polyester plates and printer

[RawDog]

Bear with me folks, as I new to this.

My hubby however has been a press operator for 20 years, but still knows little about CTP. We got a Cheif 17 last year, which he has tuned in nicely, it runs sweet (guy who sold it to us thought it was broken). We just recently aquired a nice Imperial 46 paper cutter for a killer price. And now we're thinking of getting a CTP for a few jobs that will need to be changed often and won't be practical to purchase a negative to burn a plate each time. We are moving slowly on having a home based small printing company.

I have done a little research but most of what I find for CTP is large units that cost waaaaayy more than what we want to spend. I did find a local HP Lazerjet 5000 (won't have to pay shipping, nice). We were thinking of getting that but I have a few questions.

Here comes the noobi -

If we get the HP 5000, polyester plates are what we need correct? Does the printer have 2 printing heads (or sections) one for the paper printing and one for the plastic plate. OR just one and the toner is burned into the plastic plate? Then the ink in the press sticks to those burned places? OR do you wash the burned toner off with water or is there a chemical to develop? Also what fountain solution is the best? Xpedex has the Silver Master brand pink universal fountain solution, will that work?

I apologize in advance for what might seem like stupid questions. I just want to understand the process before spending money on the printer and polyester plates.

I did spend some time reading the other posts here which was helpful. But as I said, I am very new to this.

Thanks for the patience and support,
Niki

 

[jotterpinky]

The HP 5000 is just your basic desktop laser printer. It prints just like a copier - toner onto a substrate. You are correct in that the toner acts as the ink carrier on press, with this printer you would need to make sure your settings are as hot as possible to ensure the toner is correctly fused with the sheet. If it's not hot enough the toner will start to degrade rapidly on press (sometimes after only a few sheets) The HP5000 is recommended by many "laser plate" manufacturers because of the size it prints as well as it's ability to generate a "nice" halftone dot and the temperature that it runs at. You'll notice I put nice in quotes because you're not going to get much over 105 lpi, but sometimes that's adequate for some work. This type of plate is limited at any rate by the size of the dot because real small dots will almost wipe off. Probably a good option to start up, especially since your press probably won't maintain much over 133 lpi. Another option you might consider is the Xante Platemaker which uses much the same technology but Xante has their own proprietary plates and have tweaked a laser printer to get better quality.

To answer your question directly, yes the printer just prints an image with toner onto a poly plate which you then clean lightly to remove toner scatter, then you stick it on your press...no other processing required.

I would recommend calling a distributor of the plates and getting some sample plates before you commit yourself. Since the HP5000 is local they should have no problem letting you run some samples so you can test it out. Each brand plate has cleaner and fountain solution they recommend (usually the pink stuff) but we find it doesn't matter as much on the fountain solution just so long as you keep the plate really wet.

If you're coming from an aluminum plate background you need to realize that while these will work it takes more effort to keep the plate from building up ink and toning. In my experience these require a lot more water. Good luck!

 

[SilvaJr]

Hi there, I'd like to include two comments:

1) We bought some polyester plates from this Ebay Seller some months ago from Canada:
eBay My World - printerspartsequipment

Good price.

2) Depending of your press, you may will need a Plate Punch Pin Bar. Check first, may the same Ebay seller can sell it for you.

Thanks,

 

[RawDog]

Thank you so much for the replies. Hubby did mention that we'll need to get a punch. That is a great idea to get a distributor or manufacturer to send sample plates first. This place is great. Thanks for all the help.

Niki

 

[graficworx]

I have run poly plates on a Chief 117 before, and they run quite well. If you do not have a Kompac dampening unit, I would recommend getting one. The poly laser plates run a little better with a Kompac. I've run up to 10,000 impressions with a poly plate, and it runs just fine. Its definately not for tight registration work, as the plates will stretch if your pressures aren't set right, and even if they are, it will still stretch a little.

These are the kind of printing plates you will need: 11 x 18 SmartPlate™ Original [CLP1652] - $145.83 : Hurst Chemical Company

Those can be imaged on the HP.

Since the Chief has a pin-bar plate clamp, you will need to also use the re-inforcing strips on the plates, or they will stretch.

100 Pack Plate Strips [CLA671001] - $74.97 : Hurst Chemical Company

You put the re-inforcing strip on before you punch the plate. For short runs of a poly plate, if you don't want to use a re-inforcing strip, you can spray the plate cylinder with a little spray adhesive, and it will help prevent it from stretching, but its very messy to clean up.

You will also need the plate etch and prep:

392 SmartPlate Etch [CPC0392P] - $19.11 : Hurst Chemical Company

394 SmartPlate Prep [CPC0394P] - $17.16 : Hurst Chemical Company

If you are going to run nothing but poly plates, you can use their fountain solution as well.

390 Fountain Solution - 1/2 Gallon [CFC0390HG] - $48.45 : Hurst Chemical Company

If you have questions about the setting on your HP printer, here is the guy to ask:

Home

Here is a quick breakdown on the plate making process:

Page 3

And here is a video of the Platemaker 5, which is really just a fancy laser printer, and does the same thing your HP does:

YouTube - ‪Platemaker5‬‏