Preventive Maintenance

[LoSeR1695]

Dear all,

I'm a newbie in offset printing industry, and I'm responsible for maintenance team. As maintenance team had just been set up, there are no senior staffs guiding me. Would like to ask about what preventive maintenance should be carry out as practice rather than just cleaning blankets and greasing? Need suggestions from senior here, Thanks very much for your suggestion. May I have some suggestions of preventive maintenance schedule please? Thanks very much.

 

[Kaoticor]

Hi there!

Cleaning blankets is more from production, and wouldn't necessarily fall under preventative maintenance. You will know when you need to clean blankets, so maybe we can provide some other comments

The schedule you need to follow can vary greatly depending on your press and your workload. If you would like more specific answers, tell us what type of press(es) you have, the year it is, as well as how much you are running it! Some shops dont invest the time or money for preventative maintenance and there is only so much you can do if management doesn't want to cooperate.

1 - Read the press manual and follow the lubrication instructions. This will tell you almost everything you need to do. One of our newer guys who had the lead a while back just went around and greased whatever points he could find at regular intervals... Dont do that. Make sure you find all lubrication points and do them regularly to the extent possible.

A few other points:

2 - Keep your cylinder bearers in good condition. Keep them oiled, preferrably on a daily basis if possible.

3 - If your press has a main oil resevoir, make that part of a VERY regular check. Depending on how much you run, you need to check it often, possibly even daily. It only takes a second and could save you from 10's of thousands of $$$.

4 - Take care of your cylinders! Establish whatever maintenance is necessary to make sure whatever cylinders your press has are taken care of very well. Your cylinders are your life in printing, whether you have a sheetfed or web offset press.

 

[LoSeR1695]

Thanks very much for your info, we are currently following the lubrication schedule of the manual. My boss thinks that cleaning blankets and machine are maintenance team's job, so I had to do it,

If you don't mind, can you please explain to me what's the function and importance of bearer? Can't really find any information. Please and thanks.

 

[printerpete]

Thanks very much for your info, we are currently following the lubrication schedule of the manual. My boss thinks that cleaning blankets and machine are maintenance team's job, so I had to do it,

If you don't mind, can you please explain to me what's the function and importance of bearer? Can't really find any information. Please and thanks.

I mean this with as much respect as possible, however your saying you are responsible for the maintenance team yet you dont know what the bearers are on a Press?

 

[LoSeR1695]

I mean this with as much respect as possible, however your saying you are responsible for the maintenance team yet you dont know what the bearers are on a Press?

I know what is bearer, but I'm not really understand the function of it. Some of them tell me it's for iron to iron settings, some of them said iron to iron is set by cylinder surface, not the bearer, so I get confused. I am new to this industry, my boss just hire me, and hire two more technicians for me, and ask me to build up the maintenance team, without guide from an experienced crew, and no training provided, I can only do some basic jobs. I wish to improve myself, and gain as much knowledge as possible.

Newbie always ask stupid questions my friend, thanks for your tolerance.

 

[smalloffsetpressexperts]

I know what is bearer, but I'm not really understand the function of it. Some of them tell me it's for iron to iron settings, some of them said iron to iron is set by cylinder surface, not the bearer, so I get confused. I am new to this industry, my boss just hire me, and hire two more technicians for me, and ask me to build up the maintenance team, without guide from an experienced crew, and no training provided, I can only do some basic jobs. I wish to improve myself, and gain as much knowledge as possible.

Newbie always ask stupid questions my friend, thanks for your tolerance.

I am not sure but I think the bearers keep the rollers and such from dropping in to the open gaps and causing bounce and shock lines. Plus the packing maintains perfect ability to fit all images in register.
I only deal with smaller presses that have no bearers so I apologize if I am wrong.
Wish you well in your new job and helping to keep offset printing alive.

 

[LoSeR1695]

I am not sure but I think the bearers keep the rollers and such from dropping in to the open gaps and causing bounce and shock lines. Plus the packing maintains perfect ability to fit all images in register.
I only deal with smaller presses that have no bearers so I apologize if I am wrong.
Wish you well in your new job and helping to keep offset printing alive.

Thanks very much for your info, wish you all the best

 

[Al Ferrari]

Contact the manufactures for each of the presses that you have and pose the same questions to each of them. Most press manufacturers have extensive training resources, some free of charge, others for a fee. This is an investment your management should be willing to make.

Al

 

[Kaoticor]

Thanks very much for your info, we are currently following the lubrication schedule of the manual. My boss thinks that cleaning blankets and machine are maintenance team's job, so I had to do it,

If you don't mind, can you please explain to me what's the function and importance of bearer? Can't really find any information. Please and thanks.

Hi again,

Here is some info about the bearers on the press:

Not all presses run with the bearers contacting each other. But on a lot of presses, they do. If you have a "bearer-contact" press, they perform several important functions:

1 - They act as a reference point so you can measure the actual height of the plate or blanket when you add packing. They will represent the the effective diameter of the cylinder.

2- They help alignment. When they bearers touch at both ends, the blanket to plate cylinder alignment is set.

