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1

Plastic filling simulation comparison analysis of the gating system in injection moulding parameter

Umor M. Z., Mohd A., Efendee A. M., Khir M., Bahiyah Baba N.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 112, nr 2

64--69

EN

Purpose: The paper is discussed the anticipation of the simulation software precision with the real moulding process by setting up the distinctive metering stroke separation. Design/methodology/approach: The Inventor CAD software was used to design the product experiment and perform the simulation by applying MoldFlow application to produce the processing parameter defining for the injection moulding machines. Findings: The results predicted by this filling simulation appears reasonable result as compared to the injected product. Prediction analysis given by the software is exceptionally valuable for the injection moulding parameter setting machines which can diminish the time of mould setup and can reduce the trial stage on the production line. Research limitations/implications: The gating system is the most crucial part in injection moulding process and the limitation is to get the accurate filling time and injection pressure to ensure the cavity is fully filled before the material at the gate solidify. Originality/value: Gating system configurations are utilized to optimize the filling conditions of injection moulding parts. This important element was developed for achieving product quality. The utilize of simulation software is exceptionally supportive in the model designing stage to predict the quality and process capacity for the product. This paper presents the filling simulation of the side gate system to the injection moulding parameter.

2

Optimization of a Gating System by Means of Simulation Software to Eliminate Cold Shut Defects in Casting

Šabík Vladimír, Futáš Peter, Pribulová Alena, Delimanová Petra

Journal of Casting & Materials Engineering

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2021

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Vol. 5, no. 1

1--4

EN

The current trend in foundries is to achieve the production of high quality and competitive cast components. The innovation and optimization of current processes is a necessary element to achieve this goal. With the help of numerical simulations, it is possible to replace financially demanding and time-consuming experiments in real conditions with simulations that can reliably represent foundry process using computer technology. By a detailed analysis of the simulation results, we can predict various risks that could negatively affect the production process. This article monitors the influence of changes in the design of the gating system on the surface quality of a clutch wheel casting made of ductile iron, in the production of which two models of the gating system for casting were constructed in CAD software. Verification of gating systems was performed using the simulation software NovaFlow & Solid. The aim of the design change of the gating system is to reduce the amount of liquid metal used per casting, which can have a significant economic impact on industrial production. For this purpose, several simulations of the gating system of the casting were performed, while 2 which are the most representative for the mentioned problem were selected for the needs of the article. The main task of the simulation was to set the cellular network and conditions as close as possible to the reality of casting and the subsequent design and modification of the gating system.

3

Possibilities of Bifilm Amount Reduction in Al Castings by Gating System Design Optimization

Brůna Marek, Galčík M., Sládek A., Martinec D.

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 2

549--559

EN

Submitted work deals with the possibilities of reducing reoxidation by improved gating system design. The result of the reoxidation is the of furled oxide layers - bifilms. During experimental works, non-pressurized and naturally pressurized gating systems designs were introduced and evaluated. Mechanical properties, fracture area, hot tearing index, bifilm index and EDX analysis were used during evaluation. Paper aim is also to clarify the reoxidation phenomenon by visualization with the aid of ProCAST numerical simulation software. Achieved results clearly confirmed the positive effect of the naturally pressurized gating system, main emphasis needs to focus on finding the proper way to reduce the melt velocity. By using vortex element extension at the end of the runner was achieved positive results in term of reoxidation suppression.

4

Influence of Overflow Connecting Channel Cross-Section Design on Selected Parameters of High Pressure Die Casting

Majernik J., Podařil M., Gojdan D.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 2

75--80

EN

High pressure die casting technology (HPDC) is a method enabling the production of shape-complex casts with good mechanical properties, with high repeatability of production within narrow tolerance limits. However, the casts show, to some extent, basic porosity, which may reduce their mechanical and qualitative properties. One of the main areas to focus on in order to reduce the porosity of casts is the correct design and structure of the gating and overflow system. Submitted article is devoted to the assessment of the connecting channel cross-section design for connecting the overflows to the cast on selected parameters of the casting process. Five different cross-section designs of connecting channels are considered, enabling the removal of gases and vapors from the volume during the molding. The connecting channels are designed with a constant width g = 10mm and variable height h1 =1.50 mm, h2 = 1.25 mm, h3 = 1.00 mm, h4 = 0.75 mm and h5 = 0.6 mm. The primary monitored parameter is the gas entrapment in selected points of the cast. The following is an evaluation of the pressure conditions change in the mold cavity at the end of the filling mode and local overheating of the mold material just below the surface of the mold face. With regard to the monitored parameters, based on the performed analyzes, the most suitable design solution of the connecting channel is assessed and recommendations for the design and structure of the overflows and their connection to the cast are derived.

