RE: What's the NCC mold, NVD mold and ExpressTool mold?

From: RePliForm Info (info@repliforminc.com)
Date: Thu Oct 11 2001 - 14:57:40 EEST


Peter,
Since I am involved in one of these processes I hope it is appropriate for
me to comment on these.

NCC tooling stands for Nickel Ceramic Composite and it is a technique that
was pioneered by CEMCOM Corp about 7 years ago. The methods used to make
these molds were to electroform nickel over a matched plate SLA model to
make the core and cavity mold faces from a high strength metal. The
thickness of the metal deposited ranged from 1-5 mm with an average of about
2.5 mm. The shells were then backed, prior to demolding, so that the
alignment of the shells were maintained and to avoid any distortion of the
shells during the demolding process. The NCC molds are suitable for runs of
tens of thousands of parts. The technique can also be used copper faced
molds a low melting-point alloy (LMA) can be substituted for the ceramic but
there are some deviations from the procedures. The life of the copper faced
molds and the LMA backed molds is less than the NCC. CEMCOM went out of
business about two years ago and I have bought the assets associated with
plating and backing so mold inserts are now available from RePliForm Inc. in
Baltimore, MD using this technology. Go to www.repliforminc.com for a more
complete description.

NVD stands for Nickel Vapor Deposition. This process uses gaseous Nickel
Carbonyl to grow a shell of nickel over a pattern. The deposition takes
place at ~175 degrees C where the Ni(CO)4 decomposes to Ni metal and CO. It
is important that the pattern be very stable at this high temperature and
that it conduct heat well since this is an endothermic process and heat must
be constantly resupplied to mold to keep the process going. The patterns
used are either machined aluminum or a thin shelled high temperature epoxy.
Once the shell is made, it is backed by an epoxy to make a solid mold. Due
to the toxicity of the nickel carbonyl and there are very few places to get
this done. (I can only think of two and would be happy to give the info to
people off list since I am not certain if these parties are still doing it.)

ExpressTool is a trade name and the name of a company that was started by
LaserFare in Rhode Island. They made molds by electroforming in a similar
fashion to the NCC process but used machined graphite models in order to
obtain better accuracy than you could get from RP. Their claim to fame was
not the ability to make tools faster than machining but that their tools ran
faster in the press because they could easily be conformally cooled. I am
not sure of the availability of this technology at this time but you might
find some thing at the LaserFare web site.

Hope this helps.

Sean Wise
RePliForm Inc.
1583 Sulphur Spring Road, Suite 126
Baltimore, MD 21227
Phone 410 242-5110
Fax 530 325-4768
email: sean@repliforminc.com
URL: www.repliforminc.com

  -----Original Message-----
  From: owner-rp-ml@rapid.lpt.fi [mailto:owner-rp-ml@rapid.lpt.fi]On Behalf
Of petecyy
  Sent: Wednesday, October 10, 2001 10:08 AM
  To: rp-ml@rapid.lpt.fi
  Subject: What's the NCC mold, NVD mold and ExpressTool mold?

  What's the NCC mold, NVD mold and ExpressTool mold?
  The only thing I know is that all of them are belong to Rapid Tooling.
  The principles and procedures of these Rapid Tooling are my focus
question.

  Best regards,

  Peter Y.Y. Chiu

For more information about the rp-ml, see http://rapid.lpt.fi/rp-ml/



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