How can you recycle 3D printing waste sustainably in a manufacturing setting?

Recycling 3D Printed waste can be streamlined at the end , by choosing the materials you print with carefully and in a sustainable way. Choosing to use materials which allready have a route to be recycled in the current chain, is far more sustainable than attempting to recycle multiple plastics which don't have a end of life use locally. Helping our clients make better material choices with local existing recycling solutions , can allow us to create a extremely efficient recycling system in house and limiting the amount of materials and waste we generate overall.

Reflecting on the importance of identifying and quantifying waste from 3D printing processes, it's also essential to maintain non-contamination. Expert waste management service, Biffa, did a study on this which revealed that nearly one-fifth of waste labeled as 'recyclable' in England and Wales is actually non-recyclable due to contamination. Hence, for 3D printing waste recycling to be effective, it's crucial to 'pre-cycle.' This involves meticulously removing any contaminants from the waste before storing them in dedicated recycling bins or containers, ensuring that they are primed for the subsequent recycling steps.

I agree, considering not only the characteristics of your waste, but of what you’re printing. Oftentimes, 3D printing can consists of heavy plastics such as ABS, but starting to look into more sustainable materials can help to making the recycling process that much smoother. For example, using PLA more often could potentially lead to an easier recycling process down the line. However, PLA isn’t the strongest material, especially for prints that require heavy use; but it is a start. Looking into using other materials such as PETG can aid in increasing sustainability efforts.

The problem with the waste generated in 3D printing is that it is no longer just the usual PLA, ABS, PETG, etc., but rather more complex materials that in many cases include additives to achieve certain mechanical properties. There is also the difficulty that these wastes can be in filament, powder or resin format, apart from failed solid-state prints. Not all waste managers accept all formats. The ideal would be to separate each printing material and have each manufacturer or distributor collect them to be able to manage them independently. In any case, it must be an agreement that involves users, distributors and materials manufacturers.

note that thermoplastics can only be reused a handful of times before they start breaking down into simpler oils and hydrocarbons. this is why PLA and the like are good. they might not be the best materials ever, but at the very least after they've been recycled a couple times, you can mulch them and feed them to things that can return them to the earth. note PLA is actually a stable form of lactic acid and takes a good amount of processing to mulch.

Reuse within the workplace is likely to be the most sustainable option. For smaller users of either MJF or SLS there tends to be insufficient quantities of waste to make repurposing / recycling viable for commercial services. The processes are generally very efficient, for example MJF run at recommended setting produces around 5-7.5% clean waste per run. The rest is either parts or mixed waste (with variable percentage by weight of glass blasting media). This is simply not enough waste volume to allow a third party to establish a viable route to second market. Direct reuse into parts yields the most sustainable solution. 100% available clean powder (in the case of MJF and Pa12) is reusable outside the MJF ecosystem to directly make parts.

It would be great to see machine OEM's move more towards pellet feedstocks over filamentized; even for lower volume throughput machines. This would not only open options for refeed and blend batching (for those it could be relevant for) but also drive cost/part down and bolster lower TCO. The capitol, infrastructure, and labor costs involved in vertically integrated material recycling is impractical for many -if not most- companies and even industries. It would be incredible to see a task force or consortia of mat'l and machine manufacturers along with (possibly) government to drive for a practical and sustainable means for localized, automated mat'l segregation and recycling for thermoplastics given the rise of AM adoption across industry

In my perspective, users should investigate the recycling cost per KG with a professional collection service and incorporate this into their charging system per hour. This will give the professional user ample budget to allow this recycling process to happen. For home-users, printing a press mold which can be re-used for simple ware and tare items around the house . This can be a extremely efficient way of using the modest waste generated, but can be very time consuming. We could take great inspiration from the WEEE Waste collection for the lighting industry . The service is attached to the cost of the item at the beginning of the experience which allows cost for the recycling process and the client a place to return waste.

One of the my favorite approach is use of open source machines developed by "Precious Plastics". 3D printing companies can develop this machines for internal use and recycle and reuse the plastic waste.

I disagree with the view that shredding and extruding waste is a "popular choice" for 3D printing operators. This might be viable for high-volume users with ample resources, but for many, the substantial initial equipment costs and time investment render it impractical. The risk of quality issues due to polymer degradation after repeated extrusions cannot be overlooked. A professional recycling service, costing approximately ￡4-5 per kilogram, emerges as a more viable alternative. When compared to the average cost of PLA at ￡20-25 per kilogram, this option stands out as more cost-effective and practical for a majority of 3D printing operators, ensuring quality and efficiency without the hefty investment.

When recycling 3D prints, I believe that separating them by brand and color can be beneficial. At the very least, separating them by brand is important because, for example, some brands have a wider temperature range for printing, while others have a narrower range. This temperature range difference can be as much as 20 degrees, which can potentially lower the quality of recycled filament and lead to printing errors, such as nozzle clogs. In addition to this, if the filament diameter is not consistent or constantly changing, it can result in printing failures.

Ecobricks, PET bottles packed with used plastic, offer a community-driven solution to 3D printing waste by repurposing plastic waste into reusable building blocks, thus preventing it from ending up in landfills. Despite the growth of 3D printing leading to increased waste, Ecobricks provide an innovative way for individuals and businesses to recycle plastic waste, including unwanted prints and failed prototypes. Users can create their own Ecobricks and use them in various building applications. This zero-cost solution, with over 5000 hubs worldwide, offers an accessible approach to recycling 3D printing waste. However, the time-consuming process and limitations on waste size and type pose challenges to its efficacy in waste management

In a manufacturing setting, sustainable recycling of 3D printing waste remains understated. Adopt a closed-loop system: segregate filament waste types, use on-site grinding, and reintroduce through filament extruders. Ensure recycled filament quality via checks, or blend with virgin material for hybrid filaments. Engage the community with workshops on recycling practices. Consider upcycling: transform waste into novel items like eco-bricks or art. Partner with institutions for cutting-edge recycling solutions. Offer incentives for product returns, supplying more recyclable material and showcasing commitment to sustainability. Aim for near-zero waste to lead in green 3D printing practices.

Before we look to recycle, we should consider the two streams that come before, Reduce and Reuse. Reducing waste can factor into a number of areas and is easier in some methods than others. With FDM printing you can use sparse infill support with a more solid top. Orientating models to use as little support as possible. Using machines that have an actual usable reel switch out method (markforged and bambu immediately jump to mind) rather than just a filament out relay with no real method thought out to actually change out the filament. That just leads to wasted prints and material. Reusing can be a little more tricky however I have seen efforts to melt down used filament and other plastics into further models which is effective.

One aspect to consider is your overall design of the components that you are creating via Additive. If you are making tooling, design the part to take advantage of Additive Manufacturing. Consider you have a tool that wears out in the same place over and over. Design the high wear area to be desperate, where you can use a more robust material, and replace only the small wear areas, versus the entire tool. This way you can minimize the waste being generated via your process. Another thing is to understand your local area recycling, and inquire with recyclers for different materials. We seperate our waste materials so they can be recycled, and we recycle old spools and cartridges with manufacturers when possible.

Supplier Engagement: Engage with 3D printing material suppliers that offer take-back or recycling programs. Some suppliers may have initiatives to recycle or reprocess their materials. Publicize Sustainability Initiatives: Promote your sustainable 3D printing and recycling practices to customers and stakeholders. Demonstrating environmental responsibility can enhance your company's reputation.