dross issue when cutting galvabond on Amada F0-3015 would appreciate help

[ozdan]

Hi All,
Would really appreciate any advice on cutting 2.4mm thick (13g or 0.093") galvabond sheet. Im not sure if you call it "galvabond" or some other similar product name,in the States, but just to be clear, what I am talking about is a hot dipped zinc coated steel made up of: Galvabond G2 steel, a hot dipped zinc coated commercial forming steel with a spangled surface. Am getting further and further behind on our production requirements so am desperate for help.

Regardless of the settings I change in terms power, feed rate, frequency, nozzle gap, or focus I cannot achieve a consistent dross free cut. In some directions it cuts clean and then it will not in cut clean in others, but even this is not consistent. I have tried using both Nitrogen and shop air gasses, getting slightly better result with air but blackened edges. The nozzle is centered and lens is brand new. Am using 5" lens, 2.5mm nozzle. I am not getting this issue with other materials such as stainless steel. I am left to ponder if this could be just that this material is just a bitch to cut or if we have other issues which may need addressing such as mode alignment or mirror issues. As our machine is due for service, we will soon getting new output coupler, mirrors etc, so will retry again after that.

if any one is cutting this material sucessfuly on Amada FO3015 or similar, would appreciate the settings you are using so we can try them.

 

[evans1089]

To be honest, I still get a little amount of dross no matter what gas or conditions i use. 2 companies nearby also have the same results as we usually do their larger work.

 

[jetrep]

This material is difficult to cut and slow to cut. What head/cone do you have on the machine?

On our F1 (most likely has a head/cone that cuts galvanized material better than FO cone) I think we cut this material at around 90"/min.

Fiber lasers seem to cut this material more effortlessly with better quality and higher feed rates.

 

[ozdan]

Thanks to evans1089 and jetrep for your replies. Jetrep, I am not sure what you mean by "head cone" I have only different focal length lenses or nozzles sizes to choose from. I have 5" lens and 2.5mm nozzle fitted when cutting this material.

 

[evans1089]

Our conditons on the FOM4222NT maybe different but for our 5" lens:

E0004:
FEED 2500
POWER 2000
FREQUENCY 2000
DUTY 70
GAS PRESSURE 0.30
GAS KIND 3
NOZLE GAP 1.5

FOCUS 0.5
NOZZLE 2.0
AC 12

 

[b20vtechb]

I cut some 3/16" thick hot dipped material, i basically treat it like it is stainless but cut a little slower and the focal point seems to like being extremely low.
i would try 5.0" lens 2.0mm nozzle and high pressure nitrogen .80, also you will need to lengthen the pierce times quite a bit.

 

[ozdan]

Thanks to for everyone for replies,Still getting dross but have made some improvements, will post if I get better result, still appreciate any assistance.

 

[FabproHelp]

I use the same laser and have been cutting the galvanized sheets usually clean. We also cut right around 90" per min. It seems to me that the amount of dross varies day to day when cutting that zinc coated stuff. I also use a smaller nozzle than u do. Generally a 2.0 like the others in this thread

 

[ozdan]

FabproHelp, Your point about the difference from day to day is one that I hadn't mentioned, but yes I get that too. Could I ask what are the cutting conditions you are using,ie power, Freq, duty, Gas, nozzle gap & focus?

I have made some improvements to the cut but what I have now is that I am getting a clean cut in one direction along one axis. As soon as it goes in any other direction it gets dross. I have tried a different lens, same result. Tried turning off height sensor, same result. Checked and rechecked nozzle centre, same result. Cleaned external mirrors, same result.

I'm pretty much bewildered on this one. I have a service due in the next couple of weeks, where I am getting new output coupler,mirrors,etc and can only hope that the issue may be resolved by the new components and a mode alignment.