Dear list,
I'm sorry for the all the wrong words I wrote, I guess I am immature and asked the right question in the wrong way. The lesson I learned is that I became aware of the interpretation of a question can differ widely. And I have to be more specific with my
questions. I hope that you will accept my apology.
At least there was some discussion on the rp-ml forum (some reactions were emotional) and I am beginning to understand the RP market. This is something that I needed for my report, my task is to describe the market today.
But I must conclude that I am not the only one who is interested in the answer to this question (according some people who were interested in the results). Therefore this wasn't a wrong question, and "the teacher says that asking a question is never
wrong" (though you have to ask it in the right way).
I am trying to finalise the part of the report that is about RP/RM and I hope that I can contribute to this forum in a reasonable way by explaining a problem that I am coping with for my conclusion/discussion.
The problem is the difference between the applications of the FDM and SLS process. They aren't clear to me (and maybe to some other rp-ml members as well?). The only advantage I found was that FDM allows multiple colors and ABS. The advantage of SLS
seems to be the wide range of materials and the possibility to sinter metals (which isn't done much). I hope you can react, though time costs money. Comments are welcome, but not too much criticism please. I must emphasize that you must not feel obliged
to answer my question.
Kind regards,
Bas Cornelissen
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Selective Sintering
The advantage of SLS is the wide range of materials that is available for this process. For this reason it is possible to make functional prototypes made of semi engineering plastics instead of epoxy based materials as with SLA.
SLS makes it possible to produce glass filled plastics. Glass filled plastics can be used to make moulds, because they have a very smooth surface. Glass filled plastics also have a high tensile strength.
SLS also supports the sintering of metal powder. The RP service providers at the "Kunststoffenbeurs 2000" didn?t sinter metals, because they didn?t have experience with it. And this process is still under development.
Copper Polyamide can also be used with SLS. This results in thermally conductive parts. With Copper Polyamide it is also possible to make moulds for short runs up to 400 shots.
Investment casting moulds can be made of a sintered wax model.
Continuous deposition (FDM)
Stratasys is currently the only provider of FDM equipment. The development in FDM is going fast. There is a large potential for this process, because it is simple, fast and reliable.
SLS prototypes can be made of ABS, a worldwide used engineering plastic. ABS will begin to become weak at 95oC. This plastic can not be used near the hot components, but is more suitable for parts on the outside of the projector. This makes it possible
to do visual studies. Also parts which aren?t exposed to high temperatures can be made out of ABS. To be short: after assembling the parts, the working of complete products can be evaluated.
It is possible to use multiple colors, currently one at a time. The use of colors makes it possible that it isn?t necessary to color the parts afterwards for visual studies. Every color can be made by Stratasys.
Making moulds is possible with wax models.
Fiber reinforced and ceramic materials are under development. The problem with fiber reinforced materials that the orientation of the glass fiber is unpredictable. This makes the material properties unpredictable. The advantage is the high tensile
strength.
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E-mail: bas.cornelissen@philips.com
Tel.: +31 40 27 34609 / +31 6 23388510
Philips CDS - Building SK-1
Glaslaan 2, P.O. Box 80002
5600 JB Eindhoven - The Netherlands
For more information about the rp-ml, see http://ltk.hut.fi/rp-ml/
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