Turning Old Masks Into 3D Printer Filament

Disposable masks have been a necessity during the COVID-19 pandemic, but for all the good they’ve done, their disposal represents a monumental ecological challenge that has largely been ignored in favor of more immediate concerns. What exactly are we supposed to do with the hundreds of billions of masks that are used once or twice and then thrown away?

If the research being conducted at the University of Bristol’s Design and Manufacturing Futures Lab is any indication, at least some of those masks might get a second chance at life as a 3D printed object. Noting that the ubiquitous blue disposable mask is made up largely of polypropylene and not paper as most of us would assume, the team set out to determine if they could process the masks in such a way that they would end up with a filament that could be run through a standard 3D printer. While there’s still some fine tuning to be done, the results so far are exceptionally impressive; especially as it seems the technique is well within the means of the hobbyist.

From masks to usable filament.

The first step in the process, beyond removing the elastic ear straps and any metal strip that might be in the nose, is to heat a stack of masks between two pieces of non-stick paper with a conventional iron. This causes the masks to melt together, and turn into a solid mass that’s much easier to work with. These congealed masks were then put through a consumer-grade blender to produce the fine polypropylene granules that’re suitable for extrusion.

Mounted vertically, the open source Filastruder takes a hopper-full of polypropylene and extrudes it into a 1.75 mm filament. Or at least, that’s the idea. The team notes that the first test run of filament only had an average diameter of 1.5 mm, so they’re modifying the nozzle and developing a more powerful feed mechanism to get closer to the goal diameter. Even still, by cranking up the extrusion multiplier in the slicing software, the team was able to successfully print objects using the thin polypropylene filament.

This is only-during-a-pandemic recycling, and we’re very excited to see this concept developed further. The team notes that the extrusion temperature of 260 °C (500 °F) is far beyond what’s necessary to kill the COVID-19 virus, though if you planned on attempting this with used masks, we’d imagine they would need to be washed regardless. If the hacker and maker community were able to use their 3D printers to churn out personal protective equipment (PPE) in the early days of the pandemic, it seems only fitting that some of it could now be ground up and printed into something new.

Microwave Modified For Disinfecting

We’re all hopefully a little more concerned about health these days, but with that concern comes a growing demand for products like hand sanitizer, disinfectant, and masks. Some masks are supposed to be single-use only, but with the shortage [Bob] thought it would be good if there were a way to sanitize things like masks without ruining them. He was able to modify a microwave oven to do just that.

His microwave doesn’t have a magnetron anymore, which is the part that actually produces the microwaves for cooking. In its place is an ultraviolet light which has been shown to be effective at neutralizing viruses. The mask is simply placed in the microwave and sterilized with the light. He did have to make some other modifications as well since the magnetron isn’t always powered up when cooking, so instead he wired the light into the circuit for the turntable so that it’s always powered on.

Since UV can be harmful, placing it in the microwave’s enclosure like this certainly limits risks. However, we’d like to point out that the mesh on the microwave door is specifically designed to block microwaves rather than light of any kind, and that you probably shouldn’t put your face up to the door while this thing is operating. Some other similar builds have addressed this issue. Still, it’s a great way to get some extra use out of your PPE.

A Properly Engineered UV Chamber For PPE Sanitization

Designed to be used once and then disposed of, personal protective equipment (PPE) such as N95 face masks proved to be in such short supply during the early days of the COVID-19 pandemic that getting a few extra uses out of them by sanitizing them after a shift seemed smart. And so we saw a bunch of designs for sanitizing chambers, mostly based on UV-C light and mostly, sad to say, somewhat dodgy looking. This UV-C disinfection chamber, though, looks like a much better bet.

The link above is to the final installment of a nine-part series by [Jim] from Grass Roots Engineering. The final article has links to all the earlier posts, which go back [Jim]’s early research on UV-C sanitization methods back in March. This led him to settle on an aquarium sanitizer as his UV-C source. A second-hand ultraviolet meter allowed him to quantify the lamp’s output and plan how best to use it, which he did using virtual models of various styles of masks.  Knowing that getting light on every surface of the mask is important, he designed a mechanism to move the mask around inside a reflective chamber. The finished chamber, which can be seen in the video below, is 3D-printed and looks like it means business, with an interlock for safety and a Trinket for control.

