RE: Dupont Somos 2100

From: Mark Newton (Motorola  Inc.)
To: RP-ML
Date: Thursday, April 13, 1995
Subject: RE: Dupont Somos 2100

Hi Kevin-  It's a nifty idea....   In 1993 Alcoa built several SLA tooling 
prototypes for Motorola with DuPont's SOMOS 2100 flexible (rubber-filled) 
acrylate resin from CAD data.  The mold incorporated several undercuts and thin 
features and was used to evaluate the strengths and limitations of this 
technique as a means to produce "flexible" tooling for urethane casting.  Alcoa 
varied the postcure conditions in an attempt to produce a durometer range 
approximating RTV systems.  Unfortunately, even the most flexible examples were 
still too stiff for functional "rubber" tooling applications.  Although the 
material was quite tough compared to conventional SLA resins, noticeable warpage 
and poor tear strength of this material detracted from the practicality of using 
it for this flexible SLA tooling concept.  Accuracy is also sacrificed to some 
extent because of beam scattering by the rubber in the resin. If you are still 
interested in this material, I recommend that you contact Paul Fussell or Jill 
Heddleson at the Alcoa Technical Center (412) 337-2721(Paul) -3103(Jill) and 
Bronson Hokuff at DuPont (302) 328-5635.  Jill, Paul, and Ed Gargiulo (DuPont) 
presented a paper at the Dayton conference in 1993 entitled "Methods to Produce 
Desired Cure Depth Using SOMOS 2100 on the SLA-500" in which they have published 
many tips for building with this resin.  Feel free to call on me if I can help 
out further.

Regards,
Dr. Mark Newton
Motorola, Inc.
___________________________________________________________________________To: rp-ml@cs.hut.fi@INTERNET
From: arrk@powergrid.electriciti.com@INTERNET on Wed, Apr 12, 1995 8:25 PM
Subject: Dupont Somos 2100

I recently had an inquiry regarding Dupont Somos 2100 SLA material.

     Is anyone using this material for producing parts and or molds for
     RTV casting? If so,could you provide some input on the behavior of 
     the material, properties, if software exists to create mold patterns
     from a part file, etc.

     Thanks,

     Kevin Robertson
     ARRK Creative Network
     8880 Rehco Rd. Bldg. A
     San Diego, CA 92121