Plate Cylinder Packing

[HachiZenki]

I run some Communities and 4-highs and am having a problem with the spray glue we use to pack our plate cylinders. The undercut on the plate cylinder is .014" and we use .008" plates so we pack our plate cylinders with .006" mylars. The problem is the spray glue we use seems to let the mylar slip after a few days and I'm having to replace it once a week or the total slippage gets bad enough to cause the folio to get cut in half. I'm using 3M Super 77 spray glue and recently tried Super 90 but it still allowed it to slip after a few days. I've also tried to vary the dry times before I apply the mylar from waiting a couple of minutes to immediately applying after spraying and no dice. Anyone got any ideas? I'd hate to have to resort to CA glue.

 

[turbotom1052]

dont know if its available for web presses but for sheetfed applications we use something called permapack. its a poly based packing thats very stable and comes in popular calipers. its a peel and stick thing that stays put as long as the cylinder is prepared properly and installed according to recomendations. im currently running a 6 color heidelberg that has had the same permapacks on the plate cylinder for the last 3 plus years that i know of.

 

[HachiZenki]

Well we've been cutting down the width of our plates lately in order to save money. So while the plate cylinder is 34.25" wide, the plates we're using are 27" and they're considering cutting that down further to 26".

 

[turbotom1052]

not sure im understanding

not sure im understanding

Well we've been cutting down the width of our plates lately in order to save money. So while the plate cylinder is 34.25" wide, the plates we're using are 27" and they're considering cutting that down further to 26".

why would you knowingly give up at least 6 inches of printing area?? are the savings worth loosing your ability to print at least 6 inches wider??? just food for thought..... if you continue to run plates that are smaller in width than your form rollers what do you think the result will be to your form rollers? then when you need to print out to maximum width your gonna be S.O.L.

 

[Cornishpastythighs]

We use perma packs and they work very well. Is it possible for you to use 012" plates and run the plate
.002" below bearer and increase your blanket packing by .002" that way you wouldnt have the problem. Of course you would have to make some adjustments to your 'fit'
Zenki, cutting down your plate material will ruin your forms, better to hit up the plate supplier for savings.

 

[The Heidelberg Guy]

All Heidelberg's are designed to be .006" over bearer with plate installed.

The thinking is +.006" plate, -.002" blanket = .004" pressure between the plate and blanket.

 

[Dan Roll]

Keep in mind that when packing your plates even to the bearer, your printing pressure must come from having the blankets higher than the bearers. This means that the surface of your blankets will be moving faster than the surface of your plates. If it were me running a Community, I would pack both the plates and the blankets to two thousanths over the bearers.

 

[HachiZenki]

Well we run our blankets .086" on the bench and .081" on the run. We're using cut down plates for the same reason the entire industry is running narrower webs (we run single width 22" webs normally)...namely cost savings. We're also transitioning to cut down forms and transfers but since we run 2 different widths every week (22" for our daily and 25" for certain specialty pubs) some units still have full width forms and trans. We're also transitioning to cut down blankets. Well anyway getting back to the original question...does anyone have any ideas as to a better glue or technique for glueing?

 

[vniehaus]

Are web press is old and abused so we have gone back to paper packing rather than permapak. Registration seems to work out better.

Clean your cylinders with Alcohol before you glue. Maybe? Worked with permapak.

 

[HachiZenki]

I first used our regular solvent/blanket wash to clean the cylinder then switched to acetone when the blanket wash didn't seem to evaporate as quick.

 

[sallak]

I first used our regular solvent/blanket wash to clean the cylinder then switched to acetone when the blanket wash didn't seem to evaporate as quick.

we use fuel to clean blankets

 

[rmh1013]

I used to run an Urbanite. A little bigger but basically the same press. We also used .006 mylar. To avoid slipping we would bend the lead edge and place underneath the plate clamps. Of course if you do this you may have to redo all your registration settings.

 

[HachiZenki]

we use fuel to clean blankets

EH?? You mean petrol or kerosene? Doesn't it leave a bad residue?

 

[KevinC@EFI]

EH?? You mean petrol or kerosene? Doesn't it leave a bad residue?

In some regions of the world it's quite common to use kerosene... one dealer catalog from India that I'm looking at right now has a product that is called "Kerosene additive for blanket wash".

That's tough on plates to say the least... but on the flip side I can imagine it's very difficult to get some specialized products that we take for granted in other regions of the world.

Kevin.

 

[HachiZenki]

Yeah we're currently using this stuff from Nova Chem. that's odourless (well not totally...it has a faint vanilla smell) because of all the bit**ing from the 'up front people' (as I call them anyway). It's kinda weak and not that great but it does get the job done. We used to use this stuff from Textron called Blanket Wash 1010 that was fantastic...just stunk to high heaven and kinda burned when it got past your gloves.

 

[sallak]

not kerosene, car fuel "benzene"
evaporates fast,cleans well, yes don't let it touch the plate. too damn cheap "less than 0.20 US $ per Liter"

 

[KevinC@EFI]

not kerosene, car fuel "benzene"
evaporates fast,cleans well, yes don't let it touch the plate. too damn cheap "less than 0.20 US $ per Liter"

Darn... I need some of your blanket wash to put in my car! (that's less than 1/4 the price of gas here)

 

[HachiZenki]

Wait what? .20? Damn...I'm paying $4.13 per gallon for gas here.

 

[sallak]

Wait what? .20? Damn...I'm paying $4.13 per gallon for gas here.

Libya exports oil
by the way, last year price was 0.16 per liter

 

[ohgoditsart]

Sounds like a cylinder pressure problem. I used 77 for years and it only moved when pressure would force it. You need a clean cylinder to start with no residue from chemicals. Also can a form roller be bouncing?