Need Help UV Printing Onto Brushed ACM - Edges Chipping

[DarkerKat]

Printer: HP FB750
Stock Material: Brushed ACM (8031 AluPoly)

Sorry if this is a redundant thread, I flipped through a few similar discussions but couldn't find anything addressing this particular issue.

We've had issues for years with Full color full-bleed images chipping around the edges when we go to cut them on our cnc after printing. Prints sit for a full 24 hours before cutting and still chip around the cut edge. No issues on plain black or white ACM. We've resorted to clear coating all our prints but along with destroying the brushed look of the material, this doesn't necessarily stop the prints from chipping. We want to be able to do this in house because we have all the necessary equipment, any suggestions to prevent the chipped edges?

 

[White Haus]

Have you tried any adhesion promoters? I'm not too familiar with the HP UV inksets but we've tried these with our Oce Arizona:

https://www.matthewspaint.com/getme...626c64e0/MPC322-plastic-prep-cleaner.pdf.aspx

https://www.supply55.com/adhesion-promoters-s/78.htm

https://www.mimakiinkjet.com/SPC-05...hazardous-material-no-air-shipping_p_130.html

Listed in order of harshness/effectiveness. Matthews I find is a step above just prepping w/ alcohol/water, but the Supply 55 and Mimaki are HARSH chemicals that drastically improve adhesion but will stink up your shop. Use carefully and with lots of ventilation and safety gear.

The only thing you can do aside from improving adhesion is to pre-cut, which since you're using a hybrid I'm going to assume isn't ideal.

Hope that helps.

 

[DarkerKat]

Are you using an upcut bit?
What size bit and how fast is it turning, how fast is the router moving?ect.

Honestly, not sure. I'll check with our CNC guy, thanks for the suggestion.

 

[DarkerKat]

Have you tried any adhesion promoters?

I don't think any were used on this job. for regular acm we seem to be able to skip them but they might be worth looking into for the brushed material. Thx!

 

[Superior_Adam]

we print/route regularly on the brushed material. Make sure your bit is sharp.

 

[bowtievega]

We cut our printed ACM with a single flute down cut but, never have chipping issues. We have a mimaki flatbed and use their primer when printing, makes a huge difference with adhesion. We clear coat a lot of our prints so those get scuffed before printing as well.

 

[CMYKENGINEERING]

Promoter is a great suggestion, though some UV inks do not require it to adhere well to ACM. Do you print white on the ACM?

 

[Pr1nth3@d1357]

Printer: HP FB750
Stock Material: Brushed ACM (8031 AluPoly)

Sorry if this is a redundant thread, I flipped through a few similar discussions but couldn't find anything addressing this particular issue.

We've had issues for years with Full color full-bleed images chipping around the edges when we go to cut them on our cnc after printing. Prints sit for a full 24 hours before cutting and still chip around the cut edge. No issues on plain black or white ACM. We've resorted to clear coating all our prints but along with destroying the brushed look of the material, this doesn't necessarily stop the prints from chipping. We want to be able to do this in house because we have all the necessary equipment, any suggestions to prevent the chipped edges?

 

[Pr1nth3@d1357]

Hello, I run an old Anapurna M1600. Had the same issue. We started bumping up the UV lamp settings to 7, shot white first, (large choke) and no problems now. We're also had to make sure our router bit was in good condition. Hope this helps.

 

[Bly]

How about kiss cutting the path before routing?

 

[Boudica]

We always tape the ACM (or any substrate) with R-Tape before sending them to the C&C cutter. It protects the print during the cutting process.