Key Engineering Materials Vol. 501

Abstract: The conception of the modular design is introduced in design and manufacture of cold feeding rubber extruders; and the realization of process is expounded in details. It improves design efficiency and product quality significantly, and meets the needs of the time.

Abstract: Differential injection molding is one of the key technologies for micro-manufacture. The mechanism of melt pump based on the differential injection molding is presented. The differential injection molding system is added into the traditional injection machines. Melt is plasticized by the plastication system, then after being split, pressurized and measured by the differential system, it enters the cavity to realize the function of multiple micro injection molding machines. Moldex 3D software is used to simulate the filling history of the micro-structure via differential injection molding technology. The product's filling volume under different processing parameters is compared, which provides theoretical basis for the optimization of the molding parameters in differential injection molding technology.

Abstract: The low-temperature reversible thermochromic microcapsules was prepared by interfacial polymerization, which an aqueous phase containing CoCl₂ was used as the internal water phase (W₁), cyclohexane was used as the oil phase (O), polyvinyl alcohol was used as the external water phase (W₂) to form the uniform W₁/O/W₂ multiple emulsion. The structures of microcapsules were investigated using infrared spectrum (IR), electron microscopy (SEM) and polarization microscope. The properties of microcapsules, such as thermochromism and solvent resistance were also investigated. The results presented that the particle size of capsules was uniform, their walls were transparency, and the microcapsules were provided with excellent sensitivity to heat, reversibility and solvent resistance.

Abstract: Polystyrene microcellular foams blowing with supercritical CO₂ were prepared with a novel polymer foam processing simulator. Key parameters influencing Polystyrene cell morphology were investigated. The effect of processing temperature and saturation pressure on cell morphology was observed by scanning electron microscope and the average cell diameter and cell size distribution was calculated. The results show that the cell density decrease and cell size increase with the increase of foaming temperature. The cell density increase and cell size decrease with the increase of saturation pressure. And the cell size distribution shows a narrow distribution at lower foaming temperature and higher saturation pressure.

Abstract: Rotor speed is one of the most important technical characteristics of the internal mixer. The effects of rotor speed on mixing process have been studied. In the experiments, three types of synchronous rotors which were two-wing synchronous rotor, four-wing synchronous rotor and six-wing synchronous rotor were used. The experimental results indicated that there was a proper speed of different rotor structure for mixing process. And along with the increase of rotor speed, the maximum power, the unit consumption of energy and discharging temperature increase, while the physical and mechanical properties of mixed rubber got a better value.

Abstract: Extrusion and molding is one of the most important manufacturing processes of short fiber-rubber composite material. In order to be used to tire tread, the short fibers in rubber are wanted to be radial orientated. But the orientation of short fibers depends on the die structure, and the performances of short fiber-rubber composite material depend on the radial orientation degree of short fibers. So, the die structure has been studied by experiments in order to get a proper die structure for manufacturing of short fiber-rubber composite material. The experimental results indicate that the proper die structure parameters are: the molding length is 15mm, the molding height is 9mm, the channel length is 75mm, the channel height is 12mm and the channel angle is 135º.

Abstract: Abstract. In this paper, taking the tripod of twin tripod sliding universal joint as three-dimensional solid model, it uses ANSYS to carry on the vibration analysis. We can obtain the first 10 natural frequencies, the stress and displacement frequency curve, the stress and displacement contour of tripod and some valuable conclusions by vibration analysis. So, it offers a theoretical reference for the optimization design and development of the twin tripod sliding universal joint.

Abstract: Rolling resistance can impact on the fuel economy and dynamics of automobile. Numerical simulation can predict the rolling resistance and reduce the experimental cost. So, a simulation model was established base on ANSYS to compute the rolling resistance. Firstly, the 3D model finite element model of a radial tire was setup to solve the strain and stress of a rolling tire. Secondly ,the temperature field of tire was analyzed in line with the analytical result of the strain and stress. Thirdly, the rolling energy loss was calculated to solve the rolling resistance. The simulation method is conducive to the structural design of tire and computation or prediction of the rolling resistance of tire.

Abstract: Erythromycin molecularly imprinted polymeric microspheres（EM-MIPMs) which have good shape and well-distributed size were prepared by suspension polymerization in aqueous phase, using EM as a template and methacrylic acid (MAA) as a functional monomer. The size of MIPMs is about 50.17 μm characterized by laser particle size analyzer and polarizing microscope. The interaction between the template and monomer, and selective binding performance were investigated by ultraviolet spectrum analysis, equilibrium binding experiments and Scatchard analysis. The results show tha t hydrogen bonding may contribute to the interaction between EM and MAA, EM-MIPMs demonstrated much higher adsorption capacity compared with the NMIPMs. It has also been found that there are two kinds of binding sites in EM-MIPMs and only one kind in NMIPMs.

Abstract: In this article, the structure of the differential pump is introduced, which is the core part of the differential injection system. The micro-gear with a shaft collar is simulated as it is an important micro-part and has great potential application in mechanical transmission. The Moldex 3D simulation software is used to investigate effects of processing parameters on the micro-gear such as melt temperature, mold temperature, injection time and packing time etc. By comparing the micro-gear's warpage under different processing parameters, it can be concluded that melt temperature has a greater impact on the molding quality than mold temperature. In addition, the effects of injection time and packing time on the micro-gear's molding quality are also investigated.