I never liked the thought of carrying a two sided piece of glass in my pocket. With older models I place the glass on the inside, plastic on the outside. Is it just me?
This is all utter nonsense. Please look at the the first frame on this site http://www.apple.com/iphone/design/. This was suppose to be a very strong engineered glass. If I recall they even showed a video segment during the announcement that demonstrated the strength.
"Strength" is very ambiguous. IIRC, it needs an adjective to have meaning, like "torsional" or "compressive" strength.
Strength may have little to do with scratch resistance. And a scratch on glass is where it breaks - even temperature changes can crack scratched glass.
I'm pretty sure that the type of strength demonstrated by Apple has little to do with the current scratching/cracking phenomenon.
That's a very interesting photo. I hope that there are some test engineers here to help:
I notice that there are two pressure points pressing down, rather than one in the center. Why?
All the surfaces touching the glass have a relatively large radius. Will sharp points crack the glass, as opposed to the relatively wide presure points being applied?
The two upper pressure points are at the edges of the bend area. The center is void. I can't figure that out. Is it just to make a more dramatic photo? Or is it part of some standard test procedure? If the latter, why is the test set up like that?
The upper pressure points seem to be at an angle to the bottom ones, and not parallel. It is hard to be certain about that, due to the quality of the photo. But it looks like the two upper ones are splayed out as they recede into the distance. Why? If the pressure was applied with parallel bars, would that result in the center cracking? Were the bars' angles chosen for photo purposes, or for test purposes?
IMO anyone who uses a slide-on case and doesn't check for dirt or sand before they slide it on is just a fool. How is this Apple's fault?
...
The issue is that glass (being, you know glass), has a tendency to shatter along fault lines. Even gorilla glass (which this is pretty much the same as) will shatter if it has a flaw and then subsequently receives an impact.
One way to conceptualize the situation is through the lens of "foreseeable misuse". Using that conceptual framework, one could question whether a manufacturer should use a glass case for an item that often encounters scratches and impacts through normal use and/or forseeable misuse.
That's a very interesting photo. I hope that there are some test engineers here to help:
I notice that there are two pressure points pressing down, rather than one in the center. Why?
This is to create uniform moment between the two point (uniform moment = constant stress). This way they have larger uniformly stressed area of the specimen causing the failure to happen at the weakest point, which is not necessarily at the center. If you put a point load at the center you usually get higher failure stress. This test is called Third-Point Loading Test or Four Point Test and it is a standard ASTM test for determining the flexure strength.
Quote:
All the surfaces touching the glass have a relatively large radius. Will sharp points crack the glass, as opposed to the relatively wide presure points being applied?
Sharp points could cause friction and stress concentrations. Round loading points reduces such effects.
Quote:
The two upper pressure points are at the edges of the bend area. The center is void. I can't figure that out. Is it just to make a more dramatic photo? Or is it part of some standard test procedure? If the latter, why is the test set up like that?
As I said before, the area between the loading points will be under uniform moment. Having the points further apart will test larger area.
Quote:
The upper pressure points seem to be at an angle to the bottom ones, and not parallel. It is hard to be certain about that, due to the quality of the photo. But it looks like the two upper ones are splayed out as they recede into the distance. Why? If the pressure was applied with parallel bars, would that result in the center cracking? Were the bars' angles chosen for photo purposes, or for test purposes?
I have never even given it a thought. I don't use any cases as I love the look and feel of an iPhone as designed by the best design team in the World. I don't see why I'd want to cover it with some junk designed by a bag company. It would be like having my Mercedes always wrapped in a bin liner so as to keep dust of it! I'd rather see it! BTW my car also has glass in many places too!
No kidding. The video had it doing some crazy bending without breaking. When I read this the first thing that came to mind was that part of the initial video.
Yes, as long as there is not a stress-riser / crack initiator. Just like a plastic potato-chip bag that is extremely strong, except where a little notch is cut in the side. At that spot, it tears as easily as paper.
I hope the "fix" does not consist of instructions to NOT USE A CASE!
Sorry, not trolling, just a little humor. I think the material is fine. I've had an iphone and ipod touch. Both are used robustly and neither of them have had scratch problems in the least, and the iPhone is used with a slide-in case.
I have never even given it a thought. I don't use any cases as I love the look and feel of an iPhone as designed by the best design team in the World. I don't see why I'd want to cover it with some junk designed by a bag company. It would be like having my Mercedes always wrapped in a bin liner so as to keep dust of it! I'd rather see it! BTW my car also has glass in many places too!
