Toilet Paper Tube Pulls Dissolved Resin From IPA, Cures It For Disposal

October 12, 2022 by Donald Papp 53 Comments

SLA 3D printing with resin typically means rinsing parts with IPA (isopropyl alcohol). That process results in cloudy, used IPA containing a high concentration of dissolved resin. The dual goals of cleaning and reusing IPA are important ones, and we have to say, [Jan Mrázek]’s unusual experiment involving a UV source and slowly-rotating paper tube to extract and cure dissolved resin might look odd, but the results are definitely intriguing.

Dissolved resin successfully pulled from IPA and cured onto a cardboard roll. This particular one rotated a bit too quickly, trapping IPA in the curing process and yielding a slightly rubbery wad instead of a hard solid.

The best way to dispose of liquid resin is to cure it into a solid, therefore making it safe to throw away. But what about resin that has been dissolved into a cleaning liquid like IPA? [Jan] felt that there was surely a way to extract the dissolved resin somehow, which would also leave the IPA clean for re-use. His solution? The device shown here, which uses a cardboard tube to pull dissolved resin from an IPA bath and a UV source to cure it onto the tube.

Here’s how it works: the tube’s bottom third sits in dirty IPA, and UV LEDs shine on the top of the tube. The IPA is agitated with a magnetic stirrer for best results. A motor slowly rotates the cardboard tube; dissolved resin gets on the tube at the bottom, UV cures it at the top, and the whole thing repeats. Thin layers of cured resin slowly build up, and after long enough, the roll of cured resin can be thrown away and the IPA should be clean enough for reuse.

So far it’s a pretty successful test of a concept, but [Jan] points out that there are still some rough edges. Results depend on turning the tube at a good rate; turning it too quickly results in IPA trapped with the cured residue. On the plus side, the UV source doesn’t need to be particularly powerful. [Jan] says that Ideally this would be a device one could run in a sealed container, cleaning it over one or two days.

Resin printing is great, but it’s a messy process, so anything that makes it less wasteful is worth checking out. Got any ideas for improving or building on this concept? If so, don’t keep ’em to yourself! Let us know in the comments.

Faster IPA Recycling For Your Resin Print Workflow

November 9, 2021 by Al Williams 29 Comments

If you’ve printed with photopolymer resins, you know that you need alcohol. Lots of alcohol. It makes sense that people would like to reuse the alcohol both to be environmentally responsible and to save a little money. The problem is that the alcohol eventually becomes so dirty that you have to do something. Given time, the polymer residue will settle to the bottom and you can easily pour off most of the clean liquid. You can also use filters with some success. But [Makers Mashup] had a different idea. Borrowing inspiration from water treatment plants, he found a chemical that will hasten the settling process. You can see a video of his process below.

The experimentation started with fish tank clarifier, which is — apparently — mostly alum. Alum’s been used to treat wastewater for a long time. Even the ancient Romans used it for that purpose in the first century. Alum causes coagulation and flocculation so that particles in the water wind up sinking to the bottom.

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Better Beer Through Gene Editing

March 27, 2018 by Kristina Panos 63 Comments

As much as today’s American beer drinker seems to like hoppy IPAs and other pale ales, it’s a shame that hops are so expensive to produce and transport. Did you know that it can take 50 pints of water to grow enough hops to produce one pint of craft beer? While hops aren’t critical to beer brewing, they do add essential oils and aromas that turn otherwise flat-tasting beer into delicious suds.

Using UC Berkley’s own simple and affordable CRISPR-CaS9 gene editing system, researchers [Charles Denby] and [Rachel Li] have edited strains of brewer’s yeast to make it taste like hops. These modified strains both ferment the beer and provide the hoppy flavor notes that beer drinkers crave. The notes come from mint and basil genes, which the researchers spliced in to yeast genes along with the CaS9 protein and promoters that help make the edit successful. It was especially challenging because brewer’s yeast has four sets of chromosomes, so they had to do everything four times. Otherwise, the yeast might reject the donor genes.

So, how does it taste? A group of employees from a nearby brewery participated in a blind taste test and agreed that the genetically modified beer tasted even hoppier than the control beer. That’s something to raise a glass to. Call and cab and drive across the break for a quick video.

Have you always wanted to brew your own beer, but don’t know where to start? If you have a sous vide cooker, you’re in luck.

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Ask Hackaday: How Should Hackers Handle IP Agreements?

March 6, 2017 by Dan Maloney 82 Comments

My buddy Harold recently landed a new job at a great technology company. It came at a perfect time for him, having just been laid off from the corporate behemoth where he’d toiled away as an anonymous cog for 19 years. But the day before he was to start, the new company’s HR folks sent him some last-minute documents to sign. One was a broad and vaguely worded non-compete agreement which essentially said he was barred from working in any related industry for a year after leaving the company.

Harold was tempted not to sign, but eventually relented because one needs to put food on the table. Thankfully he’s now thriving at the new company, but his experience got me thinking about all the complications hackers face with the day jobs that so many of us need to maintain. Non-competes and non-disclosures are bad enough, but there’s one agreement that can really foul things up for a hacker: the Intellectual Property Agreement.

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