Particular Graphic Eats Vinyl While Cutting

[kirsmith]

Hi everyone,

I have a Mimaki CG130-FXii here at work. I've recently replaced the cutting strip, the pen holder and have brand new mimaki blades for it. I have everything set so that it usually cuts through the vinyl&laminate like butter.
But there is one graphic in particular that I do that always breaks my blades or ruins the decals but eating the edges or skipping. I do a bunch of different decals here of all sizes and shapes but this one seems to really be the one that causes all the difficulty.
(It seems to have a lot of sharp, small edges. Also comes in 2 sizes and both the small and large do this) It plots by starting with the buffalos, which seem to kill the blades, and then the letters have no chance
They've been doing this decal for years now, way before my time here. There used to be an elaborate mountain in the background that I've convinced the design team to get rid of because it was a nightmare to weed. So now it's just a buffalo with letters.
Is there a better way to set up my plotter as to not ruin an entire sheet of decals and my blade every time I do one of these things? Currently set at 60 speed, 100 Pressure and .30 offset. Vinyl is 4.2mil and laminate is 4.2mil. Any suggestions greatly welcomed!
I am a year and a half into doing this and had training from people who didn't know what they were doing either. Thanks to you guys I've realized the laminator was never set up properly (for the past 10 years!)

 

[Zoogee World]

There are a couple things that come to mind, first is that the ink isn't quite dried enough prior to cutting, second it that the cut pressure is too high and last is the speed is too fast. Try slowing down the cut speed to something like 20. As for the pressure you want it to cut through, but just barely so it leaves just a little lines on the backer, you don't want it cutting too deep into the backer paper. Hope this helps.

 

[kirsmith]

There are a couple things that come to mind, first is that the ink isn't quite dried enough prior to cutting, second it that the cut pressure is too high and last is the speed is too fast. Try slowing down the cut speed to something like 20. As for the pressure you want it to cut through, but just barely so it leaves just a little lines on the backer, you don't want it cutting too deep into the backer paper. Hope this helps.

I slowed the speed down to 30 and it helped significantly! I will lower it to 20 for the next one. The pressure at 100 barely leaves an indentation on the backer, any less and it doesn't cut through most of the time. Thanks so much!!

 

[Zoogee World]

If that's the case, you can always try a little more cut pressure too, as it could be there isn't enough pressure and it's peeling up those edges.

 

[Adam Vreeke]

Few things come to mind for me:

1. What angle of blade are you using? This matters, a 30 degree blade is used for detail work, where as a 60 degree blade is used for doing thick cuts.

2. Try adjusting your speed and pressure, both seem just a little high for me. But i would work on adjusting speed first. Very generally speaking you get the ripped corners like that when the blade doesn't have enough time to spin around while cutting, this is what will create looped corners or potentially torn corners.

3. Check the file, depending on your terminology, the points or nodes of the cut line. Is the cut line as simplified as it can be? Or is there just hundreds of points or nodes?

4. If all else fails, customize it, especially if you keep doing this job. For instance with the "I" instead of it being a rectangle, make it 4 separate lines, all overcut, this will allow the knife time to turn while cutting.

5. Does this same file do the same thing, but on different material?

 

[unclebun]

Slowing down the plotter will help a lot. But if the decal is just all black silhouettes and you do a lot of it, you'd do even better to have the company buy a roll of black vinyl (intermediate would have same or better life than what you're using, high performance would have double the life) and cut that instead of an 8.4 mil laminated print. Save money, time, and aggravation.

 

[jcskikus]

Another question that may or may not have to do with your problem, but needs to be asked:
What program(s) are you using to open/create the vector, and what RIP are you using to cut said graphic?

 

[Ronny Axelsson]

Many good tips here, and especially about the speed, that's where I would start and slow it down to 15 - 20.
But, vinyl + laminate + small details and sharp corners is a perfect recipe for creating the kind of things seen in your buffalo screenshots, but the text???

Had a similar job with about 15 stickers yesterday that cut almost perfectly, but there where three or four small parts that for some reason got the same lifting in corners and small skipped parts as can be seen in your images.
Three stickers could be perfect and then one had this problem in one place, then maybe three perfect ones again and then another one with the problem in a different spot, and I could not figure out why, it just happened.

