Printing Directly To Acrylic Vs. Face Mounting

[Lindquist]

We routinely print acrylic on a Scitex FB700. We are reverse printing with white ink and in generally works okay. The prints are fragile, and we often put a clear backer on them to protect the print. That is somewhat annoying, but it hasn't been a big deal.

However, without fail, we end up with at least one piece of acrylic that prints wrong. Sometimes the material moves during printing. Other times the feed rate seems to be off near the end of the print. And other times we end up with the margins wrong (though this one could be human error more than anything).

Because the prints scratch easily, we are always able to take the ink off and try again, but it is time-consuming. Just this morning we had 10-12 acrylic small acrylic prints to complete (24" x 24" and smaller). It took the entire morning. We had to clean off and reprint at least two pieces, and the whole procedure just takes a lot longer than we would like.

I sometimes send overflow work to a vendor, and they face mount prints on acrylic using some kind of optically clear adhesive. What product(s) can I use to try this? We used to print clear vinyl and add white backers to acrylic; that was prone to a lot of error as well and was also time-consuming. We're trying to find a way to produce acrylic prints more reliably. A lot of our lost time is due to redoing prints regularly. We just want a way to get it right the first time.

So, I'm looking for advice to print directly on acrylic more reliably or how to try face mounting prints as an alternative.

 

[ChrisN]

If you want more scratch resistance, try some adhesion promoter. I use Supply55 AP3155 with good results. Also, you could try digital acrylic - it is supposed to have better adhesion than regular acrylic.

If you are having problems with small pieces of acrylic slipping while printing, make sure the vacuum is focused on the piece you're printing. I'm not sure how the HP vacuum system is, but on our Agfa, I could turn off half the bed to focus the vacuum only on the half that had the printed piece on it. Also, try feeding a scrap piece behind the piece you are printing. What can happen is that as the print gets to the back edge of the piece, there is less vacuum holding it to the belt, and it can slip. Feeding a piece of scrap after printed piece will mask off the vacuum area and help to keep the vacuum high enough so the printed piece does not slip. Also, if it is against the printed piece, the scrap piece can push the printed piece through if the vacuum isn't quite high enough.

 

[Pauly]

The first problem is using a hybrid flatbed. I'm personally not a huge fan, especially for printing on acrylics or in my case glass. The problems i see are that acrylic is never flat and you cannot suction it down that much on a hybrid. Also tracking, as you're experiencing.
But you're managing which is good.
Anyway, As stated by ChrisN you can get a "digital acrylic" which has some coating to help ink stick. I use this and have no issues with it. You can get adhesion promotors but i have not had to much luck with them as some can leave streaks in the acrylic, and the fact acrylic scratches easy and it can show up in the print.
I'd first try to get a digital acrylic. It'll cost a little more but it should work.

 

[boxerbay]

facemounting will take more time and cost than your reprinting. If small pieces are shifting you need to mask off the open areas of the belt so there is more suction. We use chip board around the acrylic and close off the areas we dont have acrylics on. Time is money so you need to figure out if cleaning the messed up acrylics cost more than just having extra ones. Cost of acrylic VS cost of labor. If you have someone making 15/hr fiddling for an hour on a $5.00 piece of acrylic your better off just having a couple extras and build those extras into your quoted price.

"feed rate being off and the end of print"? call tech support. If we see slight banding after 18" of clean print it is usually an air bubble in the line. purge your inks.

 

[Andy D]

You're right, direct printing to small pieces of acrylic or other substrates on a hybrid flatbed is problematic:
Adhesion isn't great.
If you need a over bleed, you have to spend a lot of time taping off or get ink on your belt.
printing to small pieces on a flat bed is risky, the lights can cause the substrate to bow up and you could have a head strike.

Can you cut acrylic after it's been printed?
We almost always used polycarbonate & what I used to do is run the full 4'x8' sheet of polycarbonate through the laminator and mount clear Oracal to it, print, and then shear to size... ink will stick much better to the vinyl than polycarbonate or acrylic, and if there is an issue, it's much easier to remove.

Also, as others have said, I always try and print 1-3 extra, it's much more economical
than redo's and if there are no mistakes I will often give the extras to the customer.

 

[Pauly]

You're right, direct printing to small pieces of acrylic or other substrates on a hybrid flatbed is problematic:
Adhesion isn't great.
If you need a over bleed, you have to spend a lot of time taping off or get ink on your belt.
printing to small pieces on a flat bed is risky, the lights can cause the substrate to bow up and you could have a head strike.

Can you cut acrylic after it's been printed?
We almost always used polycarbonate & what I used to do is run the full 4'x8' sheet of polycarbonate through the laminator and mount clear Oracal to it, print, and then shear to size... ink will stick much better to the vinyl than polycarbonate or acrylic, and if there is an issue, it's much easier to remove.

Also, as others have said, I always try and print 1-3 extra, it's much more economical
than redo's and if there are no mistakes I will often give the extras to the customer.

I've never had any issue with acrylic expanding on the flatbed, big or small. I've had sheets 2500x2500mm on it no issues. i've had small a4 (210x300mm) for profiling on there and it's all fine.

Cutting printed acrylic? I pre cut mine. Risk of it chipping cutting printed acrylic. It's possible but not worth the risk.

 

[boxerbay]

the only time we get acrylic to bow is very thin sheets and when we do them we run only one of the 2 lamps.

 

[Andy D]

I've never had any issue with acrylic expanding on the flatbed, big or small. I've had sheets 2500x2500mm on it no issues. i've had small a4 (210x300mm) for profiling on there and it's all fine.

