Cutting PETG film (COVID19 related)

[Ignas Kaz]

I'm in the process of planning a HUGE run of face shields (only transparent part, not the band).
In the morning i'm getting 300kg spool of 510mm wide 0.5mm thick PETG film delivered and need to know if there are any particular tricks to this material. I know its safe to cut, but is more melty than burny (feel free to correct me if i'm wrong).
The machine is 80W (sustained) CO2 glass tube (CDWG). Will be using pass through hatch to spool material in (by hand).
I'm interested in speeds and power required, if any tricks to help get better edge, type of bed should i be cutting it on (material is thin and floppy).

Will probably have to come up with some sort of positioning jig to just keep pressing RUN on the machine.
I have a standard honeycomb at the moment, but have lots of other materials to make a bed out of (Acryllic, PP, HDPE, MDF, steel).

Presently i'm putting my laser back together from it being reengineered, so just thinking ahead.

Just thinking about 30k item order makes me nervous...

[Tim Mellor]

If you are sticking with the Honeycomb then get hold of some 3-4mm thick x 25mm steel strip in advance to keep the thin sheets in place and hold them as flat as you can on the edges. As it is rolled it will get harder to hold flat the further into the roll you get.

I haven't cut PETG other than playing with a soft drink bottle so I am out on that front. Good Luck

[Gene Uselman]

I cut quite a bit of PETG and it cuts very well [especially .020 thick] I use lots of power and just raise the speed as high as possible. If your honeycomb is ferrous metal you could use magnets but most are aluminum- as Tim sez, thin strips of metal for holddowns.

[Doug Fisher]

>>As it is rolled it will get harder to hold flat the further into the roll you get.<<

Fortunately, this usually isn't the case with high quality PETG. In my experience, it unrolls nice and flat through the hole roll.

[Ignas Kaz]

Yeah my honeycomb is ferrous, magnets all the way.

Did a run of 80 shield visors in an hour, just to gauge how many i can crank out. Roll is 510mm so only 2 visors fit , and only because my machine has Y motor and drive shaft in the way of pass-thru slot - stupidest thing to engineer that way. Cant lay it flat over all of bed area. Dont want to force flatten for fear of creasing. Stupid...

First thought after half an hour of popping magnets on, pulling on a roll and pressing the start button - OW MY BACK.... Machine is way too low. Will probably prop it up with some pallets to raise it about a foot.

Cutting at 200mm/ps and ~50% power, cant go faster as piddly Y motor begins to stall.

Decided to make some flat/wide magnets out of magnetic sign material to lessen time messing about and increase actual cutting.
Also, got only a rewound part of the roll, not the whole 300kg, so, since supplier has a guilliotine they will make sheets to fit 4 for one cut (instead of 2 and too much messing about flatening).

[Gary Thompson]

Hi Ignas

I'm in Belfast and have been doing the same. I've run out of PETG though! Can I ask where you got your supplies from? (especially if it's from Northern Ireland).

Here's the link I'm working from. Is it the same one you're doing?

https://www.protohaven.org/proto-shield/

[Ignas Kaz]

I'm making only the visor as per order, they probably have some sort of permanent headband with replaceable/dispossable visors.

No idea where film comes from. Just order to make from some other companies subcontractor.