| abstract |
The problems caused by chemical and thermal shrinkage of hard roll covers, are reduced by the inclusion of one or more intermediate compressive layers between the metal roll substrate and the outer cover, or cover. A compressive layer has the properties of being rigid enough to allow the cover to be applied to the roll, and compressible enough to deform and absorb the stresses which occur as the cover is shrinking during processing. n In one embodiment, the intermediate compressive layer comprises a three dimensional fabric that is filled preferably with a thermoset resin system which cures at lower temperature than cover. In a second embodiment, the precise amount of shrinkage in the roll is predetermined to a high enough degree of accuracy so that a depth for the fabric layer can be used to compensate for the amount of shrinkage, thereby eliminating the need for filling. In a third embodiment, the compressive layer is comprised of a meltable material wherein said material melts at cure temperatures. The resulting cavity is then filled with a thermoset resin. n The problems caused by chemical and thermal shrinkage are further reduced through a method based on applying a polymeric cover layer over one or more intermediate compressive layers, curing at an elevated temperature, and, allowing the cover to shrink during curing or hardening. |