Abstract

Abstract

In this work the mechanical behaviour of a epoxy resin reinforced with small particles has been studied. This study has been carried out by means of Finite Element Modelling (FEM). A number of models have been prepared with different volume fractions of particles and different particle geometry. The particles had different thickness to surface ratios. These particles were randomly distributed in the matrix with main surfaces parallel to the loading direction. In this study it was found that, as the thickness to surface ratio decreases, the stiffening effect of the particles is more effective. This behaviour was observed for all volume fractions studied. On the other hand, in mechanical tests carried out in parallel experimental programs it was observed that the addition of degassers and reducers of surface tension in the manufacture of the test pieces had an appreciable effect on the final mechanical properties. Due to this, the influence of the porosity on the aparent elastic modulus of the resins was also modelled.

Abstract

Big rollers are used in the paper manufacturing industry, they are composed of layers of different materials (metallic core, polyurethane and composite with epoxy resin between others). The company TECNOCAUCHO is dedicated to the manufacturing of these rollers and towether with AIMPLAS have modified two epoxy resins that are used in two rollers (guide and calendering). In both cases the epoxy resin layer was the weak point of the rollers, consequently the mechanic properties of the resin were improved in order to extend the useful life of each roller and also the conductivity of the guide roller and the roughness and brightness of the calendering roller were improved. Currently, a epoxy resin with the improved properties achieved in this paper is not available on the market.

Guide roller: mechanic properties of the epoxy resin were improved 7,7% compared to original comercial resin through nanofiller addition. Besides, resistivity values below 100 Ωm (company´s target value) were achieved, minimizing the sparks generation.

Calendering roller: mechanic properties were improved to 18,6% (tensile strenght at 130ºC), brightness and roughness (Rz below to 0,2 microns, company´s target value) through nanofillers addition, improving significantly the superficial properties of the paper.