The Move to Digital Pt. 5

Well this has been a pretty interesting process.

I’ve had time over the last couple of days to do more research, and I’ve got to say – I really didn’t realize how new this technology was. Or the knowledge hadn’t sunk in.

From what I can tell, as of 2005 only 9% of the world’s printing was digital. And that includes printing on paper. So who knows how much textile printing is done digitally but I expect it is a very small section of the industry.

Now, our printers are inkjet. Most people probably know what an inkjet printer is at this point, though the ones kept at home tend to have disposable cartridges rather than industrial level fixed heads.

We also use acid dyes. Now, this is interesting because acid dyes are sodium based organic acids and would generally be used on other organic materials such as wool, and even silk. But our only fabrics are synthetic; nylon and polyester (I’m told silk is in the works).

The reason (apparently) that acid dyes are used on nylon then is because like natural fibers, nylon is cationic. This is where I get really excited and all the fussy technical or scientific information pops up.

Cationic refers to an ion with fewer electrons than protons, giving it a positive charge, and allowing these acidic dyes to latch on and do their thing.

I’m hoping to learn as much about the chemical processes involved as I can, though for the moment the acid dyes are really the only ones we are using. The problems mentioned before with polyester keep us from getting in to how those dyes are reacting to the polyester. I’m sure we will get there. I’m guessing that the poly requires a reactive dye but the details will have to wait for a later date.

The only other thing I’d like to mention is the issue with keeping the inkjet nozzles clean. As they are used, ink dries around the edges and will eventually clog the nozzles. However, at this point it isn’t practical to build a cleaning mechanism into the printer, which uses a cleaning fluid. This means that the nozzles get cleaned by pumping more ink through, with the intention of pushing away the dried bits, and then using a small wiper blade (not totally unlike your windshield wipers) to clear the debris.

This means that every time you clean the nozzles, you are wasting extra ink. Now to be fair it takes about a month of constant use to produce even a few liters of waste this way – but it is still something that needs to be fixed eventually.

The only thing that is holy these days is efficiency right?