I know it's a different product but I hate the slippery feel of the iPod touch. A case of some sort is essential for that product.
In contrast I've never held an iPhone 3 that had a case and the only person I know with a case has one with a built-in battery because he's in sales and is on his phone all day long.
There are two people in my office with iPhone 4s. Both have free bumpers on theirs. They feel OK that way, but if I had one I'd want something that offered greater shock absorption because no matter how careful you are eventually everything gets dropped onto a hard surface.
How is it even Apple's problem that third party cases might have something to do with cracked glass?
I also wanted to add that scratching issue? What scratching issue? I mean I was one of those idiots that had to have a stupid sticker on their phone for ages. It just looks ugly and impedes the touch screen. without it I'm much happier and low and behold the glass doesn't scratch. hmmmm.
I know people who carry their iPhone 4 around in their pocket WITH KEYS! I honestly don't understand the mentality of some people, like they lack all common sense on how to keep from breaking their phone.
I keep mine in a pocket by itself & I've never had any issues with scratches, though if you live in an area with lots of sand (beaches or desert areas) you might get sand in your pocket & some bits of sand could probably get in the case & cause pretty nasty scratches when sliding the case. I had this happen with my case on my 3GS, scratched deep grooves in the back.
As strong as the iPhone 4 glass is you are probably better off with a bumper, though it's the back of your phone & frankly I don't think I'd even care. I use a case to protect against shattering, not to keep little scratches off the back of my phone.
I know people who carry their iPhone 4 around in their pocket WITH KEYS! I honestly don't understand the mentality of some people, like they lack all common sense on how to keep from breaking their phone.
Then it is the designer's fault, not the user's fault.
If I recall, the tempered optical glass they use, which has further been treated - Owens Corning style with the Gorilla glass treatment - is still only 6.8 on the Mohs scale - just under quartz in hardness. So anything 6.9 or above is going to scratch it. Most keys are made out of brass - so no your keys are not going to scratch it, as I demonstrate to my friends from time to time. a hardened steel anything will, depending on the hardness. An emery board will. if you don't clear out the lint and debris in your pockets, you pockets can trap particles of all kinds of minerals just walking around - which can include sand, which is general quartz or a similar mineral - which will scratch it. Gravel in your pocket will as will diamonds, sapphires and rubies, topaz, but NOT pearls or opals. SO for example some keyrings use stainless hardened split rings which you pry open and wind your keys on - this may scratch your glass surface. Next time you toss your pants in the washer - turn your pockets out, but don't, DON'T send your iPhone thru the washer - it could get scratched.
What DO they teach in the schools these days?? How about remedial Materials 101 for everyone?
Great advice. So next time I'm out on the town with one pocket full of sapphires and another full of opals I'm going to put my iPhone in the pocket full of opals.
So if you are careless, and get sand in between the case and the phone, which causes scratches, and then you are further careless enough to drop the phone, yes, it will shatter.
So, you live your life inside of a selectively permeable force membrane that excludes sand and silica? Wow. Cool.
This is to create uniform moment between the two point (uniform moment = constant stress). This way they have larger uniformly stressed area of the specimen causing the failure to happen at the weakest point, which is not necessarily at the center. If you put a point load at the center you usually get higher failure stress. This test is called Third-Point Loading Test or Four Point Test and it is a standard ASTM test for determining the flexure strength.
Sharp points could cause friction and stress concentrations. Round loading points reduces such effects.
As I said before, the area between the loading points will be under uniform moment. Having the points further apart will test larger area.
I don't think there is any reason for that.
Thank you very much. I know nothing about testing. I have some tangential experience only, from reading some test reports of sprayed-on concrete over rebar (the testing showed misapplication - DOH!) inside a 12 foot diameter penstock filled with water at about 50 feet of head.
BTW, do you think the top pressure points are splayed out? Or am I misreading the distortion of a wide-angle lens? Or do they look parallel to you?
I know people who carry their iPhone 4 around in their pocket WITH KEYS! I honestly don't understand the mentality of some people, like they lack all common sense on how to keep from breaking their phone.
Quote:
Originally Posted by samab
Then it is the designer's fault, not the user's fault.
Interesting. I suppose carrying dynamite in a car is the designer's fault too if your car explodes.
Comments
I never liked the thought of carrying a two sided piece of glass in my pocket. With older models I place the glass on the inside, plastic on the outside. Is it just me?
You're not the only one.
This is all utter nonsense. Please look at the the first frame on this site http://www.apple.com/iphone/design/. This was suppose to be a very strong engineered glass. If I recall they even showed a video segment during the announcement that demonstrated the strength.
