Need Help Coroplast issues - seeking tips and tricks

[DylanBJS]

Hey all I always end up on these forums searching for help so i decided to finally create an account for myself!

My current issue is printing coroplast on our big flatbed printer. We get in 4x8' sheets of coro and we have a big flatbed laser that we use to cut the coro to shape (typically just basic yard sign sizes but occasionally a human cut out ect.) and our issue is getting the coroplast to lay down flat for printing. Most sheets come in with a bow in them anyways and we usually are doing a full print to the edges so taping the sides down isnt an option or using double sided tape because it will pull off the print from the back side. We usually just do custom acrylic awards and medals and ACM metal signs and everything works great its just this dang coroplast that i will not let win the battle.

Ideas we came up with and will try next week is:
1. Cut the coroplast with a 0.5" margin around it so we can tape that portion down and then we can hand cut out the final size (using the laser to cut a perforation around the size we need)
2. maybe try a heat gun to get the edges down so the flatbed printers vacuum will hold it flat
3. Use the roll to roll printer and just print the signs on vinyl and apply those to the coroplast (we are going to do this anyways as R&D but have yet to try that but is more cost)

Any tips would be super appreciated!

 

[White Haus]

What kind of flatbed printer are you using? I'm surprised it doesn't have enough vacuum power to hold down a sheet of coroplast. I don't know that a heat gun will help here. Usually all you need is a bit of pressure/weight on the ends if a sheet is warped - as soon as it seals the vacuum will usually continue to hold the sheet until it's turned off. Sometimes we'll use a big safety ruler on each end, turn on center vacuum zone then turn L & R on until you get a tight seal.

This is all assuming you have a true flatbed - if you're running a hybrid I don't think any of those tricks will help with material hold down.

What kind of coroplast are you using, and how are you ordering/storing it? (Buying and storing on a skid is best to avoid handling, warping, contamination etc.)

If you have a roll-to-roll or hybrid UV printer, printing to cheap vinyl and mounting is certainly an option, just adds a lot more time and material costs. You also wouldn't want to be shape cutting on a laser after you've applied PVC vinyl to the sheets. I'm not even sure if cutting coroplast on a laser is technically kosher, but someone will correct me if I'm wrong there.

 

[DylanBJS]

What kind of flatbed printer are you using? I'm surprised it doesn't have enough vacuum power to hold down a sheet of coroplast. I don't know that a heat gun will help here. Usually all you need is a bit of pressure/weight on the ends if a sheet is warped - as soon as it seals the vacuum will usually continue to hold the sheet until it's turned off. Sometimes we'll use a big safety ruler on each end, turn on center vacuum zone then turn L & R on until you get a tight seal.

This is all assuming you have a true flatbed - if you're running a hybrid I don't think any of those tricks will help with material hold down.

What kind of coroplast are you using, and how are you ordering/storing it? (Buying and storing on a skid is best to avoid handling, warping, contamination etc.)

If you have a roll-to-roll or hybrid UV printer, printing to cheap vinyl and mounting is certainly an option, just adds a lot more time and material costs. You also wouldn't want to be shape cutting on a laser after you've applied PVC vinyl to the sheets. I'm not even sure if cutting coroplast on a laser is technically kosher, but someone will correct me if I'm wrong there.

We have a Roland LEC2 640S F300 it is a newer model they got (we actually got the first one produced which sucks because now they come standard with a static bar and new LED light strips, not to mention the techs are still learning it so we have had to work a lot in collaboration for issues).

The printer is technically the same as their hybrid but they removed all roll to roll features, it has a 5x8' printing area and the vacuum is for the front half or the back half and we can turn it up to about 70-80% suction before it blows the fuse in the printers podium (another issue we are having to deal with from having the first model and have had all sorts of electricians come out and add the different things Nazdar was wanting to try).

We are using a thin paper that they recommend, i think the issue is just the edges of the coroplast are turning up and im not sure that it isnt the laser doing that. It might be melting it and bit and that pulls up the sides sometimes but it really doesnt look that way.

Im not sure on the supplier for the coroplast id have to ask the owner but we are getting them in with our acrylic shipments (also 4x8 sheets of different thicknesses) and we have been standing them on their sides with 4x8 sheets of ACM on it but ill be honest we didnt have a lot of space as it was for them. We just built a little loft above all of our acrylic specifically for the stack of coroplast sheets in hopes they can stay flat and we put weight on top of them.

