How to cut eva foam?

[geminni024]

Hi!

I am new with laser cutting technology so I'm still learning the basics.
Now I'm learning to work with eva foam. I have a problem with cutting edges, they are little bit burned, they have black stripes. How can I remove that?

I have tried slow speed, fast speed all in combinations with low or high power, same result. With slower it starts to melts.

[zax15uk]

You want to use a fast speed and air assist (for optimum performance you should look at using Nitrogen but it probably isn't necessary).

Zax.

[geminni024]

Thanks! I tried today like you said, with fast speed. Yesterday i did it with slow speed. The results are similar but in both cases when working with circle shapes it can be seen where the laser starts and stops.
For that I have tried changing all the parameters but with no success. Is that normal or I'm just to picky?

The laser machine is Golden Laser JG-13070 and it has 4 parameters to work with: Work energy, Minimum energy, Work speed, Work acc.

In that order, these are the new parameters: 80, 60, 30, 300.

[zax15uk]

There should also be a setting, maybe in a deeper menu that changes the laser on dwell. When the machine switches the laser on there is a short pause before it begins moving, to ensure the beam has reached full power. You want to reduce that dwell.

It may be called 'cut delay' or something similar.

It's the same principal that is used with CNC machines, you turn the cutter on before plunging into material and there is a dwell to ensure it is up to speed, of course with a laser the delay is much shorter. A setting of 0.25-1ms is typical.

Zax.

[geminni024]

I think I got it now

Now i wonder how to attach those strings that connect foam with metal ring?
http://100-gift.com/uploads/upimg5/E...gs_1543364.jpg

I guess that I need some flame to melt the sting. Is there a machine for that or I have to do every piece by hands?!