Shearing Stainless Steel Mesh

[negativentropy]

Im manufacturing a heat exchanger for a prototype. It requires a stack of hundreds of discs 1.4" in diameter of #400 stainless steel mesh. Any obvious solutions that stand out? Right now Im trying to make a die to stamp them out from large sheets but its not going well...

 

[davidh]

whats happening when you punch them out ? whats the thickness ? how big is the sheet your working with ? what are you using to punch them with ? pictures. pictures.

my first thought was to punch them, making a die set, and using a arbor press or hydraulic press.

 

[JimDawson]

My first thought was punching them out also, but given the mesh wire size of about 0.001, that would take a pretty accurate punch & die with < 0.001 clearance. And then a very ridged setup to hold everything in position.

I think I would have those laser cut. Doing that might also weld the ends a bit to keep them from fraying.

 

[Bill C.]

My first thought was punching them out also, but given the mesh wire size of about 0.001, that would take a pretty accurate punch & die with < 0.001 clearance. And then a very ridged setup to hold everything in position.

I think I would have those laser cut. Doing that might also weld the ends a bit to keep them from fraying.

Laser cutting might be best. By the time you build a die set with a pressure plate and a shop with a press to use it the laser may be cheaper. Is the material in strips or sheets? I think sheets would be a good candidate for laser cutting.

I hope your project is a success

 

[negativentropy]

Well I got it to work - made a stamp on the lathe as sharp as I could get it (not very), hardened it using my friends forge and quenching in oil. Then I just set the mesh on a HDPE plate and smashed the stamp with a hammer a few times. Works well enough, was able to make 200 discs in less than two hours. The aluminum looking thing is what holds the discs, there is 170... Fun times.

 

[kd4gij]

Nice job.:thumbsup2: I was going to say to hone the die after harding, but your doing just fine.

 

[negativentropy]

I gave some thought of how to sharpen the stamp after hardening, but being circular the best I could come up with was throwing it back on the lathe and running some emery cloth over the outside edge. Without some fancy jigs how would you hone a circular cutting edge?

 

[XXXXX]

I would throw it on the lathe and use a file in a jig (or a rest) to get the edge, then a stone to hone it.

Cool project

 

[ScubaSteve]

So how does a heat exchanger involve mesh? Don't you need separate coolant and product channels in close contact with eachother?

 

[John Hasler]

So how does a heat exchanger involve mesh? Don't you need separate coolant and product channels in close contact with eachother?

The mesh makes the flow turbulent so the heat is efficiently transferred to the mesh and then to the tube it resides in, which is presumably coupled somehow to the other fluid. Another possibility is that this is for a Stirling engine or thermoacoustic device. In that case the mesh stores heat for the next cycle.