Mythbusting ~ Acer 6xxx PBT dyesub Alps compatible keycaps

[ohaimark]

I've done a good amount of research on Alps compatible dyesub keycaps. It is said consistently that Acer 6xxx boards with top printed legends have dyesub caps. This Acer 6311-AW fits the bill. (Unless I'm mistaken and these are pad prints... Correct me if I'm wrong.)
Confirmed.

I've also heard that the caps yellow as if they aren't PBT. Use the white Acer switch slider as a reference for color.
Confirmed.

Photos:
https://www.flickr.com/photos/adevriesc ... 0267831940

I'll purchase some acetone to test the plastic soon. If it passes the acetone test and turns out to be PBT, it shows conclusively that bromine compounds (or unknown factors) can cause that type of plastic to yellow.

If it isn't PBT, what other plastics could handle the dye sublimation process? I didn't think ABS could survive the temperatures involved.

[fohat]

Good work.

Alps caps in PBT are always welcome. Now to find a horizontal Enter and 2x Backspace.

[Chyros]

Cool, so they ARE dyesubbed, right? Just out of curiosity, how did you test it?

Don't bother with the acetone test. I've tested it on my KB-101A as well as on several 6300 and 6500 models. Definitely all ABS.

[ohaimark]

They are most definitely dyesubbed. I paid $5 for it, so (in the name of keyboard knowledge) I could slice a key in half and confirm the dyesub definitively with photographs.

[Chyros]

Excellent! That's good, that way I don't have to correct my Acer vids xD . Thanks!

[gogusrl]

I just got my hands on a NIB Acer 6312 T4F/FR that either have an awesome pad printing or they're dyesubs (still not 100% sure after ogling them for 5 mins with a torchlight).

[ohaimark]

I know! I did the exact same thing. If they're pad prints I'll eat my boots... But there's always that nagging doubt.

That settles it. I'm cutting one open when I get home.

[fohat]

If they're pad prints I'll eat my boots.

Now those are the photos that we want posted.

[gogusrl]

Cut the Scroll Lock or Esc or something irrelevant or easily replaceable.

[Chyros]

They are most definitely dyesubbed. I paid $5 for it, so (in the name of keyboard knowledge) I could slice a key in half and confirm the dyesub definitively with photographs.

Sorry, I misread that at first, I thought you HAD sliced one in half and confirmed it yet.

Anyway, I have hundreds of these caps, I find Acers every goddamn week. So here's one I killed from a 6312-TW:





You know what? I'm STILL not sure.

Don't know how deep this dye sublimation is supposed to go, but the cap is viewed from behind so you shouldn't be able to see pad printing, and the darkened lines definitely reach into the material around 0,25 mm deep. Which would lead me to believe it's dye-sublimed, or at least not pad-printed. But when viewed from the top, the letters just look different from the rest of the cap, and I can't see that sort of effect on any of my other PBT caps. If anything, the caps look more like they're lasered or something.

I'm confused as hell.

[Muirium]

The penetration into the cap is a good solid sign of dye sublimation. Even the deepest dyesub doesn't have to go all the way through the plastic. It's not built up from behind, like doubleshot!

A better picture of the top of the cap would be good. The one you have there looks like a dodgy exposure. Or is the legend really that inconsistent around the line?

[chzel]

It is either inconsistent, or a highlight top right, which would indicate a raised surface.
Are we sure they aren't lasered? Which does penetrate the cap a little bit.

[Chyros]

The penetration into the cap is a good solid sign of dye sublimation. Even the deepest dyesub doesn't have to go all the way through the plastic. It's not built up from behind, like doubleshot!

A better picture of the top of the cap would be good. The one you have there looks like a dodgy exposure. Or is the legend really that inconsistent around the line?

I'm not sure "inconsistent" is the right word. It just appears to be a different texture than the rest of the cap.

I thought of something else; cut a thin slice off. This should reveal only white plastic if it's pad-printed, and a hollow slice if it's lasered. But it's definitely coloured plastic on top and below!

[Muirium]

Lasering shouldn't affect any great depth of plastic. (Think microns more than full fractions of a millimetre.) The cross section looks dyesub to me. Perhaps shitey quality, but the right method all the same!

[chzel]

Could be, could be...
Where is that 100mm f2.8 Macro??? We need detail!

[Chyros]

Could be, could be...
Where is that 100mm f2.8 Macro??? We need detail!

It'll be here very soon if you ship it to me tomorrow! :p

[Daniel Beardsmore]

I'm not sure "inconsistent" is the right word. It just appears to be a different texture than the rest of the cap.

That is exactly what mine are not: they are totally indistinguishable from the beige plastic besides the colour. The legends are a perfect continuation of the beige plastic, with no step or change in texture or reflectivity. That is, if you point the keyboard towards a bright light, the legends reflect the light in exactly the same way. Surface ink normally reflects light to a different extent.

Your photos look like laser charring, because your legends seem to be a greyish tone typical of that process. Some later Acer keyboards did use laser charring which is what yours seem to be, and the charring could in theory extend below the surface of the keycap. Laser charring does create quite a rough surface. You'd have to take some other beige lasered keycaps and cut those open — although now you've left the UK you may not have yet regained access to a ready supply of cheap keyboards to sacrifice.

The legends on my 6312-TW 4U are pure jet black, totally smooth, and curiously they exhibit artefacts suggesting a flat sheet was used to apply them, and that liquid ink was used. Some of the legends are subtly warped as though the definition sheet wasn't quite straight (suggesting dye sub or silkscreen), and there are runs and feathering like you get with inkjet ink on rough paper. Most of the legends though have perfectly straight edges.

You can see the feathering here:



The feathering and warping seems to rule out laser, but the yellowing of the plastic implies ABS and thus rules out dye sublimation.

My keyboard is completely screwed now, so maybe I should send off the keycaps for examination and bin the rest.

[fohat]

The differences between "Page Up" and "Page Down" are striking, especially the "E"s.