From: Shane Collins (eoswest@adelphia.net)
Date: Wed Sep 07 2005 - 21:16:29 EEST
Hi Tracy,
As you indicate the recycle bin in an automated powder feed system such as
the EOS IPCM, is not homogenous. After several builds the recycled powder
stabilizes into a predictable mixture where each nominally 60 micron
particle has been cycled in a range from one to many powder cakes. Good and
consistent results are achieved by automatically mixing the recycle bin with
40-60% virgin powder.
Shane
Shane Collins
Regional Manager
EOS of North America, Inc.
805 427 0019
-----Original Message-----
From: owner-rp-ml@rapid.lpt.fi [mailto:owner-rp-ml@rapid.lpt.fi] On Behalf
Of EXT-Taylor, Tracy L
Sent: Tuesday, September 06, 2005 12:51 PM
To: Shane Collins; rp-ml@rapid.lpt.fi
Subject: RE: [rp-ml] SLS - How much material can be recycled?
Shane
While I agree that the new powder feed systems are, as you stated,
"effortless and accurate"...How well do they work in practice. Since I have
no experience with such a feeder there is one big question in my mind.
If the powder added into the recycle hopper isn't close to or the same as
what is already there... OR If the powder in the recycle hopper isn't
homogeneous...Wouldn't your powder blend ratio need to change during your
build to give you a consistent end result?
We blend in batches to make sure the powder is consistent. Just curious how
you achieve that with a continuous feed system.
Tracy Taylor
818-586-9266
Pratt & Whitney Rocketdyne, Inc.
-----Original Message-----
From: Shane Collins [mailto:eoswest@adelphia.net]
Sent: Friday, September 02, 2005 1:32 PM
To: ricalumby@yahoo.com.br; rp-ml@rapid.lpt.fi
Subject: RE: [rp-ml] SLS - How much material can be recycled?
Dear Ricardo,
EOS has a new PA-12 based laser sintering powder designed specifically for
increased recycling. The new powder called PrimePart(TM) is now available.
As David points out, processing parameters effect powder performance, but
the use of a modern powder feed system makes the mixing procedure effortless
and accurate. Shane
Shane Collins
Regional Manager
EOS of North America, Inc.
805 427 0019
-----Original Message-----
From: owner-rp-ml@rapid.lpt.fi [mailto:owner-rp-ml@rapid.lpt.fi] On Behalf
Of David K. Leigh
Sent: Thursday, September 01, 2005 1:51 PM
To: ricalumby@yahoo.com.br; rp-ml@rapid.lpt.fi
Subject: RE: [rp-ml] SLS - How much material can be recycled?
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 dkleigh@harvest-tech.com
-----Original Message-----
From: Raffaele Martinoni [mailto:raf@ticino.com]
Sent: Thursday, September 01, 2005 1:08 PM
To: ricalumby@yahoo.com.br; rp-ml@rapid.lpt.fi
Subject: R: [rp-ml] SLS - How much material can be recycled?
Hi
the problem by recycling is mostly orange peel. OUsed material could improve
properties like elongation.
Regards
Raf
>
>
>---- Messaggio originale ----
>Da: ricalumby@yahoo.com.br
>A: rp-ml@rapid.lpt.fi
>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?
>>
>>Thanks,
>>
>>Ricardo Calumby.
>>
>>__________________________________________________
>>Converse com seus amigos em tempo real com o Yahoo! Messenger
>>http://br.download.yahoo.com/messenger/
This archive was generated by hypermail 2.1.7 : Mon Jan 02 2006 - 08:09:20 EET