3 - They help to transfer power smoothly between the cylinders. When they are set correctly, they roll smoothly and help gaurd against what is called "run-out" between the driving gear, and the gear that is being driven. Without a good bearer setting, you can get gear streaks showing up on your print.

4- They help protect against excessive wear on your gears. When the bearers touch, this should automatically mean a good "mesh" between the gears (or the gears should fit nicely together inside providing you have good bearer settings). When your bearers do not run at the correct setting, your normal gear mesh is probably not right, and you are causing excess wear on them. This is important when running at higher speeds and heavier loads on the press.

Hope this helps,

-K

 

[LoSeR1695]

Thanks Al, will contact engineers from manufacturer.

 

[LoSeR1695]

Hi again,

Here is some info about the bearers on the press:

Not all presses run with the bearers contacting each other. But on a lot of presses, they do. If you have a "bearer-contact" press, they perform several important functions:

1 - They act as a reference point so you can measure the actual height of the plate or blanket when you add packing. They will represent the the effective diameter of the cylinder.

2- They help alignment. When they bearers touch at both ends, the blanket to plate cylinder alignment is set.

3 - They help to transfer power smoothly between the cylinders. When they are set correctly, they roll smoothly and help gaurd against what is called "run-out" between the driving gear, and the gear that is being driven. Without a good bearer setting, you can get gear streaks showing up on your print.

4- They help protect against excessive wear on your gears. When the bearers touch, this should automatically mean a good "mesh" between the gears (or the gears should fit nicely together inside providing you have good bearer settings). When your bearers do not run at the correct setting, your normal gear mesh is probably not right, and you are causing excess wear on them. This is important when running at higher speeds and heavier loads on the press.

Hope this helps,

-K

Thanks you very much for your explanation Sir, appreciate.

 

[GazKL440]

As stated, the operation manual is your most important tool with regards to maintenance. You'll be able to pinpoint every grease point on the press and it will provide you with the correct procedure and time frame in which particular grease points require input.

Honestly, you'd be suprised how easy it is to miss the grease nipples at times... Grime or dust can cover them and without the manual you'll never even know they're there!

One thing I'd recommend is removing the blankets and running an oil soaked rag over the blanket cylinder face. These are usually not chromed and WILL rust eventually unless the surface is kept oiled. They tend to get wet and the inherent heat makes for a prefect environment for rust. I'd actually talk to your supervisor/employer about putting a sealing coat of anti-rust paint or some such thing... Mention that it's a VERY expensive fix if they begin to rust!!

Blanket cleaning and press cleaning- ducts, cylinders, rollers etc should be the responsibilty of the press crew. General cleaning.... Well perhaps maintenance crew but I've found that using a broom and running a rag over things has never hurt me... That's up to your managers I guess!

Good luck with it mate

 

[jbeniston]

You have just inherited a difficult job. First you need the cooperation of the press crews. Blanket washing is their job and not a maintenaence job.
Read mark learn and inwardly digest the maintenance manual for every press you have and make a plan of the lubrication schedule and the types of grease and oils you ought to be using. Figure out how long it takes to completely lube and wipe down one press. Take your info to the plant manager and production manager. Now comes the hard bit. You need a commitment from them to get planned down time to schedule the maintenance and then get on it. It must be all finished on time and you just let the manager know that the machine is ready for production again.
You should instigate a clean and check program at every shift start where the operators(feeder and pressman together) check quickly over the machine, get the floor swept ink knives cleaned, cleaning rags ready old cans thrown out and so on. Allow 15 minutes for it Ask for a copy of their report. It will give you some idea what might be failing so you can relate for it.
Keep exact records and dates of everything you do and make sure that the guys clean all the grease nipples and don't over grease. If you can run the press at about 10000 iph for about 5 minutes after lubricating it, and then have all the blankets and impression cylinders cleaned because any excess grease will be slung off the grippers and will land on those surfaces.
Do not worry too much about the bearers make sure that they are clean clean clean. Some machines have bearer wipers on them(Komori and Man Roland direct drive) make sure the wipers are soaked in the appropriate oil. On some machines the bearers need to remain dry. Find out from the manufacturer. The bearers are very important and give the press it's printing characteristics. You can check with a gauge that the blanket surface is at the correct height reference the bearers, and note any unit that's wrong. Pass this data to the supervisor as its his job to make sure those things are correct.
Never try to adjust the bearer pressures yourself unless you have been factory trained. You could schedule a bearer check with the manufacturer once a year as part of your maintenance program.
Check all air hoses and connections for leaks and have someone listen to all the pumps and motors on the press. Make sure that all air filters are regularly replaced and have the motors checked by a qualified electrician
The electrician should grease the motors too. It is very easy to over grease the bearings and this is just as bad as not greasing at all as it can overheat the bearing, by increasing the drag when it's running.
Check the main compressed air supply for dryness and cleanliness. There must be no water in the supply or rust.
All lithographic presses need
Electricity. High voltage and amperage get a professional to make sure the system is clean and safe and keep unauthorized people out of the vault.
Water: Check the supply pressure because if you're using dosers to meter chemicals on the press they might rely on water pressure to have accurate dosages. Make sure the RO system is functioning if you use RO water. Arrange for the filters and membrane to be changed once a year in spring after the winter is best for us as the run off from the snow and ice gets them all clogged.
Oil and Grease: keep a good ready use supply of that stuff
Make sure you have oil filters on hand. Check out the main oil specs and frequency of oil changes .
Make a "kanban" room where things that get used all the time such as feeder suckers and stripper springs. Stuff that the presses use, that they should not have to worry about. They should be just able to go get what they need without asking or filling out forms. Designate someone to look after the Kanban room and make sure that it is always stocked up
There is a lot more to your job but. I don't have enough time right now to add more.
You have to look into drying systems if you have them ink delivery systems , dampening fluid systems plus the safe storage of wash up solvents and so on and so forth.
Cooperation from your management is essential and in my experience hard to get. There are always excuses why you cannot do maintenance to day or any day . The penalty for not getting it done is about 10 times more than it costs to do it on schedule.
Good Luck

