Manufacturing method of foam

[tecnoz]

Hello !
I am looking for a manufacturing method that can be used to form a round and tubular shape with foam.
The foam is about be about 10 mm thick,
A Foam Cover on top of microphones is a good example of this part.

If you have any suggestions on material or manufacturing process or some companies who do this, pls let me know.

thanks
Hari

 

[WardHollowayPE]

I worked for three years in a Foam plant. I believe you should be able to purchase the foam in an extruded shape very close to what your looking for. If your want to cut the shape out of a block of foam, try using a hot wire. You can build one by hooking up some heavy gauge wire to a variable power supply. Simply turn up the power until the wire gets hot. The wire can be bent to form many shapes before you hook it up to power. I have seen smaller units that use two "D" size batteries too heat a small wire. Hot wire cuts foam very quickly, but can burn the surface a little.
Good Luck

 

[tecnoz]

thanks Ward,

actually the part will be like a hemi-sphere at one end.
you can imagine a "condom".

So I was thinking about some method that can allow this foam to be molded into that shape around a core that can be withdrawn later can help.
But, the cosmetics of this part are VERY important, no seam lines or joints should be visible.

pls advise.

thanks & regards
Hari

 

[WardHollowayPE]

You could bend your hot wire into a 90deg arc, plunge it into the top of the foam, and rotate 360deg. A machine for this proccess would make a nice cut. Another trick is to build a model of the hemi-sphere out of an aluminum blank. Use it to squash or deform the foam, and run it through a band saw right at the tip of the blank. Dont cut the blank, just get as close as you can to it. Sometimes this work really well, sometimes you have to adjust the black to account for foam deflection.