The Offset Pressman

In many pressrooms today the major problem is not the usual ones of productivity, waste, or quality.  The major problem is manning the presses.  Joggers seem to be arriving and leaving as if there were a revolving door into and out of the pressroom.  One plant in Connecticut recently paid moving expenses for joggers from Wisconsin.  Even that did not work.  High wages have not been too successful either.  So what can a reasonable plant manager do to stem this parade of frustration?  Here are several directions that a manager can take to resolve his problem. "You just might find that career pressman." First , the basic concept of viewing the new hire as a temporary must be changed.  When you consider that almost all of your skilled craftsmen were hired originally as joggers, you should regard each new hire as a potential pressman.  The hiring interview should be an in depth discussion of the opportunities and challenges of the job and the future that this entry level o

Duke Water Pickup Tester Water pickup value should tell us the size of the ink and water balance window - or so it would seem to a pressman.  It is however often misunderstood as the determining factor in the size of the lithographic window.  For example, an ink producer may put a number like 50 on the certificate of analysis from a certain batch of ink.  What this really means is that the ink retained about 30% of the water in the test performed, perhaps a Duke Water Pickup Tester.  A rating of 10 would mean 9% whereas a reading of 100 would mean 50%. The reading in fact relates less to the lithographic process as it does to the ink’s rheological properties that are affected by the rating.  For example, viscosity and flow are two factors that can be greatly affected by this value.  So really it is the inks behavior as opposed to an ink and water balance window measurement by a pressman. What further complicates the matter is that different vehicles and pigments will be

Troubleshooting blanket wash systems for web Troubleshooting an automatic blanket washing system is not rocket science, but there are a few elusive facts to be aware of when trying to figure out why your blankets are not cleaning up on the washes.  Here are a few things to be aware of when troubleshooting your blanket washing system. First of all, you must understand how an automatic blanket washing system works.  Quite simply, it is designed to spray solvent and water onto the blanket and have it cleaned off by a brush or cloth.  The devices are simple in design but have nuances that must be monitored closely.  To start, here is a problem that is common to most systems and manufacturers still need to find a way to effectively deal with. Dripping On The Web Sometimes the upper lines that evacuate the solvent will get plugged.  When this happens, you simply have to clean out the lines.  Some will take a wet-vac and suck it out the end.  Since it is basically a sludge that f

Coldset Newspaper Press Coldset offset printing by definition is simply a process by which ink dries on a printing press.  The ink absorbs into the paper and dries by evaporation.  It can be contrasted to heatset printing which dries by means of a dryer transferring heat to the paper and forcing the ink to evaporate. Coldset Printing Is Mainly Newspapers The majority of the worlds newspapers rely on coldset printing to print their dailies.  Being one of the more economical forms of fast printing, it allows printers to use cheaper uncoated paper and a less energy consuming process to produce their product.  In contrast glossy magazines do not allow the ink to absorb into the paper and therefore require a different process. Coldset Printing However a pressman will debate whether coldset printing might better be called heatset printing and vice versa.  Why?  In reality, what we call " coldset printing " is a process that relies on heat to dry the ink.  On the

An automatic blanket washing system on a heatset web press can be a real money-maker if it works right. I currently use an 2010 OXY-Dry Baldwin system that was purchased in 2010. Regardless of the type though, the principles are the same. Such systems offer a competitive advantage over shutting down and having the pressman manually wash the blankets. Waste, downtime and the potential downtime that is avoided all make it a worthwhile investment. Here are some points to keep in mind if you have or are planning to purchase one for your offset printing press. How It Works Automatic blanket cleaning brush Quite simple, automatic blanket washing is accomplished by means of a spray bar and a brush. The bar is injected with solvent which sprays the printing blanket while the brush scrubs the blanket. With the impressions on, most of the solvent then stays on the paper and goes to the oven . With impressions off, most of the solvent drips down into a tray and is drained off

Cracked offset printing plates can occur for several reasons.  So for this article, I would like to discuss several reasons why plates may crack, as well as a troubleshooting guide that a pressman can use to address the problem.  Let's discuss five reasons why printing plates may crack, particularly near the gap of the press cylinder. 1.  Human Error It stands to reason that this is the first place to look for the cause of cracked plates.  Often when plates are hung on the press, there is room for error.  If any part of the plate, including the edges, is not hugging the press cylinder then the continuous movement when the impression goes on will eventually crack it.  Be sure that the pressman is hanging the plate correctly. 2.  Heavy Ink and Water Forms Especially at high speeds, the cylinder gap presents a mechanical problem for presses.  With the impression on, there is a slight impact when the gap on the lead edge of the plate first impacts the blankets and the forms.