Cutting printed acrylic? I pre cut mine. Risk of it chipping cutting printed acrylic. It's possible but not worth the risk.

Acrylic isn't nearly as bad as other materials like polystyrene or Sintra.. but keep in mind there are many different brands and types of acrylic not mention printers, if you haven't had issues with acrylic bowing, that's great, but I have.

By far, the quickest and least problematic way to print a bunch of small signs for me has always
been to nest them onto a large sheet, print, laminate and shear or route them afterwards...
Plus, this prevents cutting shavings from contaminating my prints.

 

[Pauly]

Acrylic isn't nearly as bad as other materials like polystyrene or Sintra.. but keep in mind there are many different brands and types of acrylic not mention printers, if you haven't had issues with acrylic bowing, that's great, but I have.

By far, the quickest and least problematic way to print a bunch of small signs for me has always
been to nest them onto a large sheet, print, laminate and shear or route them afterwards...
Plus, this prevents cutting shavings from contaminating my prints.

Actually yes i have also got acrylic routed once printed. Not often i do that though. usually when i do tags.

 

[IGNITION]

We mount C-prints 2nd surface onto clear acrylic all the time with optically clear adhesive (our go-to is ViewBond) - you could also print image/white/image on clear SAV and mount that onto the back (though that doesn't look quite as nice)

 

[boxerbay]

smaller pieces we banner tape them to a larger 40x30 chipboard. this way the large chipboard gets sucked down hard and the small piece doesnt shift.

 

[Lindquist]

Just to add some more detail about our specific situation: we are normally printing odd sizes but nothing extremely small. Typical prints are 30" x 30" or 20" x 12". They are interior displays that are resized to fit whatever wall space is available. Most of the prints are one-offs, so printing extras is not a great option. The acrylic we print is most commonly 3/8" thick.

I can appreciate that a more traditional flatbed printer would have less trouble than our hybrid. I will have my operator try using a second piece behind the print (per ChrisN's suggestion) to see if that helps. I am also going to consider cutting the sheets after printing, but I'm concerned that my crew may not be delicate enough with the product for that to work reliably (but we do already cut some other materials after printing, so ti's not a completely new process).

I asked a vendor to send me a sample roll of an optically clear adhesive to give that a shot too.

Thanks for the advice. I appreciate it!

 

[702displays]

Just to add some more detail about our specific situation: we are normally printing odd sizes but nothing extremely small. Typical prints are 30" x 30" or 20" x 12". They are interior displays that are resized to fit whatever wall space is available. Most of the prints are one-offs, so printing extras is not a great option. The acrylic we print is most commonly 3/8" thick.

I can appreciate that a more traditional flatbed printer would have less trouble than our hybrid. I will have my operator try using a second piece behind the print (per ChrisN's suggestion) to see if that helps. I am also going to consider cutting the sheets after printing, but I'm concerned that my crew may not be delicate enough with the product for that to work reliably (but we do already cut some other materials after printing, so ti's not a completely new process).

I asked a vendor to send me a sample roll of an optically clear adhesive to give that a shot too.

Thanks for the advice. I appreciate it!

We mirror our image and print on clear gloss laminate, then we cover it with a piece of white vinyl (protects the print and works as your white ink). Then we mount it to the back side of our acrylic cut piece. Rapid Tac is your friend when applying it to the acrylic so you don't get any bubbles. Direct print is much less time, but I like the old school approach too.

 

[chafro]

Hello! I do hundreds of acrylics a month. We used to do only facemount C-prints.

Now with our swissqprint we direct print also. We offer both,, face mount is way more expensive but also has more quality.

A lot of clients liked the better prices and when direct print, many others still like the quality of face mounting and pay for the difference. Mostly art, fine art decoration and studio people prints.

We do like 50-50 of each..

We cut on our ESKO after we print our ink doesn’t chip on acrylic, never. It’s way faster to print 4x8s with many images on them and then cut.

Fotochrome Digital on Instagram: “CNC finishing some acrylic facemounts. Busy day for our router. [HASHTAG]#montadoacrilico[/HASHTAG] [HASHTAG]#fotosmontadas[/HASHTAG] [HASHTAG]#hdprinting[/HASHTAG] #silverhalidephotography…”

Fotochrome Digital on Instagram: “Cortando Acrilicos con CNC. La manera correcta de cortar Acrilicos para lograr escuadras perfectas y perímetros con buen acabado.…”


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[ProColorGraphics]

Hello! I do hundreds of acrylics a month. We used to do only facemount C-prints.

Now with our swissqprint we direct print also. We offer both,, face mount is way more expensive but also has more quality.

A lot of clients liked the better prices and when direct print, many others still like the quality of face mounting and pay for the difference. Mostly art, fine art decoration and studio people prints.

We do like 50-50 of each..

We cut on our ESKO after we print our ink doesn’t chip on acrylic, never. It’s way faster to print 4x8s with many images on them and then cut.

Fotochrome Digital on Instagram: “CNC finishing some acrylic facemounts. Busy day for our router. [HASHTAG]#montadoacrilico[/HASHTAG] [HASHTAG]#fotosmontadas[/HASHTAG] [HASHTAG]#hdprinting[/HASHTAG] #silverhalidephotography…”

Fotochrome Digital on Instagram: “Cortando Acrilicos con CNC. La manera correcta de cortar Acrilicos para lograr escuadras perfectas y perímetros con buen acabado.…”


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What material and thickness did you use in those videos?

 

[chafro]

3mm acrylic and a 3mm sintra at the back.


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