Patented Post Processing Techniques (Re: DuraDye)

From: David K. Leigh (
Date: Fri Sep 26 1997 - 21:51:02 EEST

The press release reguarding the post processing technique for SOMOS is
interesting and brings up a question:

Can you patent a process that uses a commercially available product on
another commercially available product. And if so, can you make it stick.

Case in point:

SOMOS is patented (I assume) by DuPont.
The process in SLS Machine is patented by DTM (I assume).

1 material manufacturer.
1 machine manufacturer.
But. . .

Potentially many users.

So, as a user of this material, I have noticed that it is pourous and
dusty. It came to me that if the part could be infiltrated with a low
viscocity fluid that then hardened, it could help improve surface finish
and possibly the tendency it has to leak fluids. The key to the infiltrant
is that it needs to have similar properties.

So. . .

Food coloring gives it a very nice color but comes off.
Material dyes make it look real good but the dye will fade over time.
Clear silicon works pretty good but doesn't penetrate the material.
Clear silicon diluted with mineral spirits helps, but then the part stinks
and it is very hard to apply.
Rubber coating for tools (handle grips) comes in many colors and works
pretty well. It penetrates approx 1/16" into the part and acts to seal and
color the part. This can be applied with an aerosol spray or a liquid dip.
A very good alternative is commercially available, low durometer urethanes.
 The urethanes infiltrate well until they set and can be dyed to give you a
color of choice.

My point is. . .

You can patent a car. And you can patent the wax. But you can't patent
the process of applying wax to the car. That is what you call a trade
secret. Like the CocaCola formula. No one can keep me from mixing food
coloring and carbonation and syrup, etc. But you don't have to give me the

Good luck though . . .

(BTW Elaine, is this a good use of information for our little group?)

David K. Leigh phone (254) 742-1822
Harvest Technologies fax (254) 742-0053
Rapid Prototyping Services

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