Slowly ramp up the heat of the roll to prevent fracturing or "crazing" of the chromium deposit. We recommend increasing temperature from ambient to operating temperature at 60 degrees F per hour while the roll is rotating to allow the base metal and the chromium to expand at the same rate.
Try soap and water first. Always try your cleaning approach on the area outside of the web. Minimize contact with bare hands; if that can not 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 finger prints, hand prints, smudges, or light oils we recommend Formula 40 glass cleaner.
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 cleanser know as Bon Ami. It does have a light grit, but it does not have any chlorine in it. Never use anything with chlorine in it. Chlorine attacks the chromium.
Mirror - The term "Mirror Finish" is used to define almost any smooth or reflective finish. It is important to define Ra. Some industries the term "Mirror Finish" can be used to define a smooth reflective finish ranging from 4- 8 Ra. 4 Ra and lower refers to surface finishes with higher degrees of luster and reflection generated by precision belt and stone polishing operations.
When calendering heating or cooling a web such as, clear plastic sheeting or film, where perfection of the chromium plated surface is imperative, your finish should be optical mirror. An optical mirror finish is measured below 1 Ra and down to .2 Ra.