recycling

103 Articles

Reducing Poop On Multicolor Prints

November 5, 2023 by 25 Comments

While multicolor printing eliminates painting steps and produces vibrant objects, there are two significant downsides; filament consumption and print time. A single-nozzle filament printer needs to switch from one color to another, and doing so involves switching to the other filament and then purging the transition filament that contains a mixture of both colors, before resuming the print with the clean new color.

[teachingtech] tests out a variety of methods for reducing print time and waste. One surprising result was that purging into the infill didn’t result in significant savings, even when the infill was as high as 50%. Things that did have a positive effect included reducing the amount of purge per transition based on light to dark color changes, and printing multiple copies at once so that even though the total amount of waste was the same as a single part, the waste per part was reduced.

All of the tests were with the same model, which had 229 color changes within a small part, so your mileage may vary, but it’s an interesting investigation into some of the deeper settings within the slicer. Reducing filament waste and print time is an admirable goal, and if you make your own extruder, you can turn all of that purge waste into various shades of greenish brownish filament. Continue reading “Reducing Poop On Multicolor Prints” →

Lessons In Printer Poop Recycling

November 4, 2023 by 33 Comments

The fundamental problem with multi-color 3D printing using a single hotend is that they poop an awful lot. Every time they change filaments, they’ve got to purge the single nozzle, which results in a huge number of technicolor “purge poops” which on some machines are even ejected out a chute at the back of the printer. The jokes practically write themselves.

What’s not a joke, though, is the sheer mass of plastic waste this can produce. [Stefan] from CNC Kitchen managed to generate over a kilo of printer poop for a 500-gram multi-color print. So he set about looking for ways to turn printer poops back into filament, with interesting results. The tests are based around a commercial lab-scale filament extruder, a 3Devo Composer, but should apply to almost any filament extruder, even the homebrew ones. A few process tips quickly became evident. First, purge poops are too big and stringy (ick) to feed directly into a filament extruder, so shredding was necessary.

Second, everything needs to be very clean — no cross-contamination with plastics other than PLA, no metal bits in the chopped-up plastic bits, and most importantly, no water contamination. [Stefan]’s first batch of recycled filament came from purge poops that had been sitting around a while, and sucked a lot of water vapor from the air. A treatment in a heated vacuum chamber seems to help, but what worked best was using purge poops hot and fresh from a print run. Again, ick.

[Stefan] eventually got a process down that produced decent, usable filament that would jam the printer or result in poor print quality. It even had a pretty nice color, which of course is totally dependent on the mix of colors you start with. Granted, not everyone has access to a fancy filament extruder like his, so this may not be practical for everyone, but it at least shows that there’s a path to reducing the waste stream from any printer, especially multi-material ones.

Continue reading “Lessons In Printer Poop Recycling” →

Two men in black shirts stand between a white and a blue exercise bike sitting on a table in front of them. The exercise bikes have black drums slightly larger than a coffee can affixed to the front of the bike which houses the shredding mechanism. In the background is a "Precious Plastics Torino" circular logo.

Getting Shredded Plastic…and Legs

September 23, 2023 by 10 Comments

While electric motors have taken the drudgery out of many tasks, human power has its advantages. [Precious Plastic Torino] has developed a human-powered plastic shredder for those times when an electric motor just won’t do.

Designed primarily for educational purposes at venues where electricity can be difficult to source, but also useful for off-grid environments, this exercise bike-based shredder can take small pieces of plastic and shred them into tiny pieces suitable for use with any of the other machines in the Precious Plastics ecosystem like their injection molding machine. As with all [Precious Plastics] projects, the files are will be open source; however, there is a six month exclusivity period for Patreon subscribers to help fund development efforts.

The build is relatively simple: take an old exercise bike, remove the unnecessary bits, and run the chain up to drive a shredding mechanism mounted on the front of the bike. We think they should’ve kept the flywheel to help keep the momentum going while shredding but can’t fault them for wanting to keep the prototype as simple as possible. Maybe the next step is getting these in spin classes around the country so people can get their exercise and help recycle in their community at the same time!

If this shredder doesn’t suit your fancy, maybe recycle your plastic with SHREDII or this other DIY effort. If you’d rather generate electricity on your exercise bike, then try building this bike generator.

