Creasing vinyl while cutting, how do i avoid?

[Hugh Potter]

I’m not sure there’s a lot you can do other than ensure the basket is lined up front and rear. On long runs I always wait by it until its scanned all the reg marks, you usually have an idea by then if it’s rolling smoothly, on really long cuts I tend to stand over it for a while at least.

[RobertLambie]

Hi Simon

I am guessing your machine is elevated on a stand?
I am only mentioning it because many many moons ago we switched from a Gerber 4B (desktop cutter) to a Roland 610 wide cutter and we declined the stand for the extra £300 or so. BIG mistake. it was like the tortoise and the hair, in speed comparisons. Jams, kinks and more all followed. 🤨

• Having Media catch bags opened out front and rear helps, but does not stop kinks and jams.
• Try slowing down the pace at which the machine is feeding the vinyl back and forth. I am not sure if this is an option on all cutters.
• As Hugh suggests, stand over the machine until the media has been pre-measured and return to start cutting. Assisting the vinyl to easily fold in on itself during this process helps a lot. then it should be fine to run un-assisted.

The main reason for the vinyl kinking and bunching as it drops into the bag is the rate it flies into the bags or hits the floor.

• Once a kink in the vinyl happens, it will find that weak spot every time it hits the bag again and only get worse, or jam.
• Some vinyl with cheap thin paper liners can kink and react worse than others. This is because there is no real body to the material to hold its shape as it whizzes back and forth.
• If you have loads of lines of text and graphics cutting then the material can kink easier because of all the cut lines and shapes in the material. Again, these can be weak points.
• If you have slightly too much blade pressure when you are cutting, this too can escalate the chance of kinks forming as the vinyl whizzes back and forth because again, you are creating crease score lines in the backing paper.

This suggestion is probably not going to work for everyone due to different software and cutters.
But combining the following will help a lot when you have long cuts to run/track.

• Slow down the “tracking and/or cutting speed” of the cutter.
• Make sure the cutter blade pressure is just right, and not leaving a score in the paper.
• “Optimise the cutting sequence” This one is going to significantly improve your cutting speed, tracking and overall performance. Cutting sequences means that the machine may only travel up and down the gantry of the machine cutting the letters in sequence, then nudging forward and cutting the next row of letters and graphics up and down the machine.
  Because it is hardly travelling, the overall speed of the job is greatly reduced and the accuracy is increased. moreover, when there is little to no whizzing back and forth all the time, the chance of it kinking and jamming is kept to a bare minimum.

Hope this helps mate.

[Simon Worrall]

Thanks.
Yes Im doing all those things. Got a stand and everything. Slow rate helps. On the graphtec there is a feature called minimise material movement or something like that, which REALLY slows it down as the head tracks all the way from side to side even for the inside of an A, then comes back to the other side. Must say it all helps but doesnt eliminate the crease forming, and as you say it repeats the same movement until it turns into a jam.

Environment makes a difference. Cold vinyl, warm room can cause creasing.

I did think of one thing, but havent acted on it yet…the Graphtecs catching bags are soft cloth, which seem to have a bit of a sag in the middle, causing a misdirection of the moving vinyl. On my previous plotter (roland) I actually made the catchers from PVC banner vinyl which was much more rigid than these cloth thingies and it held its shape better… and thinking about it, the creasing was maybe not so frequent.

I might do that again with this one – its an easy fix.

Having said all that I am not usually cutting anything more than a couple of meters at a time so its not chronic. But when I have an issue like this I get fixated on trying to eliminate it.
I think thats called OCD, or PDF, or one of those three letter things that all signwriters have.🤣