Super Soft, Very Low Compression Set, Material for Pressure Roller Application

Abstract

Compression set of a material is critical in fusing system applications and is therefore desired to be as low as possible, less than 10%. Greater compression set introduces issues of loss of nip over time and elevated temperatures, adversely affecting the performance. With very soft materials, such as foam rubbers, compression set can be much greater than 20%. Tensile strength and elongation of materials are values that indicate the strength of a material under pressure in the fusing nip. Accordingly, a material with higher tensile strength and elongation is preferred. The hardness or softness of a pressure roller is dependent upon the base rubber material. Critical physical parameters of the material chosen are the hardness, compression set, elongation, tensile strength and dynamic responses under temperature and pressure.This paper describes the evaluation of a silicone, non foam, rubber material with a softness of 15 Asker C and a compression set 8% or less, as applied to differing material thickness for pressure roller applications. Physical and dynamic properties of the super soft silicone rubber are compared against other rubber materials used in pressure roller applications.