In your case, if there is no real reason for printing, use colored vinyl instead and skip the laminate.
If that isn't possible, try adjusting the speed and pressure, check the file to make sure there are no unnecessary nodes or "impossible" angles.
One more thing: After a couple of "bad cuts" there may be remnants of vinyl left on the knife. Check to make sure it is clean and that it can rotate freely in the holder.

The expensive solution: Get a flatbed cutter with a tangential knife.

 

[jtiii]

I'm not sure what size these are and what software you're using but CorelDraw has a Corners tool that lets you set a radius as small as .01" and rounds your sharp corners. It's not perfect but it usually only chokes if there's two nodes right on top of each other. I put a radius on just about everything now.

 

[Joseph44708]

You can also make it a two cut job.
1st cut, Kiss cut then cut over that with your regular cut. Only adds a few extra minutes to the job but way less wear on your blades.

 

[kirsmith]

Thanks for all the help, y'all!
I've slowed all my cuts down to 30, it's a lot slower but it seems to work great for the smaller stuff. We do about 2000 different decals in all colors for machines here, the majority are just boxes or ovals but a handful are intricate, and it's definitely helped with those.
As for changing the vinyl/laminate. I've tried to get higher quality stuff (they sent me expensive stuff when backordered once, I was spoiled!) but it is $$$ and I got through a 150ft roll every 2 days of both, so they said no no to that.
I use Adobe Illustrator with Fine Cut for the cuts. I am not too sure about 'impossible angles' or nodes. Usually our graphic designers make the cut files, and they don't know how to use the decal making equipment so its safe to say there is a bit of a disconnect when it comes to this

 

[Adam Vreeke]

Thanks for all the help, y'all!
I've slowed all my cuts down to 30, it's a lot slower but it seems to work great for the smaller stuff. We do about 2000 different decals in all colors for machines here, the majority are just boxes or ovals but a handful are intricate, and it's definitely helped with those.
As for changing the vinyl/laminate. I've tried to get higher quality stuff (they sent me expensive stuff when backordered once, I was spoiled!) but it is $$$ and I got through a 150ft roll every 2 days of both, so they said no no to that.
I use Adobe Illustrator with Fine Cut for the cuts. I am not too sure about 'impossible angles' or nodes. Usually our graphic designers make the cut files, and they don't know how to use the decal making equipment so its safe to say there is a bit of a disconnect when it comes to this

There is nothing better than a cross trained graphic designer, I know, I am one, and there are a few other on here as well. Get your Designers out into the shop and start training on machines, they will have a much better understanding on not only how to do stuff but why it is they do it.

The nodes of a line are the points on said line that tell the knife where to go. So if you have a corner, there is a node or point where those two lines meet. Go into Illustrator, open a file with a dieline and click on the line with your direct select tool (shortcut is 'A') or the white pointer on your toolbar. All the points of that line should now show. The fewer you have, the better it is, makes for less points the knife has to hit, and generally a smoother faster cut.

 

[Ronny Axelsson]

In addition to what Adam wrote, and regarding "impossible angles":

If you select a node with the Direct Selection tool (A), you will see node handles coming out from it (if the connecting segments are curves instead of lines),
and if these two handles are at almost at the same angle, it means that the knife has to do a very sharp turn where that node is.
This is normally not a problem, the Mimaki CG-FXII handles this well, but with thick materials and many sharp angles near each other, the material may start lifting.
And, as Adam also pointed out, too many nodes not only slows cutting down, if there are many unnecessary nodes very close to each other, they may also make the knife "stammer".

Another problem (in rare cases) can also be that the node handles point in the wrong direction.
The handle that is supposed to point towards the left segment, points to the right, and vice versa.
If an angle looks normal but is cut in an unexpected way, if you zoom in really close to that node and check the segments coming out from it, they may in fact form a small "loop" instead of an angled corner.

Here's a screenshot showing a loop (it is from CorelDRAW but looks pretty much the same in Illustrator):

 

[Gino]

For sh!ts & giggles, have you tried just cutting the graphic without printing anything ?? That would rule out ink participation and then you'd know which direction to go towards.

 

[McDonald Signs]

Try "Slightly" rounding all corners of the buffalo and letters? I do that alot if a graphic has sharp corners. It helps alot on cutting and weeding graphics.