5

Casting Quality Improvement by Gating System Optimization

Bruna M., Galčík M.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 1

132--136

EN

One of the main reason for decreased internal homogeneity of aluminium alloy castings is reoxidation. The resulting products of reoxidation are doubled oxides, so called "bifilms". Submitted paper deals with optimization of gating system design in order to reduce reoxidation processes taking place in mold cavity. Experimental work compares and evaluates three gating systems designs based on non-pressurized and naturally pressurized principles. Unconventional spin trap extension of runner was used in third design. Among the evaluated aspects were: mechanical properties, hot tearing index, visual inspection of average porosity amount, numerical simulation of velocity, turbulence and oxide amount. Paper aim is also to clarify the reoxidation phenomenon by visualization with the aid of ProCAST numerical simulation software. Results of mechanical properties and hot tear index clearly confirmed the positive effect of the naturally pressurized gating system with applied element for velocity reduction.

6

Analysis of Reoxidation Processes with Aid of Computer Simulation

Remišová A., Brůna M.

Archives of Foundry Engineering

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2019

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iss. 4

55--60

EN

Submitted work deals with the analysis of reoxidation processes for aluminium alloys. Due to the aluminium high affinity to the oxygen, the oxidation and consequently reoxidation will occur. Paper focuses on the gating system design in order to suppress and minimize reoxidation processes. Design of the gating system is considered as one of the most important aspect, which can reduce the presence of reoxidation products - bifilms. The main reason for the reoxidation occurrence is turbulence during filling of the mold. By correctly designing the individual parts of gating system, it is possible to minimize turbulence and to ensure a smooth process of the mold filling. The aim of the work is an innovative approach in the construction of gating system by using unconventional elements, such as a naturally pressurized system or vortex elements. The aim is also to clarify the phenomenon during the gating system filling by visualization with the aid of ProCAST numerical simulation software. ProCAST can calculate different indicators which allow to better quantify the filling pattern.

7

Simulation and Casting Process of Aluminum Alloy Multi-Way Valve Body with Various Gating Systems

Rong L., Lunjun C., Ming S., Qi Z., Yong L., Heng W.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 2

84--94

EN

In order to study the effects of various gating systems on the casting of a complex aluminum alloyed multi-way valve body, both software simulation analysis and optimization were carried out. Following, the aluminum alloyed multi-way valve body was cast to check the pouring of the aluminum alloy valve body. The computer simulation results demonstrated that compared to the single side casting mode, the casting method of both sides of the gating system would reduce the filling of the external gas, while the air contact time would be lower. Adversely, due to the pouring on both sides, the melt cannot reach at the same time, leading to the liquid metal speed into the cavity to differ, which affected the liquid metal filling stability. The riser unreasonable setting led to the solidification time extension, resulting in a high amount of casting defects during solidification. Also, both gating systems led the entire casting inconsequential solidification. To overcome the latter problems, a straight gate was set at the middle pouring and the horizontal gate diversion occurred on both sides of pouring, which could provide better casting results for the aluminum alloyed multi-valve body.

8

Impact of Sprue Base in Gating System on Quality of Filling – the Compromise Between Theory and Practice

Siodmok B., Jezierski J. R., Dorula J., Romelczyk R.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

167--172

EN

Foundry technologists use their own style of gating system designing. Most of their patterns are caused by experience. The designs differ from plant to plant and give better or worse results. This shows that the theory of gating systems is not brought into general use sufficiently and therefore not applied in practise very often. Hence, this paper describes the theory and practical development of one part of gating systems - sprue base for automated horizontal moulding lines used for iron castings. Different geometries of sprue bases with gating system and casting were drawn in Solid Edge ST9. The metal flow through the gating systems was then simulated with use of MAGMA Express 5.3.1.0, and the results were achieved. The quality of flow was considered in a few categories: splashes, air entrapment, vortex generation and air contact. The economical aspect (weight of runner) was also taken under consideration. After quantitative evaluation, the best shape was chosen and optimised in other simulations with special attention on its impact on filling velocity and mould erosion. This design (a sprue base with notch placed in drag and cope) is recommended to be used in mass production iron foundries to reduce oxide creation in liquid metal and especially to still metal stream to improve filtration.

