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Showing posts from May, 2011

How To Make Printing Ink

  Introduction Printing ink is so much more than just the black stuff that you put on a page. It has been around for thousands of years, and it's been used in everything from newspaper presses to digital printers. As you can see, we're not talking about offset printing ink which is oil based. I want to have a little fun and talk about how you can make your own ink for your printer.  At home! Ready? Ingredients You will need the following ingredients: Soot (5 tbsp) : This is as purest as it gest. You can make the soot yourself by holding a glass up to a flame. This will allow you to slowly accumulate the soot. Water (2 tbsp): For the base of your ink, use distilled water so that you don't introduce any impurities into the mix. Distilled water is also easier to clean up than tap water because there are no minerals or residue left behind from tap water. Alcohol (2 tbsp) (grain alcohol): This ingredient works as a preservative for your ink and allows it to last for several mo

Color Management – Helping Your Pressman Adapt

In recent decades, colour management has really become the hot topic in printing.  There are now many standards (such as SWOP , GraCOL , ISO , etc.) that all offer the possibility of creating predictable print results, with much happier customers in the end.  For some pressmen , though, learning to adapt to some of these new concepts can be a challenge.  How can they combine their years of knowledge and troubleshooting with a newer, technology driven environment? Make sure you train pressman well.   If a pressman is used to doing everything by eye and by ‘feel’, they will be uncomfortable with all the tools getting thrown at them.  Give them training and time to get familiar with densitometry, colorimetry, etc.  Perhaps invest in a good training course (many are available, such as GATF ).  Part of good training in colour management might mean getting them to spend a little time with prepress learning how proofing and plate making are being affecte

Remedies For Those Who Stand All Day

When you look at the qualifications for those who want to work in the printing industry, you will often find this requirement - "Able to stand for long periods of time."  That's fine and dandy, but the reality is that just like fine sandpaper, standing on concrete day in and day out can wear on your bones and muscles.  So what practical things can those in the offset printing industry do (or any trade for that matter) to ward off the inevitable problems of lower back pain or foot problems. I don't know about too many other pressmen, but there is no tolerance for sitting down on the job where I have worked.  Not only does it make you look lazy but you have to be able to respond at any moment to the myriad of variables while the press is running.  So if your employer isn't gracious enough to follow tradition of big Japanese companies that allow their employees to take ergonomic breaks, here are some practical things you can do on a day to day basis to offset

Advantages and Disadvantages of Gapless Blanket Printing

When it comes to web offset printing, Goss International struck gold when it patented and constructed a tubular gapless blanket .  It has zealously protected its patent against other commercial press manufacturers such as Man Roland, against whom they settle out of court in 2008.  Since then, MAN has produced their own gapless presses. As there are only a handful gapless presses in the world, the question now begs: What advantages have become apparent to both the pressman and publisher?  I had a chance to visit a Sunday 3000 press installation in 2010 and got to talk with both.  Here is what they told me. Advantages MAN Roland now has it's own gapless presses. 1.  Paper savings.  With virtually no gap (and I say virtually since there is a tiny gap on the plate cylinder), must less paper is wasted.  Whereas some older presses cannot print on 3/4" of the impression, gapless printing allows you to utilize almost all of it.  Couple that with a pinless folder and you hav

How Blankets Are Contstructed

Blankets for offset printing are constructed to meet high demands.  Printers want a blanket that not only transfers a quality image from the plate to the blanket, but can function at high speeds with different papers.  They want a blanket that can resist change from different chemicals such as solvent, fountain solution and ink.  The want it to bend nicely around the cylinder and into the gap and at the same time maintain the stiffness necessary to hold together under extreme conditions at high speeds.  And they want it to maintain its height for a long time and be resistant to piling .  Offset blankets are constructed to meet all these demands.  Let's look at the two main components of an offset printing blanket. The Blanket Face This part of the blanket is more commonly described as the surface layer - the part that comes in contact with the plate and paper.  The blanket face is constructed in such a way that it can transfer image as sharp as possible.  To do this, blanket

How to Keep Blanket Piling to a Minimum

Blanket piling is a long studied phenomenon in offset printing.  The reasons as to why it happens are just as complex.  If you're like me, you've tried to control it without really understanding why it happens for a long time. I've recently taken the time to understand the causes and remedies behind it by consulting with ink chemists and paper manufacturers .  And it turns out that the reasons are not so complex as first thought. I speak about reverse piling in this entry, that is, piling on the non-image areas of the blanket.  However some principles can be equally applied to normal piling.  Causes of Blanket Piling Let's start with a list of the most common causes of blanket piling.  Some are related to the raw materials consumed in the press room, others from the way the press is run.  Here are the main raw consumables that cause piling Paper Type of dampening solution used. Inks Blankets By listing those things above, we've covered almost every majo

