Sintra is a very dense vinyl foam that comes in a variety of colors and thicknesses and is easily glued and milled. I was hoping it could be a potential Glowforge material. So I ran a quickie test this morning.
In a word, nope.
It can be cut and engraved at reduced settings, but it changes color, heat-curls the cut edges, produces lots of soot and Gawd-knows what kind of poison gasses from the cutting. At full power cutting, the residual heat from the laser striking the steel crumb tray matrix actually traveled into the piece, making a burned grid around the edges.
On top of that Sintra is PVC foam. When you hit it with the laser, it makes chlorine gas which combines with water in the air to make hydrochloric acid. This is very corrosive to many parts in your machine and will destroy it.
A little searching will produce pictures of the inside of laser cutters after cutting too much PVC. They’re pretty ugly.
I’m trying not to pile on but I really don’t want to see someone hurt or their machine ruined.
PLEASE DON’T experiment anymore without knowing what it is. There is butt tons of information here and on the internet. If those come in dry there is always the msds.
When it comes to experimental lasering, you don’t want to do it your way, or regrets, you’ll have a few. Start spreadin’ the news, and don’t do somethin’ stupid or instead of having the world on a string, your machine might blow up and fly you to the moon. But if you stay safe, the best is yet to come and and I’ve got high hopes that it will be a very good year.
From a material perspective (ie the material caused damage to the unit), only Proofgrade is warranted, in that sense. Proofgrade is guaranteed not to hurt your machine, cause damage by fire, etc. (when Proofgrade settings are used). Any damage caused by non-PG materials is your damage to own.
Yeah, chlorinated vinyl is not something you ever want to play around with around heat – if you’re looking for an expanded foam you can safely laser, your best bet is probably EVA foam (ethyl vinyl acetate) – doesn’t have a chloride group so it won’t eat your laser, and provided it’s good quality and doesn’t have a bunch of added brominated flame retardants or something, it generally laser cuts and engraves quite well.