Surface Hardness
Material hardness measurements for elastomeric coverings on industrial rollers determine the degree of deformation under load. Rubber roller durometer is usually expressed on the Shore A scale for the types of rollers used in printing and converting. This value influences how the roller interacts with the web and the chemicals it carries during the print run.
Contact Geometry
Softer rollers with a lower rating provide a larger contact area or nip width for a given pressure which is advantageous for certain coating weights. A specific rubber roller durometer is selected based on the thickness of the substrate and the viscosity of the fluid being transferred. High durometer rollers offer better dimensional stability and resistance to swelling in the presence of aggressive solvents.
They are preferred for high speed applications where heat generation must be limited to prevent thermal expansion. The hardness of the material is checked using a handheld meter that measures the depth of an indentation.
Operational Life
Regular monitoring of this property identifies changes caused by chemical exposure or thermal aging over time. If the rubber roller durometer increases significantly, the roller may become brittle and lose its ability to conform to the web. This leads to uneven transfer.
