Double Blanket & Single Blanket Confusion

Hello Dear Forum Members,

What is the difference between a Single Blanket Press and a Double Blanket Press?
Do Komori Presses have a Double Blanket?
How does a double blanket help in the printing process?
Also, where to look for in a press to identify what kind of blanket does it have

Thanks

 

Who the hell told you that ????

 

I think he means common blanket on those T-head presses?

Komoris defo don't have common blankets

 

I had the idea he was talking about the double impression & transfer cylinders but it did not sound like it...
It sounded more like a joke.....

 

double blanket press

Komori's do not have double blankets. Years ago, I ran some Royal Zenith presses that used double blankets on each blanket cylinder. The top blanket was bolted into a blanket bar, while the under blanket was only bolted into the gripper edge bar of the blanket. If I remember correctly, this system was used to give just a little bit more of the compressible blanket effect to the printed product being run on the press.

 

No No.
I am just a new press operator from glasgow.
I have an Indian Friend in city who told me that there is a single blanket in american machines while european machines have double blanket.
I infer that the blanket size is thicker than the american machines.
U am really confused to so as what does this concept refer to?

 

Def it is not the T-Head presses i am refer to in small 2 color presses.
I am talking about bigger presses.

 

Aaaaaaah, the undercut, yes very true, at least for Heidelbergs they are, off the top of my head, because it's been a long time running a European Heidelberg, I think the blanket undercut was .125" which allows for an underblanket, the Americans by and large prefer a less compressible blanket which I think is undercut by .080" or is it .090"?. In any case, yes you're correct, I can't speak for Komoris or other presses though.

 

Thanks notagooner.
This is exactly what i am referring to as a single blanket or double blanket ( the second blanket refers to a packing sheet underneath the blanket ).
Does the american komori have a smaller undercut compared to european like in heidelberg or is it the same in komori?

Also how does a biggerundercut aid the printing process.

 

In my view, it makes no difference, some people claim you get a sharper dot with less compressibility.

In any case, you can get compressible and non compressible blankets on either press.

 

I have had quite a bit of experience with "double blanket" configurations and they have both advantages and drawbacks. The extra compressible layer seems to to provide better resistance to smashes and it is an easy install. I also like that the packing will be made according to specifications, so there will only be one sheet instead of multiple. This prevents packing creep.

The drawbacks I found are mostly to do with quality. I was unable to print sharp, high quality solids generally speaking. I noticed this even more so when we had to print on lower quality paper. Our focus is on high quality at our shop, so we did away with the "2nd blanket" packing. Perhaps with a different set up in a different shop it might work better. Plus, you can now buy semi-hard packing sheets custom thickness so that is also another option to eliminate packing creep.

 

ive worked with european Heidelbergs with the big undercut and the underblanket configuration and found it good in preventing smashups as someone mentioned. Once i was given a feeder operator that could run the feeder without sending bad sheets through the press i did away with the underblanket and got my desired height with paper packing. I definitely printed sharper with packing under a single 4 ply blanket of app .077"thickness

 

Sometimes, the feeder is not to blame, ever had one of those sheets go through where the papermaker has spliced them together with thick tape?

BANG! all six units blankets smashed

 

right , but then at least you have some one who will pay for the new...

 

No, not necessarily, my company were loathe to complain to our paper supplier because of it's existing relationship, we had to eat the cost, plus of course, there's the downtime of changing and torquing 6 blankets.

 

Your company took the hit for that many blankets and downtime with an obvious paper problem like that? If I was a paper supplier, I would love to have your account!

 

Yeah I hear you, who knows, they were probably getting it on the cheap in the first place.