Oil condensate on Textil backlit HP 560

Hi,

just got delivery on a new HP560 and hitted some issues directly when printing backlit textile. Substrate used is PONGS Printex Mambo Printmode is 16p 200 % Curting temps that was used 116 degress C and 110 degrees C. with 400ms interpass delay. Issue the same at both curing temps.

Enviromental conditions: Temp in area 22 degrees C, and humidity 25 %. Ventilation through AC. Printer is not having direct sunligth on it. And air is circulated in the room.

Problem: After approx 2m printing with high ink coverage sticky oil condensate starts tp penetrate substrate from its backside and towards up against the frontside. After done some checks the condensate is generated between the platen in curing unit and the backside of the textile. If one remove the substrate from printer the half wdith next to the frontpanel side is covered with this sticky condensate. The condensate migrates with the textile in thoose areas where the platen touches the substrate.

Have used the platen cover protectors but same issue. The sticky oil condensate penetrates this protectors as well and later on hits the substrate..

I have also checked if the suction from the condensator unit work, and it works. Even if I think that the suction inlet might be quite small....as far I can see it only is suction in the front of the curing unit close by the door to the curingunit in the front.

I enclose photo showing the backside of media. Picture HP650_1 is showing the backside of substrate Picture HP650_2 is showing how it looked on the printer when printer had done curing finished and gone back to start position. The is happening inside the curing unit.

A lot of waste is produced rigth now : ( What is the opinion of HP about this and what will the fix be ?

BR Krimat

It seems you are following proper procedures but 200%ink density is very high.

You should print an ink density test for the particular media you are using to select the lowest ink density as well as lower the temperature further as well as adding extra Inter Swath Delay. Depending on the final application you can also try printing with fewer passes but this is up to you.

It may also be that the media has not been stored properly and contains moisture. Hopefully, the media does not have plasticizers but you should check with the media vendor.

If the issues persist then you should contact support to check that the printer is functioning properly.

Well the substrate is a Certfied Latex media and profile was downloaded from the Media Locator. In order to achive good result high ink density is needed since it is intended for backlit lightboxes. I have also checked the HP Cookbok or textile printing. Question has been asked to the media vendor for plasticizers in the substrate, and the answer was YES .

I have modified the ink density and still have issues with this sticky condensate . I went down to 180% going far more than 180 will loose color when installed in lightbox.

I need more references for backlit material and I would like to ask you which material for textile backlit you can recommend for succesful printing?

I do not think they are condensates between the platen and the material ... normally the condensates are in the metallic part of the top (above the material) ... the only thing that comes to my mind is that due to the porous nature of textile media, the ink on the media tends to evaporate differently than with other materials. Evaporated components of the ink may condensate on cold surfaces of the printer, leaving an oily finish. Meaning that you need to do the cleaning maintenance regularly that we recommend in the cookbook -the last chapter-page 22-

I have made a very simple sketch of the platen in profile. Blue lines are were condensate appears, between platen and backside of substrate. When the condensate starts to move when its volume has increased it flowt down, and when it come to the edges ( see purple circles) it seems to stay and grow in volume and then later on touch the backside and migration appears.

When looking after printing, you see on the places where the purpule cirles are that thhere are really large drops hanging on the edges...

#5 Hello Krimat,

In the cookbook is explained all the process on how to clean the specific parts when having condensates. However. in the user guide we also explain that you should use the output platen protector to avoid/delay the condensates. Please read the following chapter on the user guide: Chapter 3 Handle the substrate and troubleshoot substrate issues, and let us know if this works. I hope this information helps

Hi,

thanks for you reply.

i have studied the cookbook and the manual in this matter.

My problem is that this happens during print and oil condensate migrates through the platen protectors and soakes the substrate = waste

Please note that I use platen protectors, and I do clean the platen afterwards with cloth .

Is there anything to prevent this to happen so I dont produce any more waste ?

Hello again Krimat,

If you are already using all the recommended printer settings, 116ºC of curing temperature and you are also using the output platen protectors… the only thing that you can try is to put the máximum airflow and also try to print slower, that means 20 passes… but, unfortunately, you will have a bit more waste to play with the different settings. Finally, if you can't avoid the condansates, I would recommend you to change the material to another more porous or with more amount of polyester.

Hi Raúl

many thanks for your answer.

I have done that check as well with 20p and also increased the airpressure from 175 to 200. When we print this kind of jobs we print lager jobs. Are you able to contact me via email? I guess you can see my registered email here...?

Case pretty much solved now I am very happy about that Some adjustment in the printer were needed to be done..not by me ..then it worked

I am happy you finally solved the issue!

Hi Krimat,

That's great news! Happy that you can print the material with no issues now. If you have any other issues in the futre, just let us know

Hi Sonia & Raúl

Yes very happy now : ) Well it was not me solving it , some settings inside the printer needed to be changed when wanting to focus on textile print..it was all done by a collegue to you via remote access.