// Measuring the viscosity is the best indicator of what is happening to a coating. The measured viscosity indicates when a correction is necessary!

Our Automatic Viscosity Control system incorporates an unique Intelligent Inline Sensor manufactured by a market leader. The unique inline installation provides real time, dynamic viscosity measurements while installing easily to most presses with or without automatic wash-up systems. The positioning of the viscometer "inline" (ie in the coating pathway prior to the coating metering system) is key to enabling the viscometer to adapt to the varying coating conditions intuitively, while allowing the operator to relate the coating viscosity control to the actual printing results.

Key attributes of the viscometer are:

• Maintenance free operation
• No moving parts and no mechanical seals to wear out or replace
• Can be integrated into the coating circuit directly or in a bypass circuit
• All wetted surfaces are high grade stainless steel
• Continuous measurements, not periodic time measurements
• Compatible with water-based and solvent-based coatings
• Viscosity range 1 to 1,000 Centipoints (mPa*s)

// Intelligent Software Interface

Without an intelligent software interface, a viscometer on its own is not enough for an effective viscosity control system. The software interface monitors the coating viscosity continuously and makes minute corrective addi-tions of the appropriate Adjusting Fluid to maintain the desired Viscosity set point. The measurements displayed on the touch screen can be set to match the manual viscosity cup measurement units (e.g. Ford cup 4, Zahn # 2). Additionally, Coating Cooling can be integrated and both the Viscosity and Temperature set points can be set and controlled from the main screen or a remote local screen. 

// A Question of Coating Chemistry "101" 

To correct the viscosity of a water-based coating, should you just have to add water?

//Answer:

Actually although this common practice worldwide it is the wrong way to maintain the coating viscosity. Adding water with a pH around 6.5 - 7.5 (and usually overdosing) results in diluting the coating chemistry and eventually lowering of the pH below operating specifications. On short runs additions of water may be acceptable but the shelf life of the ‘returned' or unused coating” will be negatively affected.

// Without proper and ongoing viscosity control, here are some of the problems that you may experience:

• Color density from the beginning to the end of runs is not consistent, colors start to fade / wash-out
• Foaming increases (especially micro foam) requiring additions of defoamer or anti-foaming agents; too much will cause fish-eyes to appear on the printed board
• Separation of the coating (sludge begins to form on the bottom of the coating pail)
• Printing plates and aniloxes start to dirty up, print defects begin to appear
• Drying characteristics of the board slow-down, press jams or wrap-arounds may occur