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Article

Kushalkumar Thakkar, Suhas Suresh Ambekar and Manoj Hudnurkar

Longitudinal facial cracks (LFC) are one of the major defects occurring in the continuous-casting stage of thin slab caster using funnel molds. Longitudinal cracks occur…

Abstract

Purpose

Longitudinal facial cracks (LFC) are one of the major defects occurring in the continuous-casting stage of thin slab caster using funnel molds. Longitudinal cracks occur mainly owing to non-uniform cooling, varying thermal conductivity along mold length and use of high superheat during casting, improper casting powder characteristics. These defects are difficult to capture and are visible only in the final stages of a process or even at the customer end. Besides, there is a seasonality associated with this defect where defect intensity increases during the winter season. To address the issue, a model-based on data analytics is developed.

Design/methodology/approach

Around six-month data of steel manufacturing process is taken and around 60 data collection point is analyzed. The model uses different classification machine learning algorithms such as logistic regression, decision tree, ensemble methods of a decision tree, support vector machine and Naïve Bays (for different cut off level) to investigate data.

Findings

Proposed research framework shows that most of models give good results between cut off level 0.6–0.8 and random forest, gradient boosting for decision trees and support vector machine model performs better compared to other model.

Practical implications

Based on predictions of model steel manufacturing companies can identify the optimal operating range where this defect can be reduced.

Originality/value

An analytical approach to identify LFC defects provides objective models for reduction of LFC defects. By reducing LFC defects, quality of steel can be improved.

Details

International Journal of Innovation Science, vol. 13 no. 1
Type: Research Article
ISSN: 1757-2223

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Article

Zbigniew Buliński and Andrzej J. Nowak

The purpose of this paper is to present a numerical and mathematical model of a moulding process of a dry electrical transformer. Moreover, the calculated results are…

Abstract

Purpose

The purpose of this paper is to present a numerical and mathematical model of a moulding process of a dry electrical transformer. Moreover, the calculated results are reported and compared with experimental measurements.

Design/methodology/approach

An experimental rig, for carrying out and monitoring a moulding process, has been designed and built. Two experiments were preformed. First was an isothermal experiment in which an analog liquid was used. The second experiment was a non‐isothermal one in which an epoxy resin was used. For the rig geometry, the numerical mesh, with the use of the commercial code Gambit, was built. All necessary physical properties, including viscosity, surface tension and contact angle of fluids used in the experiments were measured.

Findings

The Euler approach for modelling multiphase flow with a free surface is addressed in the presented work. Comparison of the computational results with measurements on the designed experimental rig revealed good agreement. Comparison was carried out through measurements of free surface characteristic features captured with a digital camera and through temperature measurements for the nonisothermal case. Richardson extrapolation method was successfully applied to estimate the numerical discretisation error, proving that a grid independent solution was obtained.

Originality/value

This paper is useful for researchers and industrialists involved in the modelling of moulding processes, giving guidance on the available mathematical models appropriate for this kind of problem. Moreover, it provides valuable information as to how to perform validation and verification procedures for such real‐life processes.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 18 no. 3/4
Type: Research Article
ISSN: 0961-5539

Keywords

Abstract

Purpose

The purpose of this study is to analyse the problem of high binder content in sand mould and to solve it. Meanwhile, to increase build speed, especially for heavy casting’s sand mould with a high value in layer height, such as 2 mm in construction instead of the industry standard of 0.3 mm, line forming for three-dimensional (3D) sand mould printing is researched.

Design/methodology/approach

Brief introduction of 3D sand mould printing and key issues are given first. Then, this paper quantitatively analyses binder content in sand mould. Finally, to acquire sand mould with appropriate binder content and high build speed, line forming combining traditional furan no-bake sand manufacture technique is researched, as well as relevant feasible schemes and current progress.

Findings

The study shows that compared with traditional technique, binder content in sand mould produced by available 3D printing technique is too high, bad for sand mould’s properties and quality of castings, while line forming brings guaranteed binder content and improved build speed.

Research limitations/implications

More experiments are needed to demonstrate quantitative analysis of binder content and to obtain flowability of moist sand, detailed structure design of nozzle and practical build speed, as well as methods of circulation of materials considering solidification time.

Practical implications

Line forming with higher build speed and suitable binder content means excellent properties of sand mould and castings as well, bringing obvious implication for moulds industries and manufacturing industry.

Originality/value

This new method could increase build speed and meanwhile guarantee binder content. Thus, its application prospect is promising.

Details

Rapid Prototyping Journal, vol. 25 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

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Article

F.T. Seyidov, Y. Mansoori and J. Taghi Nezhad

This paper seeks to address the preparation of new compositions of hydrophobicizing liquids as release agent for press moulds in the production of plastic articles of all…

Abstract

Purpose

This paper seeks to address the preparation of new compositions of hydrophobicizing liquids as release agent for press moulds in the production of plastic articles of all kinds of polymers.

