Presstek cylinder pressures

[cmcfarling]

According the Presstek 52DI manual the blanket should measure 0.1mm over the bearer. The manual shows the plate being 0.178mm thick but it doesn't spec the plate cylinder undercut. According to the diagram the plate clearly extends above the plate cylinder bearer. I'm trying to determine how much over the bearer the plate is supposed to be and therefore what the recommended plate cylinder to blanket cylinder squeeze should be. Note that I'm doing this remotely so I can't physically look at the press. In addition we don't have a packing gauge to measure what it actually is.

This is a bearer-contact press so the squeeze would have to be >.1mm based on the diagrams (.1mm + plate-to-bearer height).

I spoke to a Presstek tech today about his. When I told him I wasn't a press operator he got a little attitude with me and questioned why I was even asking him this. After we got over that little episode he claimed that the squeeze should be .1mm. But that can't be right if this diagram is correct?

Would anyone happen to know this information?

 

[Frank Rieder]

You are right, the diagram looks weird.
The squeeze should almost always be .1mm/.004" between plate and blanket and
about the same to the substrate.
If you pack the blanket above bearer, the plate is most likely on bearer height.
This gives you the .1mm squeeze.

 

[Cornishpastythighs]

Not indicating the plate and blanket undercuts makes it more difficult to calculate correct printing squeeze, note also that the diagram says Blanket/Packing should = 0.104" yet if you add the numbers they give for Blanket thickness(.077") and packing(.028") that equals 0.105"

 

[Frank Rieder]

That's right, but the discrepancies are from the conversion metric/standard.
The press has a 2.55mm blanket cylinder undercut. The manufacturer recommends
the blanket to be .1mm above bearer and the plate, since it's off a roll is on the
plate cylinder without packing. The two cylinders run on their bearers, meaning
if you do how it is recommended you should get a good result. If you are having
problems, reduce/increase the blanket packing and adjust the pressure setting.