Roller Nip Indicator
Roller nip is critical for offset printing since it both transports and processes the ink and fountain solution. the technology is unique in that the process components, ink and water, are mixed under pressure during printing, creating a new solution.
Contact width – estimated by applying ink to the rollers, rotating them and measuring the width of the strip – varies acording to type of ink and final viscosity after mechanical mixing. The dymanic properties of the rubber roller constantly change too. The rubber ages, hardens and is also affected by the heat generated from friction during printing.
|Static sensor length||300 mm|
|Dynamic sensor length||300 mm|
|Nip width||2 – 20 mm|
|Roller diameter||30 – 200 mm|
|Roller surface||metal / rubber
hard Plastic / rubber
rubber / rubber
|Rubber hardness||20 – 60° shore A|
IGT Digital Ink Rub Tester
The Sutherland type ink rub tester is an automated instrument for rub a test strip under specified pressure, speed and temperature over a print determining the resistance to abrasion of the print. Abrasion resistance is a critical property for printed materials. Damage due to abrasion can occur during transport, storage, handling or use, resulting in deterioration of the image and readability of the information.
The ink Rub tester allows comparison of the abrasion resistance of different materials under controlled conditions.
Weights for higher or lower forces as well as heated weights are available.
Rub resistance determines the suitability of printed matter, folding cartons, brochures, newspapers, and wrappers for further processing, mailing or other purposes. It is influenced by the properties and combinations of ink, substrate, spray powder, varnish and dampening liquid. Therefore, test of rub resistance is vital to printers, converters and manufacturers of inks and substrate.