Papers by Keyword: Polymer Material

Abstract: With today's proliferation of various polymers, it is necessary to assess the feasibility and feasibility of replacing rubber with more modern materials. The purpose of the tests was to study the effect of abrasive wear, the effect of temperature on material properties, resistance to chipping and other types of wear. This will allow assessing the possibility of application in well conditions, as well as determining the magnitude of the effect of each type of wear on the product. We were faced with the task of testing new protectors in conditions close to full-scale ones. For this, a stand was designed, which allows you to reproduce the lateral load, add abrasive and corrosive agents that affect the wear of the product, ensure circulation of the model fluid, with the characteristics of the drilling fluid, as well as study the effect of elevated temperature on the change in material properties. Due to the fact that in a real well the protector is not under constant load, especially in the vertical sections of the wellbore, but can rotate on the pipe, a day on the test bench can be equivalent to months when the protector is in the well. Therefore, the tests carried out can predict the wear of tread parts, as well as assess the reliability of the use of treads made of polymer materials.

Abstract: The drilling conditions are becoming more severe, which leads to the need to select new polymeric materials that can withstand heavy loads, provide a longer resource and are more resistant to high temperatures. To solve the problem, a set of laboratory tests on standard and specialized tribological equipment is proposed. The friction force, wear resistance under various conditions and according to various criteria, hardness at normal and elevated temperatures, thermal field during tests, change in the roughness of a steel counterbody as a result of tests are evaluated. Wear resistance is determined using a PBD-40 friction machine. Samples are cylindrical bodies with a diameter of (5.0 ± 0.5) mm, a height of 10.0 mm from the materials under study. The samples are fixed in the designed fixture. As a result of the tests, the average values ​​of the parameters for the investigated materials were determined, and the effects arising from friction were noted. The criteria for choosing a material have been formulated and the most suitable material for the tread has been selected.

Abstract: The paper considers the dependence of the strength properties of 3D-printed parts on FDM printing modes (temperature and speed), as well as the layer arrangement. PETG (polyethylene glycol terephthalate) based filament was chosen as the basis. A 3D printer was used to produce samples with strictly defined orientation of layers — longitudinal and transverse tensile force at different temperature and printing speed. The experiment has established the effect of these two factors on the tensile strength. The strength of the samples printed transversely was higher than the strength of samples printed longitudinally. This indicates a higher interlayer adhesion.

Abstract: As polymer parts are made by injection molding, most defects are usually caused by the shrinkage of material during solidification. These defects are then source of cracks in these parts. Present contribution is dealing with central cracked compression loaded polymer cylinder. In order to describe crack behavior under operational load, parametrical finite element model was developed. As results of this study stress intensity factors for central crack with different crack lengths are determined to describe crack behavior.

Abstract: The washing solution of Zhundong coal is a multi-ions mixed system, and the extraction reactions of the alkali and alkaline earth metal ions in the water washing solution with polymer material of dicyclohexyl-18-crown-6 were investigated. The results show that the content of Na in the washing solution is highest, followed by K. Dicyclohexyl-18-crown-6 has better extraction rate of K due to the diameter of K has the same size with the hole diameter of dicyclohexyl-18-crown-6, which enables it could effectively separate Na and K, while did not cause excessive pollution of aqueous solution. Alkali and alkaline earth metal ions were extracted by dicyclohexyl-18-crown-6 in the form of 1:1. Improving the concentration of dicyclohexyl-18- crown-6 in organic phase could effectively enhance the extraction rate. It is not conducive to the extraction reaction by increasing temperature, as the extraction reaction is exothermic.

Abstract: In recent years, a large number of toxic and hazardous substances were discharged into environment because of the simple landfill and accumulation of vehivle dismantling waste. Therefore, it is very important to develop the recycling technology of vehivle dismantling waste for the harmless, stability, reduction and resource utilization of vehivle dismantling waste. In this paper, the compositions of vehicle dismantling waste from two different dismantling processes were investigated by manual sorting, infrared spectroscopy and X-ray fluorescence spectrometer, experimental results showed that the vehicle waste from manual dismantling contained more polyurethane, foamed plastic and rubber with low value and the size of waste is lager, the vehicle waste from mechanical dismantling contained more metal and brittle polymer and their size was smaller. The concentration of metal in two kinds of wastes are less than 1%, the total concentration of carbon and hydrogen reach about 70%, so vehicle dismantling waste was suital for recovering ernergy, but the pollution of chlrone from polyvinyl chloride need to be prevented.

Abstract: Based on the advantages of polymer materials over other materials, rotors which are made of the polymer material, are the functional elements of the rotor-assembled strand, and rotate under certain mass flow rate to obtain heat transfer enhancement and online automatic cleaning. The paper carried out numerical studies on heat transfer and friction loss characteristics of the tube fitted with rotors of different spaces. The comparison of the field synergy angle between plain tube and the tube fitted with rotors was also presented in the paper. The numerical data had good agreement with the experimental data. The numerical studies indicated that the field synergy angle of the rotors inserted tube were significantly smaller than that of the plain tube, which validated that the rotors could significantly enhance heat transfer process and had a better comprehensive performance of heat transfer enhancement though extra friction loss was generated. In addition, both the Nusselt number and friction factor of the tube fitted with rotors increased with the increasing space between rotors; the thermal performance factor of the rotors were all higher than 1, which validated the heat transfer enhancement function of the rotors; meanwhile, the thermal performance factor increased with the space between rotors.

Abstract: In order to verify the possibility that polymer materials for micro heat exchanger could replace metal materials, polymer micro heat exchangers are regarded as the study object. In terms of the experiments and the simulations by Flo EFD software, temperatures, pressures and speeds on micro heat exchanger made by aluminum and conductive plastic Polyphenylene Sulfide (PPS) were carried out analysis respectively. The results showed that the cooling capacities of micro-heat exchangers made by these two materials are quite the same. According to cooling capacity, manufacturing cost and weight, the micro heat exchanger made by conductive plastic is entirely possible to replace the existing metal heat exchanger.

Abstract: The principle of acoustic emission (AE) technology was introduced in this work, as well as the application and the achievements of AE in recent years, such as the utilization in unidirectional carbon fiber reinforced composite. References for in-depth research of material properties and failure mechanism were provided in this article.

Abstract: In order to solve the bottleneck problem of polymer product processing striving for micro scale and precision or macro scale and complication in modern manufacturing, a concept of differential and integral method applied in advanced manufacture of polymer materials is brought up. On the base of this concept, principles of injection molding, extrusion, electrostatic spinning, nano-composite processing and structure innovation of polymer products have been studied; a series of new methods of polymer processing and molding, new equipments, and new technologies of product application have been invented. Some industrial application results prove that, the concept of differential and integral method applied in advanced manufacture of polymer materials is a valuable guide to break through the restriction of traditional manufacturing mode, and to develop new method of polymer processing and new technologies of polymer products application.