Re: Materials for SLS (SLS101)

From: David K. Leigh (
Date: Thu Jul 13 2000 - 19:59:02 EEST


PVC was tried once, but a bad reaction with moisture and air yielded
hydochloric acid. So. . . bad idea. But I don't think it was run in an
"inert" atmosphere. The resulting off gassing pitted the metal in the

Polycarbonate and Wax were the first 2 mainstays. Polycarbonate is
amorphous and density was an issue and had to be infiltrated with epoxy for

Nylon was then tried but was brittle and burned. They went to an inert
environment and things worked out.

Glass was added to the nylon and was successful. glass fibers yielded too
much directional strength, so spherical glass particals were used with

A finer grade of nylon was tested and then used. The Fine Nylon and Glass
Filled Fine Nylon became the go-to materials.

Wax wasn't workin' out too well, so they started wax dipping the
polycarbonate parts for investment casting with success. But shell issues
forced them to investigate other investment casting materials. . .

True-form (i'm not sure which material it was) was used but never fit the
bill due to shrinkage issues. They then investigated and put into works
polystyrene for investment casting patterns (Castform PS).

Europe had some success with a different type of nylon and DTM switched the
Fine Nylon and Glass Filled Fine Nylon for the "Duraform and Duraform GF."
This is a polyamide, but not sure on details.

Somos was developed by DuPont, but it is very niche. Metals have also been
pursued and developed.

Polyethylene and Polypropelene don't really offer tremendous material
advantages. To get the flexible properties of PE, you have to have a very
dense melt, which lends to material processing difficulties.

David K. Leigh ph(254) 933-1000
Harvest Technologies fax(254) 298-0125

----- Original Message -----
From: raf <>
To: <>
Sent: Thursday, July 13, 2000 10:40 AM
Subject: MATERIALS for SLS

> Hallo!
> Question : what are the possible and until today used materials in SLS?
> Did someone try with POM or PE or PP?
> All suggestions are wellcome!!
> Best regards
> R. Casanova
> For more information about the rp-ml, see

For more information about the rp-ml, see

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