Sorry for the long reply just trying to get you all the info, let me know if you could see anything that stands out in our process or if that explanation gave you any ideas!

 

[Boudica]

Coro is inherently a PITA. If you can't tape it down on the edges, you can try masking around it to give the vacuum more suction power.

 

[FireSprint.com]

Try coro from a different vendor.

It's not all the same. Maybe see if http://www.regalplastic.com/ in your area (They sell TCC and Laminacorr) will sell you sheets.

Matraplast is also a bit flatter.

I know people get stuck on finding coro at the lowest cost, because it's a low cost product. But you can eat up $2 or $3 in labor and tape really fast.

(Or just let us handle it for you. We're up in Omaha, and offer free shipping on coro under 36")

 

[DylanBJS]

Try coro from a different vendor.

It's not all the same. Maybe see if http://www.regalplastic.com/ in your area (They sell TCC and Laminacorr) will sell you sheets.

Matraplast is also a bit flatter.

I know people get stuck on finding coro at the lowest cost, because it's a low cost product. But you can eat up $2 or $3 in labor and tape really fast.

(Or just let us handle it for you. We're up in Omaha, and offer free shipping on coro under 36")

We us a company called E&T Plastic and order 4mm fluted polypro is what they call it.

I am not too knowledgeable on the different types of coroplast but i will do some research, thanks for the tip!

 

[CC-CMYK]

We have a Roland LEC2 640S F300 it is a newer model they got (we actually got the first one produced which sucks because now they come standard with a static bar and new LED light strips, not to mention the techs are still learning it so we have had to work a lot in collaboration for issues).

The printer is technically the same as their hybrid but they removed all roll to roll features, it has a 5x8' printing area and the vacuum is for the front half or the back half and we can turn it up to about 70-80% suction before it blows the fuse in the printers podium (another issue we are having to deal with from having the first model and have had all sorts of electricians come out and add the different things Nazdar was wanting to try).

We are using a thin paper that they recommend, i think the issue is just the edges of the coroplast are turning up and im not sure that it isnt the laser doing that. It might be melting it and bit and that pulls up the sides sometimes but it really doesnt look that way.

Im not sure on the supplier for the coroplast id have to ask the owner but we are getting them in with our acrylic shipments (also 4x8 sheets of different thicknesses) and we have been standing them on their sides with 4x8 sheets of ACM on it but ill be honest we didnt have a lot of space as it was for them. We just built a little loft above all of our acrylic specifically for the stack of coroplast sheets in hopes they can stay flat and we put weight on top of them.

Sorry for the long reply just trying to get you all the info, let me know if you could see anything that stands out in our process or if that explanation gave you any ideas!

Are you liking your Roland flatbed? We just got our Roland Versa object 640. It’s pretty much the same printer just renamed with an anti static bar. I really like the quality so far. We just did some Ada braille signs and they turned out great!

 

[Modern Ink Signs]

Matraplast square cut. Never have had a problem

 

[ikarasu]

Why not print on a 4x8 sheet and then cut the coro on your laser?

Coro doesnt like heat...and laser cutting might lift it a bit. And if its a flat 4x8... you can tape the edges down, then do the cut if you need to... but I expect printing on a full 4x8 sheet would be fine on your printer.


We have a hold down... but thats how we do it typically.

 

[DylanBJS]

Why not print on a 4x8 sheet and then cut the coro on your laser?

Coro doesnt like heat...and laser cutting might lift it a bit. And if its a flat 4x8... you can tape the edges down, then do the cut if you need to... but I expect printing on a full 4x8 sheet would be fine on your printer.


We have a hold down... but thats how we do it typically.

That is definitely something that we considered but we havent tried printing first then cutting out. We currently have a job for 25 double sided signs where the art goes to the edges and although printing one side and then flipping the sheet and getting it to line up could work in theory (despite human error) we dont have any straight edge to line it up on the laser.

Our laser has a knife blade bed and the whole bed itself is bigger than the laserable* area so we would have to float it and i guess we just have the concern that it would move as it cuts from either the airflow in the room or the air assist on the laser itself or even warping from the heat on the laser. Also the sheets as mentioned are not super flat.

With the details on our operation, do you have any ideas that might work to try it that way?

 

[DylanBJS]

Are you liking your Roland flatbed? We just got our Roland Versa object 640. It’s pretty much the same printer just renamed with an anti static bar. I really like the quality so far. We just did some Ada braille signs and they turned out great!

