Carly, and the Cornell article that Mark found do not claim that the droplets of ink leaking the printhead are that hot, only that the surface that vaporizes the bubble behind the droplet reaches that temperature briefly.  The ink that gets vaporized gets heated to 570 degrees (and is rapidly cooled by the rapid expansion of the bubble), and the ink that's propelled out of the printhead is probably barely heated by the process.

One thing I found frustrating about the Cornell article is that it never says how hot the printhead gets!  It only gives the RATE of heating (1 billion degrees per second), but since the period of heating is a tiny fraction of a second, the actual temperature achieved is a much smaller number.  I guess, if the article gives the duration of the heating cycle, we could calculate the temperature, if we assume the heating rate is constant/linear, but I wish they had simply stated it.

-----Original Message-----
From: Shahan, Ray [mailto:[log in to unmask]]
Sent: Thursday, July 24, 2003 6:57 AM
To: [log in to unmask]
Subject: Re: Carly interview - "Dave Packard did fire and his nickname
was The Evil One "


A quick Google search shows the surface temp of the sun to be close to
10,000 Fahrenheit, so each droplet would then be just under 30,000
Fahrenheit.  I'm fairly confident that this droplet temperature should
result in some really HOT sales for hp's new paper that can handle this new
ink...way to go Carly!!

I'm sorry, I just couldn't resist...again.   :-)

Ray Shahan

"There is so much good in the worst of us,
and so much bad in the best of us,
that it behooves none of us
to talk about the rest of us"
                  --Robert Louis Stevenson?

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