Design/methodology/approach

Mixtures of thermo‐stable polyethers (copolymer of ethylene oxide and propylene oxide) and polyols esters/mixed esters in the presence of phenothiazine as antioxidant were prepared and tested.

Findings

All compositions were tested and compared with silicone oil polymethylsiloxane‐100 (PMS‐100). The lubricant was manually applied on a hot surface (160‐190°C) of tray of press mould, without any change in the operating cycle. The finished products were easily removed from press mould, and showed higher durability. The release agent was also checked for production of polyethylene lids by automatic moulding at 170‐200°C, and 17 lids have been obtained on one application. This is quite a good result compared with silicone oil PMS‐100, which produced only four to five lids.

Research limitations/implications

Because of complexity of obtained mixture, it was impossible to study the structure and composition of the obtained products by modern spectroscopy techniques.

Practical implications

In order to obtain compositions of optimum properties a lot of mixtures were prepared and tested. Only compositions which showed suitable properties were reported.

Originality/value

This paper provides detailed information on the experimental preparation of 37 compositions for hydrophobicizing mould release agents. Testing of different obtained hydrophobicizing liquids showed positive results, in production of plastic household articles, over silicone oil PMS‐100. The finished products were easily removed from press mould and prepared hydrophobicizing liquids showed higher durability than silicone oil PMS‐100. The obtained compositions are also favored from the point of view of commercial availability and ecology and can be considered as replacements for PMS‐100 release agent.

Details

Industrial Lubrication and Tribology, vol. 59 no. 5
Type: Research Article
ISSN: 0036-8792

Keywords

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Book part

Saba S. Colakoglu, Niclas Erhardt, Stephanie Pougnet-Rozan and Carlos Martin-Rios

Creativity and innovation have been buzzwords of managerial discourse over the last few decades as they contribute to the long-term survival and competitiveness of firms…

Abstract

Creativity and innovation have been buzzwords of managerial discourse over the last few decades as they contribute to the long-term survival and competitiveness of firms. Given the non-linear, causally ambiguous, and intangible nature of all innovation-related phenomena, management scholars have been trying to uncover factors that contribute to creativity and innovation from multiple lenses ranging from organizational behavior at the micro-level to strategic management at the macro-level. Along with important and insightful developments in these research streams that evolved independently from one another, human resource management (HRM) research – especially from a strategic perspective – has only recently started to contribute to a better understanding of both creativity and innovation. The goal of this chapter is to review the contributions of strategic HRM research to an improved understanding of creativity at the individual-level and innovation at the firm-level. In organizing this review, the authors rely on the open innovation funnel as a metaphor to review research on both HRM practices and HRM systems that contribute to creativity and innovation. In the last section, the authors focus on more recent developments in HRM research that focus on ambidexterity – as a way for HRM to simultaneously facilitate exploration and exploitation. This chapter concludes with a discussion of future research directions.

Details

Research in Personnel and Human Resources Management
Type: Book
ISBN: 978-1-78973-852-0

Keywords

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Article

Amit Kumar, Mangey Ram and Rohit Singh Rawat

The quality of production is an essential factor for the performance measure of a system; a casting process is the same section. It is a type of metal-forming practice in…

Abstract

Purpose

The quality of production is an essential factor for the performance measure of a system; a casting process is the same section. It is a type of metal-forming practice in which the required shape of metal is acquired by pouring molten metal into the mold cavity and allowing it to solidify. Casting is done to provide strength and rigidity to the parts of a system for bearing mechanical impacts. The purpose of this paper is to investigate the various aspects which affect the casting process in the foundry industry, in order to optimize the quality of casting, with the assumption that sufficient repair facility is always available.

Design/methodology/approach

The considered casting system can have many defects such as the mold shift defect, blowhole defect, defect of shrinkage and porosity, defect of inclusion, defect of cold shut and much more. The studied system can be in three states during the process, namely, good state, failed state and degraded state. The system can repair after minor failures as well as a major failure. The average failure rates of various defects of the system considered as constant and repairs follow the general time distribution. The system is analyzed with the help of the supplementary variable technique and the Laplace transformation for evaluating its various performance measures in order to improve its performance/production.

Findings

This work provides a strong understanding of the casting industry, that which failure affects the production of casting and how much. For better understanding, the results have been demonstrated with the help of graphs.

Originality/value

In the present paper, a mathematical model based on the casting process in manufacturing industry has been developed.

