Key Engineering Materials Vol. 561

Abstract: One-stage mixing refers to put rubber and additions into the mixing room and make a cycle mixing process. Two-stage mixing refers to make another cycle mixing process to the compound which producted by the one-stage mixing process after parking a certain time.In this paper, traditional internal mixer’s two-stage mixing experiments under different parking time were studied and the experimental results were that the best parking time was 8 hours.

Abstract: Rotational speed is one of the important parameters that impact lifting capacity of full-metal single screw pump .Firstly using the finite volume method to establish a full-metal single screw pump 3D model, secondly using FLUENT software to calculate outlet pressure changes with different series of rotational speed value of the pump in condition of the same inlet pressure .Lastly drawing outlet pressure change curves to evaluate the concrete effect of rotational speed on the performance of the pump. The results indicate that the lifting capacity of the pump and pressure bearing capacity of single stage increase with the rotational speed increasing. The centrifugal performance of the full metal single screw pump is more obvious. So it needs to give full consideration to the effect of rotational speed on characteristics of screw pump in the process of screw pump designing and using, especially the selection of pump series and rotational speed .Increasing the rotational speed of the screw pump can not only reduce the pump series and the structural size, but also can reduce the load torque, improve the reliability of drive system.Now,most of traditional rubber stator is cast one layer rubber that is of double helix surface in the metal enclosure, which can be used together with the metal rotor whose outer surface is plated by hard chrome, while working, the stator can be easily damaged because of the swelling, temperature expansion, and easy to aging of the rubber. As the stator is connected with the tubing, while the stator is damaged and we need to replace a new one, we should disassemble both the poles and string, and it leads to a high cost and the stator can not be used any more, which is apparently a great waste of resource. Besides, that the rubber in the inner surface is hard to clear is also one reason leading to the useless of the stator^[1]. Full-metal single screw pump can avoid these shortcomings for its stator and rotor are made of metal materials and they take way of clearance fit. This can ensure the screw pump develops the higher working efficiency in normal operation. However the full-metal single screw pump developed quite late, its theoretical study and basic theory is less and not mature^[2]. Rotational speed is the main parameter in the designing and using of full metal screw pump ,so in order to help improve the screw pump performance and for further study of the basic theory of metal screw pump, this paper will focus on the study of effect of rotational speed on the pump performance .

Abstract: The rubber melt flow processes was studied through the numerical simulation methods. According to the two important factors of the melt temperature and mold temperature, the paper designs three plans, analyzed rubber melt flow front temperature, volume curing rate and volume curing rate at the end of filling in different melt temperature and mold temperature and found the best solution, so that curing time was shorten and production efficiency was improved under the precondition of filling smoothly mold and ensuring quality of products.

Abstract: With the same recipe and technological conditions, experimental research on fill factor about rubber compound of all-steel radial tire was conducted in four types of X(S)M-1.7L mixers: intermeshing rotor mixer, variable intermeshing clearance mixer, shearing rotor mixer and variable shearing clearance mixer. Based on the summary and analysis of experiments, the authors discussed the influence of fill factor on performance of internal mixers and physical and mechanical properties of the rubber compound. And the optimal values of fill factor of different types mixer were determined.

Abstract: This experiment adapt orthogonal experimental method, producing the experimental study on the impact of the open mill mixing process technological parameters on the mixing quality, using the open mill intelligent mixing experimental platform which are designed and developed dependently and a variety of advanced experimental equipment. Finally, find the optimal technological parameters for the open mill mixing process, and are the roller spacing 0.6mm, the best roller speed 29r/min, the best roller speed ratio 1.25, the best mixing temperature50°C, the best mixing time 18.5min, respectively.

Abstract: Conventional cleaning technology and equipments could hardly satisfy effective cleaning of slit micropores from the precision parts, but using supercritical carbon dioxide(SCCO2) and ultrasonic cleaning technology with would solve this problem. SCCO2 have characteristics of low surface tension, fast moving, high dissolubility, strong diffusivity, no chemical additives and recyclable use. The precision parts would widely use this cleaning technology. In the article the precision parts cleaning equipment using SCCO2 and ultrasonic is proposed, and the equipment could use supercritical cleanout and ultrasonic oscillation together, and could rotate the parts, increase the quantity of the parts, improve the cleaning effect, it is an absolutely necessary to guarantee the cleaning effect of precision parts.

Abstract: Proper foam statics index can give essential indications on foam dynamic behavior in porous media. In this paper, the statics characteristics are investigated through air-flow method for foam generated with Sodium Dodecyl Sulfate (SDS) surfactant. Parameters of foam height, foam half period time are recorded for various gas phases, surfactant concentrations and injecting gas flow rate, and foam morphology are also visually monitored. It is found the N2 generated foam has better characteristics on foam height, while poorer characteristics on foam half-time period compared to air and CO2 foam. Widely employed Foam Composite Index (FCI) is no longer suitable for predicting foam dynamic behavior, a Foam Index for predicting Dynamic Behavior in Porous Media (FIDBPM) is therefore defined to predict properly the foam transient propagation process in porous media.

Abstract: In this paper, we analyze the abrasion wear of the ring die in the theoretical way. Firstly, we obtain the abrasion wear belonging to three-dimensional abrasion wear and soft material wear , then realize three-d modeling of the ring die with the aid of Pro/Engineering. Lastly, we conduct numerical simulation by using finite element analysis software ANSYS, and we draw a conclusion that die cone angle and radian are the important elements to the life of the ring die.

Abstract: Three different kinds of carcass A, B and C for aircraft tires were presented in the article, which is based on the different length of rolling up for carcass cord across the bead ring. And then they were simulated by applying finite element analysis method when aircraft tire was landing in an instant. The simulation results indicated that, the carcass structure of rolling up from the side of bead extending to the other bead (A type) has the minimum deformation, which can reduce the outward of bulge for the side wall and effectively resolve the failure problem for rubber in the sidewall of tire , what’s more , it can prolong the life of aircraft tire to a certain degree and provide good braking performance.

Abstract: Hot probe method for measuring thermal conductivity has the advantages of easy operation, time saving, high accuracy and low poison. In this study, experimental device with high precision for measuring thermal conductivity by hot probe was designed. The measurement error of experimental device is less than 2.4%. This experimental device was used to measure thermal conductivities of pure paraffin (octadecane) and copper nano-particles/octadecane composite phase change materials (PCMs). The composite PCMs were prepared with copper nano-particles doping levels of 0.1, 0.2, 0.5, 1and 2 wt%. The experimental results showed that hot probe method is an effective method to measure the thermal conductivities of PCMs; copper nano-particles added into paraffin can improve thermal conductivity effectively. What’s more, the thermal conductivities of PCMs increase with the growing mass fraction of copper nano-particles.