We love the level of detail [Jim] put into these posts and the thoughtful engineering approach he took toward this project. And we appreciate his careful testing, too — after all, it wouldn’t do to use a germicidal lamp that actually doesn’t emit UV-C.

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Brainstorming COVID-19 Hack Chat

Join us on Wednesday, April 8 at noon Pacific for the Brainstorming COVID-19 Hack Chat!

The COVID-19 pandemic has been sweeping across the globe now for three months. In that time it has encountered little resistance in its advances, being a novel virus with just the right mix of transmissibility and virulence that our human immune systems have never encountered. The virus is racking up win after win across the world, crippling public health and medical systems, shutting down entire economies, and forcing billions of people into isolation for the foreseeable future.

While social distancing is certainly an effective way to limit the spread of the disease, it feels more like hiding than fighting. Bored and stuck at home, millions of fertile minds are looking for an outlet for this frustration, a more affirmative way to fight the good fight and build solutions that the world sorely needs. And thus we’ve seen the outpouring of designs, ideas, and prototypes of everything from social distancing helpers to personal protective equipment (PPE) hacks.

In this Hack Chat, we’ll try to provide a framework around which hackers can start to turn their ideas into COVID-19 solutions. There are a ton of problems right now, but the most acute and most approachable seem to revolve around making sure healthcare providers have the PPE they need to do their job safely. Hacking at the edges of managing social distancing seems doable, too, both in terms of helping people keep a healthy distance from each other and in managing the isolation that causes. And let’s not forget about managing boredom; idle hands lead to idle minds, and staying healthy mentally is just as important as good handwashing and nutrition.

Join us on Wednesday for this group-led Hack Chat and bring your best ideas for attacking COVID-19 head-on.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, April 8 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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NIH Approved 3D-Printed Face Shield Design For Hospitals Running Out Of PPE

As the world faces a pandemic of monumental proportions, hospitals have been hit hard. The dual problems of disrupted manufacturing and supply chains and huge spikes in demand have led to many medical centres running out of protective gear. Makers have stepped up to help in many ways by producing equipment, with varying results. [Packy] has shared a link to a 3D-printable face shield that, unlike some designs floating around, is actually approved by the National Institute of Health in the USA.

The shield consists of a 3D printed headband, which is then coupled with a transparent piece of plastic for the face shield itself. This can be lasercut, or sourced from a document cover or transparency sheet. The design is printable in PLA or a variety of other common materials, and can be assembled easily with office supplies where necessary.

The design is available from the NIH here. (Update: 4/1/2020 here’s an alternate link as original link seems to be suffering from heavy server load) For those eager to help out, it’s important to do so in an organised fashion that doesn’t unduly take resources away from healthcare professionals trying to get an important job done. We’ve seen other hacks too, such as these 3D printed ventilator components being rushed into service in Italy. 

Hacked Protective Gear Keeps Doctor Safe In The Hot Zone

It’s rarely a wise idea to put a plastic bag over one’s head, but when the choice is between that and possibly being exposed to a dangerous virus, you do what you have to. So you might as well do it right and build a field-expedient positive pressure hood.

We’ve all been keeping tabs on the continuing coronavirus outbreak in China, but nobody is following as closely as our many friends in China. Hackaday contributor [Naomi Wu] is in from Shenzhen, posting regularly from the quarantined zone, and she found this little gem of ingenuity from a [Doctor Cui] in one of the hospitals in Wuhan. Quarantines and travel restrictions have put personal protective equipment like masks and gowns in limited supply, with the more advanced gear needed by those deal most closely with coronavirus patients difficult to come by.

There’s no build information, but from the pictures we can guess at what [Dr. Cui] came up with. The boxy bit is an AirPro Car, a HEPA filter meant to clean the cabin air in a motor vehicle. He glued on a USB battery pack to power it, used a scrap of plastic and some silicone adhesive to adapt a heat-moisture exchange filter from a mechanical ventilator to the AirPro’s outlet, and stuck the tube into a plastic bag sealed around his neck. The filter provides dry, positive pressure air to keep the bag from fogging up, and to keep [Dr. Cui] from asphyxiating. Plus he’s protected from droplet contact, which is a big plus over simple paper masks.

With the news always so dark, it’s heartening to see stories of ingenuity like this. We wish [Dr. Cui] and all our friends in China the best during this outbreak.