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Rheology and the Letterpress Printing Process
Author(s) -
Casson N.
Publication year - 1953
Publication title -
journal of the society of dyers and colourists
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.297
H-Index - 49
eISSN - 1478-4408
pISSN - 0037-9859
DOI - 10.1111/j.1478-4408.1953.tb02800.x
Subject(s) - rheology , shear rate , shearing (physics) , viscosity , materials science , shear stress , polymer science , composite material , thermodynamics , physics
Since most printing inks do not obey the Newtonian flow equation, their rheological properties cannot be characterised by a single coefficient of viscosity. However, in the majority of printing inks the shearing stress‐rate of shear relation becomes linear at high rates of shear, allowing the now curve to be defined by two quantities, viz. U the “plastic viscosity” and f the “yield value”. The validity and the usefulness of this procedure are discussed. The effects of the U and f values of an ink on its printing performance are considered in outline.