RE: [rp-ml] SLS - How much material can be recycled?

From: David K. Leigh (
Date: Thu Sep 01 2005 - 23:51:11 EEST

There are several things that go into the recycling of the material: base
material, machine operating parameters, mix ratio, and mixing philosophy.

Philosophy: Do you mix in new or run to extinction. You will have more
consistent results if you blend virgin powder with used.

Base Material: EOS PA requires more virgin than 3D Duraform. GF requires
more than PA. etc.

Machine Settings: The hotter you run the build, the more the powder
degrades and the more virgin you need to mix into it.

Mix Ratio: Virgin material is added to used material in a ratio range of
30-60% depending on the above. You basically have to figure out what works
for you and your tolerance for "orange-peel" and be consistent. It's as
much art as science early on until you get used to it.

Actual tensile properties don't suffer greatly. It's more cosmetic and
tolerance specs taht are effected.

David K. Leigh (254)933-1000
Harvest Technologies fax(254)298-0125
Rapid Prototyping Services

-----Original Message-----
From: Raffaele Martinoni []
Sent: Thursday, September 01, 2005 1:08 PM
Subject: R: [rp-ml] SLS - How much material can be recycled?


the problem by recycling is mostly orange peel. OUsed material could
improve properties like elongation.

>---- Messaggio originale ----
>Oggetto: R: [rp-ml] SLS - How much material can be recycled?
>Data: Wed, 31 Aug 2005 16:26:49 -0300 (ART)
>>Dear list,
>>Regarding the SLS process, does anyone have experience on material
>recycling? How much material can be recycled without implicating
>the mechanical properties of the parts?
>>Ricardo Calumby.
>>Converse com seus amigos em tempo real com o Yahoo! Messenger

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