"Strength" is very ambiguous. IIRC, it needs an adjective to have meaning, like "torsional" or "compressive" strength.
Strength may have little to do with scratch resistance. And a scratch on glass is where it breaks - even temperature changes can crack scratched glass.
I'm pretty sure that the type of strength demonstrated by Apple has little to do with the current scratching/cracking phenomenon.
You mean this:
That's a very interesting photo. I hope that there are some test engineers here to help:
I notice that there are two pressure points pressing down, rather than one in the center. Why?
All the surfaces touching the glass have a relatively large radius. Will sharp points crack the glass, as opposed to the relatively wide presure points being applied?
The two upper pressure points are at the edges of the bend area. The center is void. I can't figure that out. Is it just to make a more dramatic photo? Or is it part of some standard test procedure? If the latter, why is the test set up like that?
The upper pressure points seem to be at an angle to the bottom ones, and not parallel. It is hard to be certain about that, due to the quality of the photo. But it looks like the two upper ones are splayed out as they recede into the distance. Why? If the pressure was applied with parallel bars, would that result in the center cracking? Were the bars' angles chosen for photo purposes, or for test purposes?
This is why I replaced the back glass panel on my iPhone 4 with brushed aluminum, not only does it look sexy by my back is safe forever.
Is it anodized?
IMO anyone who uses a slide-on case and doesn't check for dirt or sand before they slide it on is just a fool. How is this Apple's fault?
...
The issue is that glass (being, you know glass), has a tendency to shatter along fault lines. Even gorilla glass (which this is pretty much the same as) will shatter if it has a flaw and then subsequently receives an impact.
One way to conceptualize the situation is through the lens of "foreseeable misuse". Using that conceptual framework, one could question whether a manufacturer should use a glass case for an item that often encounters scratches and impacts through normal use and/or forseeable misuse.
That's a very interesting photo. I hope that there are some test engineers here to help:
I notice that there are two pressure points pressing down, rather than one in the center. Why?
This is to create uniform moment between the two point (uniform moment = constant stress). This way they have larger uniformly stressed area of the specimen causing the failure to happen at the weakest point, which is not necessarily at the center. If you put a point load at the center you usually get higher failure stress. This test is called Third-Point Loading Test or Four Point Test and it is a standard ASTM test for determining the flexure strength.
All the surfaces touching the glass have a relatively large radius. Will sharp points crack the glass, as opposed to the relatively wide presure points being applied?
Sharp points could cause friction and stress concentrations. Round loading points reduces such effects.
The two upper pressure points are at the edges of the bend area. The center is void. I can't figure that out. Is it just to make a more dramatic photo? Or is it part of some standard test procedure? If the latter, why is the test set up like that?
As I said before, the area between the loading points will be under uniform moment. Having the points further apart will test larger area.
The upper pressure points seem to be at an angle to the bottom ones, and not parallel. It is hard to be certain about that, due to the quality of the photo. But it looks like the two upper ones are splayed out as they recede into the distance. Why? If the pressure was applied with parallel bars, would that result in the center cracking? Were the bars' angles chosen for photo purposes, or for test purposes?
I don't think there is any reason for that.
I have never even given it a thought. I don't use any cases as I love the look and feel of an iPhone as designed by the best design team in the World. I don't see why I'd want to cover it with some junk designed by a bag company. It would be like having my Mercedes always wrapped in a bin liner so as to keep dust of it! I'd rather see it! BTW my car also has glass in many places too!
I agree.
No kidding. The video had it doing some crazy bending without breaking. When I read this the first thing that came to mind was that part of the initial video.
Yes, as long as there is not a stress-riser / crack initiator. Just like a plastic potato-chip bag that is extremely strong, except where a little notch is cut in the side. At that spot, it tears as easily as paper.
Sorry, not trolling, just a little humor. I think the material is fine. I've had an iphone and ipod touch. Both are used robustly and neither of them have had scratch problems in the least, and the iPhone is used with a slide-in case.
I have never even given it a thought. I don't use any cases as I love the look and feel of an iPhone as designed by the best design team in the World. I don't see why I'd want to cover it with some junk designed by a bag company. It would be like having my Mercedes always wrapped in a bin liner so as to keep dust of it! I'd rather see it! BTW my car also has glass in many places too!
I know it's a different product but I hate the slippery feel of the iPod touch. A case of some sort is essential for that product.