Yes and no. The printer itself has opened up a LOT of production possibilities for sure, but we keep running into the dumbest issues. Currently it keeps dropping connection to versa mid print and theres no way to start again and these signs are big ACM signs and a dark black print that we cant cover in one pass of white.

Also idk about yours but our potentiometer? is sooo sensitive and the dial moves so easily that we have also lost prints to the head raising too much. It took us, nazdar, and the field tech like 6 months before we could all figure out why the print head would go up like 4-5 inches during a print, since figuring that out we are now more reliably able to print and look at it everyday but we even got a replacement and the dial is still crazy easy to move even when taped down lol

And we mainly are printing beds full of different acrylics which creates a LOT of static and we have to clean most prints because they cant seem to get us a damn static bar. They have had our money for months and keep saying oh it should ship next week but never did so we just said give us that 5k back..

 

[ikarasu]

That is definitely something that we considered but we havent tried printing first then cutting out. We currently have a job for 25 double sided signs where the art goes to the edges and although printing one side and then flipping the sheet and getting it to line up could work in theory (despite human error) we dont have any straight edge to line it up on the laser.

Our laser has a knife blade bed and the whole bed itself is bigger than the laserable* area so we would have to float it and i guess we just have the concern that it would move as it cuts from either the airflow in the room or the air assist on the laser itself or even warping from the heat on the laser. Also the sheets as mentioned are not super flat.

With the details on our operation, do you have any ideas that might work to try it that way?

Does your laser software not support print and cut?

I don't have a 4x8... Mines only 24 x 42". I use lightburn, it allows you to put 2 crosshairs on the print anywhere you want... You move your laser to the center of the crosshair, tell it thats position 2, move it to the other crosshair... Position 2, and then it knows where everything is on the sheet, whether it's loaded crooked or not.

For any coro that's not flat, I just throw a magnet on-top of the printed area where I know the laser won't cut. It cuts hairline perfect. I'd check whatever software you use for a print and cut function, or see if your laser works in lightburn... It's pretty cheap software.

I print on our flatbed all the time and cut - the laser will cut through the coro and the print with no marks or damage. I couldn't imagine doing a cutout and then loading it on the flatbed and hoping its aligned perfectly, or printing bleed on the flatbed - imo, the print and cut option is much easier!

 

[DylanBJS]

Does your laser software not support print and cut?

I don't have a 4x8... Mines only 24 x 42". I use lightburn, it allows you to put 2 crosshairs on the print anywhere you want... You move your laser to the center of the crosshair, tell it thats position 2, move it to the other crosshair... Position 2, and then it knows where everything is on the sheet, whether it's loaded crooked or not.

For any coro that's not flat, I just throw a magnet on-top of the printed area where I know the laser won't cut. It cuts hairline perfect. I'd check whatever software you use for a print and cut function, or see if your laser works in lightburn... It's pretty cheap software.

I print on our flatbed all the time and cut - the laser will cut through the coro and the print with no marks or damage. I couldn't imagine doing a cutout and then loading it on the flatbed and hoping its aligned perfectly, or printing bleed on the flatbed - imo, the print and cut option is much easier!

So we use lightburn for our BossLaser Hp5598 and Versaworks for our Roland flatbed printer, i will look into that lightburn function and see if we can try that. A big issue we also get is the laser catching a flame from residue on our knife bed. It builds up from all the material and wood we cut on it and try to use a brush and solution to clean them off but it takes so long and we use it practically open to close everyday, so i am not sure how well the UV print would clean up if there is smoke on it.

 

[ikarasu]

Throw a sheet of 4x8 aluminum panel, or even light thin gauge aluminum underneath the coro when you're cutting it, the laser won't cut through it and you'll have a clean surface every time you're cutting... No worrying about flame UPS.

Hard to say since I haven't seen your laser of course. I do a ton of coro print and cut, as long as it's under 40in wide I can even do 8 ft on my small cutter as I just passed it through the feed tray and use more alignment marks to finish cutting.

Having a large 4X8 would be awesome though! I think figuring out how to print and then cut afterwards is probably your best bet, and would end up saving you a lot of time.

I probably only do one 4x8 sheet a day... But never any issues doing it as a print and cut

 

[DylanBJS]

Throw a sheet of 4x8 aluminum panel, or even light thin gauge aluminum underneath the coro when you're cutting it, the laser won't cut through it and you'll have a clean surface every time you're cutting... No worrying about flame UPS.

Hard to say since I haven't seen your laser of course. I do a ton of coro print and cut, as long as it's under 40in wide I can even do 8 ft on my small cutter as I just passed it through the feed tray and use more alignment marks to finish cutting.

