DIY PAD printing - anyone tried?

[Gurner]

I'm toying with the idea of knocking up some way of doing pad printing.

For those that don't know, pad printing basically involves pressing down a silicon pad onto an etched plate (the etched bit here would be your stompbox artwork), the recesses of the etched plate contain the ink & then once the pad is loaded with ink, press it down onto your stompbox. A simple theory...but the devil seems to be in the detail.

Re the etched plates -well,  the pros use steel plates, but hobbyists can use polymer plates - apparently they're quite cheap (I've yet to establish the UK cost but I read on one site under £5.00 per plate ...or about $8).

The plate making process is much like etching a PCB, so I won't dwell (make your artwork, expose UV through the artwork onto your plate - develop - apparently 20 microns is about optimum, which is a shame becuase copper board is about 35 microns & that would have been great for most of us - we've got the process/chemicals already!)

The silicon pad (which have the unfortinate name of tampon pads...makes Googling interesting!) are basically used as a medium to lift the ink out of the etched plates....and over to the intended printing surface (this bit is not insurmountable for those that think creatively).

The tricky bit of this equation is dispensing the ink - the ink is solvent based and therefore can't be exposed to air for long. Typically a pad printing machine contains an air tight ink well, which dumps ink into the recesses of the etched plate more or less immediately prior to the silicon pad then 'pickup up' the paint...so the challenge would be replicating that using things immediately available to us as DIYers.

Anyoine done pad printing?

[potul]

what about using screen printing instead? Isn't it simpler to do as a DIY?

[Gurner]

what about using screen printing instead? Isn't it simpler to do as a DIY?

What appeals is the etching aspect - wrt Pad printing, the recommendation seems to be etching 20 microns deep - alas, FR4 is about 35 microns. I'd like to know how significat this 50% extra depth is in practise!

If it works, imagine how simple it could be for diystompers - most already have copper etching kit (& are familiar with the process) ...so there could be some good synergies....ie create some artwork, etch it into copper, fill the etched 'recess' with ink, press a pad into the ink, now align/press it onto your pedal - job done!

[jpreskitt]

Pad printing with the hydraulic automation is why it's expensive. You can get very detailed results from screen printing.
This company, http://www.teenyscreenies.com/, makes 6"x4" screens, for much cheaper than any pad printing out there I've seen.

[duck_arse]

when I was working for a computer assembling company, their pad print process went backwards. the pad was a silicone blank that was loaded with ink, and the front-panel being padded had the company logo in raised relief.

it strikes me that 3d printers would make some aspects of this process easier, no?