From: Kirk Alcond (email@example.com)
Date: Wed Mar 12 2003 - 17:48:33 EET
To: <Don_smith@mail1.myexcel.com>, <firstname.lastname@example.org>
Subject: Re: clear aorta model
Greg Pettengill's suggestion to rotocast your part is definitely the
answer. Your part has small passageways, though, so make sure you seal your
mold and pressurize it a bit. Rapid Prototype your mold, then drill a hole
in it and epoxy in a tire stem. Then run the pressure up to 40 pounds or
so. (you will do well to experiment to find the best pressure) This air
pressure eliminates all bubbles and foaming, and is critical in producing a
beautiful small part. Use a catalytically activated, clear silicone rubber,
thinned as directed by the manufacturer. Your finished part will be beautiful!
Let us know how you make out.
Kirk Alcond, UCLA Architecture, Shop Supervisor,
I will be a very interested in what you end up doing on this, so please let
If you want a thin walled part with a consistent wall thickness then I would
suggest that you consider using Rotary Casting. This is commonly used to
make flexible parts in thermoplastics but can also be used with RTV
materials. Besides being relatively inexpensive it will also enable you to
avoid all the issues and difficulties of a core.
Cote' Art & Engineering
----- Original Message -----
From: "Don Smith" <Don_smith@mail1.>
To: <email@example.com>; <firstname.lastname@example.org>
Sent: Tuesday, March 11, 2003 10:41 PM
Subject: Re: clear aorta model
> Thank you for the encouragement.
> I am receiving many responses informing me of the expertise
> available to do this, using several methods.
> Pouring urethane (or silicone)into a mold is the most common.
> An existing mold for a vinyl aortic arch.
> Production process using a variable orifice extrusion
> Don Smith
> Baxter Healthcare Corp.
> ---------- Original Message ----------------------------------
> From: "Greg Pettengill" <email@example.com>
> Date: Mon, 10 Mar 2003 10:16:26 -0500
> >Hi Don,
> >Without a much better understanding of exactly what you're trying
> >accomplish I would be reluctant to make recommendations.
> However, I do feel
> >that it would be a mistake on your part to reject a "poured"
> piece out of
> >hand. True, it may take more time and effort then some of the
> >methods, but results are usually far better especially for things
> >require optical transparency or translucency.
> >Best Regards
> >Greg Pettengill
> >Cote' Art & Engineering
> >----- Original Message -----
> >From: "Don Smith" <Don_smith@mail1.myexcel.com>
> >To: <firstname.lastname@example.org>
> >Sent: Sunday, March 09, 2003 11:25 AM
> >Subject: clear aorta model
> >> List:
> >> I am making a model of the Aortic Arch, from the top of the
> >> down to and including the bifurcation of the iliacs. The total
> >> length of the part is about 22".
> >> Requirements are:
> >> 1.)ability to see through; (not clear)
> >> 2.)pliable (like silicone tubing)
> >> 3.)Tear Strength (pumping during lab tests)
> >> I plan on using a thin wall z-corp pattern of the bloodflow
> >> Polishing the pattern, and brushing on clear latex. After curing
> >> break out the z-corp pattern.
> >> I have thought through molding the part using a wax core and RTV
> >> mold; and I think the core would be too difficult to register;
> >> the mold too difficult to fill without getting voids.
> >> I have produced a similar part by successive dipping in alphatic
> >> urethane, but this produces a part with varying wall thickness.
> >> Any suggestions will be helpful.
> >> Don
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