 

[jbeniston]

You have just inherited a difficult job. First you need the cooperation of the press crews. Blanket washing is their job and not a maintenaence job.
Read mark learn and inwardly digest the maintenance manual for every press you have and make a plan of the lubrication schedule and the types of grease and oils you ought to be using. Figure out how long it takes to completely lube and wipe down one press. Take your info to the plant manager and production manager. Now comes the hard bit. You need a commitment from them to get planned down time to schedule the maintenance and then get on it. It must be all finished on time and you just let the manager know that the machine is ready for production again.
You should instigate a clean and check program at every shift start where the operators(feeder and pressman together) check quickly over the machine, get the floor swept ink knives cleaned, cleaning rags ready old cans thrown out and so on. Allow 15 minutes for it Ask for a copy of their report. It will give you some idea what might be failing so you can relate for it.
Keep exact records and dates of everything you do and make sure that the guys clean all the grease nipples and don't over grease. If you can run the press at about 10000 iph for about 5 minutes after lubricating it, and then have all the blankets and impression cylinders cleaned because any excess grease will be slung off the grippers and will land on those surfaces.
Do not worry too much about the bearers make sure that they are clean clean clean. Some machines have bearer wipers on them(Komori and Man Roland direct drive) make sure the wipers are soaked in the appropriate oil. On some machines the bearers need to remain dry. Find out from the manufacturer. The bearers are very important and give the press it's printing characteristics. You can check with a gauge that the blanket surface is at the correct height reference the bearers, and note any unit that's wrong. Pass this data to the supervisor as its his job to make sure those things are correct.
Never try to adjust the bearer pressures yourself unless you have been factory trained. You could schedule a bearer check with the manufacturer once a year as part of your maintenance program.
Check all air hoses and connections for leaks and have someone listen to all the pumps and motors on the press. Make sure that all air filters are regularly replaced and have the motors checked by a qualified electrician
The electrician should grease the motors too. It is very easy to over grease the bearings and this is just as bad as not greasing at all as it can overheat the bearing, by increasing the drag when it's running.
Check the main compressed air supply for dryness and cleanliness. There must be no water in the supply or rust.
All lithographic presses need
Electricity. High voltage and amperage get a professional to make sure the system is clean and safe and keep unauthorized people out of the vault.
Water: Check the supply pressure because if you're using dosers to meter chemicals on the press they might rely on water pressure to have accurate dosages. Make sure the RO system is functioning if you use RO water. Arrange for the filters and membrane to be changed once a year in spring after the winter is best for us as the run off from the snow and ice gets them all clogged.
Oil and Grease: keep a good ready use supply of that stuff
Make sure you have oil filters on hand. Check out the main oil specs and frequency of oil changes .
Make a "kanban" room where things that get used all the time such as feeder suckers and stripper springs. Stuff that the presses use, that they should not have to worry about. They should be just able to go get what they need without asking or filling out forms. Designate someone to look after the Kanban room and make sure that it is always stocked up
There is a lot more to your job but. I don't have enough time right now to add more.
You have to look into drying systems if you have them ink delivery systems , dampening fluid systems plus the safe storage of wash up solvents and so on and so forth.
Cooperation from your management is essential and in my experience hard to get. There are always excuses why you cannot do maintenance to day or any day . The penalty for not getting it done is about 10 times more than it costs to do it on schedule.
Good Luck

 

[Dan Roll]

Maintenance falls into two categories, scheduled and un-scheduled. One is good, the other bad. I once worked at a plant where a maintenance team would stripe the rollers, check the cylinders for packing heights, work the various mechanisms (brackets. clamps, adjustments, etc) looking for potential problems, and lubricate everything that moved, all the time making us poor operators clean the press until it looked like it had never been used. This happened more or less on a schedule, but whenever the press wasn't running they would show up and take over. Those presses ran great, until...

New management thought these guys were a waste of money and fired them all. Then for some reason, the presses gradually became less reliable with a tendency to develop problems at the worst possible moments. Management blamed the operators, many of whom (like me) left the company, which went out of business a year or so later.