Cutting Strip with Channel

[InkHead]

This is probably a weird question but Im going to throw it out there. 99% of our work is Die Cut decals/stickers so we are always cutting through the material which means the cutting strip takes a good beating as well as the blade.

Is there a cutting strip with a "channel" so the blade can still go through the media without hitting the cutting strip but still be able to support the media. Similar to how Graphtec has a perf channel. If not, any ideas on making one and if it would even work?

 

[Saturn]

I never quite understood how a hard perf channel could make cleaner cuts than even a worn soft/rubber cut strip. Seems like the cut strip would always offer better tear-out protection. I mean if it gets a little groove in it, then there ya go, there's the perf channel. ;p

Maybe I change my strip too often, I've never felt like it was the cause of poor cuts or overly fuzzy edges though.

 

[InkHead]

I think it is because there is always some friction on the blade getting caught where there might not be a channel/groove in the strip so the blade bounces from it being uneven. That is just my take of what I see happening

 

[Saturn]

Are you actually getting bad cuts/edges, or are you just worried about the wear and tear? I cuts tens of thousands of complex die-cut stickers before I even have to consider a blade or strip change. If you're doing 20,000+ a week I could see it start to get old, but if you are going a month or two between changes it's not so bad. Keeps you sharp on the initial blade adjustments too. ;p

I do see what you're saying about the blade tip dragging/catching on the rubber, but I haven't noticed it ever really becoming a factor in my own setup. Are you running a drag knife model, or tangential? Also, are you doing the actual "Perf" cut option or just cutting normally with the blade extended and extra pressure?

 

[InkHead]

We are getting maybe a month max. Die Cut is basically all we do all day long. What we are seeing is that we get some cuts that don't go all the way through especially on the x-axis. It seems to always be at the same spots across the media. We will play around with blade adjustments and pressure as well as swapping the blade to see if it might be the blade and it usually doesn't make a difference. Changing the cutting strip fixes it right up.

We use the Summa S2 T160 OPOS Cam. We tried the FlexCut option but it was leaving the "+" overcuts on complex cuts in the inside corners. I tried fiddling with all the settings and nothing really alleviates the overcuts even went set to 0. So now we have great success with normal cutting and extra pressure so we are able to pop the decals right out without them coming loose on their own.

So that got me thinking about the whole Graphtec channel and if it was possible on the Summa since die cuts is all we really do. I guess it is something I could think about rigging. Something like 2 pieces of double sided tape put sideways to stick against the wall of the cutting strip channel and only leaving a slight gap where the blade comes down. Maybe even the foam adhesive weather stripping... I'll look into it the next time we have to change out the strip. If anyone has any ideas on something that might work better than double sided tape I am all ears.

 

[Saturn]

I don't think a channel on the Summa is the way to go, and I don't think the strip is what's causing your bad cut, but I do love tinkering and hearing about modifications that improve things! Keep us posted!

One thought though, is that the bearings/wheels that sit beside the blade on a tangential are not going to like having to spin around and over a channel. It would be one thing if the blade only traveled left to right doing a straight cut and the wheels effectively just spanned the gap, but you have to thinking about them riding in and over that gap as they turn. Specifically when they turn to cut "vertically" they'll be in a little divot and there would be the tiniest rise and fall as they went in and out. I don't believe Graphtec has any tangentials, so nothing but the blade is ever coming down and touching the material?

 

[InkHead]

You are absolutely right! I did not think about the wheels riding the strip and having to turn. With a channel present, it probably would not like it when it has to turn or when the blade/nose turns for vertical cuts. I assume the wheels would stick down into the channel and probably get weird cuts. Is their a nose piece without the wheels? I haven't looked into it yet. Just thinking out loud here.

The Graphtec FC9000 has a Tangential mode but where I think it just overcuts the corners and then lifts the tool. Still drag knife I believe and only for straight corners.

For your complex die cuts, are you using flex cut or just normal with extra pressure/extended blade?

 

[Saturn]

I do just like you described and skip the flexcut and just do two passes of a normal cut. If you design smooth cut lines without corners, so the head never has to go up and down, it can be really fast. I know it can be done with a single pass (on like 3mil laminated stuff), and I've even heard of some shops doing three passes, but two seemed to be a good compromise in speed for me. I gave flexcut a good try back when I was learning things, and I never determined what it would be better at than just doing a regular cut... at least for my usage.

 

[InkHead]

Thanks for the info. Interesting on the 2 passes. We have been doing single passes and it cuts right through our materials but maybe it is putting too much stress on the blade and I suppose cutting into the strip more.

With 2 passes, are you using the same pressure for the 2nd pass as the first? the materials we use are around ~12 mil total with liner

 

[Saturn]

Yeah same pressure, it just does one pass right after the other, and it's always spot on. No drift or worries like that, the second cut is ALWAYS exactly on top of the first. The only downside is time. But if you're actually making money on them and doing them all day, the investment of a second or even third cutter is not all that bad in the scheme of things.

I would MUCH rather stick with a single pass, as it's half the time, but 2+ passes really makes the cuts more consistently easy to pop out and allows a little bit lighter pressure overall. I'd think it would be especially helpful on 10+ mil stuff. I recently gave a 6 mil material that was laminated 15 mil substance stuff a try (so 21 total plus liner), and there was no way, even at 600 grams, that one pass would work well. Two passes worked great, although three might have been even better.

 

[InkHead]

I will definitely give 2 passes a try and see how that works out. We have been thinking about getting another but wanted to make sure we are utilizing this one to the max which we basically are now before we purchased another. I've only been in the wide format game for less then a year (I come front the label printing world). So we just wanted to make sure we could get this going before we invest in more equipment. The other thing is we wanted to be sure that we purchased the right cutter for the job or if we should give consideration the graphtec since it has the channel. Otherwise love the summa for its precision and speed.

Now just need to figure out cutting reflective/prismatic/holographic materials. Got some samples and the Cam is going crazy trying to read the reg marks. Thinking about putting a filter over the eye to see if that helps with the light bouncing off the material. I'll research the forum for that and hopefully come up with a solution.

Saturn... Thanks for all the info. I greatly appreciate it!

 

[Saturn]

I don't print on anything but white material yet, but there's lots of suggestions for getting the eye/camera to read on reflective stuff in the forum, just gotta do a lotta digging. ;p

Good luck!

 

[InkHead]

Yup. Will be doing some reading and researching tonight. Thanks again