Frequently Asked Questions

This page is devoted to answering questions about problems, their possible causes, and suggested solutions. We hope they can be a valuable source of information. Please feel free to suggest additional questions or solutions you believe would be helpful to others viewing this information.

If you have a specific question not answered in this section, please contact us and we'll do our best to answer it.

What can I do to improve the performance of a fouled cooling roll?

Problem: The roll is no longer cooling properly and the problem has been getting progressively worse, with acid cleaning becoming less and less effective.

We have made the assumption that the roll in question is all welded construction, with internal spirals designed for maximum cooling, and has a nominal 1/2" thick outer shell. The typical roll design is a double shell design with multiple metal spirals. Unfortunately, this is generally the case with a roll that has a multiple flow path design, if the water flowing through it contains hardness.

Rolls of this design should always be used in a closed loop cooling system, with control of the water quality and the hardness of any "make up" water added to maintain the volume of water in the system. Water will always take the path of least resistance and, as a result, if one of the flow paths begins to foul, it will get less flow. Heat transfer over this flow path can become progressively worse as deposits continue to build, and flow through this path continues to drop off. If the roll gets to the point where flow through this path is significantly restricted, the problem is compounded; during acid cleaning the acid solution takes the alternate, lower pressure drop, path and it becomes difficult (in the worse case, impossible) to remove the fouling.

If this is your problem, your best solution is likely to be a new roll. It is typically more expensive to salvage a roll of this design than it is to build a new one, because the outer shell needs to be removed and replaced with a new outer shell after the internals are cleaned and the spirals replaced. The resulting distortion of the journals requires weld buildup and grinding of the journal diameters in order to correct for welding distortion.

Typically the outer shell, the chromium finishing of the outer shell, and the finishing of the journals represent most of the cost of a new roll. If you also consider disassembly cost, cleaning cost, and the fact that you do not end up with a new roll, a new roll is usually a better choice.

What's the best way to clean chromium plated finishes?

Try soap and water first. Always try your cleaning approach on the area of the roll face that is outside of the web. Minimize contact with bare hands; if that can't be avoided, wash hands thoroughly to remove dirt and natural acidity before touching the surface.

Always use soft cotton cloths - paper towels can have hard content that will scratch the roll face.

For fingerprints, handprints, smudges, or light oils, we recommend Formula 40 Glass Cleaner for the Graphic Arts Industry, manufactured by Sprayway, Inc., of Addison, IL.

If light polishing is required, try cleaning compounds such as those used to clean and polish metals and jewelry.

As a last resort, or if the roll face finish is not critical, try the commercial kitchen cleaner known as Bon Ami. It does have a light grit in it, but it does not have any chlorine in it. Never use anything with chlorine in it. Chlorine attacks chromium.