Cutting

[Jeffie3]

I want to cut some 0.060 think polyethylene. I have been reading. Can you cut this with a 1w or 2w laser? If not 5w? A bit of advise would ever be so helpful.

Thank you,

Jeff

 

[weeba2kv]

0.060 mm , inch ?????? more information needed color ? more info !!!

 

[Jeffie3]

0.060 inches. 1.52 mm The color is white. The letters on it is HDPE.

 

[Sigurthr]

High density polyethylene, used as a neutron moderator in the radiation industry. I believe they use saws for cutting it normally, as their applicaiton requires very thick blocks and the thermal stress from laser cutting would change the density too much.

Just some useless info for you. =)

Is the HDPE colored at all? I would suspect that if it is the common white stuff it would reflect/scatter too much light to be cut by a visible spectrum laser. You'd probably need a non vis/NIR laser, like a CO2.

 

[chipdouglas]

With a 1 watt blue you could burn through it but it would take some time. A long duty cycle. Not to mention the reflection which would be unsafe.

Impossible, no... Impractical, yes.

Michael

 

[Jeffie3]

I would like to thank you all for answering my questions. I have been looking at some co2 lasers. I guess my next question. Why do all the co2 lasers I see use mirrors? Cold you possible use fiber optics? The do need to find a way to cut the HDPE. But I would like to build an all purpose machine. Change the head and make it a router, laser, and an engraving mill.

 

[millirad]

Maybe this?................

NEW CO2 LASER ENGRAVING CUTTING MACHINE ENGRAVER 40W m6 | eBay

 

[Jeffie3]

Nice looking machine. What I need is one that is 5 foot x 10 foot. The sheets I need to cut right now are 3 foot x 4 foot. I own a machine and welding shop. So building something is easy. Even the cnc part of it I have under my belt. The laser part is where I have trouble.

 

[Sigurthr]

Ahh, you should do fine with a DIY CO2 laser then!

Just grab a 40W tube and power supply off ebay, hook em up, and supply the water cooling. You should be able to figure out the rest of the setup rather easily once you get the tube running. Nice thing about CO2 tubes is that can be run at lower powers than the rating; you can run a 40W at 10W to engrave thin stuff.

Offtopic; from an Ex-Welder to a weld shop owner; do us all a favor and switch over to ceriated/lanthanated tig electrodes from thoriated, if you haven't already. Too many of my friends have died from hot particle lung cancer. At the very least, make sure they use a ventillation and dust particle containment/removal system at the grind station. Trust me, rapid lung deterioration from embedded ThO2's Alpha emission is a VIOLENT death.

 

[Jeffie3]

Thank you for the info on tig welding. We are going to buy a tig soon.
Back to the question. Why don't people use fiber optics instead of mirrors?

 

[00Giorge]

I do know someone that does have a laser cutter and will not use it to cut any plastics, it melts the plastic and leaves burnt plastic edges and makes the plastic brittle on the cut edge, not to mention the toxic smoke that the plastic gives off.