9

Dependence of Reoxidation Effect on a Type of Gating System in Investment Casting Technology

Herman A., Vratny O.

Archives of Foundry Engineering

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2018

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Vol. 18, iss. 3

107--112

EN

Nowadays, there are growing demands on the accuracy of production. Most of this is reflected in precise manufacturing, such as the investment casting process. Foundries are looking for causes of defects in some cases for a very long time, and it may happen that the source of defects is completely different from what was originally assumed. During the casting process there exist potential causes of defects as oxygen inclusions. This paper represents a summary of the beginnings of a wider research that will address the problems of gating systems in investment casting technology. In general, the influence of the melt flow is underestimated and the aim of the whole scientific research is to demonstrate the significant influence of laminar or turbulent flow on the resulting casting quality. Specifically, the paper deals with the analysis of the most frequent types of defects found in castings made of expensive types of materials casted in an open atmosphere and demonstration of connection with the design of gating systems in the future.

10

Gas Emissivity of a Modified Cellulose Mix at the Temperature of 900°C

Zawieja Z., Sawicki J.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 3

91--94

EN

This paper presents the findings of a study of gas emissivity and the volumetric gas flow rate from a patented modified cellulose mix used in production of disposable sand casting moulds. The modified cellulose mix with such additives as expanded perlite, expanded vermiculite and microspheres was used as the study material. The results for gas emissivity and the gas flow rate for the modified cellulose mix were compared with the gas emissivity of the commercial material used in gating systems in disposable sand casting moulds. The results have shown that the modified cellulose mix is characterized by a lower gas emissivity by as much as 50% and lower gas flow rate per unit mass during the process of thermal degradation at the temperature of 900°C, compared to the commercial mix. It was also noted that the amount of microspheres considerably affected the amount of gas produced.

11

Investigation of an Advanced Cellulose Profile Used for the Manufacture of Gating Systems

Zawieja Z., Sawicki J., Gumienny G., Sobczyk-Guzenda A.

Archives of Foundry Engineering

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2014

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Vol. 14, iss. 3

123--128

EN

The here in paper contains the results of investigations on a new type of cellulose blend used for the manufacture of profiles applied in the process of making gating systems in the foundry industry. A standard cellulose profile was subjected to an experiment. During the experiment the profile was filled with a liquid cast iron and at the same time the temperatures of the liquid metal crystallizing inside the profile were measured as well as the temperature of the outer layer of the profile was controlled. Further, the microstructure of the cast iron, which crystallized out inside the cellulose profile, was analysed and the cellulose, thermally degraded after the experiment, was verified with the use of the chemical analysis method. Moreover, a quality analysis of the original as well as the degraded cellulose profile was run with the use of the FTIR infrared spectroscopy. The presented results revealed that the cellulose blend is aluminium silicate enriched and contains organic binder additives. The cast iron, which crystallized out, tended to have an equilibrium pearlitic structure with the release of graphite and carbides. The generation of disequilibrium ausferrite phases was also observed in the structure.

12

Thermal degradation behavior of cellulose-based material for gating systems in iron casting production

Grabowska B., Szucki M., Suchy J. S., Eichholz S., Hodor K.

Polimery

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2013

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T. 58, nr 1

39-44

EN

This study presents a fragment of research aimed at determining the thermal stability of a cellulose-based composite material used for building gating systems for large iron castings. The behavior of the material itself at elevated temperatures is of major significance for the mould filling process. In this research, thermal analysis methods (DTG, TG, DSC) were used to explain the course of the thermal degradation of the analysed material by establishing thermal effects of transformations occurring during its heating as well as its structural and mass changes. The research was conducted at the temperature range of 40—1000 °C. The degradation process was found to start at the temperature of approx. 300 °C, and the total mass loss at the range of 300—750 °C amounted to 48.8 %. The mass loss observed is accompanied by very strong exothermal effects. The remaining part of the sample mass which had not decomposed up to the temperature of 1000 °C (approx. 51.2 %) probably represents the carbon fibres and ceramic clay present in the material, because these decompose at a temperature higher than the range of the performed thermal analysis and higher than the temperature of the liquid metal fed into the gating system (about 1300— 1400 °C). In addition, volatile products of degradation were analysed using IR spectrum and the thermogravimetry (TG) method coupled online with mass spectrometry (MS). In the temperature range 300—750 °C signals for small molecular masses were noticed, which indicates that the degradation process and fragmentation of polymer chains in the cellulose occur as well as formation of small particle compounds, primarily H2O and CO2. No signals given off by aromatic compounds were detected.

