Rational Technological Parameters Research Articles

MODELING OF POLYMER PRODUCTS SHRINKAGE IN INJECTION MOLDING

Injection molding is one of the main ways of plastics processing, which allows to produce parts of simple and complex shapes. There are used thermoplastics without fillers or particulate fillers for the producing tools. The main prerequisites for the systematic identification, analysis of causes and elimination of tools’ defects is the optimal design of the mold, the correct setting of the machine and the establishment of rational technological parameters of molding. The deformation is characterized by the distinction of the part from the desired shape. Causes of deformation can be due to settings or design. Ways to eliminate the deformation is to decrease the dwell pressure; increase the temperature of the mold and to increase the injection speed; increase the temperature of the cylinder; cooling the mold uniformly and to withstand the temperature regime; change the geometric shape of the product taking into account the nature of the polymer.A specific configuration and dimensions of the product takes form and further cooling causes a change in volume of the polymer and the reduction of linear dimensions, that is, the appearance of shrinkage. Shrinkage describes the reduction of linear dimensions relative to the size of the form. The aim of the research is to conduct numerical studies of the process of injection molding by the action of such factors as the temperature of the melt and shape, stay in shape in order to minimize deformation and shrinkage details. The thin-walled casting product of the "cover" type from low density polyethylene has been considered. It is shown, the simulation results helped to identify the dependence of the deformation, the average shrinkage of time staying in shape and time of temperature completion of the form. The simulation results also allowed to set the minimum required time of mold filling and pressure drop. From the simulation results it is seen that with increasing temperature decreases the deformation of the product, the necessary pressure drop and time of form filling, however, increases the time of stay in shape. That is, the increase in temperature has a positive effect on most parameters of the injection molding and the quality of the product, but reduces performance.

STUDY OF THE PROCESS OF CALIBRATION OF CONFECTIONERY SUNFLOWER SEEDS

The aim of the research was to make the mechanical and technological process of calibrating confectionery sunflower seeds with a vibrating sieve more effective by giving reasons for its rational methodical and technological parameters. The study of calibration of confectionery sunflower seeds had two stages: numerical simulation and experimental verification. For the first stage, the physical models for numerical simulation (in the STAR-CCM+ software package) of the movement of seeds with a vibrating sieve were: k-ɛ model of separated flow turbulence, gravity field, Van der Waals real gas model, discrete elements model, multiphase interaction model. The second stage, experimental verification of the models obtained, was carried out on a calibration machine (sizer) OKMF. Sieves of three types were selected: perforated sieves, rod sieves, and precision sieves (produced by laser cutting). The numerical simulation of moving the confectionery sunflower seeds with a vibrating sieve has allowed determining how changes in total concentration and productivity depend on the way of the input of the seeds, the sieve angle, the vibration frequency and vibration amplitude of the sieve. To make the seed separation process effective, the vibrating sieve is to operate with the maximum productivity equal to the seed input (1,202 kg/h), with the maximum total seed concentration (10.83%). Experimental studies of moving the seeds of confectionery sunflower with vibrating sieves of different types (perforated screens, rod sieves, and precision sieves) have allowed establishing how changes in total concentration, productivity, and consumed power of the calibrating machine depend on the seed input, sieve angle, and frequency of vibrations of the sieve. To make the seed separation process effective, the vibrating sieve is to operate with the maximum productivity equal to the seed input (perforated screens – 1.116 kg/h, rod sieves – 1,518 kg/h, precision sieves – 1,781 kg/h), with the following total seed concentrations: perforated sieves – 14.54%, rod sieves – 12.45%, precision sieves – 10.41%, and power P (perforated sieves – 0.24 kW, rod sieves – 0.30 kW, precision sieves – 0.35 kW) consumed by the calibrating machine must be minimum. Precision sieves (produced by laser cutting) have the best characteristics of their performance (q=1781 kg/h) and quality (θ=10.41%). For this, the frequency of their vibrations should be 5.9 Hz, and their angle should be 5°.

A METHOD OF PRODUCING TUBE TWISTER YARN FOR KNITTED WEAR PRODUCTION IN TWO PLYINGS

The article considers the issues of research of physico-mechanical characteristics of tube twister yarn in two plyings obtained through modernised aerodynamic twiner (the ADT), the rational parameters of formation of linen and flax tow yarn are determined, a comparative analysis of yarn unevenness by mass formed from roving of intensive chemical treatment is conducted. The rational values of technological parameters of tube twister twiner equipped with the ADT of triple tube twister, are determined based on an analysis of investigations of physico-mechanical characteristics of the tube twister. The use of the ADT of triple tube twister expands the range of tube twister yarns obtained, due to possibility of producing flax tow yarn in two plyings. The rational technological parameters of flax tow spinning are defined by experimental mode.

