Two colored plastic films are loosely tied over the entrances to two plastic containers.

Cooking Up Plastics In The Kitchen

October 28, 2025 by Aaron Beckendorf 3 Comments

The earliest useful plastics were made out of natural materials like cellulose and casein, but since the Bakelite revolution, their use has dwindled away and left them mostly as curiosities and children’s science experiments. Fortunately, though, the raw materials for bioplastics are readily available in most grocery stores, and as [Ben] from NightHawkInLight demonstrates, it’s still possible to find new uses for them.

His first recipe was for a clear gelatine thermoplastic, using honey as a plasticizer, which he formed into the clear packet around some instant noodles: simply throw the whole packet into hot water, and the plastic dissolves away. With some help from the home bioplastics investigator [Giestas], [Ben] next created a starch-based plastic out of starch, vinegar, and glycerine. Starch is a good infrared emitter in the atmospheric window, and researchers have made a starch-plastic aerogel that radiates enough heat to become cooler than its surroundings. Unfortunately, this requires freeze-drying, and while encouraging freezer burn in a normal freezer can have the same effect, it’ll take a few months to get a usable quantity of the material.

The other problem with starch-based plastics is their tendency to absorb water, at least when paired with plasticizers like glycerine or honey. Bioplastics based on alginate, however, are easy to make waterproof. A solution of sodium alginate, derived from seaweed, reacts with calcium ions to make a cross-linked waterproof film. Unfortunately, the film forms so quickly that it separates the solutions of calcium ions from the alginate, and the reaction stops. To get around this, [Ben] mixed a sodium alginate solution with powdered calcium carbonate, which is insoluble and therefore won’t react. To make the plastic set, he added glucono delta lactone, which slowly breaks down in water to release gluconic acid, which dissolves the calcium carbonate and lets the reaction proceed.

The soluble noodle package reminded us of a similar edible package, which included flavoring in the plastic. We’ve also seen alginate used to make conductive string, and rice used to make 3D printer filament. It’s worth some caution, though – not all biologically-derived plastics are healthier than synthetic materials.

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Hackaday Links: September 21, 2025

September 21, 2025 by Dan Maloney 7 Comments

Remember AOL? For a lot of folks, America Online was their first ISP, the place where they got their first exposure to the Internet, or at least a highly curated version of it. Remembered by the cool kids mainly as the place that the normies used as their ISP and for the mark of shame an “@aol.com” email address bore, the company nevertheless became a media juggernaut, to the point that “AOL Time Warner” was a thing in the early 2000s. We’d have thought the company was long gone by now, but it turns out it’s still around and powerful enough of a brand that it’s being shopped around for $1.5 billion. We’d imagine a large part of that value comes from Yahoo!, which previous owner Verizon merged with AOL before selling most of the combined entity off in 2021, but either way, it’s not chump change.

For our part, the most memorable aspect of AOL was the endless number of CDs they stuffed into mailboxes in the 90s. There was barely a day that went by that one of those things didn’t cross your path, either through the mail or in free bins at store checkouts, or even inside magazines. They were everywhere, and unless you were tempted by the whole “You’ve got mail!” kitsch, they were utterly useless; they didn’t even make good coasters thanks to the hole in the middle. So most of the estimated 2 billion CDs just ended up in the trash, which got us thinking: How much plastic was that? A bit of poking around indicates that a CD contains about 15 grams of polycarbonate, so that’s something like 30,000 metric tonnes! To put that into perspective, the Great Pacific Garbage Patch is said to contain “only” around 80,000 metric tonnes of plastic. Clearly the patch isn’t 37% AOL CDs, but it still gives one pause to consider how many resources AOL put into marketing.

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A photo montage of scrap plastic being vacuumed up, processed in the main chamber, and bottled in gas tanks.

Solar Powered Pyrolysis Facility Converts Scrap Plastic Into Fuel

August 23, 2025 by John Elliot V 60 Comments

[naturejab] shows off his solar powered pyrolysis machine which can convert scrap plastic into fuel. According to the video, this is the world’s most complex hand-made pyrolysis reactor ever made. We will give him some wiggle room there around “complex” and “hand-made”, because whatever else you have to say about it this machine is incredibly cool!

As you may know pyrolysis is a process wherein heat is applied to organic material in an inert environment (such as a vacuum) which causes the separation of its covalent bonds thereby causing it to decompose. In this case we decompose scrap plastic into what it was made from: natural gas and petroleum.

His facility is one hundred percent solar powered. The battery is a 100 kWh Komodo commercial power tank. He has in the order of twenty solar power panels laying in the grass behind the facility giving him eight or nine kilowatts. The first step in using the machine, after turning it on, is to load scrap plastic into it; this is done by means of a vacuum pump attached to a large flexible tube. The plastic gets pumped through the top chamber into the bottom chamber, which contains blades that help move the plastic through it. The two chambers are isolated by a valve — operating it allows either chamber to be pumped down to vacuum independently.

