HP R1000 on 6mm bevelled Sintra

[sbergman]

Hi,

Customer wants an image printed on 6mm sintra with a bevelled edge all sides and full bleed. We are cutting the Sintra on our CNC and then loading on our HP R1000 with -1/2" margins all sides. The ink appears on the bevelled edge, but seems like it could be denser and doesn't seem to be getting all the way to the edge (some white still showing). We are printing on the printer's belt, so I can confirm the printer is printing in the right areas, just not doing the job we need on the bevelled edges.

Viewing the product head-on it looks good, but if you look closely at the edges the amount of ink is minimal and it appears like the printer isn't printing all the way to the edge. I understand that this situation is hard for the printer, because it is dropping ink from above and expecting the surface to be at 6mm and in the area where I need more ink the distance is greater, so the ink might even be missing.

Does anyone have any tips or tricks for making this work better? I need to print (20) images and all are different. Some light and some dark. Not all can be solved by using black sintra and white ink.

Details:
Images size: 21"x21"
Board size: 20"x20"
Margin settings on R1000: -1/2" all sides
Rip: Caldera
Printer: HP R1000

Link to photos:

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[balstestrat]

Less vacuum on printzone or zero. Ink is getting sucked on the belt and below.

 

[sbergman]

Less vacuum on printzone or zero. Ink is getting sucked on the belt and below.

That's a really good suggestion. I am going to try that now. Thanks so much. Will report back later.

 

[balstestrat]

I was going to add that you will always end up spraying some ink away because of the motions of the carriage and ink drops falling away. So you won't get the same quality ever on the edges.

 

[sbergman]

That's a really good suggestion. I am going to try that now. Thanks so much. Will report back later.

Unfortunately, zero vacuum in the print zone (normal vacuum input and curing) did not solve the problem. I am not looking for stellar print quality. Just the best I can possibly achieve without moving mountains.

Pix:

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[signheremd]

if your shape is accurate, you could create a file with black in just that 1/2"(?) area and print that. It would essentially give you a second hit of ink on the edge without doing so on the face. (If your image bleeds, you could mask off so that only that outside 1/2" prints again.) Just print normal, don't move the piece and print the edge only file.

 

[Gino]

Why are you not starting with black substrate ?? If you can't print white, I'd suggest using a rattle can of black and build your edges up til ya like the look. Then, print.

 

[sbergman]

Why are you not starting with black substrate ?? If you can't print white, I'd suggest using a rattle can of black and build your edges up til ya like the look. Then, print.

I will need to look at each image. The first image is has a black background, but there are (20) images and some

 

[sbergman]

I will need to look at each image. The first image is has a black background, but there are (20) images and some

Not all the images are black background. There are (20) in all. I think I have a sheet of black sintra. I'll try that with white ink to see if I get better results and will report back. Thanks for your suggestion.

 

[sbergman]

Why are you not starting with black substrate ?? If you can't print white, I'd suggest using a rattle can of black and build your edges up til ya like the look. Then, print.

I tried black sintra with white underflood, but that doesn't work because not all my images have a black background. See test images below (1 with light background and 1 with black background). With the black sintra I now have insufficient white underflood on the bevelled edge. Same problem as when I was printing on white sintra and the sample with the black background did not have enough black ink on the bevelled edge. Same problem just different color substrate.

Any other suggestions for how to get better ink density/coverage on the beveled edge?

FYI, normal suction in print zone for Sintra is 1,300. I backed it down to 0 on my second set of test prints and that didn't help. For the attached samples I backed it down to 750.

Tests photos

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[Owen Signcraft]

A good digital wrap would make quick work of these I think. Have you considered wrapping in vinyl instead of direct print?

 

[sbergman]

A good digital wrap would make quick work of these I think. Have you considered wrapping in vinyl instead of direct print?

That's a really good idea and under normal circumstances I would do it in a heartbeat and it would solve all my problems. Unfortunately, this is being installed in a mental health area of a hospital where patients would likely pick at it and either remove it or remove it and try and use it in a dangerous manner. These are being attached to the wall with construction adhesive.

 

[balstestrat]

I don't think you can print it any better than that.

 

[White Haus]

I don't think you can print it any better than that.

Agreed. You're trying to get the printer to do something that just isn't possible.

I'm assuming the beveled edges are a requirement from the client given the location, but can you talk them into chamfered edges instead?

If you had a sharp(er) edge / angle on the top at least, the ink would have better odds of sticking. You could always soften the back edge on a router table after printing.

Part of the issue is also that you're trying to get ink to land and cure on the PVC core which is super porous and not exactly ideal for ink reception.

 

[White Haus]

Duplicate post

 

[Gettin'By]

Would priming before printing help that ink reception?