Welding breakthrough could transform manufacturing
hw.ac.uk
hw.ac.uk
Most eyeglass facilities also would not touch used frames, given the potential for frames pre-existing damage and wear, and how that creates liabilities for the lab while installing new lenses.
Sounds like your eyeglass facility really wanted you to buy new frames.
To my knowledge opto-technician will map and cut new lenses using your frames or old lenses as a template.
Also looking at the prices, it looks to me that most of the profits are in selling the lenses (unless you buying designer frames for gazillion $). Where I live no-name frames are very often free or for extremely low price (< 30$).
EDIT: also it would be an insane task to mass manufacture specific lenses for specific frames, just due to the fact of variability of eye conditions: near-sightedness, far-sightedness, astigmatism and varying strength on these conditions (cylinder angle and diopter).
I've had the same Nike frames for probably over 10 years now and the previous ones (same brand & style) for about 5 years until I broke them. My prescription changes very slowly, so I've only updated the lens once. But except for that one frame breakage, I actually have every eyeglass frame I've ever purchased since I first got glasses in 1993.
I'll burn more gasoline driving home from work than the mass of a pair of eyeglasses. And I'll burn it in a car that has a 10-15 year lifespan and weighs about as much as 100,000 pairs of glasses (I'm guessing here, but it's at least in the tens of thousands).
Bikeshedding for purpose of condescension is one of the biggest and most avoidable sins of environmentalism. Don't do that.
Throw those broken glasses out, throw on a new pair, and get back to work working on something important.
It's insignificant for eye glass frames, but not so much for other stuff, like packaging.
It’s not as if this is nuclear waste. Toss it in the ground, wrap it up nicely, and we’ll revisit it in 50-100 years.
Disclaimer: recovering recycling evangelist
Hubris my man. Pure hubris. I'm not saying it's not possible, but when there are strong financial interests tied to NOT doing exactly that, it doesn't feel like something I'd say I'm confident in.
Also "soon enough" to undo all the damage that things like the Pacific Garbage Patch have done to the environment? Soon enough to remove all the mercury in food chain? There's literal things dying because of this. I think the hand wringing is justified. You can make it a value prop (we save X human lives because of products packaged in this manner, so fuck these bees) but there's still actual consequences to our planetary roommates.
Your pacific garbage patch example is disingenuous. It would not occur if poor countries had proper waste disposal infrastructure (ie collection and landfills).
Sure, and if we just provide food for everyone then nobody will be hungry.
That's some high quality hand waving there my friend. The whole "don't worry, we'll figure it out" attitude just comes across as useless. There aren't realistic solutions in place right now. People are working on solutions though. This doesn't mean that there's any reason to assume these solutions would work on a global scale.
When dealing with problems like this, we're going to require extraordinary solutions. Confusing "possible" and "probable" is my issue here.
Without that expansion joint, directly welded together, I'm curious how say, a Pixel 3 with the screen welded to the metal case would do. I can imagine a situation where the case and screen expand differently and end up cracking the screen.
Materials like Kovar are designed such that it very closely matches the expansion curve of glass so that it forms a hermetic seal without any kind of sealant between the glass and the metal.
Since we need to heat the system to speed up the outgasing process, the expansion coefficients for the joints between metall and glass must be very closely matched.
This sounds like a "we have to hype up the practical applications of our research because that's what you do if you want more funding for next year" type of article. They don't even include hypothetical example applications.
Still, the article says that glass and metal are already put together with adhesive. Unless the adhesive is stretchy, it must mean that, within certain limits, it's already OK. Presumably it gets worse as the length increases since expansion is cumulative, which suggests that smaller lengths are OK.
Also, there are probably ways you can design around it like creating gaps in the metal or shaping it so that the metal can bend.
Professor Duncan Hand, director of the five-university EPSRC Centre for Innovative Manufacturing in Laser-based Production Processes based at Heriot-Watt, said: “Traditionally it has been very difficult to weld together dissimilar materials like glass and metal due to their different thermal properties - the high temperatures and highly different thermal expansions involved cause the glass to shatter.
For joints that are intended to remain at a constant temperature, no problem. For very small structures where thermal expansion amounts to very little relative displacements, also no problem.
But, yeah, this isn't a solution for joining outdoor windows to metal frames.
Says who? Welds held up to pretty harsh conditions -50C to 90C.
The glass portion, however, could crack depending on its size/geometry and the temperature change.
The article doesn't make clear exactly what kind of manufacturing operation they're intending. I suspect this is a technology to replace glue/epoxy in certain scenarios where one joins metal and glass.
Wonder what the safety factor actually is?
There are three basic types of temperature exposures:
One, a journey. Got super hot, or cold for a while, then returned to moderate, or acceptable range.
Two, excursions. Got extreme and stayed there for a non trivial time. (Scaled to the properties of whatever it is)
Three, wild ride! Journeys all over the place.
In addition, these can be one off events, or cyclic.
Windows get a kind of cyclic ride in many places. A bond holding "for a while" always has the question of what "while" really means.
Microfractures due to highly localized stress and strain, pre loaded in as an artifact of welding, would be my primary concern.
So, it seems like they're aiming for applications where temperatures stay in the ranges of human habitats.
http://web.archive.org/web/20190410160012/https://www.hw.ac....
So while I'm not 100% sure, it sounds like this technique would be more useful for product design scale stuff like phones, nano machines, miniaturised optical systems.
This is a constructed example to demonstrate the type of thing that could be done now that we've figured out a possible way to do it. It's probably not a good example, but it is clearly distinct from the thin-film processes we consider common today.
EDIT: See below’s multi-paragraph writeup of why my “now you can do this” example is not a good example in practice.
That joint is going to have to handle 300C in order to make it into my kitchen. I might go for a glass/ceramic liner in an aluminum pan, particularly if the ceramic is BAM, but that's going to get hot.
I'd actually look for this first in LED lenses bonded to aluminum heat sinks. A good bond there might allow for higher wattage through the electronic parts. An operating range between -50C and 90C encompasses the operating range of most consumer electronics, plus some margin.
Pure aluminum or pure steel is easier.
It's not like the metal recycling industry doesn't already deal with huge amounts impurities and other material entering the process. If you happen to have tons of metal welded glass to scrap you're not going to get as much money for it because it needs more processing so it will enter the supply chain at a lower price point. It's like the difference between scrapping a car and scrapping machine shop chips.
> At the moment, equipment and products that involve glass and metal are often held together by adhesives, which are messy to apply and parts can gradually creep, or move. Outgassing is also an issue - organic chemicals from the adhesive can be gradually released and can lead to reduced product lifetime.
presumably this is going to be very handy for high temperature applications.
Unless iFixit et al releases an affordable home glass-to-aluminum welding solution, I think Apple may win the cat-and-mouse 3rd party repair game for now.
Sad, really.
It's hard as hell for a transparent ceramic, obvious military applications but useful in other places as well.