RE: [rp-ml] Equipment for SLS powder mixing..

Javier,

A vertical ribbon blender is a great option for SLS powders. They can be customized to unload into a standard powder container, they don't shear the material, and there is minimal heat built up which can possibly degrade the material. Here is a good descriptive website:

http://www.mixers.com/Proddetails.asp?ProdID=77

If you keep your material in a standard "office" environment with 24 hr air conditioning, humidity shouldn't be a problem. In addition, the system typically dries the material because of the N2 chamber and heat.

If you are running filled materials, you may want to monitor powder density. The recycling of filled materials will see a long-term segregation of the filler because the filler is not embedded or attached to the active powder ingrediant (typically PA).

You can monitor powder quality visually or by using a melt flow index. If you are disciplined in powder mixture, you can set your ratio of used powder cake/overflow/virgin and have consistent results. A melt flow index device will give you some quantitative analysis, but is very sensitive to humidity in the powder.
________________________________________________________

David K. Leigh | Rapid Prototyping and Production Services

Harvest Technologies | 1000 Industrial Park Rd. | Belton | TX | 76513

Phone: 254.933.1000 | Fax: 254.298.0125

www.harvest-tech.com | "Where Innovation Takes Shape"

-----Original Message-----
From: owner-rp-ml@rapid.lpt.fi [mailto:owner-rp-ml@rapid.lpt.fi] On Behalf Of Javier Munguia/UPC
Sent: Wednesday, February 13, 2008 6:41 AM
To: rp-ml@rapid.lpt.fi
Subject: [rp-ml] Equipment for SLS powder mixing..

Dear colleagues,
We have a DTM vanguard sls machine and we´re looking forward to improve the
quality of our powder mixing. I´d apreciate if you could guide us proposing
a method or equipment provider, or simply parameters to observe, like
humidity, etc. We´d really like to retire our loyal concrete mixer :)

Thanks to all in advance!

Fco. Javier
Javier Munguía
Grupo FPS (Fabricación en PEqueñas Series)
Universidad Politécnica de Cataluña
www.grupofps.r8.org
AV. Diagonal 637 Edificio ETSEIB Planta 10, Barcelona
Tel: +34 934010706
Movil: 637292695
javier.munguia@upc.edu
Received on Wed Feb 13 15:53:02 2008