PL

Przedstawiono wycinek badań dotyczących termicznej stabilności wieloskładnikowego tworzywa na bazie celulozy, stosowanego do budowy układów wlewowych przeznaczonych do wielkogabarytowych odlewów żeliwnych. Zachowanie się samego materiału w podwyższonej temperaturze ma istotne znaczenie dla procesu zalewania formy odlewniczej ciekłym metalem. Metodami analizy termicznej (DTG, TG, DSC) badano przebieg degradacji termicznej stosowanego tworzywa, ustalając efekty cieplne przemian zachodzących podczas jego ogrzewania, zmiany strukturalne oraz masę. Analizę prowadzono w temperaturze z zakresu 40—1000 °C. Ustalono, że proces degradacji rozpoczyna się w temp. ok. 300 °C, a całkowity ubytek masy w temperaturze z zakresu 300—750 °C wynosi 48,8 %. Zaobserwowanym ubytkom masy towarzyszą bardzo silne efekty egzotermiczne. Pozostała część masy próbki nie uległa rozkładowi do temp. 1000 °C (ok. 51,2 %), co prawdopodobnie jest związane z obecnością w składzie włókien węglowych oraz materiałów ceramicznych, rozkładających się w temperaturze o wartości powyżej zakresu przeprowadzanej analizy termicznej, a zarazem powyżej temperatury ciekłego metalu wprowadzanego do układu wlewowego (ok. 1300—1400 °C). Przeprowadzono ponadto analizę lotnych produktów rozkładu, stosując metodę spektroskopii IR oraz termograwimetrii (TG), sprzężonej „on-line” ze spektrometrią masową (MS). W temperaturze z zakresu 300—750 °C stwierdzono sygnały odpowiadające małym ciężarom cząsteczkowym, świadczące o zachodzeniu procesu degradacji, fragmentaryzacji łańcuchów polimerowych w celulozie i tworzeniu się małocząsteczkowych związków, w tym przede wszystkim H2O i CO2. Nie stwierdzono obecności sygnałów pochodzących od związków aromatycznych.

13

Zastosowanie narzędzi CAx w projektowaniu form wtryskowych

Ziobro J., Marciniec A.

Polimery

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2010

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T. 55, nr 11-12

877-862

PL

Artykuł ma charakter przekrojowy, omówiono w nim zastosowanie wzajemnie skorelowanych narzędzi CAx [wieloaspektowy termin opisujący zastosowanie ogółu technik inżynierskich i narzędzi komputerowego wspomagania: projektowania (CAD), analiz (CAE), wytwarzania (CAE), itp.]. Zasadniczą część procesu konstruowania wykonano w parametrycznym programie Inventor. Sprawdzenie poprawności działania formy prowadzono w programie MSC.MARC. Realizację zdolności wypełnienia gniazda formy realizowano w programie Mold-flow. Za pomocą tej aplikacji dokonano również oceny wpływu parametrów geometrycznych układu zasilania formy wtryskowej na ciśnienie i siłę zamknięcia. Ogół tych działań przeprowadzono z uwzględnieniem kryterium minimalizacji obciążenia formy. Biorąc pod uwagę wyniki analiz zbudowano ćwiartkowy model geometryczny formy w aplikacji Inventor. Zastosowana metoda analizy sprzężonej w programie MSC.MARC pozwoliła na dokonanie sprawdzenia formy pod względem występujących deformacji oraz związaną z tym możliwość rozszczelnienia układu. Wskazano źródła powstających wypływek oraz występujących niebezpieczeństw. Poprawność działania formy analizowano przede wszystkim pod względem możliwości zakleszczeń występujących w węźle słup-tuleja prowadząca. Na podstawie numerycznych analiz zaproponowano rozwiązanie konstrukcji węzła słup-tuleja, pozwalające na wyeliminowanie tego niepożądanego zjawiska. Wskazano również najbardziej korzystne pasowanie tego węzła oraz jego wymaganą czynną długość styku. Kompletny model geometryczny formy zbudowano w programie Inventor na podstawie modeli wynikających z przeprowadzonych badań symulacyjnych.

