A New Method for the Measurement of Flowability of Green Moulding Sand

Abstract The production of castings by green sand moulds is a very important method for the manufacture of final products for different sectors of industry. In this green sand moulding process the quality of castings depends strongly on the quality of the mould, which in turn is determined by parameters such as the type of foundry machine, the characteristics of the moulding sand and the specifications of the patterns. The mould’s stability for use casting is achieved by filling and compacting moulding sand. This means, that the clay-bonded moulding sand is changed from the free flowing to the compacted state. In this process flowability is a very important parameter. Therefore, a variety of methods for the determination of flowability have been in use. However, it is fair to say that these methods do no longer meet the requirements of the modern moulding process. This paper introduces a new method for the determination of flowability of clay-bonded moulding sand using a specifically designed type of density sensor that was developed by a research team led by Professor Jürgen L. Bast at the Mechanical Department of Technical University Bergakademie Freiberg. The high levels of accuracy in the determination of flowability that this method is capable of achieving have been tested and indeed proven by varying sand parameters such as water and clay content, grain composition, mixing time, and compaction pressure. A further innovative characteristics of this new method of sensor-based flowability measurement is the possibility of using the sensor not only for the lab-based testing of sands but in the actual mould during the production process in the foundry, which allows to determine whether the sand in the mould has the required qualities based on real-time flowability measurements.

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NEW METHOD AND DEVICE FOR FAST EVALUATING THE QUALITY OF GREEN SAND

Journal of Mechanical Engineering ◽

10.3901/jme.2000.01.059 ◽

2000 ◽

Vol 36 (01) ◽

pp. 59 ◽

Cited By ~ 1

Author(s):

Dayong Li

Keyword(s):

New Method ◽

Green Sand

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Regression model of the influence of the height of drum mixer blades on the quality of mixture

E3S Web of Conferences ◽

10.1051/e3sconf/202017505047 ◽

2020 ◽

Vol 175 ◽

pp. 05047

Author(s):

Konstantin Fudin ◽

Vladimir Konovalov ◽

Vladimir Zaitsev ◽

Vyacheslav Teryushkov

Keyword(s):

Coefficient Of Variation ◽

Experimental Error ◽

Functional Dependence ◽

Mixing Time ◽

Computer Processing ◽

Fourth Level ◽

Drum Mixer ◽

Design Factors

The aim of the research was to establish the influence of the number and height of blades of a drum mixer on the quality of the prepared mixture of concentrated feed. The research method of the drum mixer provided for the experimental determination of the coefficient of variation (unevenness) of the mixture with a three-level combination of the blades height and their number. The absence of an extremum according to the obtained data required the use of a fourth level of the number of blades. Computer processing of the results made it possible to establish a functional dependence of the influence of design factors on the quality of the mixture. The implementation of the used research methodology for the operation of the drum mixer made it possible to establish an adequate functional dependence of the influence of the number of blades and their height on the quality of the mixture. The number of blades used practically does not affect the coefficient of variation of the content of the control component. The values change less than experimental error. However, existing trends indicate a slight (about 1%) decrease in the coefficient of variation of the mixture with an increase in the number of blades from 2 to 8 pcs. For 50 kg of feed in a drum capacity of 0.26 m3, the height of the blades is about 0.15 m. The increase or decrease in the height to 0.125 m or 0.175 m affects the quality of the mixture, increasing the coefficient of variation from 20.6% to 34-50% at the proportion of the control component of 1% and the mixing time of 200 seconds.

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Quality and Choice of Potter Bucky Grids: I. A New Method for the Unambiguous Determination of the Quality of a Grid

Acta Radiologica ◽

10.1177/028418515905100612 ◽

1959 ◽

Vol Original Series, Volume 51 (6) ◽

pp. 479-489

Author(s):

J. G. Bonenkamp ◽

W. H. Boldingh

Keyword(s):

New Method ◽

Unambiguous Determination

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A New Proposal for Setting Parameter Values in Restricted Randomization Methods

Methods of Information in Medicine ◽

10.1160/me0398 ◽

2007 ◽

Vol 46 (04) ◽

pp. 440-449 ◽

Cited By ~ 11

Author(s):

G. Kundt

Keyword(s):

