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Science

Glass Molded Like Plastic Could Usher In New Era of Complex Glass Shapes (sciencemag.org) 41

sciencehabit shares a report from Science Magazine: The production of glass -- one of humanity's oldest materials -- is getting a 21st century makeover. A new approach to glassmaking treats the material like plastic, allowing scientists to injection mold vaccine vials, sinuous channels for carrying out lab chemistry, and other complex shapes.

The scientists created a printable powder by mixing silica nanoparticles with a polymer that could be cured with ultraviolet (UV) light. After printing the shapes they wanted, they cured the polymer with UV light so it would hold its shape. They then fired the mix in an oven to burn off the polymer and fuse the silica particles into a continuous glass structure. The approach worked, making it possible to craft shapes such as tiny pretzels and replica castle gates. The work garnered interest from companies wanting to build minute lenses and other complex transparent optical components for telecommunications equipment. But the procedure was slow, turning out components one by one, rather than a fully industrial approach that could produce parts en masse, as is done with plastic.

To speed things up, [the researchers] have now extended their nanocomposite approach to work with injection molding, a process used to mass produce plastic parts like toys and car bumpers by the ton. The researchers again started with tiny silica particles. The team then mixed the silica with two polymers, polyethylene glycol (PEG) and polyvinyl butyral (PVB). The mixture created a dry powder with the consistency of toothpaste. The team fed the paste into an extruder that pressed it into a preformed mold with shapes such as a disc or tiny gear. To harden them, the researchers used water to wash away the PEG. They then fired the remaining material in two stages: First at 600C to burn out the PVB, and second at 1300C to fuse the silica particles into the final piece. Outside of the mold, the parts hold their shape because myriad weak attractive bonds, called van der Waals interactions, form between neighboring silica particles. But the parts are still fragile.
The report has been published in the journal Science.
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Glass Molded Like Plastic Could Usher In New Era of Complex Glass Shapes

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  • by rossdee ( 243626 ) on Saturday April 10, 2021 @02:03AM (#61257726)

    and how fragile is it?

    • by Anonymous Coward
      It's super fragile due to the porosity introduced from burning out the PEG and PVB binders. Neither the article nor the paper seem to mention the shrinkage and distortion introduced in the process. This is a modification on the approach to what's been done with 3D printed resin ceramics which go into a kiln after UV curing to burn out the epoxy components. The parts are always subject to some shrinkage and if they aren't designed specifically to account for that then they will literally tear themselves apar
      • I just tought: That's gonna a shrink a LOT.

        But if they did what you said, it's even worse than I imagined!

        In any case: No good, except for specialized application.

    • There's a step after the fragile state that turns it into solid silica glass, with all the optical and physical properties one would expect. Photos of the end result don't have the frosted appearance you'd get if there were lots of tiny voids in the material - it just looks like clear glass. It's odd how the story was cut off in the summary.

      This seems to work a bit like steel 3D prints, where there's a fragile "green" state after the binder is burned away, and a finishing step that fills the voids with meta

  • So long, plastic bottles! Soon I'll be drinking all my beverages from futuristic glass ones!

    • This right there!

      What about this is new? I mean apart form using a shittier method to achieve the same results...

      I've seen very fine details in cast glass too.

  • Is anyone else surprised that an injection-molding-like process doesn't already exist for mass-producing glassware? How are vaccine vials currently produced? One at a time? I seem to remember seeing factory footage of soda bottles being mass-produced by machines blowing molten glass into molds 70 years ago. What am I missing?

    • Is anyone else surprised that an injection-molding-like process doesn't already exist for mass-producing glassware? How are vaccine vials currently produced? One at a time? I seem to remember seeing factory footage of soda bottles being mass-produced by machines blowing molten glass into molds 70 years ago. What am I missing?

      They are claiming they can do the glass product mass production in a lower temperature (1300C), without actually melting the glass (2000C). So the manufacturing process is supposed to be more energy efficient.

    • Is anyone else surprised that an injection-molding-like process doesn't already exist for mass-producing glassware?

      Yes, I was but then I looked at the temperature: it melts at 1400 degrees C or so, a little lower than steel. It softens to mouldability (think glass blowing) at 800 degrees C or so. The best high speed steels are hard up to 550 degrees C, so the moulds would become quite soft by the time glass gets squidgy. I expect you could make moulds out of exotic high temperature nickel alloys, but those

      • When I read the bit in the summary about finally being able to mass-produce vaccine vials with this new breakthrough technology I had an image of the poor glassblower making them today with a tiny cocktail straw and how that guy's life is about to change.

      • by HiThere ( 15173 )

        Wouldn't they use ceramic for the mould? It's not as strong (usually) and more brittle, but it can take a much higher temperature.

  • For the dildo / bong industry I suppose.
    • For the dildo / bong industry I suppose.

      Clearly you didn't see the one where a gaggle of female porn stars gathered 'round the ol' Squidward Signature series 8-way octo-dong, along with a 3-foot long triple-headed dildo that looked like something out of a John Carpenter horror flick.

      If that industry is being held back by design limitations today, they're really going to get screwed soon.

      • I didn't expect a connoisseur! Well done.
        • I didn't expect a connoisseur! Well done.

          Connoisseur? Well, not by choice...

          [Fiction...kind of.]

          [0400 hours.]

          (Officer) "Johnson!"

          (Johnson) "Sir, yes Sir!"

          (Officer) "Coffee ain't cutting it anymore. Time for a kick!"

