Making hickeys an endangered species

Apr 1, 2008 12:00 PM, By Raymond J. Prince

How many hickeys are allowed in a printed piece? For today's buyer, the answer is easy: none. Years ago, there were internal company standards for dark center (ink color) hickeys and for white voids in solids/type. These specks and spots in the image, as well as non-image, areas of the print plagued the industry for many years. Today, it is possible to eliminate virtually all of the specks and spots that can occur on sheetfed web presses.

Many would say the first step would be to track down the root cause. This might be true, but it is time consuming, expensive and, at times, confusing. The press operator wants to print and have high chargeable press hours. The key is to remove all sources of debris/contamination that occur or could occur. Let's solve the problem for good, not for just one job.

Step 1

Clean up the plant, the pressroom and the presses. Where does debris come from? It seems to be from everywhere.

The ceiling

If you have a high ceiling in the plant, it should be cleaned four times each year, especially if you use spray powder or if there is paper dust. Many times I have seen dropped ceilings that cover the entire press; this keeps dirt that has accumulated over the presses from falling into the press.

The floor

The floor should be painted and sealed — or at least sealed. There should be no deteriorating cement. Once cement begins breaking down, it will find its way into the press. Now we have a severe problem.

The water supply

Filter incoming water. Sand and other contaminates can enter the system through water, especially if it is from an onsite well.

The press rags

Make sure that the rags you are using on press have not seen service in a machine shop. Metal specs/fragments will cause havoc on press — hickeys, scratches and gouges in plates. Once the press is contaminated with metal, it will take weeks to remove it all.

The press

Four times per year, all rubber rollers should be removed from the press and hand cleaned, inspected and replaced if necessary. Likewise, the side frames should be wiped down and all cross bars cleaned.

The substrate

There are many types of sheetfed and web cleaners on the market with a wide range of prices. For paper, the contact type is preferred by most printers. Removing debris as early as possible is advisable.

The ink

It is rare to find bad new ink, but it is very common to find very old ink that has been stored improperly. Sheetfed ink over one year old should not be used unless it was in a vacuum-sealed can and not opened.

Step 2

After cleaning, install hickey removing devices on the press itself. These devices normally take the form of modified dampening systems that remove debris from the plate. There are many types on the market today.

Also, look to any and all engineering/handling solutions for your pressroom workflow that can reduce damage or stress to the substrate. For sheetfed printers, one soution that has many benefits, including the reductions of hickeys, is a jogger aerator. Another great solution is the use of quick-release blankets.

With all the above, your goal should be no hickeys.

Editor's note:
Ray Prince's “Tech Thought” series appears each month in AP's New Products section. See www.americanprinter.com. And, don't miss his new podcasts at www.napl.org.

Raymond J. Prince is a leading expert in pressroom technical and operational issues. He is vice president and senior consultant, operations management, NAPL (Paramus, NJ). Contact him at (605) 941-1492 or e-mail rprince@napl.org.