NUMERICAL SIMULATION FOR RUBBER CURING PROCESS USING MODIFIED K-S MODEL

ABSTRACT High-precision curing kinetics models are of great significance for the rubber curing simulation. To establish a mature curing model, five sets of isothermal curing experiments were conducted to evaluate the traditional Kamal–Sourour (K-S) model. The results show that this model exhibits relatively large prediction deviations during both the initial curing stage and the thermal curing stage. To improve the model, two modifications were proposed: (1) introducing the initial degree of cure and proportional parameters and (2) treating the reaction order and proportional parameters as linear functions of temperature. The prediction error of the modified model is <5%, and its universality has been verified through experiments on five different rubber compounds. To simulate the nonisothermal curing process of thick-walled rubber products, the nonisothermal process was discretized into a finite number of isothermal steps and an ABAQUS UMATHT subroutine based on FORTRAN was developed to achieve coupled simulation of nonisothermal curing and heat transfer in thick-walled rubber products. Finally, the reliability of the numerical simulation method was verified through thermocouple experiments and rubber process analyzer tests.