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Eyeglasses with frames welded to the lenses would be kinda cool, and may even justify current commercial price points (not that they would be sold for them).
The vast majority of Rx eyeglass lenses are various forms of plastic now (CR39, polycarbonate, etc). True glass Rx lenses are still available but very few labs process them and even fewer doctors recommend them.
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The vast majority of Rx eyeglass lenses are various forms of plastic now (CR39, polycarbonate, etc). True glass Rx lenses are still available but very few labs process them and even fewer doctors recommend them.
How about iPhone screens to the case then? That's borosilicate glass.
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I think it depends on the application and scale whether or not that is an issue. 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.
> 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.
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.
Sounds really interesting. The only potential downside I see is that metal and glass generally expand differently under heat and have different tensile strengths etc. I wonder how they plan to deal with that.
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.
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That's not how eyeglasses work. Lenses are supplied to opticians as a round blank, which are then cut to fit the frame. Any optician should be able to re-glaze any frame, regardless of age or manufacturer; their equipment measures the frame, then cuts the lens to fit. It's really quite impressive to watch: https://www.youtube.com/watch?v=uCjGNUPO0WU
Things are changing again. My optician used to work as you described, but for my last set of glasses I would choose the frame and he would enter my lens specification into the manufacturers webpage. The manufacturer (a German brand) with a Singapore factory would produce then the desired frame and equip it with the fitting lenses and send off the bundle to my optician here in Germany. As I had the same lens specs as…
Eyeglasses with frames welded to the lenses would be kinda cool, and may even justify current commercial price points (not that they would be sold for them).