Table Marks, Vector Cut Acrylic?

[JB Lynn]

Hello :)

I have a simple question, or maybe an observation?

I've been doing vector cutting on 2 different lasers for about 3 years, lots of matteboard and 1/8" paper-masked engraver's plastic, always perfect. However, I am relatively new to vector cutting acrylic (I've done bronze, smoke, clear and transluscent colors)

When doing a single pass cut with 1/8" thick acrylic, I notice a very faint pattern along the backside of the substrate's cut edge that mimicks the pattern of my vector table. I am using a 35 watt machine (settings 100P/.06S/750 PPI) and am cutting my acrylic on a metal wire grid.

The faint marks I mention are NOT actual burns on the acrylic just a subtle and tiny shadow along the vector cut edge where the arylic rests on the wire grid; to tell the truth most people would hardly notice it and I've made hundreds of items with this and the customers have never questioned it.

Just want to know if this is normal? I guess cutting acrylic with the mask would help, but this doesn't seem an option for acrylic. Do standard honeycomb table do this too? Thanks for any help :)

Regards, JB Lynn

[Lee DeRaud]

The beam is reflecting off the wire back onto the backside of the acrylic. And yes, the honeycomb tables do the same thing.

Don't know why you think cutting with the mask is a problem. If the stuff that comes on the acrylic doesn't laser properly, just peel it off and use transfer tape instead. Fixes that problem right up and keeps scratches off the surface.

[Rodne Gold]

We hardly ever use our vector tables anymore due to backflash , mars the pieces. We just elevate the piece off our table with scraps of 8mm thick pex and cut. We use a piece of anodised ally on the table itself as a "backstop" and to keep the table clean. Anodised ally aborbs and doesnt reflect the laser. We ALWAYS leave the maks on when cutting , the masks only gets taken off right at the last moment after assembly or fabrication and in fact when we cut letters etc , we supply it to the customer with the masks.