EN

In this review paper, the application of correlated CAx tools - a multi-aspect terminology used to describe the application of general engineering techniques as well as the computer aid tools for design (CAD), analysis (CAE), production (CAE) etc. has been presented. The fundamental part of the construction process was performed with the aid of the parametrical program Inventor. The verification of the functionality of the form was performed with the MSC.MARC program. The optimal mold-filling capabilities were determined in the Moldflow program. This program was also used to evaluate the influence of geometric parameters of the gating system of the mold on injection pressure and clamp force. Most of these studies were done with special consideration the criterion of minimizing the load of the mold. On the basis of the results of the performed analysis, a quarter of the geometric model of the mold was built using Inventor applications. The applied analysis method together with the MSC.MARC program allowed for the testing of the molds in terms of deformation and also permeability resulting from it. The potential sources of flashes and dangers were also indicated. The effectiveness of mold activity was analyzed taking into consideration, first and foremost, the possibility of jams occurring in the leader pin-guide bushing. On the basis of numerical analysis a construction solution for the leader pin-guide bushing has been proposed which would eliminate this most undesired phenomenon. The most suitable position as well as the required active contact length of this kinematic pair was shown. The complete geometric model of the mold was constructed according to Inventor program on the basis of the models obtained from the performed simulation studies.

14

Influence of gating system design on tensile properties of AlSi7Mg0.3 alloy

Kasala J., Pernis R., Čaplovič L'.

Archives of Foundry Engineering

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2010

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Vol. 10, iss. 1 spec.

117--120

EN

Aluminium-silicon castings are typically produced by gravity casting. Bottom gated systems are usually required if surface turbulence is to be eliminated. Latest research has demonstrated, that for every liquid metal there is critical velocity above which the surface will fold over and entrain itself in the bulk of the metal. Therefore the strength properties the aluminium castings are largely determined by microstructural defects, particularly pores and oxide films which are created by surface turbulence. The purpose of this paper is to investigate tensile properties and microstructure of aluminium alloy in a casted state two different designs of gating system. The first is the usual bottom gating system and the second is novel design of gating system named a vortex-gate introduced by Campbell [1]. The results of the mechanical tests revealed that there is a small improvement in ultimate tensile strength for vortex-gate design of pouring system. The oxide film defects were observed in microstructure of a sample taken from poured casting by using the bottom gated system.

15

Wyznaczanie minimalnej grubości wlewu doprowadzającego

Borowiecki B.

Archiwum Odlewnictwa

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2006

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R. 6, nr 22

95-100

PL

Minimalna grubość wlewu doprowadzającego powinna być większa od trzech grubości warstwy przyściennej metalu, która zależy z kolei od łącznej grubości warstw: reologicznej i krzepnącej. Zastępczy parametr reologiczny można oznaczyć na podstawie prób lejności. Uwzględniając zastępczy parametr reologiczny i ciśnienie metalostatyczne (położenie przekroju wlewu) można określić grubość reologicznej warstwy przyściennej na przekroju danego wlewu doprowadzającego. Grubość krzepnącej warstwy przyściennej oblicza się uwzględniając czas zalewania i stałą krzepnięcia wyznaczoną z zastosowanego wzoru Chvorinova.

EN

The minimum thickness of runner in gating system depends on boundary layers: rheological and solidifying. The rheological boundary layer thickness of metal has been calculated on the basis of rheological parameters defined in fluidity test. The solidifying boundary layer thickness of metal after determination of solidifying constant and flow time has been calculated.

16

Rozwinięcie iloczynowej formuły współczynnika sprawności przepływu żeliwa w układzie wlewowym

Borowiecki B.

Krzepnięcie Metali i Stopów

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1998

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nr 36

71--77

PL

Przedstawiono koncepcję rozwinięcia iloczynowej formuły współczynnika sprawności przepływu żeliwa przez układ wlewowy w formie piaskowej. Zaproponowano określenie: cząstkowego współczynnika drożności kanałów w zależności od długości kanału i przekroju poprzecznego oraz parametru określającego właściwości reologiczne żeliwa, a współczynnika stygnięcia warstwy przyściennej jako funkcji właściwości termofizycznych materiału formy. Wartości parametrów β i K charakteryzujące proces wymiany ciepła w strudze na granicy metal-forma wyznaczono doświadczalnie.

EN

It has been presented the conception extension of the productive formula of efficiency coefficient of the grey cast iron flow in channel of the casting mould. It has been proposed determine of the efficiency partial coefficient in dependance for the lengt and cross section of channel and rheologic propriety and become cool partial coefficient of the boundary layer for thermophisic function a material of casting mould. The value of the coefficients has been experimental determined.