Re: Urethanes for SLA Systems

From: Wade Williams (
Date: Wed Jan 20 1999 - 18:50:01 EET

Dear Al:

Most urethanes are catalytic agents, not the typical materials used in RP
machines that photocure (SLA, Cubital) fuse (FDM, desktop modelers) sinter
(SLS) or slice (LOM). Since they are usually mixed then cast, so no
popular RP machines are working with them yet.

The biggest shortfall of urethanes, related to Rapid Manufacturing, is they
must be compatible with the Rapid Tooling materials like RTV. Quite often,
urethanes are substituted for popular production materials like ABS, PP and
PC by matching the top needed physical properties required, such as
durometer, heat deflection, abrasion resistance, etc. You get the
performance you need in a Rapid Manufacturing material.

Our processes rely on Rapid Prototypes as the initial phase, but then
compensate for any shortfalls in texture or detail with craftsmanship from
our modeling technicians. Our process is dependent upon advancement in
technology, but our customers require speed and quality. Hence our hybrid

Until the new machines and processes can completely eliminate the interim
production steps, casting houses like PDSI supplement the molding industry
with our niche specialties.

Please contact us if you'd like any more data.


Wade Williams

> -- [ From: Al Hastbacka * EMC.Ver #2.5.3 ] --
> I find it kind of interesting that many RP shops use an SLA machine to
> make an epoxy master, to be followed by an RTV molding process so that
> they can make a urethane part for the end use of the customer.
> How about bypassing some of these steps by making the urethane model in
> the SLA System in the first place?
> Al Hastbacka
> For more information about the rp-ml, see

For more information about the rp-ml, see

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