Continue reading “Getting Shredded Plastic…and Legs” →

There’s Cash In Them Old Solar Panels

April 12, 2023 by 82 Comments

The first solar panels may have rolled out of Bell Labs in the 1950s, with major press around their inconsistent and patchy adoption in the decades that followed, but despite the fanfare they were not been able to compete on a price per kilowatt compared to other methods of power generation until much more recently. Since then the amount of solar farms has increased exponentially, and while generating energy from the sun is much cleaner than most other methods of energy production and contributes no greenhouse gasses in the process there are some concerns with disposal of solar panels as they reach the end of their 30-year lifespan. Some companies are planning on making money on recycling these old modules rather than letting them be landfilled. Continue reading “There’s Cash In Them Old Solar Panels” →

Repurposing Old Smartphones: When Reusing Makes More Sense Than Recycling

February 28, 2023 by 89 Comments

When looking at the specifications of smartphones that have been released over the past years, it’s remarkable to see how aspects like CPU cores, clockspeeds and GPU performance have improved during this time, with even new budget smartphones offering a lot of computing power, as well as a smattering of sensors. Perhaps even more remarkable is that of the approximately 1.5 billion smartphones sold each year, many will be discarded again after a mere two years of use. This seems rather wasteful, and a recent paper by Jennifer Switzer and colleagues proposes that a so-called Computational Carbon Intensity (CCI) metric should be used to determine when it makes more sense to recycle a device than to keep using it.

What complicates the decision of when it makes more sense to reuse than recycle is that there are many ways to define when a device is no longer ‘fit for purpose’. It could be argued that the average smartphone is still more than good enough after two years to be continued as a smartphone for another few years at least, or at least until the manufacturer stops supplying updates. Beyond the use as a smartphone, they’re still devices with a screen, WiFi connection and a capable processor, which should make it suitable for a myriad of roles.

Unfortunately, as we have seen with the disaster that was Samsung’s ‘upcycling’ concept a few years ago, or Google’s defunct Project Ara, as promising as the whole idea of ‘reuse, upcycle, recycle’ sounds, establishing an industry standard here is frustratingly complicated. Worse, over the years smartphones have become ever more sealed-up, glued-together devices that complicate the ‘reuse’ narrative.

Continue reading “Repurposing Old Smartphones: When Reusing Makes More Sense Than Recycling” →

A man with dark skin in a red shirt and khaki shorts sits in a chair. His left leg has a prosthetic below the knee. The upper half of the prosthethic is an off white plastic socket with flecks of different off white plastic throughout hinting at the recycled nature of the plastic. The lower half is a metal tube attached to an artificial foot in black sandals.

Precious Plastic Prosthetics

February 20, 2023 by 8 Comments

Plastic waste is a major problem, but what if you could turn the world’s trash into treasure? [Yayasan Kaki Kita Sukasada (YKKS)] in Indonesia is doing this by using recycled plastic to make prosthetic legs.

Polypropylene source material is shredded and formed into a sheet which is molded into the required shape for the socket. A layer of cloth and foam is used to cushion the interface between the patient and the socket itself. Using waste plastic to make parts for the prosthetics lowers the price for patients as well as helps to keep this material out of the landfill.

What makes this project really exciting is that [YKKS] employs disabled people who develop the prosthetics and also trains patients on how to maintain and repair their prosthetics with easily sourced tools and materials. With some medical device companies abandoning their devices, this is certainly a welcome difference.

We’ve previously covered the Precious Plastic machines used to make the plastic sheets and the organization’s developments at small scale injection molding.

Continue reading “Precious Plastic Prosthetics” →

Utility Mat Turns Waste Epoxy Into Useful Tools

February 9, 2023 by 46 Comments

Epoxy is a great and useful material typically prepared by mixing two components together. But often we find ourselves mixing too much epoxy for the job at hand, and we end up with some waste left behind. [Keith Decent’s] utility mat aims to make good use of what is otherwise waste material.

The concept is simple yet ingenious. It’s a flexible mat that serves as a mold for all kinds of simple little plastic workshop tools. The idea is that when you have some epoxy left over from pouring a finish on a table or laying up some composites, you can then pour the excess into various sections of the utility mat. The epoxy can then be left to harden, producing all manner of useful little tools.

It may seem silly, but it could save your workshop plenty of nickels and dimes. Why keep buying box after box of stir sticks when you can simply make a few with zero effort from the epoxy left from your last job? The utility mat also makes other useful nicknacks like glue spreaders, scrapers, wedges, and painter’s pyramids.

We’ve seen other great recycling hacks over the years too. Video after the break.

Continue reading “Utility Mat Turns Waste Epoxy Into Useful Tools” →