The lightly cross-linked polymers (eg: vulcanized rubber) are cured to prevent the material deforming indefinitely under load.
Professor James Jackson Geologist with an interest in earthquakes, using earthquake source seismology to examine how continents are deforming today.
R.C.A. Hindmarsh (1997), Deforming beds: viscous and plastic scales of deformation of subglacial sediment ' ', Quat.
It is of interest to note that, very approximately, this deforming force varies inversely as the cube of the distance of the attracting body.