RESEARCHES OF NITROGEN-PHOSPHORUS SOLUTIONS

A pilot plant for producing nitrogen-phosphorus solutions is created. Polyphosphoric acid (85 %) and ammonia hydrate (25 %) are used as the original substance. The methodology of the experiment and reagents input sequence are developed, the analysis of the resulting solution composition is carried out. The effect of phosphoric acid concentration and temperature on the conversion coefficient P2O5of the interaction with ammonia hydrate is determined, the maximum value and rational set of parameters are determined.. The reactions that occur during the interaction of reagents are determined, the mechanism and composition of the solution, which includes NH4H2PO4, (NH4)2HPO4, (NH4)2H2P2O7, (NH4)3HP2O7, (NH4)4P2O7 and H2O, is defined. In the solid phase ~ 40 % of (NH4)2HPO4 and (NH4)3xPO4 x H2O are also formed as total amount. The following rational technological parameters of the interaction process are determined: temperature, 293– 308 K; reaction time –1–4 s, mixing intensity Re = 120–200; relation NH3 x H2O to H3PO4 – 40:60; 50:50; 60:40, concentration H3PO4 – 70–85 %.

THE OPTIMIZATION OF TECHNOLOGICAL MINING PARAMETERS IN QUARRY FOR DIMENSION STONE BLOCKS QUALITY IMPROVEMENT BASED ON PHOTOGRAMMETRIC TECHNIQUES OF MEASUREMENT

Research focuses on patterns of change in the dimension stone commodity blocks quality production at a previous identification and measurement of natural cracks geometrical parameters, modelling and planning out the final dimension stone products and finished products based on the proposed digital photogrammetric techniques. Optimal parameters of surveying are investigated and influence of surveying distance to length and cracks area determination accuracy is estimated. Rational technological parameters of dimension stone blocks production are considered.

Розроблення умов глибинного біосинтезу антибіотика ландоміцину А

Background. Development of the process and biotechnology of production of antitumor antibiotic with microbial origin – landomycin A.Objective. Establishment of the rational parameters for the submerged biosynthesis of landomycin A during the cultivation in the laboratory conditions.Methods. Cultivation of the producer Streptomyces cyanogenus S136 was performed on shaking devices in the flasks. Antibiotic was extracted from culture fluid with ethyl acetate; the content of antibiotic was determined by measuring optical density of the extract.Results. Conditions and parameters for antibiotic submerged biosynthesis of the landomycin A by S. cyanogenus S136 were investigated. Alternative nutrient mediums for the biosynthesis of the landomycin A were presented. Mediums that are based on soybean’s flour extract and corn’s flour allow obtaining up to 80 mg/ml of antibiotic. The influence of mixing intensity and temperature on the rate of the product accumulation and its dynamics was established. Rational technological parameters of the producer’s submerged biosynthesis such as temperature 25 ± 1 °С mixing intensity 230–250 U/min, duration of the submerged fermentation 50–60 hours were established.Conclusions. Variants of the culture media, that were selected (based on the corn’s flour and the extract of the soybean’s flour) and the parameters of the landomycin A biosynthesis, that were set are the basis for optimization and design of the technology for obtaining the antibiotic in industrial conditions.

Development of Conditions of Submerged Biosynthesis of Landomycin A

Background. Development of the process and biotechnology of production of antitumor antibiotic with microbial origin – landomycin A. Objective. Establishment of the rational parameters for the submerged biosynthesis of landomycin A during the cultivation in the laboratory conditions. Methods. Cultivation of the producer Streptomyces cyanogenus S136 was performed on shaking devices in the flasks. Antibiotic was extracted from culture fluid with ethyl acetate; the content of antibiotic was determined by measuring optical density of the extract. Results. Conditions and parameters for antibiotic submerged biosynthesis of the landomycin A by S. cyanogenus S136 were investigated. Alternative nutrient mediums for the biosynthesis of the landomycin A were presented. Mediums that are based on soybean’s flour extract and corn’s flour allow obtaining up to 80 mg/ml of antibiotic. The influence of mixing intensity and temperature on the rate of the product accumulation and its dynamics was established. Rational technological parameters of the producer’s submerged biosynthesis such as temperature 25 ± 1 °С mixing intensity 230–250 U/min, duration of the submerged fermentation 50–60 hours were established. Conclusions. Variants of the culture media, that were selected (based on the corn’s flour and the extract of the soybean’s flour) and the parameters of the landomycin A biosynthesis, that were set are the basis for optimization and design of the technology for obtaining the antibiotic in industrial conditions.

Effect of MoO3 on vanadium based catalysts for the selective catalytic reduction of NOx with NH3 at low temperature

The selective catalytic reduction (SCR) activities of the MoO3 doped V/WTi catalysts prepared by the incipient wetness impregnation method at low temperature were investigated. The results showed that the addition of MoO3 could enhance the NOx conversion at low temperature and the best SCR activity was obtained when the dosage of MoO3 reached 5wt.%. The NH3-TPD and DRIFTS experiments indicated that the addition of MoO3 changed the type and number of acid sites on the surface of catalysts and reaction activities of acid sites were altered at the same time. The redox capacity and amount of active oxygen species got improved for V3Mo5/WTi catalyst, which could be confirmed by the H2-TPR and transient response experiments. Water vapor inhibited the NOx conversion at low temperature. Deposition of ammonium sulfate or bisulfate might be main reason for the loss of catalytic activity in the presence of SO2 at low temperature. Choosing the suitable NH3/NO ratio and elevation of reaction temperature both could weaken the influence of SO2 on the SCR activity of the V3Mo5/WTi catalyst. Thermal treatment of the deactivated catalyst at 350°C could get the low temperature activity recovered. The decrease of GHSV improved the deNOx efficiency at low temperature and we speculated that the rational technological process and operation parameters could contribute to the application of this kind of catalysts in real industrial environment.

