potential for robotic 3D printing.

For example:

• polycarbonate spools from 3D printing filaments, which we have shredded and homogenized,
• polypropylene waste from manufacturing,
• or common materials such as PETG and PLA.

But we’re also testing polymers that aren’t commonly used for printing, such as PMMA, MABS, SAN, PVC, etc.

How We Combat Yellowing in Transparent Plastics

You may have noticed that old transparent plastics turn yellow over time or when heated.

Or, when printing with transparent PLA, this is one of our biggest challenges. The heat generated during processing causes a color shift that spoils the crystal-clear appearance we’re aiming for.

That’s why we’ve developed a simple laboratory method to optically counteract this effect. We call it the “drop method.”

It works a bit like purple shampoo, which removes yellow tones from blonde hair.

We use an alcohol-based carrier (such as isopropyl alcohol) mixed with a very small amount of dye. We apply this mixture directly to the surface of the plastic pellets before printing.

The dye then optically neutralizes the unwanted yellow tint without altering the material’s behavior during extrusion or the 3D printing process itself.

In industrial production, so-called masterbatches—concentrated additives containing brighteners—are commonly used for a similar purpose. However, these make economic sense mainly for huge batches measured in metric tons.

Our droplet method, on the other hand, allows us to work more flexibly:

• it is cost-effective: we use only a minimal amount of dye
• it’s adaptive: we can adjust the shade depending on how yellow a particular batch of PLA is
• it works even for small production runs and experimental materials

Thanks to these experiments, we’re able to create products from PLA that have a visual quality close to that of glossy glass.

We use this method with both virgin PLA and recycled materials.

Do you have plastic waste?

Your next product might already be in there.

If your company works with clean and easily identifiable plastic waste, this could be an interesting starting point for a partnership. Sometimes, it doesn’t just result in recycled material, but in a completely new product, designed specifically for the material from which it was created.