Naked Science Forum

Non Life Sciences => Technology => Topic started by: Dennis Soley on 19/12/2008 09:35:42

Title: How does an ink-jet printer work?
Post by: Dennis Soley on 19/12/2008 09:35:42

Dennis Soley asked the Naked Scientists:

How can ink jet printers squirt ink on to paper so quickly and neatly with no smudging?

Forgot to add brilliant program (http://www.thenakedscientists.com/HTML/podcasts/) I learn so much, if only I could remember all of your clear answers!

What do you think?

Title: How does an ink-jet printer work?
Post by: RD on 19/12/2008 14:52:42

. [ Invalid Attachment ]

Quote

Steve Hoath
'Tails from the nozzle bank'
This was taken with a Nikon D70 with a Navitar zoom macro lens and a very short flash duration (20 ns) light source.  This image was taken during a series of experiments at the Cambridge Engineering Department, Inkjet Research Centre investigating the performance of inkjet printers.  It shows ink drops emerging from a bank of inkjet nozzles (just visible at the bottom of the picture). The image is about 2.3 mm across, the drop heads are 50 microns across and the tails are less than 10 microns wide (10 times thinner than a human hair).  Although very small the drops are moving at around 6 m/s hence the need for a very short flash to freeze the motion. The drops are in three groups with slightly different drop firing times. In some cases the drops are still attached to the nozzles by long ligaments of stretching liquid.  Other drops show separation and the formation of smaller, “satellite” drops from the collapsing ligaments.
  This image was adjusted for brightness and contrast and rotated for effect.

http://www.eng.cam.ac.uk/photocomp/2006/sdh35_1.shtml

Title: How does an ink-jet printer work?
Post by: Alandriel on 19/12/2008 19:43:31

                   [8D]


gosh... the things I'd do with a lens like that [;D]

Title: How does an ink-jet printer work?
Post by: DoctorBeaver on 20/12/2008 09:24:11

Interesting photo. I don't think Neil's Kodak Brownie could have taken it.

50 microns is pretty small.

Title: How does an ink-jet printer work?
Post by: LeeE on 21/12/2008 16:47:41

Most desktop type inkjet printers use either thermal heating or piezoelectric pressure pulses for ink propulsion.  In a thermal inkjet tiny amounts of ink are heated very quickly to a vapour in a chamber just behind the jet nozzle, creating a pressure pulse, which then exits via the jet nozzle.  In a piezoelectric inkjet a small piezo crystal, once again located just behind the jet nozzle, creates the pressure pulse.

There are also 'continuous' inkjet printer types but they're generally only used for  product code marking and stuff like that.