Физическая и математическая модели уплотнения балластного слоя роторным устройством

Objective: To develop a mathematical model and program for defining rational technological parameters and operation mode of a rotary device for tamping the ballast bed in the tie space area. Establish the veracity of calculations performed using the mathematical model and program developed via mathematical and physical experiments. Methods: Experimental and theoretical research conducted. Results: Established veracity of the mathematical model and program for calculating the technological parameters and operation mode of the device for tamping the ballastbed in the tie space area. Practical importance: The program developed provides the ability to select rational technological parameters and operation mode for the device. It is recommended that it be used when creating tools for ballast bed solidification in the ballast box area.

STUDY OF WORKING CAPACITY OF THE MARSHALLING YARD

Purpose. The scientific paper has a purpose to choose rational technological parameters of the transportation organization process, which would enable the freight train movement with the most efficient train traffic arrangement, the decrease in idle time due to the increased speed of cargo delivery and the increase in the working capacity of the marshalling yard. Methodology. The work presents the technical and operational characteristics of marshalling yards in Europe and Ukraine. The research methods include the station operation analysis, the car traffic flow analysis, analysis of the train sheet, the DU-1 natural sheets upon arrival and departure of trains. Schemes were developed for calculating working capacity of necks, rehandling capacity of marshalling hump, acceptable levels of system loading. Findings. The research resulted in the calculated working (rehandling) capacity of the main elements of the station. Daily loads of marshalling hump and turnout tracks vary significantly by variations and gradations of movement volume. This affects the idle time of trains and, in general, the value of the criterion according to which the optimal technical equipment, optimum interaction of the subsystems and gridiron of the station will be chosen. This criterion must take into account the costs of technical equipment, construction of tracks, locomotives, as well as related operating costs in all cases. Thus, the selection of the optimal interaction should establish the economically viable level of operational reliability of the sub-systems, their technical and track capacity. Originality. By increasing the productivity of train departure channel, marshalling hump and turnout tracks it is possible the thetrain handling processes and reduce the car idle time. Intensification of production processes in marshalling yards provides a reduction in car turnover and in idle time and high economic efficiency of capital investments. The work covers the issues related to improving the efficiency of functioning of marshalling yards in the railway transport reforming conditions. Practical value. Using the methods of determining the rational working (rehandling) capacity of marshalling yards for distribution of train traffic flows between them makes it possible to improve the quality indicators of marshalling yard operation.

Evaluation of technological parameters for apatite extraction by surface miners

The article describes the research results on evaluation of rational technological parameters for open pit mining of Oshurkovo apatite deposit using Wirtgen Surface Miners. Basic relations between the surface miner capacity, ground conditions and technological factors are substantiated. The authors have constructed lag models and determined optimal design capacity of the open pit mine.

Adsorption of Heavy Metals Ions from Liquid Media by Palygorskite

The process of heavy metals adsorption by natural mineral palygorskite from wastewater and food (apple juice) has been investigated. The purification processes of copper, cadmium, lead, mercury and zinc have been studied. The rational technological parameters of these processes have been determined. The mechanism for heavy metals adsorbtion from juice by palygorskite has been defined.

Recovering of fatty acids from soap stock using carbon dioxide

Since the domestic oil and fat industry is characterized by a steady production growth, the amount of waste is constantly increasing, which adversely affects the ecological situation in Ukraine. In particular, these products include soap stock - waste of alkaline refining of vegetable oils, which is a source of fatty acids. Fatty acids are a commodity product, the demand and the cost of which is much higher in the soap stock.The method of recovering fatty acids from the soap stock by carbon dioxide decomposition of their soaps was proposed. The effect of temperature, pressure of carbon dioxide and concentration of the aqueous solution of soap on the decomposition depth was experimentally proved in the paper. Studies have shown that the decomposition process of potassium salts of fatty acids by carbonate acid proceeds at a depth of over 90 %. The resulting fatty acids are well suited for use in many industries. Rational technological parameters were determined, and the approximation model of the process was obtained. It was found that after the decomposition of potassium salts of fatty acids by carbonate acid, fatty acid composition of resulting fatty acids, which was determined by gas-liquid chromatography, changes slightly.

Substantiation of the rational technological parameters for threshing high-moisture corn ears

Substantiation of the rational technological parameters for threshing high-moisture corn ears

Determining the rational technological parameters of heatresistant concrete produced with sodium silicate binder

Determining the rational technological parameters of heatresistant concrete produced with sodium silicate binder