Plastic is globally in focus when it comes to environmental pollution. While practical, it takes thousands of years to fully decompose. Microplastics are now found in oceans, in fish, and thus also in our food. In the long term, substances like PFAS cause damage to the human organism. The majority of produced plastic comes from petroleum, which further burdens the environmental balance.

Sustainable 3D printing starts precisely here: through the use of biodegradable materials from renewable resources and by recycling existing plastic waste. In this article, we show how sustainable 3D printing works in practice, which materials are used, and how a true circular economy is created.

What is sustainable 3D printing?

Sustainable 3D printing means manufacturing plastic objects with minimal environmental impact. Three levers are crucial:

• Material selection: Biodegradable filaments like PLA from plant starch instead of petroleum-based plastics
• Recycling: Plastic waste from 3D printing and everyday life is shredded and reprocessed
• On-demand manufacturing: Only print what is actually needed, no overproduction and no excess inventory

At Biocraftlab, we combine all three approaches in our workshop at Liebenauer Gürtel 10 in Graz.

PLA and recycled filament: the materials for sustainable 3D printing

The most important material for sustainable 3D printing is PLA, short for polylactide. PLA is derived from corn starch or sugarcane, is biodegradable, and does not require petroleum. It can be processed precisely and is food-safe according to EU regulations.

Additionally, we rely on recycled filament, especially rPLA and rPET. rPLA is made from shredded 3D printing waste and production scraps. rPET is produced from old PET bottles. Both filaments offer the same print quality as virgin material but save massive resources.

PLA vs PETG vs ABS: Material comparison for sustainable 3D printing

For material selection in 3D printing, three filaments are particularly common. PLA scores points for sustainability, PETG for robustness, ABS for heat resistance. The direct comparison:

Conclusion: For most applications in sustainable 3D printing, PLA is the first choice. If higher load-bearing capacity is required, rPET is a recycled compromise. ABS practically no longer plays a role in sustainable printing.

Circular economy in 3D printing: how the recycling process works

Sustainable 3D printing does not end with the material but continues with waste management. Every 3D printing production generates waste: support material, faulty prints, purge objects during material changes. This waste does not end up in the trash with us, but in the recycling process.

Step 1: Sorting. Plastic waste is separated by material type and color. We currently process four main plastics:

• PLA (Polylactide) from 3D printing waste
• PET (Polyethylene terephthalate) from bottles and packaging
• PP (Polypropylene) from laboratory disposables and packaging
• HDPE (High Density Polyethylene) from caps and containers

Step 2: Shredding. Single-sort plastics are crushed into granules.

Shredded plastics are processed into granules, which are then used for filament extrusion or injection molding.

Step 3: Reutilization. The granulate is used for pellet printers or the injection molding process with aluminum molds. It can also be used to produce new 3D printing filament.

Aluminum molds enable series production of small components from recycled plastic through injection molding.

Step 4: Product creation. New 3D printing filament or directly finished objects are created using recycling methods.

Functional objects are made again from shredded plastic waste. True circular economy in 3D printing.

Old PET bottles become new 3D printing filament

A concrete example of a living circular economy: recycled PET filament for 3D printers can be made from old PET bottles. For this, bottles are cut into fine strips and formed into round filament through a nozzle. We have documented the detailed process here: 3D Printing from Recycled PET Bottles.

Recycled filament for 3D printers is created from cut PET bottle strips.

Advantages of sustainable 3D printing over conventional manufacturing

In direct comparison with traditional manufacturing methods, sustainable 3D printing has several advantages:

• Less material consumption: 3D printing works additively, meaning it only builds material where it is needed. Traditional milling processes remove material and generate a lot of waste.
• Local production: No overseas transports, no container fuel, no CO2-intensive shipping from Asia.
• On-demand instead of mass production: Only what is needed is manufactured, no inventory that will later be destroyed.
• Closed material cycle: Print waste re-enters the process instead of ending up in residual waste.
• Biodegradable materials: PLA decomposes completely under industrial composting conditions.

How sustainable is PLA really?

PLA is biodegradable, but not in a home compost bin. Industrial composting facilities with temperatures above 60 degrees and controlled humidity decompose PLA completely into CO2, water, and biomass within a few months. In normal household waste or in nature, decomposition takes significantly longer.

The relevant standard for this is DIN EN 13432, defined by the European Bioplastics Association. It regulates the conditions under which a material is considered industrially compostable: 90 percent decomposition into CO2 and water within six months at 58 degrees Celsius.

The honest assessment: PLA is more environmentally friendly than ABS or petroleum-based PETG, but it does not replace recycling. The best 3D printing waste is that which is not generated at all or is immediately returned to the cycle. This is precisely why we combine PLA with active on-site recycling.

Applications: what can be made from sustainable 3D printing?

At Biocraftlab, we print a wide range of products with PLA and recycled filament. Popular examples from our assortment:

• Cookie cutters in over 200 designs (animals, Christmas, science)
• Vases in modern design
• Trophies, medals, and awards
• Promotional items and employee gifts
• Decorative objects and gift ideas
• Prototypes and small series for companies

Individual cookie cutters for bakeries, museum shops, and promotional items are particularly in demand.

Cookie cutters made from biodegradable PLA, produced by 3D printing at Biocraftlab.

Frequently asked questions about sustainable 3D printing

Is PLA really better than conventional plastic?
Yes, in several respects: PLA is made from renewable resources, is biodegradable, and requires less energy in production than ABS or PETG. However, it is only fully biodegradable under industrial composting conditions.

What happens to faulty 3D prints?
At Biocraftlab, faulty prints and support material are collected, sorted, shredded, and reused in injection molding or as rPLA filament. None of it ends up in residual waste.

Can I compost PLA objects at home?
No. PLA requires temperatures above 60 degrees and controlled humidity. It hardly decomposes in home compost. Industrial composting facilities are the right place.

Which recycled plastics can be processed in 3D printing?
PET, PLA, PP, and HDPE are well suited for 3D printing or injection molding processes. The prerequisite is single-sort separation before shredding.

How environmentally friendly is 3D printing compared to injection molding in China?
Local 3D printing saves container transport and enables on-demand manufacturing. For small and medium quantities, 3D printing is significantly more sustainable. For very large quantities, local injection molding with recycled material can perform similarly well.

Utilize sustainable 3D printing

Do you have an idea, a prototype, or a series project that needs to be implemented with sustainable material? Our 3D Printing Service Graz works exclusively with PLA and recycled filament and handles everything from 3D design to small series production.

Send us your inquiry via the contact form or by email to support@biocraftlab.com. You will receive an offer within 24 hours.