Torque

[Jose]

Hi, Can someone tell me that torque applied to the blanket for a Mitsubishi Diamond 3000???????
Mitsubishi recomended 98N-72 lb/ft i think is more torque
Thanks.

 

[Kaoticor]

Looks like those numbers are right according to this torque chart I have for a few different makes. - See PDF

 

[Jose]

But this is only for bottcher blankets? Or is generally for a mitsubishi machine? I thins is more torque 98N no?????????

 

[Alois Senefelder]

Blanket Torque

Blanket Torque

Hello Jose, re Bottcher List

This list is a good starting point, covers all makes of Blankets, not just Bottchers.

The crucial setting is Blanket Torque - NOT the Press !!



Regards, Alois

 

[Jose]

Ok But i think this is mitsubishi recomemded torque i apply now 65N for Accura blankets and print very good But mitsubishi rercommemnded 98N is dangerous works with less torque? What's the problem ????

 

[Al Ferrari]

Wrong Alois!

Wrong Alois!

The press is very important because the value in the chart takes the cylinder width into consideration.

Al

 

[Alois Senefelder]

Oooops !

Oooops !

Wrong - not unkown !!!


re - The crucial setting is Blanket Torque

Salient Points: the torque wrench settings are affected by - 1) Press Type 2) Size 3) Lockup System


The Physics of Tension

" A tension setting of 30 in/lbs maybe effective in the areas closest to the cylinder gap, but not in the
area directly opposite this gap. Identifying physical properties of blanket tension and its uniformity around
a cylinder may lend more credence to dot gain and print quality."



Regards, Alois


PDFs - Blanket Lockup Systems

 

[Jose]

Alois, i don´t understant this pdf sorry, I want to Know if you or another people appied the torque that recommended the manufacturer of the press. Do you think 98N is a lot of torque??
Thanks.

 

[tkemerly]

Alois, i don´t understant this pdf sorry, I want to Know if you or another people appied the torque that recommended the manufacturer of the press. Do you think 98N is a lot of torque??
Thanks.

(Determine settings for each type used)

Each blanket is a little different depending on the backing.

I would put blanket on press with a minimum setting to get started. (Document)

Run press on pressure for 50 impressions.

Shut press down and inspect sheet for register and printing defects caused by having a slight bubble from possible excessive material being stretched to the blanket gap.

Go to printing unit inspect blanket for lose fit and a slight bubble or soft spot at the gap. Information at this point should be pushing you to tighten the blanket some more.

Tighten blanket in a 10% increment. (30 lbs would be a three pound increase to the wrench.) Document.....

Inspect blanket and see if soft spot / bubble has disappeared. If it has, run another 50 sheets and check again.

Keep doing this until blanket and printing are telling you that you are set correctly. (No soft spot at the gap and no register issues at the tail.

This is the setting point and you have personally determined what the set point should be.

Blankets can and have been over-torqued in most situations that I have seen. Operators do not seem to care unless management is standing there watching and then it will be found that the torque wrench is set wrong or broken. I had to audit to keep in compliance. You as well can see issues when the blanket is tightened past the click on the wrench. I have seen blankets only getting about half their life due to being pulled so tight that the backing was stretched flat and could not take a hit.

Just some thoughts...

Tk

 

[Manprint]

Umm quick question if you don't have any kind of tension counter and you pull blanket like a maniac how does that affect print quality? -unless you manage to tear it so you get a case of beers-

 

[tkemerly]

It (Over-torquing) has more to do with shortening the life of the blanket by taking away the ability to absorb a hit or a wrinkle which then turns into equipment downtime.

Just a thought,

If a packaging press is running board at 10,000 impressions an hour and each impression is worth .30 cents. (Selling price or otherwise)

And it takes 15 minutes to change out a blanket, it is $750.00 Worth of sales dollars.

At 20% margin, this is $150.00 lost to the bottom line.

Every time you are down due to carelessness in regards of how to correctly operate the press it effects the capacity and bottom line considerably. (This is not just limited to blankets)

If the crew goes and drinks a beer while smoking a cigarette before putting on a new blanket it is $4,000 in sales and $400.00 (at 40 minutes and a 20% margin.)

Thats not even considering if the blanket bar is pulled off the rubber and can not be extracted without major issues.

A press that is running 16,000 SPH @ .30cents an impression is worth $80.00 of sales a minute.

Smoke breaks (Shutting down for breaks)
Can't find correct tools
Consumables are not prepped correctly
Poorly burned plates
Plate clamps are out of register and multiple pulls are needed for reaching printing register
Setting stripes
Can not locate the stock
The list goes on and on......

Just my thoughts.....

TK

 

[Al Ferrari]

Don't charge twice for budgeted routine maintenance.

Don't charge twice for budgeted routine maintenance.

Your post is very instructive up to a point. But you fail to take account of the fact that in a well managed operation, the Budgeted Hourly Cost for each production center already includes a certain amount of the procedures in your post, so that only those performed over and above the assumed number of instances are really additional costs for the company.

it would be better to say that if a work crew can prevent or lessen the number of times that those procedures need to be performed, then savings accrue to the plant as you describe.

Al