Inkometer
Encyclopedia
An inkometer is a specialized measuring instrument
used by the printing
industry to measure the "tack" (adhesive
ness) of an ink with the roller system on an offset press. The importance of tack is that it is not so excessive that it doesn't allow effective transfer from the rollers to the plate and then to the blanket and on to the substrate being printed. Inks can also be tack "graded" in descending sequence to allow for better trapping of one color over another. Inks with too much tack can cause the surface of the paper to pick off and interfere with transfer on subsequent printing units and copies.
The amount of tack can be controlled by changing the amount of solvent
or other diluent used in the ink.
The inkometer is made up of three rollers. The center roller is a temperature controlled brass roller, the bottom roller is an oscillating rubber distribution roller. The top roller is attached to a load cell which measures the tack. Instruments can be adjusted for various roll speeds which are meant to simulate specific press speeds based on the printing process. High speed web publication inks are typically run at 2000 rpms. Standard web fed publication and commercial web inks and some sheet fed ink are run at 1200 rpms (Sheet speed measurement such as FPM is required for this to be meaningful). Traditionally sheet fed ink has been run at 800 rpms (Sheet speed measurement such as FPM is required for this to be meaningful).
Measuring instrument
In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Established standard objects and events are used as units, and the process of measurement gives a number relating the item...
used by the printing
Printing
Printing is a process for reproducing text and image, typically with ink on paper using a printing press. It is often carried out as a large-scale industrial process, and is an essential part of publishing and transaction printing....
industry to measure the "tack" (adhesive
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...
ness) of an ink with the roller system on an offset press. The importance of tack is that it is not so excessive that it doesn't allow effective transfer from the rollers to the plate and then to the blanket and on to the substrate being printed. Inks can also be tack "graded" in descending sequence to allow for better trapping of one color over another. Inks with too much tack can cause the surface of the paper to pick off and interfere with transfer on subsequent printing units and copies.
The amount of tack can be controlled by changing the amount of solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...
or other diluent used in the ink.
The inkometer is made up of three rollers. The center roller is a temperature controlled brass roller, the bottom roller is an oscillating rubber distribution roller. The top roller is attached to a load cell which measures the tack. Instruments can be adjusted for various roll speeds which are meant to simulate specific press speeds based on the printing process. High speed web publication inks are typically run at 2000 rpms. Standard web fed publication and commercial web inks and some sheet fed ink are run at 1200 rpms (Sheet speed measurement such as FPM is required for this to be meaningful). Traditionally sheet fed ink has been run at 800 rpms (Sheet speed measurement such as FPM is required for this to be meaningful).