The advantage of this behavior is that such a
formulation has good long-term stability (G’ > G”
at low values of frequencies). If the formulation is
meant to be applied by spraying, it is
recommended that at very high frequencies
occurring in a spray system the condition G” > G’
be fulfilled. These systems can be described by
the Maxwell and Kelvin models, or their more
complex derivatives. If a material is required to
have good storage stability, it will generally need
to be predominantly elastic at low frequencies.
Similarly, if a material is to be sprayed, it should
not be too elastic at high frequencies, otherwise it
might exhibit undesirable properties, such as
‘cobwebbing’.