New Method ◽

Restricted Randomization ◽

Varying Parameters ◽

Number Of Patients ◽

Intrinsic Quality ◽

Parameter Values ◽

The Impact ◽

Exact Equality

Summary Objectives: Complete randomization could result in an undesirable imbalance in the number of patients assigned to each treatment, especially in small trials. Therefore, a variety of restricted randomization procedures has been developed. By varying parameters it is possible to appropriately modify the balancing characteristics of these designs. However, there is little information on what are sensible choices for the parameters. Therefore, we suggest a new method for suitable determination of parameter values of restricted randomization rules. Methods: For restriction to be effective, it need not yield exact equality. As the reliability of a test is not very sensitive to slight deviations from equal sample sizes we define that a given maximum tolerable imbalance d can be achieved or exceeded with a given probability p*. By using this condition, parameter values of restricted procedures are determinable. Results: For permuted-block, biased-coin, urn, and big-stick randomization we investigated the impact of parameters on balancing properties. For different extents of restriction and by using the submitted condition, the values of parameters to be chosen are determined. Conclusions: Up to now choice of parameter values has often occurred at random. Now it is possible to determine values of parameters by specifying the tolerable degree of imbalance and the risk to be worse. As a consequence restriction will, as much as possible, not be imposed and not imposed more than necessary in order to preserve the intrinsic quality of randomization.

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An Investigation of Form Errors Predicted Model for Injection Moulded Aspheric VCD Lens

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.364-366.123 ◽

2007 ◽

Vol 364-366 ◽

pp. 123-127

Author(s):

Suet To ◽

Bing Yan Jiang ◽

Can Weng ◽

Wing Bun Lee

Keyword(s):

Processing Conditions ◽

Melt Temperature ◽

Moulding Process ◽

Form Errors ◽

Diagnostic Plots ◽

Packing Pressure ◽

Predicted Model ◽

Ram Speed

The aspheric VCD lens is hard to fabricate by injection moulding due to its small volume and high precision requirement. The processing conditions have critical effects on the quality of the moulded lenses. An optic lens needs precisely controlled surface contours, so determination of the processing conditions for lens moulding becomes very complicated. This study’s purpose is to investigate experimentally some effects of the moulding conditions on the form errors of injection moulded lens. An aspheric VCD lens was moulded using polymethyl methacrylate. Different combinations of moulding conditions were used focusing on moulding process parameters of the ram speed, the mould temperature, the melt temperature and the packing pressure, The predicted model of form errors was formulated by orthogonal and regression analysis. Finally, the predicted model is proven to be valid based on the residual diagnostic plots.

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POTENSI PASIR LOKAL TANJUNG BINTANG PADA ALUMINIUM SAND CASTING TERHADAP POROSITAS PRODUK HASIL COR ALUMINIUM

Dinamika Teknik Mesin ◽

10.29303/d.v6i1.27 ◽

2016 ◽

Vol 6 (1) ◽

Author(s):

Yusup Hendronursito ◽

Yogi Prayanda

Keyword(s):

Water Content ◽

Clay Content ◽

Sand Casting ◽

Metal Casting ◽

Green Sand ◽

Aluminium Casting ◽

Porosity Defects ◽

Varied Level

Green sand is one of the most important components in the process of metal casting. The sand in Indonesia region is varied level of subtlety, size of sand, and shape of sand. Green sand used in the process of metal casting is possible can affect the quality of casting product. This aims to determine the potential of Tanjung Bintang sand as green sand and the quality of the product in terms of porosity defects. The research was conducted by varying sand river from Tanjung Bintang and sand from Maringgai. Composition made varying is 100%,75%, 50%, and 25% Tanjung Bintang sand compared Maringgai sand with bentonit and water is 10% and 5% constantly .The Examine of the green sand by SNI 15-0312-1989 among other water content, clay content, Grain Finnest Number (GFN), Shape of grain. The result said aluminium casting product with 50% Tanjung Bintang sand has the lowest value of porosity, 5.08% and the higher value with 75% composition of Tanjung Bintang sand, 6.98%.

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Monitoring of coagulation performance and determination of coagulant dosage using a pilot in-line filter

Water Science & Technology ◽

10.2166/wst.2006.147 ◽

2006 ◽

Vol 53 (4-5) ◽

pp. 411-417 ◽

Cited By ~ 1

Author(s):

S.G. Kim ◽

K.J. Choi ◽

H.J. Son ◽

Y.C. Jun ◽

J.B. Rhee ◽

...

Keyword(s):

Response Time ◽

Rapid Method ◽

New Method ◽

Jar Test ◽

Coagulation Performance ◽

Coagulant Dosage ◽

Mixing Intensity ◽

Mixed Water

A rapid method using the pilot in-line filter to detect any change in coagulation performance was proposed in this study. This method attempted to detect a change in coagulant dosage and mixing intensity by evaluating the filtrate quality of the in-line filter, which took the rapidly mixed water. Since the response time of this method was less than 10 min, it could be valuable to monitor the coagulation performance. The in-line filter was found more useful without underdrain. The in-line filter was more sensitive to a change in filtrate quality without underdrain than with underdrain. A new method, which combines a jar test with the in-line filter, was proposed to determine the coagulant dosage. This method reflected the actual plant situation more accurately than a jar test.

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