Details

International Journal of Quality & Reliability Management, vol. 34 no. 6
Type: Research Article
ISSN: 0265-671X

Keywords

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Article

S. Ghanbarpour, H. Mazaheripour, S.H. Mirmoradi and A. Barari

Self‐compacting concrete (SCC) offers several economic and technical benefits; the use of steel fibers extends its possibilities. Steel fibers bridge cracks, retard their…

Abstract

Purpose

Self‐compacting concrete (SCC) offers several economic and technical benefits; the use of steel fibers extends its possibilities. Steel fibers bridge cracks, retard their propagation, and improve several characteristics and properties of the SCC. The purpose of this paper is to investigate the effects of type and volume fraction of steel fiber on the compressive strength, split tensile strength, flexural strength and modulus of elasticity of steel fiber reinforced self‐compacting concrete (SFRSCC).

Design/methodology/approach

For this purpose, Micro wire and Wave type steel fibers with l/d ratios of 50 were used. Three different fiber volumes were added to concrete mixes at 0.5, 0.75 and 1 per cent by volume of SCC. Six different SFRSCC mixes were prepared. After 28 days of curing, compressive, split and flexural strength and modulus of elasticity were determined.

Findings

It was found that, inclusion of steel fibers significantly affect the split tensile and flexural strength of SCC accordance with type and vf. Besides, mathematical expressions were developed to estimate the flexural, modulus of elasticity and split tensile strength of SFRSCCs regarding of compressive strength.

Originality/value

It was found that inclusion of steel fibers significantly affected the split tensile and flexural strength of SCC accordance with type and f v.

Details

Journal of Engineering, Design and Technology, vol. 8 no. 3
Type: Research Article
ISSN: 1726-0531

Keywords

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Article

Sheng‐Jen Hsieh, Gary Rhoades and Sang‐Shiun Chan

One of the primary problems in the production of cement testing cubes is inconsistency in quality due to skill differences between operators and low repeatability in human…

Abstract

One of the primary problems in the production of cement testing cubes is inconsistency in quality due to skill differences between operators and low repeatability in human performance of identical operations. To eliminate this problem and to enhance productivity, a state‐of‐the‐art robot workcell system, which utilized a multitasking control strategy and tool changer and sensor technology to automatically produce cement testing cubes, was designed and integrated. A comparative analysis of compressive strength values of specimens made by human operators and robots indicated that the specimens made by the robot workcell system had lower variation than the human made ones. This study not only demonstrates that robot workcells are flexible and robust enough to be used in cement testing cube production, but also suggests that revision of American Society of Testing Methods (ASTM) procedures to facilitate implementation of high technology in the materials testing process should be considered.

Details

Industrial Robot: An International Journal, vol. 25 no. 3
Type: Research Article
ISSN: 0143-991X

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Article

James Douglas

A significant part of many building surveyors′ work is theinvestigation of building defects. In many cases a proper diagnosiscannot be made solely by visual means. Some…

Abstract

A significant part of many building surveyors′ work is the investigation of building defects. In many cases a proper diagnosis cannot be made solely by visual means. Some building problems are difficult to assess without the aid of instruments and further tests. Outlines some of the main simple diagnostic chemical tests that building surveyors may wish either to undertake themselves or to instruct specialists to carry out as an aid to their diagnosis of defects. Although such tests are indicative, they are usually sufficient to allow a preliminary diagnosis in many building pathology cases.

Details

Structural Survey, vol. 13 no. 3
Type: Research Article
ISSN: 0263-080X

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Article

Zhi Guo, Zhongde Shan, Dong Du, Mengmeng Zhao and Milan Zhang

This paper aims to determine how the viscosity and curing agent content affect the flowability of moist silica sand granules. In addition, a coating device was designed…

Abstract

Purpose

This paper aims to determine how the viscosity and curing agent content affect the flowability of moist silica sand granules. In addition, a coating device was designed according to the flow properties of silica sand granules.

Design/methodology/approach

The flowability of silica sand granules premixed with two curing agents of different viscosities is studied using a Jenike shear apparatus. An open-ended device was used in discharge testing of sand granules with a design based on the variable dip angle of the two plates and variable outlet size.

Findings

The test results show that increasing the curing agent content would significantly decrease the flowability of silica sand granules, and a curing agent of higher viscosity has a greater effect on the flowability of silica sand. The presence of a curing agent strengthens the cohesion among sand granules, lubricates them and restrains their deformation. The shape function of the coating device was obtained by theoretical derivation.

Practical implications

The flow properties provide a valuable theoretical guidance for the design of coating device for sand mold printing.

Originality/value

This paper deals with experimental work on flow properties of silica sand granules with different viscosities and curing agent content. The shape function of a wedge-shaped coating device is obtained based on experimental data.

Details

Rapid Prototyping Journal, vol. 24 no. 9
Type: Research Article
ISSN: 1355-2546

Keywords

1 – 10 of 147