Printing on clear stock

[DCPrinting]

I have a customer who would like me to print on some clear plastic. I'm having a problem getting it to go through my press. It won't go through on impression. I think the sensors can't see the substrate. Oh, I'm trying to print it on a Heidelberg MOZP. Anybody have any ideas on how to trick the press?

 

[KGM]

I have done it in the past, you need to trick the sensors into believing there is a sheet passing over. Even just taping a sheet over it will do. This has its own risks though, in the case of a misfeed or double sheet.
Litho ink wont really dry on clear plastic though, i was using translucent when i did it.

 

[DCPrinting]

But don't the electric "eyes" tell it when to go on impression. So won't it be on impression as soon as I turn on the press? And I have litho ink that will dry on plastic, it will dry on anything.

 

[KGM]

But don't the electric "eyes" tell it when to go on impression. So won't it be on impression as soon as I turn on the press? And I have litho ink that will dry on plastic, it will dry on anything.

yes that is the problem, you just have to run about 20 sheets through first to clear the ink off the impression cylinder. Its not ideal. surely there is a easier way to do the job, colour laser printer maybe.

 

[steveo]

http://www.ctlaminating.com/index.html

heres a link to a printer that specializes in plastic. not sure if that helps you. Ive only printed on plastic but was white or metalized stock , ya gotta get your ink guy involved and fountain sollution supplier and usually the plastic manufacturer has a sheet of tech-tips to run this material successfully...good luck , Im sure itll be fine probably feeding it will be the biggest annoyance , lots of static in this material , but like I said its being done somewhere so you should be able to run it also.....let us know how it turns out , do you by any chance have UV capabilitiy?

Steve

 

[marker]

i would assume this is the stream feeder version. you probably have the job done by now, but you could put a spoon ( sheet hold down) right next to the eye and after the first sheet gets there move it over the eye. almost like a manual impression. if you miss a sheet and it shuts down then move it away and re-start the same way, tuff tex ink comes in many colors and i use it on my poly and vynil plastic jobs.

 

[turbotom1052]

i feel that getting the sheet through the eyes wont be as big a problem as the actual printing on this type of substrate. my personal feelings on this are that these jobs should be exclusively printed on uv presses. this type of job is very high risk and things can get very ugly if every i isnt dotted and every t crossed. if you must take on this kind of work there are a few suggestions id make.
1 oxidizing inks are a MUST (for clear plastic you will need fully opaque inks id think)
2 allow ample spoilage when figuring on how much stock to buy
3 put your best pressman on this job and be sure he has a thourough understanding of all that is required
4 before purchasing stock make it known to the stock merchant that final sale is contingent on the results of a DYNE test done by an independant facility
then follow up and have the dyne test done. a dyne test will tell you the stocks receptivity to taking ink and eventually drying
5 if possible apply an inline aqueous coating specially formulated for non porous stocks
6 run the job in small lifts and be very gentle handling it
7 a spray powder of at least 30 to 35 microns would be advisable and be sure your powdering unit is cleaned and working in tip top shape

after all this a prayer to the gods of printing might not hurt. all the above mentioned things are one of the reasons why there are specialty printers that build their business on this sort of work.
oh yea as far as getting that sheet through the feeder you can try a little white out to cover the eyes. of course you will now need to be sure the press is feeding correctly in order to avoid a major smashup and as its been allready mentioned on this thread feeding problems are par for the course when printing on these substrates as a result of all the static these stocks hold. good luck and if after all this you still decide to take on this job please let us know how it turns out.

 

[Plastics Printer]

"Turbotom"....Is absolutly correct in all of his suggestions!!!....I have a little Ryobi 2800 and have been printing on plastics "Poly and Tyvek" for over 15 years...I can't stress enough that you have to be dead on with your fountain solution...Just using standard fountain solution won't work for my press....I have to add a ph buffer to my fount...if I don't...in about 150 sheets into the job and the image will start to fade...I even have a special fan set towards my ink train that I toggled off and on while I print depending on the humidity and temp of the press room!...all my inks are specially formulated for each color!!!...each color behaves differently in drying times and print quality...all the formulas are tweaked by me over the years because the ink company only test with a "draw down method" which isn't accurate when you are mixing fountain solution on the press!...If you are doing a short run of 2,000 sht. or less I would use "Van Son Tough Text" or "Tough Text LR for Laser safe"....they will work good, but dry very fast!!!!...get the job on and off as quick as you can with this ink!...the other word of caution....Static Electricty!....there are days when this won't be a problem and other days it will make you want to pull your hair out!... the best solution I have found was to splice in a "Ionix static eliminator" in my blower lines...they really work, but cost around $140 for my press....I guess lastly...All the plastics I print on are corona treated...this helps to prevent the plastisizers from contaminating the surface you're printing...if isn't treated you may or may not be able to print on it....and.... the plastisizers could contaminate your ink!...Gan's Ink and Supply has a special laser safe Pre-Coating "Like the Corona Treatment" that will work, but I don't think it would for printing clear?...just passing along some caution and some tips.

 

[Data]

If youre not prepared to pay for 'specific eyes' you could try semi opaque scotch or rubylith tape. Totally covering your eyes is sheer madness.

My advice would be get it printed out on UV, its far easier.