CNC Routing Premask for Pre-Applied Vinyl on Acrylic

[DisplayWorks S&G]

I am looking for advice on the best transfer tape and workflow setup for cutting vinyl-faced acrylic on a CNC router.

My Current Process:

1. Apply vinyl to the acrylic sheet.
2. Apply premask over the top to protect the surface and help hold the vinyl edges down.
3. Route the shapes using an O-flute bit.

The updraft from the O-flute bit and the vacuum system can aggressively catch the freshly cut vinyl edges, causing lifting or tearing.

Looking for recommendations on a premask that is strong enough to lock the edges down but leave a clean edge without pulling the vinyl off the acrylic or causing chips to get under the vinyl.

Would love to hear how you guys keep your edges perfectly crisp on the table. Thanks!

 

[Grizzly]

Can you route with the face down? Or you can use either a down cut bit or a compression bit. It has both upward and downward spirals to keep the vinyl face from lifting.

VTX-Rc5415-A (Compression) – VTXTOOLS.COM

Multielement multilayered “rainbow” coated, “Super” carbide, polished, compression (both up and down flute) router bit with a 4mm cutting edge diameter and max milling depth of 14mm. Please note that this bit requires a minimum thickness of 3mm for the compression feature to work. With stop ring...

vtxtools.com

 

[packratsigns]

What kind of acrylic are you routing ? Large or small parts?

We would dry laminate 3m vinyl on to 4 x 8 sheets of Cyro white 3/16.
No masking.
Vinyl face up.
Clean cuts everytime.
Our bits were Belin 13476 , now known as

Onsrud 63-310 .​

Cutting speed 150-200 ipm at 16000 rpm.

Material is held down by regen vacuum on ultralight mdf

 

[JBurton]

We would dry laminate 3m vinyl on to 4 x 8 sheets

This is key, and probably 3m as well. We have mounted 3m 3630 to 3/4" sheets with great success, same procedure except slower ipm and faster rpm's.
The couple of times we've applied vinyl wet, we either wait a day or more to route, or leave them in the sun to bake out the rapidtac. Using the laminator is more of a pain (especially with 3/4" clear), but faster and gives the best result. Masking is just another layer to gum up the bit.
Also, directionality matters. On a fresh cut, do a 3" straight cut, make note of the left/right hand side for a superior edge.

 

[GaSouthpaw]

Routing with a straight flute bit (like the Onsrud 61-000 series) will give you the result you're looking for. I've run plastic with vinyl applied using the 61-061 many, many times over my time. It always works just fine unless the operator screws up.

Not to dispute packrat, but- sooner or later- an upcut bit is likely to "lift" the edges.