Adequately Staff Your Press

Properly staffing your press adds to morale. The trend nowadays with more automation in offset printing, is to staff the press with the absolute minimum .  This trend has the obvious benefit of reducing the bottom line on labor costs.  The sad consequence is that these short-sighted managers do not realize that 80% of their costs come from materials and operating overhead, not staffing. Case In Point  I worked on an offset 5 color half web press for about 4 years for a major printer who will remain unnamed.  We were always short-handed.  We ran with 3 people and that included a roll tender and a guy on a log stacker at the end of the press.  Running around like chickens with heads cut-off was an average day.  Waste was about 12%, far above the industry norm.  But to everyone except us, the solution seemed elusive.  Management was too cheap to give another pressman.  And so it seemed, one way or another, our dimwitted management would pay anyways because the sad part is that it c

Can A Pressman Can Sue For Personal Injury?

Can a pressman sue for injury on an offset printing press? The answer is yes, and it is done all the time. The pressman simply has to prove that it was negligence on the part of the company to provide and enforce adequate safety measures. Or, he must prove that the offset printing press manufacturer did not meet adequate safety standards upon delivery of the press. Either way, lawyers duke it out in the courts to reach a settlement. Here are a few examples from different parts of the globe. 1. Repetitive Strain Washing Blankets England.  The law firm Brachers successfully sued a newspaper printer on behalf of a pressman who sustained shoulder injuries from repetitive cleaning of blankets, later requiring surgery.  This led to other successful settlements for other fellow pressmen.  The pressmen claimed that the company failed to: Assess risk associated with the repetitive cleaning and use proper equipment. Apply ergonomic principles and rotate tasks. Use automatio

How Is Offset Printing Paper Made?

  Paper for offset printing is a large and expensive operation.  After going on a tour of a paper mill that manufactures rolls of paper for offset presses, I must say I was astounded at the process .  Here is a video of a part of it.  This video shows a paper machine that has been running since the 1920's.  It has of course had many upgrades and manages to fly at a rate of 3000 feet per minute. I was told that paper machines will cost you somewhere in the range of 2 billion.  Yeah that's right, more than any offset press on the market today.  This is big business.  These companies must have orders to make these machines pay for themselves or the close down.  The folks at this mill said the machinery that grinds the logs used enough power to supply a small city.  Add to that the fact they consume immense amounts of water and you have a seriously big budget operation. The paper machine, as the video shows, consists of several basic elements. 1.  Wood is ground to fiber

How To Test Your Inks Mileage

When testing your ink for mileage, you must have a standard procedure. Too many variables can distort the results and so they must be controlled.  Unfortunately there exists no worldwide standard for determining ink mileage on press , so I am proposing a procedure that has worked for me for many years. To start with, you must realize that the following variables can greatly influence ink mileage performance. Pigment strength Absorption of paper stock Prepress methods such as UCR Ink and water balance Control Your Variables  Before starting such a test, ensure these variables are controlled by performing this test on a long print run.  The following variables must be controlled during the test. 1.  Ink coverage on the plates must remain the same throughout the test.  If the plates become worn during the test, the results will be skewed.  Ensure this variable is  maintained. 2.  Paper must be made by the same company with identical properties.  Different papers brands, ev

Reducing Delays On Your Offset Press

I was once assigned the project of heading up a company wide web offset improvements program at a major printing company.  One of our prime objectives was to reduce delay time.  You may be surprised to know that company-wide, the delay factor was 30%.  This is a very big number.  That means that almost one third of available offset printing press time was lost.  Press time sells at a range from $100 to $600 an hour.  This was a very big target to shoot at. We did extensive studies of delays to identify their major causative factors.  We were interested in why, where, and when delays occurred, and what we could do to reduce them.  Our team consisted of myself (with a press room background), a mechanical engineer, and an industrial engineer.  We had a pilot offset press to experiment with and a budget of $250,000.  Management was dead serious about this program.  Let me share some of our conclusions. What is a Delay? Let’s identify a delay.  A delay does not include a makeready or

How To Minimize Ghosting

Ghosting is an age old problem of offset printing .  In our printing plant, some presses have more of a problem with it than others.  This is due in large part to press design .  I would like to share a few pointers that help us to minimize this problem. Definition First, let’s define ghosting.  When some areas of the plate that draw large amounts of ink are directly beside areas that require minimal amounts, mechanical ghosting occurs.  This same problem can also occur if the plate “starves” part of an form roller of ink and then upon the next revolution transfers that low ink film thickness to the next revolution.  Either way, ink film thickness is is left insufficient to properly ink another image on the plate. Causes There are several factors that can cause ghosting.  Here are just a few: Short ink train. Inconsistent ink feed. Insufficient ink density. No form oscillation. Poor product design. Bad roller settings. Poor ink and water balance.