3 ms·

What is the benefit of applying the glue in a "delicate grid" of "fine, intersecting lines" (as opposed to the bad "solid slab" of glue)? Also, how are the "fi

What is the benefit of applying the glue in a "delicate grid" of "fine, intersecting lines" (as opposed to the bad "solid slab" of glue)? Also, how are the "fine, intersecting lines" of glue extruded?

gaius 13y ago
Probably not enough to be a "feature", just that the real factory and the counterfeiters happen to use a different method. Which is weird, actually. A lot of Chinese counterfeiting happens in the same factory. Say you're a famous clothing brand and you outsource making 10,000 of your ski jackets to a Chinese factory with Gore-tex. They make them and ship them back to you, then they keep the production line running with nylon, make 10,000 more and ship those to market vendors, eBay merchants, etc.
lotyrin 13y ago
Probably just greater consistency, so one fewer variable when it comes to QC.
- jonmrodriguez 13y ago
  How do you think they extruded glue in a grid? Would it be an extrusion nozzle on an XY gantry (like a MakerBot), or am I overthinking this? Maybe a simpler approach would be to extrude through a mask that has a grid-like pattern of holes? Obviously you could only make isolated dots of glue, but not overlapping lines of glue (you can't have floating islands in your mask layer). So although it wasn't the technique used in this article, I guess it could work just as well, right?
  - ygra 13y ago
    Can't one just spray the glue in that pattern with some kind of inkjet head? Or is that bound to fail due to glue's ability to ... well ... glue things together?
    - jonmrodriguez 13y ago
      If the glue is standard cyanoacrylate ("super glue"), then, since the glue is moisture-activated, maybe you could do it without the nozzle getting clogged as long as you have some kind of amazing material for the nozzle that repels moisture. Maybe someone with experience using cyanoacrylate in industrial settings can speak to this. All I know is that my hobby-store super glue nozzles (cheap plastic) get clogged almost instantly. :P http://en.wikipedia.org/wiki/Cyanoacrylate http://en.wikipedia.org/wiki/Cyanoacrylate -- But, my main concern with any kind of XY gantry (as in an inkjet printer like you describe), is that it would take frigging FOREVER. There's no way you want this glueing step to take 45 seconds per unit or more. That's the puzzle, I think, is how did they create this glue grid so quickly that it rivals the blob approach (1 - 2 seconds)?
      - Kliment 13y ago
        Stencil application, usually. Similar to the process used for solder paste or screen printing. You can use polypropylene or acetal nozzles, cyanoacrylate won't stick to those.
        jonmrodriguez 13y ago
        Awesome, thank you
  - stevenrace 13y ago
    Henkel/Loctite have XY(Z) offerings for industrial uses [1,2] as well as screen printing of UV curable glues. The ability to post cure using UV LEDs makes this much more reasonable, even given the short cure times for some cyanoacrylates. [1] http://equipment.loctite.com/productLineDetail.cfm?pl=21 http://equipment.loctite.com/productLineDetail.cfm?pl=21 [2] http://www.youtube.com/watch?v=q4RR67d8CC8 http://www.youtube.com/watch?v=q4RR67d8CC8 (larger epoxy extruder, same idea)
DanBC 13y ago
You use a controlled amount, and you use less glue. This saves cost, but is also better engineering. The glue has data sheets and tests and you know you're meeting the engineering requirements. Some glues 'dissolve' / 'melt' the surfaces to be bonded, and you only need a thin smear to get a good bond. You need to control stuff like glue or conformal coating over a run of X thousand units, otherwise you find people can use crates of the stuff. Having said all that: Maybe it's just what was drawn on the CAD drawings, and it's been followed faithfully by workers ever since, and there's no actual reason for it other than the CAD worker chose something that looked nice and not confusing.
Domenic_S 13y ago
Those flash heads get pretty hot after a bunch of 1/1 power flashes. I imagine sub-par glue would melt off.

gaius 13y ago

Probably not enough to be a "feature", just that the real factory and the counterfeiters happen to use a different method. Which is weird, actually. A lot of Chinese counterfeiting happens in the same factory. Say you're a famous clothing brand and you outsource making 10,000 of your ski jackets to a Chinese factory with Gore-tex. They make them and ship them back to you, then they keep the production line running with nylon, make 10,000 more and ship those to market vendors, eBay merchants, etc.

lotyrin 13y ago

Probably just greater consistency, so one fewer variable when it comes to QC.

jonmrodriguez 13y ago
How do you think they extruded glue in a grid? Would it be an extrusion nozzle on an XY gantry (like a MakerBot), or am I overthinking this? Maybe a simpler approach would be to extrude through a mask that has a grid-like pattern of holes? Obviously you could only make isolated dots of glue, but not overlapping lines of glue (you can't have floating islands in your mask layer). So although it wasn't the technique used in this article, I guess it could work just as well, right?
- ygra 13y ago
  Can't one just spray the glue in that pattern with some kind of inkjet head? Or is that bound to fail due to glue's ability to ... well ... glue things together?
  - jonmrodriguez 13y ago
    If the glue is standard cyanoacrylate ("super glue"), then, since the glue is moisture-activated, maybe you could do it without the nozzle getting clogged as long as you have some kind of amazing material for the nozzle that repels moisture. Maybe someone with experience using cyanoacrylate in industrial settings can speak to this. All I know is that my hobby-store super glue nozzles (cheap plastic) get clogged almost instantly. :P http://en.wikipedia.org/wiki/Cyanoacrylate http://en.wikipedia.org/wiki/Cyanoacrylate -- But, my main concern with any kind of XY gantry (as in an inkjet printer like you describe), is that it would take frigging FOREVER. There's no way you want this glueing step to take 45 seconds per unit or more. That's the puzzle, I think, is how did they create this glue grid so quickly that it rivals the blob approach (1 - 2 seconds)?
    - Kliment 13y ago
      Stencil application, usually. Similar to the process used for solder paste or screen printing. You can use polypropylene or acetal nozzles, cyanoacrylate won't stick to those.
      - jonmrodriguez 13y ago
        Awesome, thank you
- stevenrace 13y ago
  Henkel/Loctite have XY(Z) offerings for industrial uses [1,2] as well as screen printing of UV curable glues. The ability to post cure using UV LEDs makes this much more reasonable, even given the short cure times for some cyanoacrylates. [1] http://equipment.loctite.com/productLineDetail.cfm?pl=21 http://equipment.loctite.com/productLineDetail.cfm?pl=21 [2] http://www.youtube.com/watch?v=q4RR67d8CC8 http://www.youtube.com/watch?v=q4RR67d8CC8 (larger epoxy extruder, same idea)

DanBC 13y ago

You use a controlled amount, and you use less glue. This saves cost, but is also better engineering. The glue has data sheets and tests and you know you're meeting the engineering requirements. Some glues 'dissolve' / 'melt' the surfaces to be bonded, and you only need a thin smear to get a good bond. You need to control stuff like glue or conformal coating over a run of X thousand units, otherwise you find people can use crates of the stuff. Having said all that: Maybe it's just what was drawn on the CAD drawings, and it's been followed faithfully by workers ever since, and there's no actual reason for it other than the CAD worker chose something that looked nice and not confusing.

Domenic_S 13y ago

Those flash heads get pretty hot after a bunch of 1/1 power flashes. I imagine sub-par glue would melt off.