Extrusion is the main method used to produce rubber weather strips in automotive industries, and the quality of the final product largely depends on the thermal properties of the process output. Therefore, precise thermal control of the process is the key to product quality control. This study establishes a three-dimensional model of the nonisothermal viscous flow of ethylene propylene diene monomer (EPDM) rubber melts through a power law rheological model and a mixed finite element method. The rheological properties of the filled rubber compound were characterized using a capillary rheometer (Rosand) at different temperatures to evaluate the required material parameters for numerical simulation. Curing characteristics were investigated using a rubber process analyzer (RPA-2000) to construct a curing curve at different temperatures. The pressure-stabilized Petrov–Galerkin (PSPG) method and streamline upwind/Petrov–Galerkin numerical scheme were employed to solve the flow equations and increase numerical stability. The power law rheological model was combined with field equations such as continuity, momentum, and energy equations to determine the complex flow behavior in an extrusion die of real geometry. Extrusion experiments were performed in an industrial extrusion line, and temperature and pressure were measured at different extruder speeds by using special sensors mounted on the extrusion die. The results confirmed that for EPDM rubber compound, the extruder speed exerted a remarkable effect on the temperature rise and pressure drop in the extrusion die. The impact of viscous dissipation on the thermal behavior and pressure drop prediction of the rubber compound flow is also discussed. The obtained scorch time was compared with the estimated residence time in the flow domain to elucidate the influence of extruder speed on the processing characteristic. The results suggested the lack of premature vulcanization or the start of scorching inside the flow domain within the studied extruder speed range. The validity of model prediction was verified by comparison between simulation and experimental results. The predicted results of the model showed good agreement with the experimental data.

The promotion of oxidation reaction by reactive oxygen species such as OH radicals using ultrasound, ultraviolet light and photocatalyst was investigated. KI aqueous solutions into which photocatalyst (anatase-form TiO₂) was added were used as the experimental solutions and the reaction rate constant of oxidation was calculated according to KI oxidation method. In particular, the effects of the stirring speed, the dosage of photocatalyst, the input power of ultrasound and the synergism of ultrasound (US), ultraviolet light (UV) and photocatalyst were investigated. The reaction rate constants of KI oxidation by simultaneous treatment of US/UV was higher than the sum of respective rate constants obtained by US treatment alone and UV treatment alone. The oxidation reaction was promoted by photocatalytic reaction taking place not only in the solution, but also in the fine mists produced by ultrasonic atomization.

Silver-coated Al–Si alloy particles were prepared by a polyol method to develop a novel conductive filler. The influence of the reaction temperature, reaction time, concentration of silver ions, and addition of a protective agent on the size of the silver particles formed and silver coverage on the Al–Si alloy particles was investigated. The addition of polyvinylpyrrolidone into the liquid phase led to a reduction in the size of the silver particles and an increase in the silver coverage on the alloy surface. The optimum concentration of silver ions for silver coating ranged from 3.8×10⁻² to 1.5×10⁻¹ mol/L, and an excess amount of silver ions (0.3 mol/L) caused agglomeration of the particles. The coating of the alloy was achieved by the adhesion of small silver particles onto the alloy surface, followed by growth of the particles with increasing reaction time. Control of the thickness of the layer was possible by changing the silver nitrate concentration in ethylene glycol within a range not exceeding 0.3 mol/L. Silver nitrate concentrations of 7.5×10⁻³ or 1.5×10⁻² mol/L were suitable to obtain particles with a thin silver layer and high coverage. Coverage of the entire surface of Al–Si alloy particles was achieved by coating Al–Si particles at AgNO₃ concentration of 3.8×10⁻² mol/L and then recoating the coated particles at the concentration of 1.5×10⁻² mol/L. Silver consumption after first coating and recoating was 2 and 78%, respectively, based on the amount of silver in the staring material and it was confirmed that silver was efficiently used for coating in the recoating process.