Once the plastic is in the main vacuum chamber, the eight active magnetrons — the same type of device you’d find in your typical microwave oven — begin to break down the plastic. As there’s no air in the vacuum chamber, the plastic won’t catch fire when it gets hot. Instead it melts, returning to petroleum and natural gas vapor which it was made from. Eventually the resultant vapor flows through a dephlegmator cooling into crude oil and natural gas which are stored separately for later use and further processing.

If you’re interested in pyrolysis you might like to read Methane Pyrolysis: Producing Green Hydrogen Without Carbon Emissions.

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An Inexpensive Way To Break Down Plastic

March 27, 2025 by Bryan Cockfield 11 Comments

Plastic has been a revolutionary material over the past century, with an uncountable number of uses and an incredibly low price to boot. Unfortunately, this low cost has led to its use in many places where other materials might be better suited, and when this huge amount of material breaks down in the environment it can be incredibly persistent and harmful. This has led to many attempts to recycle it, and one of the more promising efforts recently came out of a lab at Northwestern University.

Plastics exist as polymers, long chains of monomers that have been joined together chemically. The holy grail of plastic recycling would be to convert the polymers back to monomers and then use them to re-make the plastics from scratch. This method uses a catalyst to break down polyethylene terephthalate (PET), one of the more common plastics. Once broken down, the PET is exposed to moist air which converts it into its constituent monomers which can then be used to make more PET for other uses.

Of course, the other thing that any “holy grail” of plastic recycling needs is to actually be cheaper and easier than making new plastic from crude oil, and since this method is still confined to the lab it remains to be seen if it will one day achieve this milestone as well. In the meantime, PET can also be recycled fairly easily by anyone who happens to have a 3D printer around.

How Do We Deal With Microplastics In The Ocean?

February 6, 2025 by Lewin Day 47 Comments

Like the lead paint and asbestos of decades past, microplastics are the new awful contaminant that we really ought to do something about. They’re particularly abundant in the aquatic environment, and that’s not a good thing. While we’ve all seen heartbreaking photos of beaches strewn with water bottles and fishing nets, it’s the invisible threat that keeps environmentalists up at night. We’re talking about microplastics – those tiny fragments that are quietly infiltrating every corner of our oceans.

We’ve dumped billions of tons of plastic waste into our environment, and all that waste breaks down into increasingly smaller particles that never truly disappear. Now, scientists are turning to an unexpected solution to clean up this pollution with the aid of seashells and plants.

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Recycling Tough Plastics Into Precursors With Some Smart Catalyst Chemistry

October 8, 2024 by Lewin Day 33 Comments

Plastics are unfortunately so cheap useful that they’ve ended up everywhere. They’re filling our landfills, polluting our rivers, and even infiltrating our food chain as microplastics. As much as we think of plastic as recyclable, too, that’s often not the case—while some plastics like PET (polyethylene terephthalate) are easily reused, others just aren’t.

Indeed, the world currently produces an immense amount of polyethylene and polypropylene waste. These materials are used for everything from plastic bags to milk jugs and for microwavable containers—and it’s all really hard to recycle. However, a team at UC Berkeley might have just figured out how to deal with this problem.

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3D Printing On Top Of Laser Cut Acrylic

September 24, 2024 by Dave Rowntree 8 Comments

[Julius Curt] needed to mark acrylic panels with a bit more clarity than the usual way of rastering the surface, so they attempted to 3D print directly to an acrylic sheet, which worked perfectly. The obvious way to do this was to bond the acrylic sheet to the bed with glue temporarily, but another way was tried, and it’s much less messy and precarious.

The bond between a 3D print and acrylic is very strong

The first step was to create a 3D model which combined a constraining ‘fence’ to contain the acrylic panel with the required artwork floating above. It was easy enough to run the print long enough to build the fence, then pause the print mid-way to add the pristine panel and restart after a quick re-prime and wipe.

There were a few simple takeaways from the video below. First, to ensure sufficient tolerance between the fence and the panel, consider the layer width (plus associated tolerance when printed) and the laser kerf of your machines to ensure a not-too-sloppy fit. Secondly, that hot nozzle won’t do the acrylic surface any favours during travel moves, so enabling Z-hopping is essential!

Another use for this simple technique is to fully incorporate an acrylic sheet within a print by pausing at an appropriate height again, dropping the panel in, and continuing the print. A degree of overlap will lock the panel tight, with the plastic bonding very firmly to the acrylic, as [Julius] demonstrates in the video.

It’s always a delight to see how techniques can combine to create the desired effects. Here’s how to use a color laser printer and toner transfer paper to apply designs to a 3D printing front panel. Whilst we’re thinking about the multitude of uses for hacking with acrylic, what about not doing that and using corrugated plastic instead?

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