I was just going to ask about this. I use HP P1006 toner. I bought a good laminator, Fellows SPL 125, two heated rollers, two pressure rollers, rated for stuff 1/8" thick.
Out of the box the top temp setting, which is 140C (284F), ran the rollers at 180C (356F). I had to bump the temp. I measured it at 220C (428F) after modification, which gave good transfers.
Lately I have realized that the smear I've been getting isn't normal. I tried adjusting the temp down a bit (just on the controls, didn't take a reading), but didn't get good adhesion.
Two days ago I lost the bottom roller, the rubber came off the metal and broke apart and jammed the thing up. So obviously I'm running too hot.
I'm going to back off the temp and find the sweet point, then I will let the group know what it is.
Also, I can back off the pressure on the rollers.
Anyone have a feel for how much pressure is needed? I was thinking maybe tighten the adjustments till I could not longer pull a board out from between the rollers by hand, then go down one more turn, but that is just a WAG.
Thoughts?
--- In Homebrew_PCBs@yahoogroups.com, DJ Delorie <dj@...> wrote:
>
> The trick with TT is to find a temperature that is hot enough to make
> the toner plastic and sticky, but not hot enough to make it liquid. If
> it's too cool, it won't stick. If it's too hot, the toner spreads out
> (smears). The "right" temp depends on the toner brand, too, with
> Brother needing a hotter temperature than others. I've been using 340 F
> for HP toner, but found that 370 F or so is needed for Brother toner.
>
> As for direct-laser: one thought is to find a water-soluble coating you
> can put on the board, so that you can laser print onto the coating but
> have it wash away in the etchant. You only need enough to keep the
> copper from discharging the static charge the laser printer uses.
>