          * Johnson confers with team on winner of 'search strings most gagged over' *

          * opens Netscape *

          * shows results *

          (Officer) "Son-Of-A-What in HOLY FUCK IS THAT!?...(heavy breathing)...Excellent work Johnson! Keep this up, and you might earn a commendation."

          (Johnson) "Sir, yes SIR!"

          [Tip: Don't try this today. Like most human cesspo

      • I haven't.

        Could you provide me with the source?
        You know... for research purposes...

        • I haven't.

          Could you provide me with the source? You know... for research purposes...

          I would, but it's now banned in my country. And 174 others.

          I hear the street price for it in North Korea is 20 minutes of internet access and a case of soju..

      • Also: They ARE screwed. Constantly. ;)

  • I can imagine that both of these issues could be a major problem trying to do this. Soot from not burning out material properly, especially in the middle of some solid part. Bubbles from burning into a gas. The latter could make the glass pieces look horrible unless the melting was done at low or high pressure.
    • I once did an experiment where I added nutritional supplement bone meal to a ceramic composition. Ceramics suppliers offer bone ash ("bone china" formulations), which is calcined, but I decided to try bone meal because it was locally available at the local grocery store. After firing, I got an unexpected result: beautiful white pieces with an orange peel texture and glassy surface, that were internally foamed and would float on water.
  • The process described in TFA is no molding but actually a 3D printing process and very similar to using a porcelain or ceramic material/filament: https://n-e-r-v-o-u-s.com/blog... [n-e-r-v-o-u-s.com]

    As referenced in the linked "n-e-r-v-o-u-s" article, there is a certain amount of shrinkage that I would expect with the glass materials that isn't addressed in the article and I'm sure causes a certain amount of problems with losing dimensional accuracy.

    Anybody have a better link to the work being done? I'm not impressed when a "sciencemag" writer doesn't know the difference between molding and 3D printing.

    • by pkphilip ( 6861 )

      It was initially available only through 3D printing but the researchers have figured out how to do injection molding as well.

      From the article:

      The scientists created a printable powder by mixing silica nanoparticles with a polymer that could be cured with ultraviolet (UV) light. After printing the shapes they wanted, they cured the polymer with UV light so it would hold its shape. They then fired the mix in an oven to burn off the polymer and fuse the silica particles into a continuous glass structure.

      And later:

      To speed things up, Kotz and his colleagues have now extended their nanocomposite approach to work with injection molding, a process used to mass produce plastic parts like toys and car bumpers by the ton. The researchers again started with tiny silica particles. The team then mixed the silica with two polymers, polyethylene glycol (PEG) and polyvinyl butyral (PVB). The mixture created a dry powder with the consistency of toothpaste. The team fed the paste into an extruder that pressed it into a preformed mold with shapes such as a disc or tiny gear.

  • I consider glass to be a solved problem ... I mean solved by using plastic instead.

    Fragile, and breaks into countless dangerous injurious fragments! Bonus!

    • Well, most people consider plastic to be a HUGE problem.

      Glass is recyclable infinite times. Most plastics are not recyclable.

      Glass does not become pollution, normal weather breaks it down and it does not kill fish.

      This looks to me like a great replacement for all that evil plastic you like.

      • You thought molding the part in plastic and then burning the plastic off helps with the problems of plastic pollution?!

  • 'Sounds pollutiony to me.

    I still don't see the problem with plain old glass. Yes, it's heavier to transport, but using extra transport energy (which is getting greener all the time), avoids pollution (and cleaning up the air, water and landfills [recycling? yeah right] is very difficult to do and uses extra energy).
  • by dsgrntlxmply ( 610492 ) on Saturday April 10, 2021 @11:20AM (#61258624)
    Richard Prosser was granted a British patent in 1840 on a method for dry pressing ceramic powders. This was taken up principally by J.-F. Bapterosses in France, with multi-die ganged tooling, to mass produce clothing buttons and decorative beads. They reportedly used casein as an organic binder. (The composition is not truly dry, it contains a few percent water.) Later evolution of the process tended toward lower-melting compositions that behave more like glass than ceramic. The process works nicely at tabletop scale with modern ceramic materials, but expect 11-13% shrinkage in firing.
  • Two years ago an article came out [bbc.com] indicating we are running out of sand. I'm sure you're thinking the same thing I was when I saw the headline.

    Except sand is not the same the world over. More specifically, the kind needed for cement and glass making is running out. The culprit? Too many people.

    “The issue of sand comes as a surprise to many, but it shouldn’t,” says Pascal Peduzzi, a researcher with the United Nations Environment Programme. “We cannot extract 50 billion tonnes per year of any material without leading to massive impacts on the planet and thus on people’s lives.”

    The main driver of this crisis is breakneck urbanisation. Every year there are more and more people on the planet, with an ever growing number of them moving from the rural countryside into cities, especially in the developing world. Across Asia, Africa, and Latin America, cities are expanding at a pace and on a scale far greater than any time in human history.

    The number of people living in urban areas has more than quadrupled since 1950 to some 4.2 billion today, and the United Nations predicts another 2.5 billion will join them in the next three decades. That’s the equivalent of adding eight cities the size of New York every single year.

    So my question is, why aren't we recycling as much glass as possible and if so, can it be used in situations like this?

  • They are going to reduce our plastic consumption by consuming plastic in the manufacture of glass?

Whoever dies with the most toys wins.

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