Re[2]: Real useful info

Date: Mon Aug 03 1998 - 11:59:05 EEST

     I am serious about this, I suspect that it would be possible to
     produce a thermal spec sheet for a given casting resin in a given mold
     material using only the mold volume and the typical cross section of
     the part. It has been my experience that the mold material acts as an
     effective insulator and the cross sectional volume plays a roll in the
     ultimate thermal rise.
     As you said, the estimates become difficult as the casting volume
     increases, but isn't that partially due to the fact that a large mold
     is more difficult to fill properly? I assumed that the viscosity of
     the casting resin begins to change as the material starts to cure,
     causing the mold to pack non-uniformly resulting in differential
     shrinkage. I may be wrong but it makes sense.
     Sounds like a good project for a masters thesis. Anybody need one?
     Larry Blasch
     Systems Administrator for Engineering Services
     OPW Fueling Components
     P.O. Box 405003 Voice: (513) 870-3356
     Cincinnati, OH 45240-5003 USA Fax: (513) 870-3338

______________________________ Reply Separator
Subject: Re: Real useful info
Author: <>
From: "markschanze" <> at internet
Date: 8/1/98 1:04 AM

Mass and part geometry are separate. If the part has a consistant .125
wall thickness then test the exotherm of .125 deep paper cup of mixed
resin. If and only if the mass is spread out evenly with an equal amount of
silicone wall thickness. But wait, if the total part mix is more than 3
ounces only the skill of a human with experience will know what to do. So
much for real useful information.
Mark Schanze
Molding Technologies Manager
CIVCO Medical Instruments
319 656 4447
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