Probably more of a materials engineering question...
Most devices (esp. handheld) with displays tend to use polycarbonate, etc. to protect the display (neglecting touch sensitive devices).
Over time, this scratches.
The packaging often precludes replacing "just" the "display protection". So, the product's useful life is reduced because a piece of plastic wasn't, in essence, "hard enough".
Can these sorts of plastics be buffed to clean them up? Aside from glass, are there any other clear materials that are suitable for this role?
Of course. There are products specifically sold for this purpose, though regular jewelers' rouge works well in most cases. 15-20 seconds buffing with a very fine rouge physically removes surface scratches at the cost of making the surface appear slightly sandblasted.
The purpose-built products are designed for heavier scratching, to match the refractive index of the parent material. They abrade the edges of the scratch slightly to "feather" them, and fill in the bottom of the trench with RI-matched material. The sandblasting effect is less pronounced with these products, and they are typically applied by hand.
In manufacturing, the lenses on cellphones and similar products are often polished before they ever even make it into the shipping materials.
A very common approach, particularly with small displays and touch-screens, is to go at this from the other end. Instead of scratching it first, then worrying about how to get the scratches back out again, people put adhesive protective foils on the display right away, which they can replace when they're worn out.
Even glass isn't really suitable for this in the long run. People who care about wrist watches have known that since about forever. Let's face it: if you actually use the thing on a regular basis its surface _will_ scratch, eventually. It may take a grain of sand getting stuck in just the wrong place, or a person with a diamond ring on their finger making a klutzy move in just the wrong moment, but it will happen.
That's why any decent wristwatch has a sapphire crystal.
Best regards, Spehro Pefhany
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Yes, I was acknowledging this in my caveat "(neglecting touch sensitive devices)". The films sacrifice some display clarity and aren't suitable for all applications.
I'm not as concerned with touch/stylus use on a display as you *expect* wear, there. Rather, I'm thinking of the sorts of "micro-scratches" that you get on a "clear window" from slipping something into and out of your pocket, etc. Not "deep scratches" like you would encounter from trauma/abuse but, instead, the slow blurring/abrading that occurs over time (which is usually harder to ignore than a single *deep* scratch would be)
Yes, but you *can* replace the "crystal" on a watch. (well, the last time I wore a watch, this was true... no idea what watches are like nowadays :< )
OTOH, it doesn't seem like the "display protector" (clumsy phrase) on a modern device is designed to be replaced or serviced in any way. Indeed, I suspect most are expected to be treated in much the same way as the device in general -- discarded after a short service life.
So, how do you address this issue when you have something "precious" that you don't want to be discarding (e.g., if your cell phone required you to shell out $2,000 to replace the phone, you'd probably hang onto it for a bit longer than 6-18 months :> You'd probably also be very annoyed if the screen became difficult to read because of these little scuffs each time it dragged against your clothing, contents of purse, etc.)
Apple & others sell similar precut film to protect iPod displays. They are not adhesive backed and are held in place by "electrostatic" force (?). Cost is a couple of dollars retail.
A car polish will remove very fine scratches and there are also special plastics polishes I believe. But these will only remove very minute scratches.
Any deeper scratches should first be removed with sandpaper. Depending on the depth of the scratch, start with grit 2000,
1000 or 600 (or even courser for very deep scratches) and work back up to 2000. Then polish the now milky white surface.
If you have to remove a lot of material, it's best to do that evenly on the whole surface, otherwise you might end op with visible dents after polishing. Use a sanding block to maintain a flat surface.
There are also 'polishing papers' up to grit 10000 or even higher. I have no experience with them but maybe they can be used instead of the (car) polish.
And please try the operation on a scrap piece of plastic before attempting to fix expensive equipment. ;-)
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Stef (remove caps, dashes and .invalid from e-mail address to reply by mail)
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Ok, must be different on your side. At KMart (not sure if you have these guys) they had the screen covers for a few dollars. They may not have been genuine apple items. Most of the covers / holsters etc here are not apple products. Apple must make a shirt load of dollars out of our kids.
Ah. When you said "Apple sells.." I thought you were referring to what's on sale in the actual Apple stores. I doubt there is an item in those stores under $10. Yes, we have K-Mart here :)
The BodyGuardz skin is an adaptation from automobile clear-coat protection. It is quite a bit tougher than the plastic covers sold in stores, it's optically clear and it has no polarization.
All the cheapo plastic skins I have encountered are polarized. I have polarized sun-glasses and with them I can see a naked iPod or iPhone screen perfectly. But if the screen is covered with one of those cheap skins I see Moiré patterns and the screen is unreadable at an angle.
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