What is causing these scratches?

[Dukenukem117]

Since theres no smearing, I don't think its the printheads. But I can't find any pattern to these chicken scratches that show up here and there. It only started recently but I don't remember any significant factors that might have precipitated it.

And what could I use to mask it on unprinted PVC white? Acrylic paint?

 

[LED Signs & Designs Texas]

The print head is to close to the print material, basically, and is swiping the material that is raised. Try to manually raise your print heads and not to much heat on the print table itself. Good luck!

 

[Christian @ 2CT Media]

The print head is to close to the print material, basically, and is swiping the material that is raised. Try to manually raise your print heads and not to much heat on the print table itself. Good luck!

There is no way to raise your print heads on a latex.

 

[greysquirrel]

heat is probably too high.

 

[Dukenukem117]

heat is probably too high.

The heater is after the printing, so that would imply the scratches are coming from the curing chamber and not the printhead. I'm not sure what in the heater can do this.

What was happening earlier was that the printhead was definitely scratching and smearing the print, and increasing the number of passes so that the material advances in smaller increments and has more time to settle and flatten (it doesnt have a vacuum since its a mesh) fixed that. But this kind of micro-scratching never went away.

I wonder if increasing the takeup reel tension would help.

 

[TrustMoore_TN]

Are you using mesh with a liner?

 

[Dukenukem117]

Are you using mesh with a liner?

No, which is why I always spool the takeup.

 

[TrustMoore_TN]

I would think that your thought about increasing the tension on the takeup reel would help... Also, if you are able to individually raise the pinch rollers (I can't remember if you can on the HP), that may help. I used have to do this with 104" Dye Sub fabric on a Mutoh because having all pinch rollers would cause the fabric to pucker in places and cause head strikes along the scan direction, but if I raised all but a few, it would help immensely. It's counterintuitive but it worked. Good Luck with it.

 

[Bly]

I mean it's mesh so you'll get away with that.
The only way to prevent head strikes on a latex is to use the edge guards and increase the vacuum.
I'd use mesh with a liner in future so the vacuum will pull it down.

 

[MMPLarge Format]

I have an HP Latex 360 and occasionally- particularly with poster paper - the material with bow or curl as it heads into the curing stage which then causes it to rub against the roof of the curing area, damaging the print. This has never happened to me with mesh banner but if you don't use the platen covers while using mesh banner it could cause the backing to stick to the platen, causing the material to bunch up making it susceptible to head strikes. Solution: just make sure you have your platen on, edge protectors in place, and vacuum on the appropriate level.

 

[Dukenukem117]

I have an HP Latex 360 and occasionally- particularly with poster paper - the material with bow or curl as it heads into the curing stage which then causes it to rub against the roof of the curing area, damaging the print. This has never happened to me with mesh banner but if you don't use the platen covers while using mesh banner it could cause the backing to stick to the platen, causing the material to bunch up making it susceptible to head strikes. Solution: just make sure you have your platen on, edge protectors in place, and vacuum on the appropriate level.

One issue I've had with the platten covers is that the material sometimes gets stuck on it during load. But I will try that cause this is a new problem. I didnt get this before and I did have the covers installed when I first got the printer.

 

[MMPLarge Format]

One issue I've had with the platten covers is that the material sometimes gets stuck on it during load. But I will try that cause this is a new problem. I didnt get this before and I did have the covers installed when I first got the printer.

Yeah that's unfortunately just one of the side effects of using the platens. You just need to make sure you have a little bit of extra material sticking out of the platen before pressing print. Honestly that a good rule of thumb for most materials and prints anyway. Aside from basic self-adhesive materials, I make sure there is at least a foot of material sticking out of the printer before pressing print. Just extra security to keep from the carriage hitting the material.

 

[Dukenukem117]

Yeah that's unfortunately just one of the side effects of using the platens. You just need to make sure you have a little bit of extra material sticking out of the platen before pressing print. Honestly that a good rule of thumb for most materials and prints anyway. Aside from basic self-adhesive materials, I make sure there is at least a foot of material sticking out of the printer before pressing print. Just extra security to keep from the carriage hitting the material.

I always use take-up reel now to avoid head strikes.

The platten covers are the two fabric things that go into the heating chamber and velcro out the bottom right? I find the material to always bunch out when trying to clear that during loading and forming a big burrito in the print area. I usually need to take my large cutting mat and pushing it from below to create a smooth slide for the material to come out the end.

 

[MMPLarge Format]

Yes, the fabric things are the platen covers. Does it continue to bunch up even if the material is already out of the platen area? What you're describing happens to me as well but only when the material first passes through. Which is why i always make sure theres enough sticking out. Once you have material sticking out there shouldn't be any issues with it curling up on itself. Of course like you said the takeup reel is also a fix to that. Either way though you may want the platens on while doing mesh material cause even with the take up reel it can still bunch up sometimes.

 

[Reveal1]

ou just need to make sure you have a little bit of extra material sticking out of the platen before pressing print. Honestly that a good rule of thumb for most materials and prints anyway.

We leave platen covers in 100% of time for workflow. Once installed correctly, just pushing a little extra material past that velcro strip does the trick. Not doing so is asking for trouble.

 

[Dukenukem117]

Yes, the fabric things are the platen covers. Does it continue to bunch up even if the material is already out of the platen area? What you're describing happens to me as well but only when the material first passes through. Which is why i always make sure theres enough sticking out. Once you have material sticking out there shouldn't be any issues with it curling up on itself. Of course like you said the takeup reel is also a fix to that. Either way though you may want the platens on while doing mesh material cause even with the take up reel it can still bunch up sometimes.

No it bunches up during loading. It has a hard time sliding past the top lip of the cover for some reason. I'll try it to see if it helps, but I thought those were for condensation?

We leave platen covers in 100% of time for workflow. Once installed correctly, just pushing a little extra material past that velcro strip does the trick. Not doing so is asking for trouble.

You don't even use the takeup? This isn't with raw mesh is it?

This really doesn't look like a head strike, more like a material defect. It's very fine, has no directional smearing, has no other defects nearby. Have you tried the attachment that removes plasticizers or what have you from banner material? Never tried it myself, but worth a shot. Also have you examined unprinted material for the same defect?

Yes, I have the foam roller installed. I don't see this on the unprinted material.

 

[eahicks]

I have an HP Latex 360 and occasionally- particularly with poster paper - the material with bow or curl as it heads into the curing stage which then causes it to rub against the roof of the curing area, damaging the print. This has never happened to me with mesh banner but if you don't use the platen covers while using mesh banner it could cause the backing to stick to the platen, causing the material to bunch up making it susceptible to head strikes. Solution: just make sure you have your platen on, edge protectors in place, and vacuum on the appropriate level.

AND make sure you feed out extra and attach to spool on takeup. Even then I have had it bunch up from sticking on the platen.

 

[Precision]

Sometimes with perf or mesh, even with the correct ICC profile, the heat will cause the material to warp/bend/ whatever.
With our Latex 360 we turn down the heat almost 20-25 degrees.
Another thing we have found is over years of use, inside the printer, on the edges of most areas where vinyl and it's glue back have passed, there is residual glue from so much use. Take some 90% alcohol and clean all of these areas thoroughly. The build up can catch just one little piece causing it to lift/jam just enough to ruin your print.
Just happened recently and giving the machine and roll path a good cleaning cured it.

I hope this helps.