In contrast I've never held an iPhone 3 that had a case and the only person I know with a case has one with a built-in battery because he's in sales and is on his phone all day long.
There are two people in my office with iPhone 4s. Both have free bumpers on theirs. They feel OK that way, but if I had one I'd want something that offered greater shock absorption because no matter how careful you are eventually everything gets dropped onto a hard surface.
Ha ha good post. As I said just above, I think an iPhone is better without a case!
What we need is clear liquid metal.
Where is Montgomery Scott when you need him?
They usually deny any knowledge of any issue and state yours is the first they ever heard of it.
How is it even Apple's problem that third party cases might have something to do with cracked glass?
I also wanted to add that scratching issue? What scratching issue? I mean I was one of those idiots that had to have a stupid sticker on their phone for ages. It just looks ugly and impedes the touch screen. without it I'm much happier and low and behold the glass doesn't scratch. hmmmm.
I know people who carry their iPhone 4 around in their pocket WITH KEYS! I honestly don't understand the mentality of some people, like they lack all common sense on how to keep from breaking their phone.
I keep mine in a pocket by itself & I've never had any issues with scratches, though if you live in an area with lots of sand (beaches or desert areas) you might get sand in your pocket & some bits of sand could probably get in the case & cause pretty nasty scratches when sliding the case. I had this happen with my case on my 3GS, scratched deep grooves in the back.
As strong as the iPhone 4 glass is you are probably better off with a bumper, though it's the back of your phone & frankly I don't think I'd even care. I use a case to protect against shattering, not to keep little scratches off the back of my phone.
I know people who carry their iPhone 4 around in their pocket WITH KEYS! I honestly don't understand the mentality of some people, like they lack all common sense on how to keep from breaking their phone.
Then it is the designer's fault, not the user's fault.
If I recall, the tempered optical glass they use, which has further been treated - Owens Corning style with the Gorilla glass treatment - is still only 6.8 on the Mohs scale - just under quartz in hardness. So anything 6.9 or above is going to scratch it. Most keys are made out of brass - so no your keys are not going to scratch it, as I demonstrate to my friends from time to time. a hardened steel anything will, depending on the hardness. An emery board will. if you don't clear out the lint and debris in your pockets, you pockets can trap particles of all kinds of minerals just walking around - which can include sand, which is general quartz or a similar mineral - which will scratch it. Gravel in your pocket will as will diamonds, sapphires and rubies, topaz, but NOT pearls or opals. SO for example some keyrings use stainless hardened split rings which you pry open and wind your keys on - this may scratch your glass surface. Next time you toss your pants in the washer - turn your pockets out, but don't, DON'T send your iPhone thru the washer - it could get scratched.
What DO they teach in the schools these days?? How about remedial Materials 101 for everyone?
Great advice. So next time I'm out on the town with one pocket full of sapphires and another full of opals I'm going to put my iPhone in the pocket full of opals.
So if you are careless, and get sand in between the case and the phone, which causes scratches, and then you are further careless enough to drop the phone, yes, it will shatter.
So, you live your life inside of a selectively permeable force membrane that excludes sand and silica? Wow. Cool.
This is to create uniform moment between the two point (uniform moment = constant stress). This way they have larger uniformly stressed area of the specimen causing the failure to happen at the weakest point, which is not necessarily at the center. If you put a point load at the center you usually get higher failure stress. This test is called Third-Point Loading Test or Four Point Test and it is a standard ASTM test for determining the flexure strength.
Sharp points could cause friction and stress concentrations. Round loading points reduces such effects.
As I said before, the area between the loading points will be under uniform moment. Having the points further apart will test larger area.
I don't think there is any reason for that.
Thank you very much. I know nothing about testing. I have some tangential experience only, from reading some test reports of sprayed-on concrete over rebar (the testing showed misapplication - DOH!) inside a 12 foot diameter penstock filled with water at about 50 feet of head.
BTW, do you think the top pressure points are splayed out? Or am I misreading the distortion of a wide-angle lens? Or do they look parallel to you?
I?m surprised Apple has even heard of this issue!
They usually deny any knowledge of any issue and state yours is the first they ever heard of it.
I think that they treat their phone support people like mushrooms.
Keep them in the dark, and cover them with manure...
I know people who carry their iPhone 4 around in their pocket WITH KEYS! I honestly don't understand the mentality of some people, like they lack all common sense on how to keep from breaking their phone.
Then it is the designer's fault, not the user's fault.
Interesting. I suppose carrying dynamite in a car is the designer's fault too if your car explodes.
(Yes, quite a random analogy, but hey...)