Ken,
Experiments with al filled epoxy were reported in Paul Jacobs' white paper
published by 3DSystems in 1996. The upshot of it was that even al filled
epoxy did very little to enhance heat transfer, I imagine that this is
because the high conducting al does not form a continuous matrix and so
conduction (which is the only form of heat transfer through the tool) is
restricted.
Regards
Neil
> -----Original Message-----
> From: Ken Richardson [mailto:kenrich1@bellsouth.net]
> Sent: 01 November 1999 18:43
> To: Neil Hopkinson
> Subject: Re: Cooling channels in direct AIM tools
>
>
> This is an interesting result and not really that suprising. I
> wonder though,
> have you tried any experiments with a combination of epoxy resin
> and aluminum
> powder. There is someone here in the US that is selling a 15%
> epoxy and 85%
> aluminum powder mix for tooling applications that may increase
> the conductivity
> enough to be worthwhile.
>
> Kendrick E. Richardson, President
> CAMmatic, Inc.
> 1000 Johnnie Dodds #103-352
> Mt. Pleasant, SC 29464
> (843) 856-4644
> Fax (843) 856-9334
> kenrich1@bellsouth.net
>
>
> Neil Hopkinson wrote:
>
> > Tine + Jan,
> >
> > Hello there, hope you are both well.
> > I will just add to some other responses regarding the low thermal
> > conductivity of epoxy and its effects (or rather, lack of effects!) on
> > cooling. We performed FEA heat transfer work showing that
> cooling channels
> > needed to be REALLY close (around 1mm) to the tool surface to have any
> > effect with epoxy tools. Generally it is not worth using
> conformal cooling
> > channels in these tools.
> > All geometries are different but generally I would recommend
> increasing tool
> > life by early ejection and then cooling the tool with
> compressed air so that
> > it will resist injection pressures with the next shot. You may
> also wish to
> > open the tool and cool the part as it sits on the core before
> then applying
> > the ejector pins.
> >
> > Hope this helps,
> > Neil
> >
> > > -----Original Message-----
> > > From: owner-rp-ml@bart.lpt.fi
[mailto:owner-rp-ml@bart.lpt.fi]On Behalf
> > Of Andrzejewski, Jan
> > Sent: 01 November 1999 13:34
> > To: 'rp-ml'
> > Subject: re: Cooling channels in direct AIM tools
> >
> >
> > Tine Hejslet Jørgensen
> > Danish Technological Institute
> > wrote:
> >
> > I am searching for some information on cooling channels in direct
> > AIM tools:
> > 1) Can I use water cooling or is the humidity resistant of the
> > stereolithograpy tool to poor?
> > 2) Do I need to use a special resin with better humidity
> > resistant like 5530
> > from Ciba?
> > 3) Has anybody done calculations on how close to the part cooling
channels
> > can be situated without damaging the mould with a certain injection
> > pressure?
> >
> > Ans 1 We would be pleased to quote you for a direct AIM tool in RPC
300ND
> > resin, this resin is moisture resistant and high temperature approx 120
> > degree C
> >
> > Ans 2 Yes, we found 5530 had the same humidity resistance as 300ND when
we
> > conducted plating trials.
> >
> > Ans 3 We have not yet looked at this yet! do you want to conduct
> > collaborative trials?
> >
> > Jan Andrzejewski jan.rp@pera.com
> > PERA
> > Technology Centre
> > Nottingham Road
> > Melton Mowbray
> > Leicestershire
> > LE13 0PB
> > UK
> > Tel +44 (0) 1664 501501 Fax +44 (0) 1664 501556
> >
> >
> > For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
> >
>
> For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
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