Having a large 4X8 would be awesome though! I think figuring out how to print and then cut afterwards is probably your best bet, and would end up saving you a lot of time.

I probably only do one 4x8 sheet a day... But never any issues doing it as a print and cut

That is some good information! Thanks for your input!

I may try throwing some aluminum underneath it, do you get flashback from yours? Our laser is 150watts and are cutting at i think 15% power and 40% speed. Also do you run your printer through LightBurn also or do you make a file on lightburn and import it to your RIP software and print then go back to laser and lightburn and tell it where the crosshairs are?

 

[tedbragg]

Whenever contour cutting is required, we print on 4x8 sheets, THEN cut. Coro warps, curls and deforms like MAD when it's cut, so best to have the entire sheet to suck down while printing.

 

[DylanBJS]

Whenever contour cutting is required, we print on 4x8 sheets, THEN cut. Coro warps, curls and deforms like MAD when it's cut, so best to have the entire sheet to suck down while printing.

Yeah that is definitely a process we are going to work on trying! We actually had some success on these currently with using a heat gun and got them to lay perfectly flat AFTER cutting them to size for the flatbed, not sure how practical it is but it didnt seem to have any negative effects lol

 

[ikarasu]

That is some good information! Thanks for your input!

I may try throwing some aluminum underneath it, do you get flashback from yours? Our laser is 150watts and are cutting at i think 15% power and 40% speed. Also do you run your printer through LightBurn also or do you make a file on lightburn and import it to your RIP software and print then go back to laser and lightburn and tell it where the crosshairs are?

We just added to the artwork, all you have to do is make two plus signs one in each corner, then you align your laser to those two crosshairs. There are a bunch of good videos about it on youtube.

I have a honeycomb bed, so when cutting acrylic and stuff I will sometimes get flashback... But I end up just throwing some paper towels underneath and wedding them and it fixes it. I don't think you get much flashback with just the knives... But again depending on your machine you could probably take some out.

I've never had flashback on Coro though. I use a 100 w, so I will check my settings when I get home later tonight. I think I use a much lower power and slower speed than you do though, I found whenever I went too fast even at higher powers the flutes tended to melt themselves back together a bit. Where as the speed I have now is perfectly clean and the coro pops right off.

I'll see if I can find a good video on print and cut, I know most videos teach you how to do it inside of lightburn designing but you can do it in illustrator or anything.

 

[DylanBJS]

We just added to the artwork, all you have to do is make two plus signs one in each corner, then you align your laser to those two crosshairs. There are a bunch of good videos about it on youtube.

I have a honeycomb bed, so when cutting acrylic and stuff I will sometimes get flashback... But I end up just throwing some paper towels underneath and wedding them and it fixes it. I don't think you get much flashback with just the knives... But again depending on your machine you could probably take some out.

I've never had flashback on Coro though. I use a 100 w, so I will check my settings when I get home later tonight. I think I use a much lower power and slower speed than you do though, I found whenever I went too fast even at higher powers the flutes tended to melt themselves back together a bit. Where as the speed I have now is perfectly clean and the coro pops right off.

I'll see if I can find a good video on print and cut, I know most videos teach you how to do it inside of lightburn designing but you can do it in illustrator or anything.

That makes sense ill look up some videos! And i was wondering about flashback if cutting coro on top of a big sheet of aluminum. To me doing that seems like it would have a lot of flashback on the metal

 

[ikarasu]

That is some good information! Thanks for your input!

I may try throwing some aluminum underneath it, do you get flashback from yours? Our laser is 150watts and are cutting at i think 15% power and 40% speed. Also do you run your printer through LightBurn also or do you make a file on lightburn and import it to your RIP software and print then go back to laser and lightburn and tell it where the crosshairs are?

So on my 100 watt I'm doing 20 speed...50 power.

TBH, I just did a few tests, saw that one worked with no leftover flutes and kept at it. I might play around and see if I can go faster with less power... but what I have works with no burnt edges or anything on UV printed materials. I have a decent amount to do this weekend so I'll play with it more.

- This video is pretty good on setup. You can do the crosshairs in Illustrator or whatever software you want... You just need to click them in lightburn, align it to the center of the crosshair (If you dont have a red light you can just send a pulse and move it until it gets in the center). Ive gotten hairline accuracy with it... its nice. Pisses me off more than graphtecs / Multicam CNC isnt as accurate as a $100 piece of software