3D Printing Recycling: For Sustainability

With the rapid development of 3D printing technology, how to effectively recycle and reuse waste generated during the printing process has become an important issue that needs to be solved in the industry. Reducing printing waste can not only reduce costs, but also is a key step to achieve sustainable development. This article will explore how to reduce waste in 3D printing and introduce some practical 3d printing recycling application cases.

Source: https://www.3dnatives.com/en/10-reasons-why-3d-printing-is-considered-sustainable-300720244/

Reduce printing waste

Before considering 3D printing recycling, minimizing waste in 3D printing is essential for sustainability and cost-effectiveness. Here are some strategies to help reduce waste in the 3D printing process:

1. Optimize design

Support structure: Minimize the need for unnecessary support when designing 3D models. Less support material means less waste. Choose support structures that are easier to remove or consider using soluble support materials. This can minimize damage to the main model.

Source: https://support.bcn3d.com/knowledge/optimize-support-material

Combine parts: Design the parts to be printed as a single piece as much as possible, which can reduce the need for support and reduce the risk of large parts failing to print.

2. Adjust printing parameters

Filling settings: Reduce the fill percentage according to the strength requirements of the model.

Layer height: Adjust the layer height according to the required details. Thicker layers can reduce printing time and material usage.

3D Printing Recycling Methods (Filament)

Making recycled filament from 3D printing waste involves several steps:

Collecting waste: Collect failed prints, support structures, and other 3D printing waste made of compatible thermoplastics such as PLA or ABS.

Crushing waste: Use a plastic crusher to crush the collected material into small pieces or pellets. The smaller size makes it easier to handle in subsequent steps.

Washing and drying: Clean the shredded plastic to remove any contaminants (such as dust or oil), then dry it thoroughly. Contaminants can affect the quality of the final filament.

Extruding filament: Feed clean, dry plastic pellets into a filament extruder. The extruder will melt the plastic and form it into a continuous strand. Set the temperature and speed based on the type of plastic used. Note that the input plastics must have the same material properties and the size of the fragments must be the same.

Cooling and winding: After the extruded filament leaves the extruder, wait for it to cool naturally. After cooling, wind the filament onto a spool.

Testing filaments: Before using recycled filaments for printing, it is important to test their diameter and quality. This ensures consistency and reliability during the printing process.

Source: https://www.sciencedirect.com/science/article/abs/pii/S2214860418307802

3D Printing Recycling in Action

More and more companies are actively exploring innovative ways to recycle and reuse printing waste. Here are three real-life cases that show how to effectively recycle and reuse waste generated during the 3D printing process.

Stratasys has developed a Selective Absorption Fusion (SAF) platform that promises to significantly increase the recycling rate of nylon powder waste. SAF technology overcomes the challenges of molecular structure changes after multiple printing cycles of powder. The key is the use of a unidirectional print frame to ensure that each position on the print bed experiences the same coating, heating and cooling time intervals, resulting in consistent heat input and uniform shrinkage. This higher degree of control over the thermal environment enables SAF to effectively integrate waste nylon powder that other technologies cannot utilize.

Since the beginning of 2021, HP has been working with Ford, SmileDirectClub and resin producer Lavergne to recycle 3D printer waste into small batches of automotive parts. These parts have better chemical and moisture resistance than traditional versions. Lavergne converted SmileDirectClub’s dental aligner molds (3D printed using HP Multi Jet Fusion) into high-quality recycled plastic pellets that can then be used for injection molding of Ford fuel line clamps. This remarkable new method has the potential to revolutionize the customization of small-volume automotive parts and accelerate sustainability.

Prusa has created a world map that currently has small-scale plastic recycling projects around the world. For 3D printing users, plastic waste is unwanted, but for small recycling businesses it is a valuable resource, so the map connects recyclers and the 3D printing community to promote the recovery and reuse of printing waste.