hi,

i think the suggestions for adding a draft angle to the walls of the mold are what you need.  i'd also suggest that stay with an aluminum mold and get the inside of the mold teflon coated.  your parts will come out without any release on them.  also you might think about cutting slots at the seam of the mold so that you can get something like a screwdriver in there to help pry the pieces of the mold apart.

phil

-----Original Message-----
From: Kasprzak, Bill (sys) USX [mailto:[log in to unmask]]
Sent: Monday, July 16, 2001 8:51 AM
To: [log in to unmask]
Subject: [TN] Recommendations for developing a mold


Hello all,

I am involved with a project that requires that I encapsulate a pc board in
mold so that when completed, it will be a ring with an ID of 1.37" and an OD
of 1.64". The ring will be .13" thick and .35" tall. There will be six, 28
AWG wires exiting the finished potted assembly. The potting compound will be
Emerson & Cumings 2651-40 with Catalyst 11.

        I have a basic 3 piece mold that works OK, but the pieces only
reflect what the final product should look like. It takes a little work to
get the mold apart even though mold release is used. The cure for the
potting is 8 - 16 hours at 180 deg F

What I'm looking for is any tricks and hints that should be incorporated
into the mold design that would facilitate easy processing. What I mean is
to make it easier to pour the material, easy to assemble into the mold, easy
to take apart, etc. etc. Right now the whole process just seems to be crude
and messy. Maybe, that's just the nature of the beast.

Any and all responses appreciated. Thanks.

Bill Kasprzak
Moog Inc., Electronic Assembly Engineering

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