Humidity and fit problems

[Brer]

It's still raining and I have run several stocks I would normally have trouble with, and all is well. This morning I am running some paper that was forgotten about 18 months ago (grain short). It did not fit the first time I ran it... but it fits today.
I am convinced the RH is helping.
Thanks for all the input.

 

[Alois Senefelder]

Fundamentals

Fundamentals

Hello Duane,


For Compressible Blankets to work correctly - they need to be overpacked by .005" (.10mm)




Regards, Alois

 

[DuaneBryant]

You are "assuming" you can not produce good quality after removing the packing. How do you KNOW they can not produce good quality without the packing? What if they remove the packing, and printing and distortion improve? What if the raw materials are out of spec? Or the person doing the measuring or packing&blanket installation made a mistake? That is all I was saying. If you do a test and make a change and things get worse, then change it back. If you make a change and things get better, that is valuable information.

I hope you understand my point now.

Also, I agree with your advice: Measure and track humidity, and it's correlation with problems experienced on press. Empirical data presented to management to justify investment in humidity control.

 

[Cornishpastythighs]

Compressible blankets require a plate/blanket squeeze of .004" to .006" The poster states he runs his press with .004" squeeze. Removing .005" packing from under his blanket without putting it back under the plate will result in a printing squeeze of Minus .001'. if you are trying to say that having a negaitive plate/blanket pressure is condusive to quality printing and smooth solids then I am sorry I do not understand your point.
Not trying to start an argument with you Duane but if someone can set me straight and educate me on correct printing squeeze for quality printing please feel free. Maybe I am missing something.

 

[DuaneBryant]

What you are missing is that mistakes happen. What you are missing is that during an investigation into a problem, you should assume nothing. Yes the person SAID that they have .004" squeeze. But what if they don't? What if their calculation, or raw material, or employee are incorrect and they've actually been running .015" squeeze, and didn't know that? That is my only point. Just take out .005" if they have actually been running with .004" squeeze, then yes the print will fail, test will be concluded, and .005" packing restored. If remove .005" and print and/or distortion improves, then that may indicate actual conditions were not as expected/stated. Like Mark Twain said: "Trust everybody. But cut the cards".