Vulcanization and stress analysis of heat vulcanizing bonding joints in fabric rubber seals

•A precise vulcanization equation was developed over a broader temperature range.•A finite element model for heat vulcanizing bonding of seals was established.•The effects of the vulcanization parameters on residual stress were revealed.•The residual stress of seal joints was reduced by optimizing the heating process. Vulcanization has a great impact on the performance of rubber products, which is difficult to analyze due to its complicated process and boundary conditions, especially for complex rubber products like aircraft fabric rubber seals. In this paper, an optimized relationship between reaction order and temperature was first developed based on the comparative study of the existing vulcanization kinetic equations, showing improved accuracy and wider applicable temperature ranges. In the temperature range of 160 °C ∼ 190 °C, the determination coefficient of the model can reach 0.9973. Then, finite element models of pure rubber and fabric rubber were established with Abaqus UMATHT and UMAT subroutines to simulate the vulcanization process and analyze the relationship between the stress in the vulcanization process and the non-uniformity of the vulcanization degree field. Finally, the process of mold core synchronous heating was adopted to reduce the non-uniformity of the vulcanization degree field for the heat vulcanizing bonding joint, so as to reduce the residual stress at the joint. Compared with the traditional upper and lower surface heating mode, the residual stress is reduced by about 20 %. This study provides a theoretical guidance for improving the quality of heat vulcanizing bonding joints of seals.